[Federal Register Volume 87, Number 137 (Tuesday, July 19, 2022)]
[Rules and Regulations]
[Pages 42951-42954]
[FR Doc No: 2022-15387]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-0878; Project Identifier MCAI-2022-00873-R;
Amendment 39-22124; AD 2022-14-51]
RIN 2120-AA64

Airworthiness Directives; Airbus Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain Airbus Helicopters Model EC225LP helicopters. This AD was
prompted by a report of a cracked main rotor hub (MRH) sleeve. This AD
requires one-time visual inspections and, depending on the results,
accomplishing additional inspections, repairing the MRH sleeve in
accordance with a certain approval, and removing the MRH sleeve from
service and installing an airworthy part. This AD also prohibits
installing an MRH sleeve unless certain inspections have been
accomplished. The FAA previously sent an emergency AD to all known U.S.
owners and operators of these helicopters. The FAA is issuing this AD
to address the unsafe condition on these products.

DATES: This AD is effective August 3, 2022. Emergency AD 2022-14-51,
issued on July 1, 2022, which contained the requirements of this
amendment, was effective with actual notice.
    The Director of the Federal Register approved the incorporation by
reference of a certain document listed in this AD as of August 3, 2022.
    The FAA must receive comments on this AD by September 2, 2022.

ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the instructions for submitting comments.
     Fax:<PHONE_NUMBER>.
     Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this final rule, contact
Airbus Helicopters, 2701 North Forum Drive, Grand Prairie, TX 75052;
telephone<PHONE_NUMBER> or<PHONE_NUMBER>; fax<PHONE_NUMBER>; or at
https://www.airbus.com/helicopters/services/technical-support.html. You
may view this service information at the FAA, Office of the Regional
Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, Fort
Worth, TX 76177. For information on the availability of this material
at the FAA, call<PHONE_NUMBER>. It is also available at https://www.regulations.gov by searching for and locating Docket No. FAA-2022-
0878.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2022-0878; or in person at
Docket Operations between 9 a.m. and 5 p.m., Monday through Friday,
except Federal holidays. The AD docket contains this final rule, the
European Union Aviation Safety Agency (EASA) AD, any comments received,
and other information. The street address for Docket Operations is
listed above.

FOR FURTHER INFORMATION CONTACT: Kristi Bradley, Program Manager, COS
Program Management Section, Operational Safety Branch, Compliance &
Airworthiness Division, FAA, 10101 Hillwood Pkwy., Fort Worth, TX
76177; telephone<PHONE_NUMBER>; email [email protected].

SUPPLEMENTARY INFORMATION:

Background

    On July 1, 2022, the FAA issued Emergency AD 2022-14-51, which
requires certain inspections and corrective actions for Airbus
Helicopters Model EC225LP helicopters with MRH sleeve part number (P/N)
332A31-3071-00 installed. The FAA sent the emergency AD to all known
U.S. owners and operators of these helicopters. That action was
prompted by EASA Emergency AD 2022-0130-E, dated June 30, 2022 (EASA AD
2022-0130-E), issued by EASA, which is the Technical Agent for the
Member States of the European Union, to correct an unsafe condition for
Airbus Helicopters (AH), formerly Eurocopter, Model EC 225 LP
helicopters. EASA advises of a crack