[Federal Register Volume 85, Number 213 (Tuesday, November 3, 2020)]
[Rules and Regulations]
[Pages 69898-69938]
[FR Doc No: 2020-21478]

Vol. 85

Tuesday,

No. 213

November 3, 2020

Part IV

Department of Transportation

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National Highway Traffic Safety Administration

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49 CFR Part 572

Anthropomorphic Test Devices; Q3s 3-Year-Old Child Side Impact Test
Dummy; Incorporation by Reference; Final Rule

Federal Register / Vol. 85 , No. 213 / Tuesday, November 3, 2020 /
Rules and Regulations

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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 572

[Docket No. NHTSA-2020-0088]
RIN 2127-AL04

Anthropomorphic Test Devices; Q3s 3-Year-Old Child Side Impact
Test Dummy; Incorporation by Reference

AGENCY: National Highway Traffic Safety Administration (NHTSA),
Department of Transportation (DOT).

ACTION: Final rule.

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SUMMARY: This final rule amends NHTSA's regulation on anthropomorphic
test devices (ATD) to add design and performance specifications for a
test dummy representing a 3-year-old child, called the ``Q3s'' test
dummy. The Q3s is an instrumented dummy that can assess the performance
of child restraint systems in protecting small children in side
impacts. Adding the Q3s provides NHTSA a new test device that can be
used to improve side impact protection for children.

DATES: The effective date of this final rule is: January 4, 2021. The
incorporation by reference of the publications listed in the rule has
been approved by the Director of the Federal Register as of January 4,
2021.
    Petitions for reconsideration: Petitions for reconsideration of
this final rule must be received not later than December 18, 2020. The
petition will be placed in the docket. Anyone is able to search the
electronic form of all documents received into any of the agency's
dockets by the name of the individual submitting the comment (or
signing the comment, if submitted on behalf of an association,
business, labor union, etc.).

ADDRESSES: Petitions for reconsideration of this final rule must refer
to the docket and regulatory information number (RIN) set forth above
and be submitted to the Administrator, National Highway Traffic Safety
Administration, 1200 New Jersey Avenue SE, Washington, DC 20590. Note
that all petitions received will be posted without change to http://www.regulations.gov, including any personal information provided. To
facilitate social distancing due to COVID-19, please email a copy of
the petition to<EMAIL_ADDRESS>    Privacy Act: In accordance with 5 U.S.C. 553(c), DOT solicits
comments from the public to better inform its rulemaking process. DOT
posts these comments, without edit, to www.regulations.gov, as
described in the system of records notice, DOT/ALL-14 FDMS, accessible
through www.dot.gov/privacy. In order to facilitate comment tracking
and response, the agency encourages commenters to provide their name,
or the name of their organization; however, submission of names is
completely optional. Whether or not commenters identify themselves, all
timely comments will be fully considered. If you wish to provide
comments containing proprietary or confidential information, please see
below.
    Confidential Business Information: If you wish to submit any
information under a claim of confidentiality, you should submit three
copies of your complete submission, including the information you claim
to be confidential business information, to the Chief Counsel, NHTSA,
at the address given under FOR FURTHER INFORMATION CONTACT. In
addition, you should submit a copy, from which you have deleted the
claimed confidential business information, to Docket Management at the
address given above. When you send a comment containing information
claimed to be confidential business information, you should include a
cover letter setting forth the information specified in NHTSA's
confidential business information regulation (49 CFR part 512). To
facilitate social distancing due to COVID-19, NHTSA is treating
electronic submission as an acceptable method for submitting
confidential business information (CBI) to the agency under 49 CFR part
512. https://www.nhtsa.gov/coronavirus.

FOR FURTHER INFORMATION CONTACT: For technical issues: Peter Martin,
NHTSA Office of Crashworthiness Standards (telephone<PHONE_NUMBER>) (fax
202-493-2990), email<EMAIL_ADDRESS>For legal issues: Deirdre
Fujita, NHTSA Office of Chief Counsel (telephone<PHONE_NUMBER>) (fax
202-366-3820), email<EMAIL_ADDRESS>Mailing address: National
Highway Traffic Safety Administration, U.S. Department of
Transportation, 1200 New Jersey Avenue SE, West Building, Washington,
DC 20590.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Executive Summary
II. Background
    a. 2013 Part 572 NPRM and 2014 FMVSS No. 213 NPRM
    b. Comments on the 2013 Part 572 NPRM
III. Summary of Differences Between the NPRM and This Final Rule
    a. Acceptance Criteria for the Qualification Tests
    b. Qualification Test Procedures
    c. Engineering Drawings and the Procedures for Assembly,
Disassembly, and Inspection (PADI)
IV. Response to Comments (Part I) on Developing the Regulation
    a. Copyright and Patent Issues
    b. Dummy Availability and Associated Data
    c. Developmental Stage of the Dummy
    d. Biofidelity
    e. Repeatability and Reproducibility (R&R)
V. Post-NPRM Test Program Overview
    a. Test Locations
    b. Other Data
    c. Component Tests in the Post-NPRM Test Program
    d. Controlling Variability
VI. Results of the Post-NPRM Test Program and the Final Acceptance
Criteria for the Qualification Tests
    a. Background
    b. Process for Setting the Final Qualification Criteria
    c. Head
    d. Neck
    e. Lumbar Column
    f. Shoulder
    g. Thorax
    h. Pelvis
VII. Response to Comments (Part II) on the Dummy Qualifications and
Test Procedures
    a. Head Qualification
    b. Neck Qualification
    c. Arm Position
VIII. Post-NPRM Data From Humanetics
    a. Qualification Tests
    b. Mass and Anthropometry Measurements
IX. Drawing Package and PADI
X. Other Issues
    a. Durability
    b. Consideration of Alternatives
XI. Rulemaking Analyses and Notices

I. Executive Summary

    This final rule amends NHTSA's regulation on anthropomorphic test
devices (49 CFR part 572) by adding a new Subpart W that sets forth
design and performance specifications and qualification tests for a
test dummy representing a 3-year-old child, called the Q3s test dummy.
The Q3s is an instrumented dummy that can assess the performance of
child restraint systems in protecting small children in side impacts.
The Q3s weighs 14.5 kilograms (kg) (32.0 pounds) and has a seated
height of 556 millimeters (mm), and is representative of a 50th
percentile 3-year-old child. The Q3s dummy's main parts (head, thorax,
neck, shoulder, spine, abdomen, pelvis, and relevant instrumentation)
and biofidelity are described in detail in a November 21, 2013 notice
of proposed rulemaking (NPRM) preceding this final rule (78 FR 69944,
69946). NHTSA plans to use the Q3s test dummy in a

proposed side impact test for child restraints.\1\
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    \1\ NPRM to amend Federal Motor Vehicle Safety Standard (FMVSS)
No. 213, ``Child restraint systems,'' January 28, 2014, 79 FR 4570.
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    This final rule incorporating the Q3s into 49 CFR part 572
standardizes NHTSA's specifications on the dummy for testing and
research purposes. Subpart W specifies a set of qualification tests and
acceptance criteria for the Q3s's head, neck, shoulder, thorax, lumbar,
and pelvis, assessing 35 response mechanisms for the dummy.\2\
Additionally, Subpart W incorporates by reference a technical data
package (TDP) for the Q3s consisting of a set of engineering drawings,
a parts list, and a user's manual that has procedures for assembly,
disassembly, and inspection (PADI) of the dummy.\3\ Q3s dummies
manufactured to meet the acceptance criteria for the qualification
tests and the TDP will be uniform in their design, construction, and
response to impact forces.
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    \2\ Test dummies specified in 49 CFR part 572 are subjected to a
series of tests, called ``qualification tests,'' to ensure that
their components are functioning properly. Conformity to the
acceptance criteria for the qualification tests qualify the dummy as
an objective and suitable test device for the assessment of occupant
safety in compliance tests specified in the FMVSSs. Conformity
assures that the dummy can respond properly in the compliance test,
while non-conformance indicates the need for adjustment, repair or
replacement. Qualification tests also monitor the response of
components that may tend to deteriorate over time. For each test,
certain dummy sensors and signal characteristics (such as the
magnitude and timing) have been specified as qualification targets.
By monitoring these sensors, the qualification tests assure that the
dummy is functioning properly. Loose or damaged dummy hardware is
often manifested in a signal that does not conform to the
qualification targets, thus indicating that dummy maintenance may be
needed. Conformity also assures that the sensors themselves are
working properly.
    \3\ The parts list, engineering drawings, and the PADI for the
Q3s are available for examination in the docket for this final rule.
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    As discussed in the November 21, 2013 NPRM, the Q3s was found to
exhibit repeatable performance in CRS side impact sled testing and in
component-level qualification testing. However, NHTSA acknowledged in
the NPRM that the agency's findings in the proposed rule were based on
only a few Q3s dummies then in existence. At the time of publication of
the NPRM, the Q3s was a proprietary product owned by Humanetics
Innovative Solutions Inc. (HIS), and HIS was the only source from which
to obtain the dummy. NHTSA developed the Q3s NPRM based on NHTSA's
testing experiences with four units that the agency had purchased from
HIS. In the NPRM, the agency expressed a desire to examine more data on
more dummies from multiple test labs and an expectation that it will
``continue to collect qualification data'' and ``will examine all
qualification data provided to us by commenters.'' 78 FR at 69959.
    NHTSA received comments on the Q3s NPRM from the Juvenile Products
Manufacturers Association (JPMA), Graco Children's Products, Inc.
(Graco), Dorel Juvenile Group (Dorel), and HIS. Several commenters said
they could not obtain the Q3s dummies from the dummy manufacturer HIS
and so had little or no information about the ATD. Some expressed
concern that the dummy's repeatability and reproducibility of
performance were not assessed across various test facilities. Some
asked for more data from tests with more dummies to round out the
qualification corridors. In addition, the commenters made several
technical comments relating to the ATD.
    Subsequently, in mid-2014, HIS began delivery of new Q3s dummies to
end-users that included NHTSA, CRS manufacturers, and testing
laboratories. In 2014 and 2015, to obtain more data on the Q3s, NHTSA
undertook systematic testing of the new units from HIS, contracting
with laboratories to carry out a full series of qualification tests
with six Q3s dummies. The units included three of the agency's original
four dummies together with new dummies manufactured in 2014.
    The agency set up a series of experiments designed to evaluate the
performance of the Q3s in several different labs, examining the
repeatability and reproducibility of the Q3s's performance. NHTSA
designed the test program to assess all sources of variability, to
quantify the degree of variability, determine its acceptability, and
assess whether the underlying cause was a non-uniform test procedure at
a lab (and among the labs), an aspect of dummy design, or the dummy
manufacturer's production of Q3s units. Data from the tests were used
to finalize the acceptance criteria for the qualification tests and
ensure that a high level of repeatability and reproducibility (R&R)
will be maintained henceforth.\4\
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    \4\ The additional data also led to NHTSA's making some
technical modifications to the proposed part 572 specifications,
i.e., NHTSA removed the requirement for the pubic load in the pelvis
impact test, revised aspects of the neck and lumbar tests, and
corrected some of the drawings for the dummy. The agency discusses
and lists the technical changes from the NPRM to this final rule
below in this preamble.
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    For this final rule, HIS has removed all proprietary rights to the
Q3s. Single-source restrictions were in place during the NPRM stage
(HIS retained rights to manufacture the dummy). However, the dummy
drawings and designs are now free of any restrictions. This includes
restrictions on their use in fabrication and in building computer
simulation models of the dummy.

Benefits and Costs

    The benefits associated with this rulemaking cannot be quantified.
The incorporation of the test dummy into 49 CFR part 572, the first-
ever child test dummy incorporated by NHTSA for use in side impacts,
has the potential to significantly improve child passenger safety in
motor vehicles. Adopting the Q3s gives NHTSA a tool to assess the
performance of dynamic side impact protection requirements for child
restraints using an ATD representative of children for whom the CRS is
designed, and quantitatively evaluate the effectiveness of CRSs in
preventing or attenuating head and chest impacts in side impacts. In
addition, the availability of this dummy in a regulated format will
provide a test tool that can potentially be used with other products
designed to benefit children in side impacts.
    This final rule does not impose any requirements on anyone. NHTSA
has proposed to use the Q3s in its compliance testing of the FMVSS No.
213 test under development, but even following adoption of the test,
manufacturers would not be required to use the Q3s or assess the
performance of their products in the manner specified in the standard.
Child restraint manufacturers would be affected by this final rule only
if they choose to use the Q3s to test their products.
    For entities choosing to own the Q3s, NHTSA estimates that the
estimated cost of an uninstrumented Q3s dummy is approximately $50,000.
Instrumentation installed within the dummy needed to perform the
qualification in accordance with part 572, subpart W, adds
approximately $20,000, for a total cost of about $70,000.

Summary of Decision

    The data presented in the 2013 NPRM and obtained in NHTSA's post-
NPRM test program demonstrate that the Q3s is a valuable tool for use
in side impact testing. Adopting the Q3s into 49 CFR part 572 enhances
NHTSA's efforts to reduce unreasonable risks posed by side crashes to
children.

II. Background

a. 2013 Part 572 NPRM and 2014 FMVSS No. 213 NPRM

    On November 21, 2013, NHTSA published an NPRM proposing design

and performance specifications and qualification tests for the Q3s, a
new test dummy representative of a 3-year-old child for use in side
impact testing (78 FR 69944). On January 28, 2014, NHTSA published an
NPRM proposing to amend FMVSS No. 213 to add a new side impact test in
which the Q3s would be used. The proposed side impact test applies to
CRSs designed for children weighing up to 18 kg (40 pounds) (79 FR
4570). The proposal responds to a statutory mandate in the ``Moving
Ahead for Progress in the 21st Century Act'' (MAP-21),\5\ that NHTSA
``issue a final rule amending Federal Motor Vehicle Safety Standard
Number 213 to improve the protection of children seated in child
restraint systems during side impact crashes.'' These two NPRMs are
referred to herein as the part 572 NPRM and the FMVSS No. 213 NPRM,
respectively.
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    \5\ Section 31501(a) of Subtitle E, ``Child Safety Standards,''
of MAP-21 (July 6, 2012) (Pub. L. 112-141).
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b. Comments on the 2013 Part 572 NPRM

    NHTSA received comments on the part 572 NPRM from HIS, Graco
Children's Products, Inc. (Graco), Dorel Juvenile Group, Inc. (Dorel),
and the Juvenile Products Manufacturers Association (JPMA). Some of the
comments on the FMVSS No. 213 NPRM discussed subjects pertaining to the
part 572 NPRM, which NHTSA discusses in this document as appropriate.
The commenters on the FMVSS No. 213 NPRM include Evenflo Company, Inc.
(Evenflo), Britax Child Safety, Inc. (Britax), Consumers Union,
Advocates for Highway and Auto Safety (Advocates), and Transport
Research Laboratory, UK (TRL).
    Commenters on the part 572 NPRM discussed issues related to the
following main areas: single source and patents; dummy and
qualification data availability, biofidelity; repeatability and
reproducibility of results (R&R); qualification test corridors, drawing
errors; and test procedure protocols. These issues and NHTSA's
responses to the comments are discussed below in this preamble.

III. Summary of Differences Between the NPRM and This Final Rule

a. Acceptance Criteria for the Qualification Tests

    A comparison of the acceptance criteria for the qualification tests
(or ``qualification limits'') in the NPRM versus the final rule is
summarized in Table 1. All changes from the NPRM are discussed below in
this preamble. The velocities and acceleration pulses of the impacting
pendulums, which ensure that qualification test conditions are uniform,
are unchanged from the NPRM.

                                        Table 1--Q3s Qualification Limits
                                              [NPRM vs. final rule]
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             Test                     Measurement            Units              NPRM              Final rule
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Head--Frontal.................  Resultant acceleration  G.............  250-297............  255-300.
                                Off-axis acceleration   G.............  -20 to +20.........  -15 to +15.
                                 (Ay).
Head--Lateral.................  Resultant acceleration  G.............  113-140............  114-140.
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                                Off-axis acceleration   G.............  -20 to +20.........  -15 to +15.
                                 (Ax).
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Neck--Flexion.................  Maximum rotation......  deg...........  70-82..............  69.5-81.0.
                                Time of max rotation..  msec..........  55-63..............  no req.
                                Peak moment (My)......  N-m...........  41-51..............  41.5-50.7.
                                Time of peak My.......  msec..........  49-62..............  note 1.
                                Decay time to 0 from    msec..........  50-54..............  45-55.
                                 peak angle.
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Neck--Lateral.................  Maximum rotation......  deg...........  77-88..............  76.5-87.5.
                                Time of max rotation..  msec..........  65-72..............  no req.
                                Peak moment (Mx)......  N-m...........  25-32..............  25.3-32.0.
                                Time of peak Mx.......  msec..........  66-73..............  note 1.
                                Decay time to 0 from    msec..........  63-69..............  61-71.
                                 peak angle.
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Neck--Torsion.................  Maximum rotation......  deg...........  75-93..............  74.5-91.0.
                                Time of max rotation..  msec..........  91-113.............  no req.
                                Peak moment (Mz)......  N-m...........  8-10...............  8.0-10.0.
                                Time of peak Mz.......  msec..........  85-105.............  note 1.
                                Decay time to 0 from    msec..........  84-103.............  85-102.
                                 peak angle.
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Shoulder......................  Lateral displacement..  mm............  16-21..............  17.0-22.0.
                                Peak probe force......  N.............  1240-1350..........  1123-1437.
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Thorax with Arm...............  Lateral displacement..  mm............  23-28..............  22.5-27.5.
                                Peak probe force......  N.............  1380-1690..........  1360-1695.
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Thorax without Arm............  Lateral displacement..  mm............  24-31..............  24.5-30.5.
                                Peak probe force......  N.............  620-770............  610-754.
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Lumbar--Flexion...............  Maximum rotation......  deg...........  48-57..............  47.0-58.5.
                                Time of max rotation..  msec..........  52-59..............  no req.
                                Peak moment (My)......  N-m...........  78-94..............  78.2-96.2.
                                Time of peak My.......  msec..........  46-57..............  note 1.
                                Decay time to 0 from    msec..........  50-56..............  49-59.
                                 peak angle.
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Lumbar--Lateral...............  Maximum rotation......  deg...........  47-59..............  46.1-58.2.

                                Time of max rotation..  msec..........  50-59..............  no req.
                                Peak moment (Mx)......  N-m...........  78-97..............  79.4-98.1.
                                Time of peak Mx.......  msec..........  46-57..............  note 1.
                                Decay time to 0 from    msec..........  47-59..............  48-59.
                                 peak angle.
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Pelvis........................  Peak pubic load.......  N.............  700-870............  no req.
                                Peak probe force......  N.............  1570-1810..........  1587-1901.
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\1\ Maximum moment occurs during the time interval while the rotation is within the specified interval.

b. Qualification Test Procedures

    The agency made a few adjustments to the proposed qualification
test procedures, which are summarized in Table 2 below. (Noteworthy
changes are discussed in this preamble.) For simplicity, the English
units that were shown in parentheses in the regulatory text of the NPRM
are omitted. The qualification tests themselves are essentially
unchanged from the NPRM.\6\
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    \6\ The qualification tests have proven reliable and sound in
qualifying the Q3s throughout the dummy's developmental stages and
in qualifying virtually all other test dummies specified in part
572.

               Table 2--Summary of Revisions to Procedures
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       Reg. text affected section             Description of change
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Sec.   572.212(c)(1) Head drop test....  Ambient temp. now 20.6-22.2 deg
                                          C.
Sec.   572.213(c)(1)(i) Neck flexion     Maximum moment now occurs when
 test, Sec.   572.213(c)(2)(i) Neck       rotation is within the
 lateral flexion test, Sec.               specified range.
 572.213(c)(3)(i) Neck torsion test,
 Sec.   572.217(c)(1)(i) Lumbar flexion
 test, Sec.   572.217(c)(2)(i) Lumbar
 lateral flexion test.
Sec.   572.213(b)(3)(ii) Neck torsion    Correction on time = 0
 test.                                    definition.
Sec.   572.213(c)(2)(ii) Neck lateral    Correction on specifying left
 flexion test, Sec.   572.217(c)(2)(ii)   vs. right mirroring in test
 Lumbar lateral flexion test.             setup figures.
Sec.   572.214(c)(4) Shoulder test,      New steps to position arm
 Sec.   572.215(c)(4) Thorax with arm     against thorax.
 tests.
Sec.   572.218(a) Pelvis assembly and    Pubic load cell now optional
 test procedure, Sec.   572.219 Test      since pubic criterion has been
 conditions and instrumentation.          omitted.
Sec.   572.212(c)(4) Head drop test,     Surface finish: 0.2-2.0 microns
 Figures W1, W2.                          RMS.
Sec.   572.212(c)(2)(ii) Lumbar lateral  Headform sagittal plane
 flexion test.                            perpendicular (not parallel)
                                          to the motion of the pendulum.
Figures W6, W7, W8, W11................  Correction on probe mass: Now
                                          3.81 kg.
Throughout regulatory text.............  English units omitted.
------------------------------------------------------------------------

    This final rule also corrects the following errors. The surface
finish of the steel plate used in the head qualification test was not
specified correctly in the NPRM. The correct specification is 0.2-2.0
microns root mean square (RMS). In the lateral lumbar qualification
test, the proposed regulatory text was unclear in how it described the
orientation of the headform, so it has been clarified. In Figures W6,
W7, W8, and W11 of the proposed regulatory text, the probe mass was
labeled incorrectly as 3.85 kg. The correct value is 3.81 kg.

c. Engineering Drawings and the Procedures for Assembly, Disassembly,
and Inspection (PADI)

    For this final rule, NHTSA has revised some of the engineering
drawings to address discrepancies between the PADI and the engineering
drawings, and some inconsistencies HIS noticed between the drawings it
provided NHTSA for development of the NPRM and the dummies HIS
produced. The changes are all valued-added revisions that either
correct errors or provide missing information. They are not alterations
that would change the dummy in any meaningful way or alter the dummy's
response in either pre-test qualification testing or dynamic sled
testing with CRSs. The changes to the drawings and the PADI are
discussed in detail in Section IX below. A comprehensive listing of
changes is described in the document, ``Q3s Engineering Drawing
Changes, Rev. J, May 2016.'' \7\ The design of the Q3s is essentially
unchanged.
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    \7\ This document can be found in the docket for this final
rule.
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IV. Response to Comments (Part I) on Developing the Regulation

a. Copyright and Patent Issues

    HIS had certain property rights in the Q3s engineering drawings
during the notice and comment period of this rulemaking. As discussed
in the NPRM (78 FR at 69965-69966), during the notice and comment
period, the Q3s engineering drawings used to fabricate the dummy were
available in the docket for public review and comment, but most
displayed the HIS name in the title block with a note restricting
copying of or using the drawings other than for commenting purposes.
NHTSA stated in the NPRM that the name, note, and all restrictions
associated with the drawings will be removed at the final rule stage.
Separately, in the NPRM, NHTSA noted its awareness that a patent
application filed by HIS may cover certain parts of the Q3s dummy.
Comments Received
    NHTSA received several comments expressing concern about the
intellectual property restrictions on the dummy. JPMA and Dorel
expressed concern that manufacturers will be bound to purchase a
single-sourced dummy that is subject to patents and unregulated price
points.

NHTSA Response
    The Q3s specified in this final rule is free of any known copyright
or patent restrictions.
    Although copyright restrictions were in place during the NPRM stage
for the Q3s engineering drawings, all restrictions are removed for this
final rule. The HIS name and the copyright note have been removed from
all of the drawings. The dummy drawings are free of any restrictions
and can be used in dummy fabrication and in building computer
simulation models of the dummy. Moreover, there are no patents
associated with the Q3s adopted by this final rule.\8\
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    \8\ The patent issue was discussed in the NPRM (78 FR at 69965).
Around the time of the NPRM, NHTSA became aware that HIS had filed a
patent application with the United States Patent and Trademark
Office potentially covering certain parts of the Q3s dummy. However,
the patent eventually issued--for a rib cage incorporating a
polyurethane material with a type of metal insert--is not used in
the current design. (See U.S. Patent No. 8,840,404 B2, ``Rib cage
for assembly for crash test dummy,'' September 23, 2014.)
Accordingly, the patent does not apply to the version of the Q3s
specified in this final rule.
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b. Dummy Availability and Associated Data

    The difficulty in obtaining the Q3s was brought up in comments to
both the part 572 and the FMVSS No. 213 NPRMs by several commenters.
JPMA indicated it was not possible to learn of the strengths and
limitations of the Q3s, particularly regarding its repeatability,
reproducibility, and reliability. Graco, Britax and Evenflo indicated
that the lack of availability of the dummy to the CRS industry and
outside test facilities has prevented a more complete evaluation of the
dummy across various test facilities and multiple CRS manufacturers.
Dorel and HIS commented that more data from more dummies are needed to
round out the qualification corridors.
NHTSA Response
    It is true that the Q3s was generally unavailable from HIS during
the original comment period which ended April 28, 2014. Because of that
unavailability, on June 4, 2014, NHTSA reopened the comment period for
the FMVSS No. 213 NPRM, granting a petition from JPMA (79 FR 32211).
NHTSA agreed at that time to reopen the comment period until October 2,
2014, because the Q3s was slated to become widely available from HIS to
CRS manufacturers around mid-2014.\9\ Since mid-2014, the dummy has
been available, as HIS has filled many orders for the Q3s since then.
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    \9\ Graco apparently was able to obtain and assess a new Q3s
unit during the reopened comment period. In a comment on the FMVSS
No. 213 NPRM, Graco states that it ``supports the use of the Q3s ATD
for side impact testing based on NHTSA's data and confirmed
structural performance during the developmental testing period.
Graco has been using the Q3s in our internal lab for about 6 months
and we are satisfied with the overall performance of the ATD.''
``Feedback Document for FMVSS 213 Side Impact [NPRM], Oct. 1, 2014,
p.10.
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    Regarding the qualification corridors, NHTSA concurs that
development of qualification corridors is benefitted when more data are
available on the ATD's performance in the qualification tests. In the
NPRM for this final rule (78 FR 69959), the agency acknowledged that
there was a limited amount of qualification data available to NHTSA for
use in setting the proposed qualification limits.\10\ NHTSA stated in
the NPRM that the agency expected to receive qualification data from
end-user commenters on the dummies tested at their own laboratories,
and that, with those data, the agency would adjust the qualification
limits to account for a greater population of dummies, and modify the
test procedures as needed.\11\
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    \10\ For the NPRM, NHTSA established qualification requirements
based on replicate trials conducted sequentially on the four NHTSA-
owned Q3s units at VRTC. These tests were used to set the upper and
lower limits of the qualification corridors. They were initially set
as follows: Either 3 standard deviations from the mean
or ten percent from the mean, whichever was narrower. Upper and
lower bounds were then rounded to the next whole number away from
the mean using three significant digits such that the final bounds
were slightly wider than the initial bounds. NHTSA expected to
refine and narrow the corridors when additional data was received on
other Q3s units.
    \11\ The adjustments made to the limits and procedures are
listed Tables 1 and 2, supra.
---------------------------------------------------------------------------

    When data from users were not forthcoming because of the
unavailability of the Q3s, NHTSA designed a test program to obtain the
desired data once the dummy became available. In mid-2014, NHTSA
borrowed three new Q3s units from existing owners (manufactured by HIS
and delivered to end-users in mid-2014) to collect comparative
qualification data with their new units. The agency systematically
tested the three new units, as well as three of the agency's older
units (manufactured in 2012 or before and used to develop the 2013 part
572 NPRM). NHTSA hired test labs to carry out a full series of
qualification tests with the six Q3s dummies.
    The agency's design of experiments allowed NHTSA to assess the
reproducibility and repeatability of the dummy and sort out sources of
variability. NHTSA examined variability due to any non-uniform test
procedure at each lab (and among the labs), variability in the dummy
design, and variability in HIS's production of multiple Q3s units.
Using this systematic process, NHTSA compiled the additional test data,
and those submitted by other end-users, to set the acceptance criteria
for the qualification tests for the Q3s. The post-NPRM test program is
discussed at length in this preamble in Sections V and VI.

c. Developmental Stage of the Dummy

Comment Received
    The NPRM referred to the Q3s as the ``build level D'' iteration of
the dummy (Build D). ``Build level'' is a term used by HIS to describe
a specific revision level of the dummy relative to previous versions it
sold. The Q3s drawings that HIS provided NHTSA prior to the publication
of the NPRM were marked as revision level D.\12\
---------------------------------------------------------------------------

    \12\ In the TDP drawings placed in the NPRM docket, the HIS
build level that HIS identified for the ATD is reflected in the top
level assembly drawing of the Q3s, 020-0100 (sheet 1). This drawing
shows that HIS marked revision level D in the title block.
---------------------------------------------------------------------------

    In its comment, HIS states that it considers the build level D
dummy to be out of date, and that the dummy specified in a final rule
should be referred to as ``Build E.'' HIS states that not using the
``Build E'' designation could cause hardship to its customers who might
not know which version of the dummy they own, or who might erroneously
assume that their build level D dummy is up to date when in fact the
ATD ``may be missing key updates.''
NHTSA Response
    For the reasons set forth below, NHTSA declines to make the change.
NHTSA does not believe that using the HIS naming conventions for this
final rule is necessary or warranted. For the final rule, the agency
has adopted a drawing package that has been periodically fine-tuned
since publication of the NPRM in 2013 (discussed in sections below), so
the revision level of the Technical Data Package had been updated from
Revision (Rev.) D to Rev. J. We do not believe that NHTSA has to name
the Q3s ``Build E'' to enable HIS to notify customers who bought Build
D units built between December 2010 and November 2013 that their units
may be missing key updates. HIS can use its sales records and customer
outreach to determine which Q3s units its customers bought and which
need updating. With those records and outreach, HIS can determine the
type of conversion needed to bring the units up to date and facilitate
their customers' updates of the previously-purchased ATDs.

Comment Received
    Dorel believed that many aspects of the Q3s, such as the fixture
used to run the neck torsion qualification tests, were not fully
engineered, and are thus not finalized and ready for sale. Dorel also
cited unavailability of specialized Q3s signal processing software as a
hold-up to its dummy evaluation.
NHTSA Response
    Dorel is mistaken in believing that the Q3s and its complementary
fixtures used in qualification testing were not fully engineered. The
NPRM for the Q3s provided all the information needed to assess the
dummy in qualification tests, including complete engineering drawings
of the neck torsion fixture. The neck torsion fixtures were not rights-
protected in the NPRM for the Q3s. The agency knows of at least two
other labs in addition to the agency's Vehicle Research and Test Center
(VRTC) that have built them on their own (MGA Research Corporation
(MGA)) and Calspan).
    With regard to Dorel's software concern, NHTSA has not developed
specific software for the express purpose of processing qualification
data for the Q3s or any other dummy. NHTSA does not provide software
that would fully automate the processing of raw signals to determine
the PASS/FAIL outcomes in each of the eleven Q3s qualification tests.
Such software is a third-party product. As with all part 572
regulations, NHTSA specifies the test procedures, the test equipment,
the instrumentation, and the filter frequencies of the test signals.
The means to process the signals (in accordance with the part 572
specifications) is left to the discretion of each test lab.
    NHTSA does maintain a library of software tools that aid in the
processing of raw signal data.\13\ This includes a collection of
Microsoft Windows graphical applications for analysis and processing of
signal data. Core algorithms in this package include minimum/maximum
applications, signal scaling, numerical integration, and digital
filtering as specified by many FMVSS and part 572 standards (including
Subpart W for the Q3s.) These tools may be used to process data
generated in Q3s qualification tests.
---------------------------------------------------------------------------

    \13\ http://www.nhtsa.gov/Research/Databases+and+Software.
---------------------------------------------------------------------------

d. Biofidelity

    The part 572 NPRM discussed NHTSA's findings that the Q3s is
suitably biofidelic overall and especially in the head, thorax and neck
which are the body segments most critical for the intended use of the
dummy in side impact testing. (78 FR at 69947-69950.)
Comment Received
    In its comment, JPMA stated its belief that the Q3s's biofidelity
is not representative of a 3-year-old, living child. JPMA stated \14\--
---------------------------------------------------------------------------

    \14\ See Docket NHTSA-2013-0118-0008, page 2.

    As the agency is aware, its assessment of the Q3s focused on (1)
a scaled-down version of post mortem adult human subject data, and
(2) cadaver testing under dynamic loading. Unfortunately, the
scaled-down adult data presumes incorrectly that adults and children
are the same internally, which is simply not the case. For example,
children's bones and bodies in general are much more flexible than
their adult counterparts. Merely scaling adult data on the basis of
mass, geometric and stiffness ratios will not represent accurate
child-centered data. Therefore, while appropriate in size and weight
to a live 3-year-old, the Q3s is not representative of live,
reactive 3-year-old children. Due to the known differences between
the Q3s and the children the ATD is supposed to represent, the
developing side impact test standard carries with it a certain level
of inherent risk -- that child restraints built to comply with the
new standard will be moving away from real-world effectiveness.
NHTSA Response
    NHTSA's biofidelity assessment of the Q3s (provided in a report in
the docket for the NPRM \15\) compared the responses of the dummy to
targets previously established for a three-year-old child. The targets
themselves were published in a Stapp Journal article by the SAE Hybrid
III Dummy Family Task Group.\16\
---------------------------------------------------------------------------

    \15\ See Docket NHTSA-2013-0118, ``Biofidelity Assessment of the
Q3s Three Year-Old Child Side Impact Dummy,'' July 2012.
    \16\ Irwin AL, Mertz HJ, Elhagediab AM, Moss S (2002).
Guidelines for Assessing Biofidelity of Side Impact Dummies of
Various Sizes and Ages. Stapp Car Crash Journal V46: 297-319, SAE
International, Warrendale, PA.
---------------------------------------------------------------------------

    For ethical reasons, biomechanical response data on children under
impact loading are very limited. Therefore, scaling techniques are
necessary to derive the child impact response targets from laboratory
tests on adult post-mortem human subjects (PMHS).\17\
---------------------------------------------------------------------------

    \17\ Aside from its response to impact, the size and shape of
the Q3s is based on child anthropometry. The size and shape of the
ATD is not scaled from an adult model or other dummy size.
---------------------------------------------------------------------------

    The SAE scaling procedure followed an impulse-momentum approach to
derive response targets for a three-year-old from targets established
previously for adults. The procedure made use of adult-to-child ratios
of mass, anthropometry, and bone stiffness. In its comments, JPMA
implied that this procedure does not account for differences in bone
flexibility between adults and children. This is not the case.
Differences in bone flexibility are integral to the scaling process,
which employs adult-to-child bone stiffness ratios. For three-year-old
vs. adult scaling, a bone stiffness ratio of 0.475 was applied. This
ratio was derived using measurements of the elastic modulus of human
bone samples from actual children as explained in the Stapp article.
The scaling ratios were all applied to a lumped mass and spring model
to arrive at biomechanical corridors for a three-year-old. Stated
differently, the scaling theory used to establish the impact response
of a human three-year-old does account for differences in flexibility
and stiffness between adults and children.
    Details on the derivation of the scaling model and its application
may be found in Mertz (1984) \18\ and Mertz, et al. (1989).\19\ NHTSA
notes that the impulse-momentum approach was used for other part 572
child dummies, including the CRABI infant dummy \20\ and the Hybrid III
family of child dummies.21 22 Thus, the biomechanical
targets used to assess the Q3s were derived the same way as the targets
for all other child dummies. Given the limitations on pediatric data,
NHTSA believes the scaling process represents an appropriate, best
available method of estimating the living, human child's response
characteristics.
---------------------------------------------------------------------------

    \18\ Mertz HJ (1984), ``A procedure for normalizing impact
response data,'' Paper No. SAE 840884, Biomechanics of Impact Injury
and Injury Tolerances of the Thorax-Shoulder Complex--PT-45, SAE
International, Warrendale, PA.
    \19\ Mertz HJ, Irwin AL, Melvin JW, Stalnaker RL, Beebe MS
(1989), ``Size, weight, and biomechanical impact response
requirements for adult size small female and large dummies,'' Paper
No. SAE 890756, Automotive Frontal Impacts, SP-782, pp 133-144, SAE
International, Warrendale PA.
    \20\ Melvin JW (1995), ``Injury assessment reference values for
the CRABI 6-month infant dummy in a rear-facing infant restraint
with airbag deployment,'' Paper No. SAE 950872, SAE Congress and
Exposition, Detroit, pp 1-12, SAE International, Warrendale PA.
    \21\ Kleinberger M, Yoganandan N, Kumaresan S (1998),
``Biomechanical considerations for child occupant protection,'' 42nd
Annual Proceedings for the Association for the Advancement of
Automotive Medicine, pp 115-136, Charlottesville, VA.
    \22\ Mertz HJ, Jarrett K, Moss S, Salloum M, Zhao Y (2001),
``The Hybrid III 10-year-old dummy,'' Paper No. 2001-22-0014, Stapp
Car Crash Journal, V45, SAE International, Warrendale, PA.
---------------------------------------------------------------------------

    To summarize, NHTSA believes that the scaling process used to
derive biomechanical response targets for the Q3s is well-founded and
reasonable. The scaling process does not presume that adults and
children are the same internally. The process assumes that the response
of the targeted subject depends

on its internal stiffness, and that internal stiffness varies by the
age of the subject. The agency is satisfied with the overall
biofidelity of the Q3s and is convinced that CRSs built to comply with
the new side impact standard using the Q3s will be effective in the
real world.
Q3s Shoulder
    NHTSA evaluated the biofidelity of the Q3s shoulder in component
testing under the loading of a pendulum. In the NPRM, NHTSA described
an ``unpadded'' test conducted involving an SAE International protocol
(Irwin, 2002) that uses a rigid pendulum in a pure lateral direction.
In the test, the Q3s shoulder showed high stiffness with respect to
lateral shoulder displacement and probe force under this test protocol.
NHTSA later reexamined shoulder biofidelity under ``padded'' conditions
that the agency believed corresponded more closely to the planned use
of the Q3s in the proposed FMVSS No. 213 test than the unpadded
condition. In the latter test, NHTSA used the Ohio State protocol
(Bolte et al., 2003), which utilizes the same impactor mass and speed
as the SAE International test but with foam padding attached to the
impactor face. NHTSA determined that the latter condition was
particularly relevant because the Q3s would most likely be exposed to a
padded side structure (``wing'') of the child restraint in the
test.\23\ The striking surface, like the probe in the Ohio State test,
would be padded.
---------------------------------------------------------------------------

    \23\ CRSs subject to a side impact test would likely use padded
side wings as one of the main countermeasures to meet side impact
protection requirements.
---------------------------------------------------------------------------

    Under the Ohio State protocol, the shoulder of the Q3s was also
stiff when assessed for biofidelity as measured by its deflection
(about 10 mm below the nominal biofidelity target). However, NHTSA
found that the magnitude of the force applied by the padded probe
(about 400 N) was well within the upper and lower limits of
biofidelity. Therefore, NHTSA believed that the Q3s's shoulder loading
of the child restraint, which could affect the overall motion of the
dummy's upper torso and head (relevant for the measurement of injury
criteria under consideration), was representative of an actual human.
(78 FR at 69949-69950.)
Comment Received
    JPMA commented that it believed the shoulder of the Q3s is too
stiff relative to a human child. The commenter stated that, because the
shoulder is too stiff, the trajectory of the head during a compliance
test will be unrealistic such that it could register artificially high
HIC values. JPMA asserted that child restraint designs will thus need
to be ultra-conservative in their ability to keep HIC low, and that
this, in turn, could necessitate a seat design that is uncomfortable
for children. JPMA was concerned that, to get comfortable, children may
take on seating postures that could ultimately put the child at higher
risk than when seated in a current CRS (i.e., one that is not designed
to meet a new side impact requirement). The commenter did not did not
provide any data or analysis supporting these views.
NHTSA Response
    It is important to highlight the point made in the NPRM that, under
conditions that correspond closest to the intended use of the Q3s in
the proposed FMVSS No. 213 side impact test (i.e., using a foam-covered
probe that is more akin to the shoulder interaction with a CRS
``wing''), the force response of the padded probe (external biofidelity
\24\) nearly matches the target.\25\ With the magnitude of the force
generated by the padded probe well within the envelope for a biofidelic
response, these data show that the Q3s shoulder is biofidelic in the
manner in which it will exert force on the CRS. Thus, this loading of
the child restraint, which would affect the overall motion of the
dummy's upper torso and head (through which the FMVSS No. 213 injury
criteria under consideration would be measured), is representative of
an actual human. JPMA did not provide any analysis or rationale
supporting its conclusions that the Q3s shoulder will cause
artificially high HIC values and that uncomfortable seat designs will
result. Given all available data and information about the test dummy,
NHTSA is satisfied with the biofidelity of the Q3s shoulder and how the
ATD's shoulder, head and torso will interact when the dummy is
restrained in a child restraint in the side impact test.
---------------------------------------------------------------------------

    \24\ For pendulum impacts, biofidelity is generally assessed as
``external'' or ``internal.'' External biofidelity is related to the
force generated on the face of a pendulum impact probe upon striking
a subject. In other words, probe forces generated by dummies are
compared against probe forces generated by PMHS. Internal
biofidelity is related to a measurement on or within the subject
itself, such as shoulder deflection or spine acceleration, for which
corresponding measurements are made on both the PMHS and the test
dummy.
    \25\ 78 FR at 69949. ``Biofidelity Assessment of the Q3s Three-
Year-Old Child Side Impact Dummy,'' July 2012, Docket No. NHTSA-
2013-0118.
---------------------------------------------------------------------------

e. Repeatability and Reproducibility (R&R)

    A test dummy's R&R may be assessed in sled tests and component
tests. ``Repeatability'' is defined here as the similarity of responses
from a single dummy when subjected to multiple repeats of a given test
condition. ``Reproducibility'' is defined as the similarity of test
responses from multiple dummies when subjected to multiple repeats of a
given test condition. Sled tests establish the consistency of the
dummy's kinematics, its impact response as an assembly, and the
integrity of the dummy's structure and instrumentation under controlled
and representative crash test conditions. In component tests, the test
conditions as well as the test equipment are carefully controlled to
assure the dummy is subjected to a tightly controlled impulse and to
minimize external effects on the dummy's responses.
Assessment of R&R
    NHTSA's assessment of R&R was based on a statistical analysis of
variance. The percent coefficient of variation (CV) is a measure of
variability expressed as a percentage of the mean. The CV is calculated
as follows:
---------------------------------------------------------------------------

    \26\ Standard deviations are based on a sample and calculated
using the ``n-1'' method.
[GRAPHIC] [TIFF OMITTED] TR03NO20.021

    NHTSA has used CVs to assess the repeatability and reproducibility
of ATDs throughout the history of part 572, starting in 1975.\27\
Separate CVs for repeatability and reproducibility, by labs and by
dummies, were computed. The CVs were used to assess the degree to which
the current population of Q3s dummies were able to attain targeted
responses. In the NPRM, we described how provisional upper and lower
limits for all qualification requirements were set at a maximum of 10%
(before rounding) from a nominal response target. For any particular
requirement, the 10% condition was always met in our post-NPRM testing
when the CVs were all below 5% for repeatability and 6% for
reproducibility. Under these circumstances, there is a high degree of
uniformity in the construction of the dummy components being tested and
in the procedures followed by the labs for that test requirement.
---------------------------------------------------------------------------

    \27\ See NPRM for the original subpart B Hybrid II 50th
percentile male ATD (40 FR 33466; August 8, 1975).
---------------------------------------------------------------------------

    For example, in the post-NPRM test series for neck flexion, neck
moments from 81 trials were recorded. In all 81 trials, the neck moment
was well within 10% of the nominal target and the CVs were all below 5%
for repeatability and below 6% for reproducibility. Thus, in our post-
NPRM assessments, when the CVs for a particular test condition were
below 5% and 6% for repeatability and reproducibility, respectively, no
further examination of the data or test condition was carried out.
    On the other hand, when a test condition produced a CV above 5% for
repeatability or 6% for reproducibility, a response in at least one
trial was usually beyond 10% of the nominal target. When a CV exceeded
10%, several trials were beyond 10% of the target. In these instances,
a close examination of the data, dummies, and procedure was performed
to pinpoint the source of the variability. Corrective actions were
taken in most cases.
    Our investigative criteria for repeatability uses a slightly lower
CV than for reproducibility (5% vs. 6%) as shown in Table 3. Since
repeatability is an assessment of the same dummy by the same test
laboratory, whereas reproducibility is an assessment of multiple
dummies at more than one lab, reproducibility assessments include many
more sources of variability. Hence, repeatability CVs are generally
lower than reproducibility CVs.

 Table 3--CV Score Categorization for Repeatability and Reproducibility
                                  \28\
------------------------------------------------------------------------
 Repeatability CV score   Reproducibility CV score       Assessment
------------------------------------------------------------------------
<5%.....................  <6%.....................  No further
                                                     investigation; all
                                                     trials within 10% of the
                                                     target response.
5%-10%..................  6%-10%..................  Sources of
                                                     variability
                                                     investigated. One
                                                     or more trials
                                                     beyond 10% of target
                                                     response.
>=10%...................  >=10%...................  Corrective actions
                                                     considered for
                                                     revisions to test
                                                     procedure or dummy
                                                     design. Several
                                                     trials beyond 10% of target
                                                     response.
------------------------------------------------------------------------

R&R in Sled Tests
    Since the Q3s dummy is being considered as a measurement device for
a proposed regulatory test that would evaluate CRS performance in side
impact crashes, NHTSA assessed the R&R of the dummy in actual CRS side
impact sled tests. This assessment was discussed in the NPRM (78 FR at
69951-69953), where two Q3s units were tested five times each. Of the
greatest importance to the assessment were the two measurements
associated with injury assessment reference values for CRS requirements
under the proposed side impact upgrade to FMVSS No. 213. These were the
response of the head \29\ and the lateral thorax displacement.
---------------------------------------------------------------------------

    \28\ The assessment categories in Table 3 differ slightly from
those applied during the NPRM stage. In the NPRM R/R analysis, a
similar Table 3 categorized the CV ranges as either ``Excellent,''
``Good,'' ``Marginal,'' or ``Poor.'' For this final rule, we do not
use these terms in the table to describe the CV ranges. Rather, the
new Table 3 provides further explanation of the action taken by the
agency when the CV for a particular test condition was in a
specified range, which, we believe, is more informative and helpful
to the reader. Also, although the previous nomenclature for the CV
ranges provided a convenient shorthand, we believe the terms it used
could be misconstrued by the reader as reflective of a final
assessment of the qualities of the ATD being tested.
    \29\ The response of the head was measured by the acceleration
of the head. Additionally, R&R of the head was also assessed via its
injury correlate, the head impact criterion (HIC). HIC is computed
from the head acceleration measurements.
---------------------------------------------------------------------------

    The CVs for the response of the head were less than 3% for all
measures of R&R. For the lateral thorax displacement, the CV for
reproducibility was also under 6%, and CV for repeatability was under
5% for one of the two Q3s units. For the other unit, the data in one of
the tests was quite different from the others. This discrepancy was
traced to an inconsistency in the pre-test position of the dummy's
elbow in one of the tests which had resulted in a CV for repeatability
of 9% for that unit.
    In consideration of the elevated CVs, NHTSA ran another
(``supplemental'') series of sled tests with an improved arm-
positioning protocol. This was also described in the NPRM (78 FR at
69952-69953). Five trials were run with a single unit. The
repeatability for the thorax displacement in this series had a CV of
4%. The response of the head again was highly uniform, with a CV of 3%.
    Given this high degree of uniformity in those tests and since the
design of the dummy was essentially unchanged, NHTSA was satisfied with
the R&R of the Q3s in sled testing and determined there was no need to
perform additional sled testing for a final rule.
Comment Received
    In its comments, Dorel said that it computed a CV of 32.6% for HIC
results from ten tests in the supplemental series.
NHTSA Response
    The agency believes that Dorel may have misread the results of this
series of tests. There were only five tests in this series, not ten as
suggested by Dorel. None of the HIC values listed by Dorel correspond
with those in NHTSA's test series, so it is unclear where Dorel's data
were derived. The agency's test data are available to the public in
NHTSA's Biomechanics Data Base (BIODB).\30\ The CV in sled testing was
only 3% for the HIC values. Given these data, Dorel's comment appears
to be mistaken. In view of this high degree of uniformity, NHTSA is
satisfied with the R&R of the Q3s in sled tests.
---------------------------------------------------------------------------

    \30\ The Biomechanics data base may be accessed at: http://www.nhtsa.gov/research-data/databases-and-software.
---------------------------------------------------------------------------

R&R in Component Qualification Tests
    In the NPRM, acceptance criteria for the qualification tests were
proposed to

assure that the high level of R&R exhibited in the sled tests would be
preserved in any dummy presented for compliance testing. In other
words, the qualifications would serve to weed out any dummy that had a
substantially different response from the uniformity of the original
four units. The proposed acceptance criteria were based on a series of
eleven component tests with multiple Q3s units in replicate trials. An
upper limit and lower limit for an acceptable response were set for
each test. The limits were chosen to be wide enough to account for
normal variations in dummy and laboratory differences, and narrow
enough to assure consistent and repeatable measurements in compliance
testing.
    As part of this analysis, R&R was assessed for each set of
qualification test outcomes. As discussed in the NPRM, most CVs were
well under 5% and all were under 10%. The agency was aware, however,
that for the NPRM the assessment was carried out using only four units,
with all tests run at a single laboratory (VRTC). NHTSA explained in
the NPRM that the agency anticipated finalizing the Q3s limits based on
additional qualification data we would receive subsequent to the NPRM
(78 FR at 69959). Various commenters responding to the NPRM expressed
the view that the repeatability and reproducibility assessment of the
Q3s ought to be assessed across various test facilities. Some asked for
more data from tests with more dummies to round out the qualification
corridors.
    After the NPRM was published, NHTSA proceeded to obtain more
qualification test data as it had planned. NHTSA investigated whether
newer dummies tested at different labs exhibited the same level of R&R
as NHTSA's original units. In the test program NHTSA designed in mid-
2014, the agency used different labs to test both newer Q3s units and
the original dummies, and obtained data that could be compared to the
existing NPRM data from the original four units.
    In 2014 and 2015, NHTSA systematically tested three new units that
HIS delivered to end-users and three of the agency's original four
dummies. NHTSA examined the R&R of the Q3s's performance to assess all
sources of variability so as to identify the degree of variability and
whether it was due to a non-uniform test procedure at a lab (and among
the labs), an aspect of dummy design, or the dummy manufacturer's
production of Q3s units. This systematic approach enabled NHTSA to
assess the potential to which factors resulting in the variability
could be remedied, adopt measures to mitigate the variances where
possible, and assess the quality of the data on the Q3s. The testing
also provided data that helped round out the qualification corridors.
The program is discussed below. Test results and analyses are discussed
in detail in a NHTSA report entitled, ``NHTSA's Q3s Qualification
Testing, 2014-2015, May 2016.'' \31\
---------------------------------------------------------------------------

    \31\ A copy of the report has been placed in the docket for this
final rule.
---------------------------------------------------------------------------

V. Post-NPRM Test Program Overview

a. Test Locations

    NHTSA collected data from tests run at three different laboratories
(Calspan, MGA and HIS) independent of NHTSA, and conducted additional
tests at NHTSA's VRTC.
    At each independent lab, a full set of qualification tests were run
(consisting of 11 different types of tests) on two NHTSA-owned units
and a new unit. Several trials, or repeat tests, were carried out on
each dummy for each of the 11 qualification tests. Tests were done
using qualification test equipment owned by each laboratory. Tests were
run in strict accord with the procedures described in the NPRM. The
input parameters for each test had to conform to the specifications set
forth in the proposed qualification procedures. For example, a test in
which the probe impact speed did not meet the required parameters did
not count toward the total test repetitions. After each test, a post-
test inspection of the dummy was carried out to determine if the ATD
incurred any damage resulting from the test.
NHTSA Tests at Outside Labs--Calspan and MGA
    NHTSA contracted the services of Calspan and MGA to perform the
series of qualification tests. The test series are summarized in Table
3. All tests were carried out between January through March 2015.
NHTSA In-House Tests (VRTC)
    Prior to shipping NHTSA's two dummies to Calspan and MGA, NHTSA
tested the ATDs to the qualification tests at VRTC, but only one trial
per test condition was carried out. These results (in addition to those
provided in the NPRM) served as a comparative baseline for subsequent
tests on the same units at the outside labs. Also, the agency arranged
with Britax to test its new Q3s dummy that Britax had received from HIS
in 2014. The tests were conducted at VRTC, and the results were added
to the data pool.
Tests at HIS
    In addition to the data NHTSA itself collected, the agency was also
given data by HIS. In 2014, NHTSA lent HIS two of NHTSA's Q3s dummies
for HIS to use to compare its qualification procedures and equipment to
that described in the NPRM. HIS ran the qualification tests and
provided NHTSA with the data from the tests. The agency also obtained
from Calspan, MGA and Britax the qualification results performed by HIS
on the new Q3s units sold to those end-users. These data were supplied
by HIS to each respective purchaser of the dummy at the time of
delivery. The owners, in turn, provided the data to NHTSA. The test
results were added to the data pool.
    Table 4, below, provides an overview of the qualification testing
conducted at each lab.

                                 Table 4--Overview of Q3s Qualification Testing
----------------------------------------------------------------------------------------------------------------
                                                                    Number of
             Lab               Q3s serial No.     Dummy owner        trials       Year of tests        Note
----------------------------------------------------------------------------------------------------------------
VRTC.........................             004  NHTSA...........               5            2012  Results shown
                                                                                in NPRM.
                                          006  NHTSA...........               5            2012  Results shown
                                                                                in NPRM.
                                          007  NHTSA...........               5            2012  Results shown
                                                                                in NPRM.
                                          007  NHTSA...........               1            2014  Prior to HIS
                                                                                testing.
                                          007  NHTSA...........               1            2015  Prior to MGA
                                                                                testing.
                                          008  NHTSA...........               5            2012  Results shown
                                                                                in NPRM.
                                          008  NHTSA...........               1            2015  Prior to MGA
                                                                                testing.
                                         3538  Britax..........               5            2015  Leased from
                                                                                Britax.

HIS..........................             004  NHTSA...........               3            2014  Leased from
                                                                                NHTSA.
                                          007  NHTSA...........               3            2014  Leased from
                                                                                NHTSA.
                                         3538  Britax..........               2            2014  Pre-delivery to
                                                                                Britax.
                                         5860  MGA.............               2            2014  Pre-delivery to
                                                                                MGA.
                                          059  Calspan.........               2            2014  Pre-delivery to
                                                                                Calspan.
MGA..........................             007  NHTSA...........               5            2015  Contract with
                                                                                NHTSA.
                                          008  NHTSA...........               5            2015  Contract with
                                                                                NHTSA.
                                         5860  MGA.............               5            2015  Contract with
                                                                                NHTSA.
Calspan                                   007  NHTSA...........               5            2015  Contract with
                                                                                NHTSA.
                                          008  NHTSA...........               5            2015  Contract with
                                                                                NHTSA.
                                          059  Calspan.........               5            2015  Contract with
                                                                                NHTSA.
----------------------------------------------------------------------------------------------------------------

b. Component Tests in the Post-NPRM Test Program

    The component tests were the 11 qualification tests proposed for
the Q3s. For each test, there were at least 2 dummy responses for a
total of 35 in all. Of the 35 responses, 20 were derived from peak
values (such as the peak resultant acceleration for the head drop test
or maximum probe force for the pendulum tests). Those 20 were assessed
for R&R.\32\ The 20 measurements that NHTSA assessed for R&R
encompassed each of the eleven types of qualification tests.
---------------------------------------------------------------------------

    \32\ The other 15 were time-related criteria (such as the time
peak at which the maximum neck rotation occurs) or criteria that
contained zero in their intervals (such as the peak off-axis
acceleration in the head drop test). NHTSA did not include these
measurements in the R&R assessment because the CV statistical
measure is not a good indicator of variability in these instances.
---------------------------------------------------------------------------

c. Controlling Variability

    An assessment of dummy R&R is dependent on controlling variability
within and among test labs in conducting the qualification tests. A
dummy must provide repeatable and reproducible results in the tests,
but a qualification test must be repeatable and reproducible to serve
its purpose to either qualify or disqualify a dummy.\33\ Controlling
variability within and among test labs is important for assuring the
qualification tests fulfill their purpose.
---------------------------------------------------------------------------

    \33\ If a dummy is qualified, it can act as an objective device
in compliance tests such as those proposed in the FMVSS No. 213
NPRM. If disqualified, a dummy must be replaced or repaired.
---------------------------------------------------------------------------

    With this in mind, when NHTSA collected post-NPRM data and observed
variability in the test results, the agency closely analyzed any effect
a test lab's internal practices, protocols and procedures might have
had on the results. Variability caused by a lab's not being able to run
a test repeatedly (``test repeatability'') is discussed in each section
below. In addition, NHTSA assessed the objectivity of the test methods
themselves, or ``test reproducibility,'' to assure that tests with the
Q3s at different labs would produce reproducible results.
    NHTSA also identified instances in which repeatability was
compromised due to a discernable problem with the dummy, such as
variability in a particular dummy's responses over time (``dummy
repeatability'').
    The agency also assessed ``dummy reproducibility,'' i.e., the
uniformity of the dummies themselves. This is partly a function of how
well HIS was able to manufacture dummies that behave uniformly. Thus,
NHTSA was especially interested in comparing the responses of older
versus newer units. The agency only used the results from the same lab
for this assessment.
Summary of Test Repeatability Assessment
    NHTSA assessed the ability of each of the three outside labs
(Calspan, MGA and HIS) to attain a repeatable response by analyzing the
effect test lab practices, protocols and procedures might have had on
the results. Test repeatability was based on same-lab trials with the
same dummy: Serial no. 007 (owned by NHTSA), the only dummy tested by
all three labs. Thirty-five responses were assessed at each lab.
    Additionally, NHTSA performed a separate assessment at Calspan and
MGA based on tests with NHTSA-owned dummy serial no. 008. (HIS did not
test serial no. 008.)
    At Calspan, all test repeatability CVs were below 5% for all tests
and for both dummies (serial nos. 007 and 008). At MGA, the CVs were
below 5% except in two instances: The Mz measurement in the ``Neck
Torsion'' test (5.9%) and in the resultant head acceleration in the
``Lateral Head Drop'' test (10.0%). Both occurred with dummy serial no.
007. All tests at MGA on serial no. 008 yielded CVs below 5% for test
repeatability. At HIS (with serial no. 007 only), the CVs where below
5% in all but two instances: The ``Lateral Head Drop'' test (5.6%) and
the ``Thorax With Arm'' test (9.3%).\34\
---------------------------------------------------------------------------

    \34\ The few instances where CVs for test repeatability were
greater than 5% are discussed in greater detail below in this
preamble.
---------------------------------------------------------------------------

    These findings demonstrate a high level of test repeatability and
the ability of the three outside labs to carry out the qualification
tests. In summary, NHTSA is confident in the data generated by the test
labs in this test program.
Summary of Test Reproducibility Assessment
    NHTSA assessed the objectivity of the test methods to provide
consistent results at different labs. The agency evaluated test results
from replicate tests on the same dummy (Q3s serial no. 007) at
different labs (this ATD was the only unit tested at all four labs).
NHTSA also assessed test reproducibility with Q3s serial no. 008, which
was tested at VRTC, MGA, and Calspan (but not HIS).
    For all 35 sets of measurements, all but three had test
reproducibility CVs under 6%. The three sets of tests that had CVs over
6% were: The resultant head acceleration in the lateral head drop test;
the Mx component in the lateral neck test; and the pubic force in the
pelvis test.\35\ The results are discussed in greater depth in a later
section below.
---------------------------------------------------------------------------

    \35\ As will be discussed later in this document, NHTSA has
corrected aspects of the lateral head drop and lateral neck test
procedures that had contributed to the elevated variability in the
results. Further, the agency has decided not to adopt the pubic
force limit in the pelvis test.
---------------------------------------------------------------------------

Summary of Dummy Repeatability
    Dummy repeatability is a measure of how much the response of a
given dummy changes during the course of testing. One with a high
degree of repeatability exhibits little change from one qualification
trial to the next. A change in response could be caused by a hardening
or softening of polymeric components over time or the

propagation of cracks and other defects that occur over repeated
impacts. Repeatability could also be affected by loose assembly
tolerances. Dummies are routinely disassembled and re-assembled, and
wide allowances for settings (such as the joint torques) could result
in poor repeatability.
    During the course of the qualification testing of the Q3s, NHTSA
closely examined the root cause of any variability in trial-by-trial
test results that might reveal a problem with the dummy (i.e., a
problem with dummy repeatability) rather than simple test variability.
There was only one instance where repeatability was compromised due to
a discernable problem with the dummy.\36\ This instance, which affected
the uniformity of the lumbar spine, is discussed below, along with
NHTSA's simple fix to the problem. Aside from that, there were no other
problems with dummy repeatability in any of the tests. Once the fix to
the lumbar was implemented, it was demonstrated to have a highly
uniform response. NHTSA also examined changes in the response of the
dummy over time and found that such changes had only a negligible
effect on dummy repeatability. This is also discussed below.
---------------------------------------------------------------------------

    \36\ Torn lumbar column. Throughout NHTSA's test experience with
the Q3s, dating back to the NPRM, there was only one instance where
dummy durability was an issue. In the very last series of tests on
serial no. 008 run at Calspan in March 2015, a tear in the rubber
column within the lumbar assembly was observed after the first
lumbar qualification trial. In subsequent tests, the tear became
visibly worse and the lumbar moment and rotation both increased with
each successive impact. The biggest jump occurred between trials 1
and 2, where the maximum neck rotation jumped from being centered
within the limits of acceptability to just outside the limits. The
agency views this instance as a successful demonstration of the
ability of the qualification test to weed out a damaged unit.
---------------------------------------------------------------------------

    Loosening of lumbar cable. NHTSA observed that in the lumbar
flexion tests, the first trial tended to register a lower moment that
subsequent trials. This was consistent with all dummies at all labs.
NHTSA examined the wire cable that runs through the center of the
rubber column, which was initially placed under tension by tightening a
lock nut with a nylon insert \37\ prior to the first trial. After the
first trial, it was apparent that the nut did not stay in its set
position. It could be loosened by hand.
---------------------------------------------------------------------------

    \37\ A nut with a nylon collar insert, often referred to by its
tradename, NYLOC, is a nut that resists turning.
---------------------------------------------------------------------------

    This affected the response of the lumbar spine, as the tension on
the cable governs the response of the lumbar column. NHTSA controls
this in the PADI by prescribing the torque for the nut on the center
cable. However, the torque on a nut with a nylon insert is partly
dependent on the condition of the nut itself. A newer nut can resist
more torque without affecting the cable tension than a worn nut. In
other words, the tension on the cable (and the moment) can vary
depending on the condition of the nylon insert of the nut. To alleviate
this situation, NHTSA has replaced the nut with two jam nuts, i.e., two
standard nuts twisted against each other.
    No pronounced changes in response over time. NHTSA assessed also
the agency's older unit, serial no. 007, for signs that one or more
responses was exhibiting a definitive change during the course of
testing due to any sort of deterioration. This unit was tested
repeatedly over the course of many years, with the initial tests pre-
dating the NPRM. NHTSA examined data from 2012 to 2015 to see if there
were any definitive trends in response changes.
    To avoid any lab-to-lab variability that could act as a confounder,
NHTSA assessed the results from a single lab, VRTC. Data were collected
in three separate periods: In 2012 (five trials for the NPRM), in 2014
(one trial prior to sending it to HIS), and in 2015 (one trial just
prior to the MGA/Calspan series). Of all the responses, only two had a
definitive change in response over the three test periods: Lumbar
moment and shoulder deflection. In these instances, the 2015 trial
produced a lower/higher response than any of the previous trials (lower
for the lumbar moment, higher for the shoulder deflection), while the
2014 trial produced a result that was between the 2015 and 2012 trials.
    Yet, even for these two instances, the change in response was
negligible. For the lumbar moment, the change in moment was just 2 Nm:
82.6 Nm (lowest of the 2012 trials), 82.1 Nm (in 2014), and 80.6 Nm (in
2015). Similarly, the change in shoulder deflection was less than 1 mm:
19.0 mm (highest of the 2012 trials), 19.5 mm (in 2014), and 19.6 mm
(in 2015). In both instances, all responses fell well within the
qualification limits specified in this final rule. NHTSA observed no
other problems with deterioration over time.
    In summary, NHTSA has determined that there are no problems with
dummy repeatability that might compromise the overall uniformity of Q3s
responses. The one problem with dummy repeatability has been resolved
and there are no further concerns.
Summary of Dummy Reproducibility Assessment
    In assessing dummy reproducibility, NHTSA examined the uniformity
of the dummies themselves. This is partially a function of how well the
manufacturer HIS produced dummies that behave uniformly. The agency was
especially interested in comparing the responses of older vs. newer
units.
    To eliminate the effects of lab-to-lab variability, NHTSA only used
same-lab results for this assessment. NHTSA also combined results for
left and right aspects since the dummy was designed to yield the same
response in impacts to both. Thus, four separate assessments of dummy
reproducibility were carried out, one per lab, against the units
referenced in Table 5 below.

Table 5--Q3s Dummies Used in Reproducibility Assessments at Various Labs
------------------------------------------------------------------------
                                   Serial numbers of   Serial numbers of
               Lab                 older NHTSA units       new units
------------------------------------------------------------------------
VRTC............................  004, 006, 007, 008  3538 (Britax-owned
                                                       unit).
HIS.............................  004, 007..........  3538 (Britax-owned
                                                       unit); 5860 (MGA-
                                                       owned unit); 059
                                                       (Calspan-owned
                                                       unit).
MGA.............................  007, 008..........  5860 (MGA-owned
                                                       unit).
Calspan.........................  007, 008..........  059 (Calspan-owned
                                                       unit).
------------------------------------------------------------------------

    As a secondary assessment, NHTSA compared only the three new units
against each other in tests at HIS (HIS was the only lab that tested
all three new units). This gave the agency a better sense as to whether
the newer units, when considered as a single lot, had more inter-dummy
variability as compared to NHTSA's original lot of four units. (As a
point of reference, NHTSA assessed dummy reproducibility in the NPRM
based on

tests with the agency's four units (serial nos. 004, 006, 007, and 008)
at VRTC and the CVs were less than 6% in all eleven qualification
tests.)
    The agency's ratings of dummy reproducibility of the new units in
the secondary assessment produced CVs in the 6% to 10% range for about
25 percent of the qualifications. The CVs of the other 75 percent were
all under 6%, and no further investigation was performed.
    NHTSA investigated any set of tests with a CV above 5% for
repeatability and 6% for reproducibility to determine the source of the
variability. Responses in the lateral head drop and thorax impact test
were non-uniform. When units manufactured since 2014 were compared to
older units as two separate sets, NHTSA observed differences in
responses for several qualifications. In general, the newer Q3s units
did not exhibit the same high level of dummy reproducibility observed
in NHTSA's four older units.
    As explained later in sections below, in a few limited instances,
values obtained from a qualification test of a newer ATD were too
dissimilar to those from tests of other Q3s units to be included within
a set of reasonable qualification limits. Including them would have
unacceptably widened the limits, lessened the uniformity of the ATDs,
and unacceptably reduced the biofidelity of the Q3s. In such instances,
the agency considered the particular dummy part substandard and the
values from tests of the part beyond the performance criteria for the
qualification test.\38\
---------------------------------------------------------------------------

    \38\ The high CVs for dummy reproducibility indicates that some
newer Q3s dummies in the field may have to have parts reworked or
replaced to produce a ``pass'' in the head drop test and thorax
without arm test. Going forward, this final rule's setting of the
acceptance criteria for the qualification tests should help provide
checks and controls in the ATD's manufacturing processes, which in
turn should facilitate the production of ATDs that meet the
acceptance criteria for the qualification tests.
---------------------------------------------------------------------------

VI. Results of the Post-NPRM Test Program and the Final Acceptance
Criteria for the Qualification Tests

a. Background

    In the NPRM, NHTSA proposed acceptance criteria based on replicate
trials conducted sequentially on four NHTSA-owned Q3s units at a single
laboratory (VRTC). These tests were used to set the upper and lower
limits of the qualification intervals and were used to assess the
repeatability of the Q3s.
    Of the 35 measurements, the bounds of 21 measurements were proposed
as 3 standard deviations from the mean. Of the 14 other
measurements that were set to 10%, 12 were set at 2 standard deviations from the mean or greater. Two had bounds
that were less than 2 standard deviations: Peak pubic load
(1.9 standard deviations) and peak neck torsion moment (0.5 standard
deviations).
    At the time of the NPRM, NHTSA recognized that 3 standard
deviations comprised a wider-than-usual bound from a probabilistic
standpoint. NHTSA regarded the bound as a starting point based wholly
on the statistics of the measurements. Three standard deviations were
wide enough to account for normal variations in dummy and laboratory
differences and narrow enough to assure consistent and repeatable
measurements in compliance testing. Moreover, many of the bounds were,
in practice, extremely narrow from an operational standpoint owing to
factors (equipment, set-ups, technicians) lending themselves to highly
repeatable testing at a single lab (VRTC).\39\ NHTSA anticipated
finalizing the Q3s limits based on additional qualification data the
agency would receive subsequent to the NPRM (78 FR at 69959).
---------------------------------------------------------------------------

    \39\ For example, the NPRM's 3-standard-deviation interval for
the time at which the peak neck moment occurs was only 7 ms.
---------------------------------------------------------------------------

b. Process for Setting the Final Qualification Limits

    The data from the post-NPRM test program and other sources,
discussed above, have helped NHTSA finalize the qualification test
procedures and round out the qualification corridors. In specifying
qualification tests and acceptance criteria for the qualification
tests, NHTSA's goal is to assure that a ``pass'' is a true indicator of
a dummy that is uniform in its design and performance. This goal is
achieved by ensuring that the tests themselves are repeatable and
reproducible, and by setting limits (or tolerances) on the
qualification targets.
    As discussed in the previous section, test and dummy R&R have been
demonstrated at four different labs. The proposed targets and
acceptance criteria for the qualification tests in the NPRM were based
entirely on the statistics of the agency's replicate tests. NHTSA
considered those targets and limits as starting points, given that the
agency did not have data from other labs. Since then, the agency has
expanded the qualification database by adding much more data on tests
with several dummies across four test labs. For this final rule, the
qualification targets and limits are based on the statistics of the
measurements, but also on the following factors.
    Other Part 572 ATDs. NHTSA considered the qualification limits of
the other part 572 ATDs in use today in setting those for the Q3s. For
example, the qualification bounds for the most recent dummy
incorporated into part 572 (the Hybrid III 10-year-old child dummy
(HIII-10C); see part 572, subpart T), are derived from tests on about
30 different dummies, with data supplied from about ten different
laboratories. For the HIII-10C, there are nine qualifications based on
a maximum measurement (such as a peak force), and the average limits
(i.e., the values defining the range of acceptable measurements) are
9.9% from the midpoint. The low is 8.4% (neck rotation in the neck
extension test) and the high is 10.8% (seen in two qualifications: neck
moment in the extension test and chest deflection in the thorax impact
test).
    A limit of 11% from the midpoint is the average for all part 572
dummies and all qualifications. NHTSA has used this value as a
benchmark for setting the limits for the Q3s in this final rule. The
agency scrutinized any limit above 11% from the midpoint to ensure it
could be justified.
    Biofidelity targets. In setting the qualification limits, the
agency considered the biofidelity targets that were used as the basic
design criteria of the Q3s during its development. The corridors
surrounding biofidelity targets are generally wider than qualification
limits owing to larger variances associated with tests with human
subjects. In the NPRM, NHTSA compared the responses of various Q3s body
regions against their respective human biofidelity corridors. For the
most part, the responses of the body regions fell within the
biofidelity corridors (including the responses for the head and
thorax). For the final rule, NHTSA made sure that a contemplated
qualification limit would not result in acceptance of a dummy response
that is outside the biofidelity corridors.
    Some body regions, such as the shoulder, were shown in the NPRM to
be stiff relative to the biofidelity targets. For these body regions,
any shifts in the qualification limits for the final rule were
generally made in a direction that was closer to the biofidelity
target. In other words, NHTSA avoided moving the nominal qualification
target further from the biofidelity target.
    Test input parameters. For this final rule, NHTSA has not changed
the input parameters in any of the eleven qualification tests from
those of the NPRM. The input parameters include

impact speeds, probe masses, drop heights, and dimensional measurements
related to dummy positioning. Tolerances on test inputs are also
unchanged.
    For this final rule, nineteen Q3s qualifications are centered
around a maxima. For these measurements, the limits proposed in the
NPRM were spread around a nominal target response by plus or minus 9.9%
(on average) of the target. The average spread in this final rule is
slightly higher, at 10.1%. However, as seen in Table 1, supra, the
limits are narrower for 11 of the nineteen qualifications, and only the
shoulder has limits greater than 12%: Internal shoulder deflection
(12.8%) and shoulder probe force (12.3%).
    Newer dummies and other test labs. NHTSA considered the population
of all dummies tested--both old and new--and all four labs that were
used. Recognizing that the newest dummies may be representative of the
future population of Q3s dummies, steps were taken to be inclusive of
them as reasonably possible. NHTSA also recognized that all four labs
were highly experienced in dummy qualification testing, so in theory
any dummy that qualified at one lab should have qualified at the
others. When this was not the case, the situation was analyzed to
determine the source of the problem.
    Balancing the factors. In setting the final qualification limits
for the final rule, NHTSA examined the test data on a trial-by-trial
basis and balanced all the factors discussed above. For example, for
the lumbar flexion qualification, while keeping the 11% goal in mind
NHTSA set the qualification limits such that serial no. 059 (a new unit
owned and tested by Calspan) was just under the upper limit in four of
five trials, while serial no. 5860 (a new unit owned by and tested by
MGA) was just over the lower limit in four of five trials. Balancing
the factors enabled NHTSA to set qualification limits spread 10.9% from
the nominal target in a manner that included as many test trials from
the new units as reasonable. In contrast, if the 10.9% limits were
centered around the average of all responses, the Calspan unit would
have failed to qualify in all trials.
    In summary, the agency analyzed the data from the testing of the
seven Q3s units (the four NHTSA-owned units and the three new units) to
the qualification tests proposed in the NPRM, assessing, among other
matters, the measurements made by the units when tested to the
qualification tests and the R&R of the dummies. Tests were run for both
right and left side impacts. Average, standard deviation, and
coefficient of variation were computed for each required measurement
parameter of each qualification procedure.

c. Head

    The head injury criterion (HIC), based on the Q3s's head
acceleration, has been proposed as a criterion in the FMVSS No. 213
side impact NPRM and is important for assessing countermeasures that
protect the child's head in side impacts. Thus, a uniform response of
the dummy's head-neck system is important to achieve. Two qualification
tests serve to assure the uniformity of the head response in an impact:
A lateral head drop test and a frontal head drop test. In both
qualification tests, the pass/fail specification is based on the
resultant acceleration measured at the center of gravity (CG) of the
head. Procedures for both tests also place limitations on the off-axis
acceleration to assure that the free-fall of the head is uniform prior
to impact.
Lateral Head Drop
    The lateral head drop test is carried out by cradling the head
within a looped wire rope, suspending the head 200 mm above a steel
plate, and releasing the wire rope. The head is oriented within the
cradle so that its lateral aspect strikes the plate. Lateral impacts
are carried out on the left and right aspects of the head.\40\
---------------------------------------------------------------------------

    \40\ Cradling of the head is shown in the regulatory text
figures, but specifics on how to release the head are left to the
operator.
---------------------------------------------------------------------------

    The NPRM proposed that the head must respond with peak resultant
acceleration between 113 g and 140 g when dropped from a 200-mm height
such that the side of the head lands onto a flat rigid surface (lateral
head drop). Off-axis acceleration was proposed to be +/-20 Gs. These
values were based on tests of NHTSA's four Q3s dummies.
    For the final rule, NHTSA has set the lateral qualification limits
as: Peak resultant acceleration is 114-140 Gs (spaced 10.2% from the
range's midpoint of 127 Gs). Off-axis acceleration: +/-15 Gs. These
values are based on tests of the seven Q3s dummies.
    Test Repeatability. Test repeatability problems became apparent
once the agency began to assess lateral head drop data from the outside
labs. NHTSA believes that the problem existed even at the time of the
NPRM as many of the CVs reported in the NPRM were just under 5%, which,
upon reexamination, were high for such a simple test. None of the CVs
for the frontal head drop was over 2 percent.
    The problem was first discovered in the initial tests performed at
MGA on serial no. 007. Fourteen trials were needed to attain the
desired sample of ten trials (five left, five right) in which the off-
axis acceleration was under the NPRM's requisite 20 Gs (and only three
of those were under 15 Gs). The CV for the resultant head acceleration
was over 8% in the trial tests, which is unacceptably high.
    The variability was eventually traced to MGA's head drop apparatus.
MGA had used a one-piece cable loop to cradle the head, and the cradle
was released via a magnetic actuator. Upon release, the head rotated
slightly during its free-fall creating elevated off-axis accelerations
and high variability in the resultant accelerations.
    For its subsequent series of tests on serial nos. 008 and 5680, MGA
developed an improved test protocol that included a two-cable cradle
that mitigated the problem. Off-axis acceleration was below 20 Gs in
all twenty trials and below 15 Gs in sixteen of the trials.\41\
---------------------------------------------------------------------------

    \41\ The cradle problem at MGA highlighted the need for a drop
test mechanism with a high degree of precision. Any slight deviation
in the point of impact was shown to produce a large variation in
both the resultant and off-axis acceleration. This was particularly
true in the lateral head drop, where the curvature of the head at
the point of impact contributes to the variation.
---------------------------------------------------------------------------

    Calspan had similar difficulty with its drop apparatus, which made
use of a pneumatic actuator to release the cradle. In its initial
tests, Calspan needed nineteen trials to attain the desired sample of 5
left and 5 right trials with an off-axis acceleration under 20 Gs.
However, like MGA, Calspan could achieve the 20 G limit in their
subsequent series (with ten trials each with serial nos. 008 and 059).
    At VRTC, the cradle was released by cutting the end of the cable.
There were no problems with keeping the off-axis accelerations below 20
Gs, though in retrospect it was still unusually high for such a simple
test (the average was 12 Gs, with a range of 7-18 Gs).
    High off-axis acceleration was particularly problematic for serial
no. 007 (one of the older, NHTSA-owned units) at all four labs where it
was tested (53 trials total). NHTSA observed that the flesh parting
line \42\ on the head coincided with the point of impact, causing added
variability for that particular unit (the effect was more pronounced
with serial no. 007 than with other dummies.) About half of the tests
with no. 007 produced off-axis accelerations greater than 15 Gs, with
13

tests (21%) greater than 20 Gs. Just 14 tests were less than 10 Gs.
---------------------------------------------------------------------------

    \42\ When two halves of a mold meet, the corresponding line or
seam appearing on the molded object is referred to as the parting
line.
---------------------------------------------------------------------------

    When data from VRTC, Calspan, and HIS were further examined, it
became apparent that elevated off-axis acceleration was correlated with
high variability in the resultant acceleration. The scatter in data is
evident in Table 6 (which represents all dummy tests, not just serial
nos. 007 and 008). The CV in the resultant acceleration is shown to
increase when the off-axis acceleration falls in higher ranges. It is
highest (10.24%) when the off-axis acceleration is above 15 Gs and it
is lowest (4.04%) when under 10 Gs. In the ranges of 0-10 Gs, 0-15 Gs,
and 10-15 Gs, the CVs are all about the same and all under the 5%.
Thus, NHTSA concludes that 15 Gs is a more appropriate limit than 20
Gs.\43\
---------------------------------------------------------------------------

    \43\ All NPRM upper/lower limits, including 20 Gs, were derived
from the statistics of the tests. With the further data obtained in
the post-NPRM program, NHTSA has determined that 20 Gs was too
broad.

          Table 6--Relationship Between Off-Axis Acceleration and Variability in Resultant Acceleration
----------------------------------------------------------------------------------------------------------------
                                                                                Resultant acceleration
                                                                     Number of   -------------------------------
                    Off-axis acceleration, Gs                         trials       Limits, % of
                                                                                midpoint         CV (%)
----------------------------------------------------------------------------------------------------------------
0-5.............................................................               0  ..............  ..............
0-10............................................................              21             7.7            4.04
0-15............................................................              84            10.2            4.47
10-15...........................................................              64            10.2            4.58
0-20............................................................             114            16.2            6.38
10-20...........................................................              94            16.2            6.71
15-20...........................................................              30            16.2            9.20
Over 15.........................................................              34            18.4           10.24
All.............................................................             118            18.4            7.34
----------------------------------------------------------------------------------------------------------------

    For this final rule, NHTSA has set the limit for off-axis
acceleration to +/-15 Gs. NHTSA notes that this limit is the same as
those for the two other part 572 side impact dummies (Subpart U--ES-2re
(50th percentile adult male) and Subpart V--SID-IIsD (small adult
female)). NHTSA believes the 15 G limit (as opposed to an even lower
limit) is sufficient to assure dummy uniformity, and that lowering it
to a lesser value is needlessly onerous on test labs because it will
likely require many more trials to achieve acceptable test results.
Unlike a frontal drop, where the direction of the drop is symmetric
with the sagittal plane of the head, the lateral drop is asymmetric,
making it difficult to attain an off-axis acceleration below 10 Gs.
    When only those tests where the off-axis acceleration was under 15
Gs were included, the CVs for repeatability and test reproducibility
for the peak resultant acceleration were all 5% or less at all labs
with all Q3s dummies.
    The agency notes that attaining the requisite +/- 15 G may require
multiple drop tests. Nonetheless, in NHTSA's test program all labs
could eventually attain this limit with each dummy they tested.
Moreover, NHTSA believes it would be a relatively simple matter for
labs to come up with a way to run the test such that the head does not
slip and turn during its free fall, which should enable them to meet
the 15 G off-axis limit without difficulty.
    Dummy Reproducibility. When assessing dummy reproducibility in the
lateral drop test, for the reasons stated above the agency also omitted
drop tests where the off-axis head acceleration is greater than 15 Gs,
and the tests at MGA on serial no. 007. There was still an ample number
of trials (84) without those tests to make a reasonable assessment of
dummy reproducibility.
    The CVs for dummy reproducibility in lateral head drop tests at the
various labs ranged for 7.0% to 11.7%, which reflects a fairly wide
range of head acceleration responses. Nonetheless, the qualification
criteria are set at 114-140 Gs, which reflects the upper and lower
limits spaced only 10.2% from the midpoint.
    NHTSA concludes that the qualification limit of 10.2% is
appropriately balanced to accommodate dummy reproducibility without
being unreasonably hard for test labs to attain. The narrowness of the
final limits is also consistent with other part 572 dummies, as shown
in Table 7 below, and is needed to assure a sufficient level of
uniformity in head response. As stated above, the head's acceleration
is an important criterion for assessment of head injury. Thus, the
acceptance criteria should be narrow enough to achieve a uniform
response of the head-neck system of the Q3s.

        Table 7--Acceptance Criteria for Resultant Head Accelerations in Head Drop Tests for Various ATDs
----------------------------------------------------------------------------------------------------------------
                                                                            Resultant head acceleration
                                                                 -----------------------------------------------
                Dummy                           Aspect                                               +/- % of
                                                                  Lower limit, G  Upper limit, G     midpoint
----------------------------------------------------------------------------------------------------------------
Q3s (final rule)....................  Lateral...................             114             140            10.2
Q3s (proposed)......................  Lateral...................             113             140            10.7
Side Impact Dummy Crash Test Dummy,   Lateral...................             115             137             8.7
 Small Adult Female (SID-IIsD).
Side Impact Crash Test Dummy 50th     Lateral...................             125             155            10.7
 Percentile Adult Male (ES-2re).
----------------------------------------------------------------------------------------------------------------
Q3s (final rule)....................  Anterior..................             255             300             8.1
Q3s (proposed)......................  Anterior..................             250             297             8.6
Hybrid III (HIII) 3-Year-Old Child    Anterior..................             250             280             5.7
 Crash Test Dummy (HIII-3C).
Six-year-old Child Test Dummy (HIII-  Anterior..................             245             300            10.1
 6C).
HIII 10-Year-Old Child Test Dummy     Anterior..................             250             300             9.1
 (HIII-10C).

HIII 5th Percentile Adult Female      Anterior..................             250             300             9.1
 (frontal) Test Dummy.
----------------------------------------------------------------------------------------------------------------

    NHTSA observed that the envelope of 114-140 Gs reflects the data
from all the considered tests of the Q3s, but that two of the three
newest dummies, those owned by Calspan and Britax, registered high head
acceleration responses relative to NHTSA's older units and the newer
MGA unit. NHTSA had to decide how to set the qualification limits for
the head given the differences in dummy head performance.
    If NHTSA had set qualification limits to include at least one test
trial from all dummies tested (the NHTSA-owned units and the three
newer units), limits greater than 13% would have resulted. The agency
was concerned that such limits would be too wide for regulatory
purposes, especially because the Q3s's head acceleration measurements
would probably determine a pass or fail in any future application of
the dummy. No other part 572 ATD has limits wider than 11% for a head
drop test (anterior or lateral).
    The agency also considered the possibility of calibrating the
limits around the new units (which generally produced higher head
accelerations) even though one or more of the NHTSA-owned units may not
be able to qualify. When only the three new units were considered
(combining data from tests at VRTC, MGA, HIS, and Calspan), limits
within 11% were possible.
    After further investigation, however, NHTSA decided against this
alternative too. The agency's first step in assessing whether to use
only the new units was to assess the biofidelity of the new Q3s units.
When the agency assessed the head of the Britax unit (which produced
the highest response) against the biofidelity targets to confirm that
it was within the limits of acceptability, the agency found it was not.
The limits of biofidelity acceptance are generally wider than
qualification limits owing to the variability associated with human
subjects. As explained in the NPRM, the test to assess lateral
biofidelity is slightly different from the qualification test (78 FR at
69949). Derived by SAE (Irwin, et al, 2002), the target response is
referenced from the non-fracture zone of the head (opposite the point
of impact). For a 3-year-old, the target resultant acceleration is 114-
171 Gs.
    The test results for the NHTSA-owned units fell squarely within
these limits. For the Britax unit, however, the tests produced a
resultant acceleration of 189 Gs, which is well beyond the limits of
acceptability. Thus, if the qualification limits were recalibrated
around the newer units, the limits would be set based on readings of a
non-biofidelic dummy. NHTSA decided that such an approach would
sacrifice dummy biofidelity and is unacceptable.
    Accordingly, NHTSA decided that the final acceptance criteria for
the lateral head drop qualification test should be centered around
essentially the same midpoint as the NPRM. Thus, all NHTSA-owned units
remain centered within the limits of acceptability. There is no
potential sacrifice in biofidelity, unlike the result if limits were
established around non-biofidelic Q3s units.
    NHTSA notes that, under the qualification limits of this final
rule, a ``pass'' was observed with the older NHTSA-owned units at all
labs and in almost every trial. Newly-manufactured Q3s dummies, on the
other hand, did not always qualify. Of the three new units tested, only
the MGA unit consistently produced a passing result against the final
qualification criteria. The Britax unit was well above the upper limit,
a result that was observed repeatedly in all trials at both labs in
which it was tested. The Calspan unit was borderline acceptable. HIS
had reported responses within the limits, but Calspan was not able to
consistently produce a passing result at its lab. Given these results,
there is a possibility that some dummy heads of newer Q3s units in the
field may need to be re-worked to pass the lateral head drop criterion
of this final rule.
Frontal Head Drop
    The NPRM proposed that the head must respond with peak resultant
acceleration between 250-297 Gs (8.6% of the midpoint) when dropped
from a 376 mm height. The head is oriented such that its sagittal plane
is parallel with the direction of impact and the anterior-most aspect
of the forehead strikes a steel plate. Off-axis acceleration was
proposed to be +/-15 Gs. These values were set based on tests of
NHTSA's 4 Q3s dummies.
    For the final rule, NHTSA has set the frontal qualification limits
as: Peak resultant acceleration is 255-300 Gs (8.1% of the midpoint).
Off-axis acceleration: +/-15 Gs (no change from NPRM). These values are
based on tests of the seven Q3s dummies.
    Test R&R. The CVs for test R&R were universally low at all labs and
for all dummies (all below 4%). Unlike a lateral drop, the motion in
the head in the frontal drop is symmetric about the sagittal plane,
i.e., rotation of the head during and after the impact takes place
about the y-axis only. This makes it much easier to produce a
repeatable response and to attain a low off-axis acceleration. In the
NPRM, the off-axis limit for acceleration was only 15 Gs (vs. 20 Gs for
the lateral drop). The 15 G off-axis limit was easily met at all labs
with all dummies. NHTSA notes that the 15 G limit for frontal drops is
also consistent with other part 572 dummies, as shown previously.
    Dummy Reproducibility. For the frontal drop test, the CVs for dummy
reproducibility were under 6% for all but one dummy--serial no. 5860,
the MGA-owned unit. Relative to the others, the MGA head registered low
responses at both labs (HIS and MGA) where it was assessed, resulting
in an elevated CV statistic of 8.0% at HIS and 5.4% at MGA. If only the
new units are considered (combining data from tests at VRTC, MGA, HIS,
and Calspan), the CV statistic is 6.8% for all three units vs. 3.4%
when the MGA unit is excluded. The Britax and Calspan units had high
responses in the lateral drop tests but were in line with each other
and with NHTSA's older units in the frontal head drop test.
    The lower limit of 255 Gs coincides with the lower limit of an
acceptable biofidelic response as described in the NPRM.\44\ At this
limit, the MGA unit did not qualify in any of its seven trials at
either of the two labs where it was tested (HIS and MGA), as its
response was too low. The highest response it produced in any of the
trials was 242 G,

well below the biofidelity target. This response is unacceptably low
(non-biofidelic). Aside from the MGA unit, only the Calspan unit was at
all marginal. Its response was borderline low in tests at HIS (253 Gs
on average), but at Calspan it was squarely within the limits.
---------------------------------------------------------------------------

    \44\ ``Biofidelity Assessment of the Q3s Three Year-Old Child
Side Impact Dummy,'' supra.
---------------------------------------------------------------------------

    NHTSA's final upper limit of 300 Gs (raised from 290 Gs in the
NPRM) is still well within the acceptable biofidelity limit of 315 G.
There were no problems staying under the upper limit for any dummy in
any trial at any lab. By raising the upper limit to 300 Gs, NHTSA is
maintaining essentially the same limit widths (8.1% of the midpoint) as
those proposed in the NPRM.
    As noted above, a uniform head response for the Q3s is particularly
important to assess child side impact protection. Thus, NHTSA has set
the resultant acceleration limits for the frontal head drop narrower
than the 11% guideline target for all responses. This approach is
consistent with other part 572 dummies. The Q3s width of 8.1% (i.e.,
the +/- limits of the nominal qualification target) is roughly the
equivalent to the average of the other dummies.

d. Neck

    A biofidelic and repeatable kinematic response of the head-neck
system is important to quantify the protection offered by CRSs in an
impact. The acceptable criteria for the neck qualification test in this
final rule consist of three test components: Lateral flexion, frontal
flexion, and torsion neck pendulum tests. These tests serve to assure
uniformity of the head kinematics in both a head impact and non-impact.
In each test, the neck moment, the rotation of the neck, and the timing
associated with the moment and rotation are assessed. All three use the
conventional part 572 swinging pendulum to apply a prescribed impulse
to the neck, with a headform designed to mimic the inertial properties
of the head attached to it.
Lateral Flexion
    The lateral flexion test specifies a 3.8 m/s impact speed with a
prescribed deceleration pulse. A column of collapsible aluminum
honeycomb is used to decelerate the pendulum at a relatively constant
level of force. Part 572 specifications for almost all other dummies
use the pendulum/honeycomb device for testing necks. Test labs
generally adjust the honeycomb in some manner (for instance, by
modifying the number of cells engaged by the impacting face of the
pendulum) to attain the prescribed pulse.
    The NPRM proposed a maximum rotation of 77-88 degrees (6.7% from
the midpoint). The maximum moment was proposed to be 25-32 Nm (12.3% of
the midpoint).
    This final rule sets the maximum rotation at 76.5-87.5 degrees
(6.7% of the midpoint). The maximum moment is set at 25.3-32.0 Nm
(11.7% of the midpoint).
    Test R&R and Dummy Reproducibility. All four labs exhibited CVs
below 5% for test repeatability in lateral flexion for both the
rotation and the moment.
    NHTSA did, however, observe some lab-to-lab variability in the
bending moment which resulted in CVs for test reproducibility that
ranged from 6.3% to 7.2% for both Q3s units that were used in the
assessment. This was not entirely unexpected.\45\ The variability in
test reproducibility is likely attributed to lab-to-lab differences in
the aluminum honeycomb, such as the lab modifications of the number of
honeycomb cells used in the qualification tests. Also, after impact,
the trajectory of the headform does not occur within a single plane of
motion because the neck bends along its non-symmetric axis. This
generally reduces test reproducibility.
---------------------------------------------------------------------------

    \45\ In the NPRM, the set of limits for the moment was
constructed via the +/-10% rule rather than +/-3 standard
deviations.
---------------------------------------------------------------------------

    The agency did not discern any trends that would indicate that the
responses of the necks have changed over time. Also, the CVs were under
5% for test reproducibility and under 6% for dummy reproducibility for
all measures of neck rotation and neck moment. This further suggests
that the variability is due to the variability in test equipment (i.e.,
honeycomb) among the various labs.
    In summary, all dummies and all labs could demonstrate a
qualification pass for both rotation and moment. The results show that
the necks themselves were highly uniform, but test labs may need to
evaluate different honeycomb configurations to demonstrate a passing
response. Experimenting with honeycomb is typical of the qualification
process with all part 572 dummies.
Frontal Flexion
    The NPRM proposed a maximum rotation of 70-82 degrees (7.9% of the
midpoint), and a maximum moment of 41-51 Nm (10.9% of the midpoint).
    For the final rule, the acceptance criteria for the frontal flexion
test are set as: Maximum rotation is 69.5-81.0 degrees (7.6% of the
midpoint). The maximum moment is 41.5-50.7 Nm (10.0% of the midpoint).
The frontal flexion test specifies a 4.7 m/s impact speed and its own
deceleration pulse. Crushing of aluminum honeycomb is also used to
generate the prescribed deceleration pulse.
    Test R&R and Dummy Reproducibility. The CVs for test R&R and dummy
reproducibility were universally low at all labs and for all dummies
and for both neck rotation and neck moment (all below 4%). Unlike the
lateral and torsion tests, the motion in the headform in the frontal
flexion test is symmetric about the sagittal plane. In other words,
rotation of the headform during and after the impact takes place about
the y-axis only. This makes it much easier to produce a repeatable
response and to attain a low off-axis acceleration.
    For the neck flexion test, the wide intervals specified in the NPRM
(built around 3 standard deviations) proved to be unnecessarily large,
even with the latest results from the additional dummies tested at
different labs added to the data pool. Therefore, NHTSA has narrowed
the limits for the final rule from those of the NPRM. All dummies at
all labs were demonstrated to pass at the narrower limits of the final
rule.
Torsion
    During CRS testing, the Q3s neck might flex with varying degrees of
neck twist. The agency, therefore, proposed a procedure to assure that
the neck is uniform under twist. The proposed neck torsion test uses a
special test fixture attached to the part 572 pendulum, which imparts a
pure torsion moment to the isolated neck. It specifies a 3.6 m/s impact
speed with a defined deceleration pulse. Qualification is based on the
rotation and moment about the long axis of the neck.
    The NPRM proposed that, for the neck torsion test, the maximum
rotation must be 75-93 degrees (10.7% of the midpoint). The maximum
moment is 8.0-10.0 Nm (11.1% of the midpoint).
    For this final rule, the final acceptance criteria for the
qualification test are set as follows. The maximum rotation limits are
74.5-91.0 degrees (10.0% of the midpoint). The maximum moment limits
are 8.0-10.0 Nm (11.1% of the midpoint) (unchanged from the NPRM).
    Test R&R and Dummy Reproducibility. All four labs exhibited low CVs
for test repeatability and reproducibility for both the rotation and
the moment, with one exception. At MGA, the variability in neck moments

on serial no. 007 was slightly elevated (CV=5.9%) for the left aspect
only. However, this elevation is mostly a function of the low moment
generated by the test (only 9 Nm nominally), where variations as little
as +/-1 Nm created a high CV. All moments were, in fact, within the
prescribed, and narrow, 8-10 Nm range specified in the NPRM. The CVs
for dummy reproducibility were universally low (below 6%) at all labs
and for all dummies, and for both neck rotation and neck moment. In
every trial, all dummies at all labs demonstrated a pass in accordance
with the acceptance criteria of this final rule.

e. Lumbar Column

    The Q3s's rubber lumbar column bends during a CRS side impact test.
This bending can affect the overall kinematics of the dummy, including
the excursion of the head. It can also affect lateral loads and the
deflection of the thorax.
    Lumbar qualification consists of two types of pendulum tests: A
lateral test and a frontal test. For both tests, the lumbar spine
element containing the flexible column is removed from the dummy, like
the neck qualification tests. The lumbar tests use the same part 572
swinging arm pendulum and the headform device used in the neck
qualification tests. The headform is not intended to represent the
inertial properties of a body region as it is with the neck tests.
Rather, it merely provides an apparatus that helps to ensure a
repeatable test condition. The lumbar tests also use crushable aluminum
honeycomb to attain a prescribed deceleration pulse.
    In the case of the lumbar qualification, lateral and frontal tests
are conducted at the same impact speed of 4.4 m/s and specify the same
pendulum impulse. The rotation of the lumbar column, the lumbar moment,
and the timing associated with the moment and rotation are set forth in
this final rule.
    The agency notes that the lumbar qualifications for lateral and
frontal tests are almost identical. This is to be expected since the
lumbar element is a circular cylinder constructed from an isotropic
material (rubber), and so, theoretically, the directional properties
should be the same for lateral vs. frontal bending. However, the agency
has established two separate sets of acceptance criteria owing to
possible dissimilarities brought on by the molding and bonding
processes and asymmetries of inertial influences due to differences in
the configuration of mounting plates and headform.
    Further, the frontal flexion test helps assure that the metal-to-
rubber bond of the lumbar is intact in a manner the lateral flexion
test does not. This was demonstrated during the very last series of
tests on NHTSA-owned serial no. 008 Q3s dummy, where NHTSA observed a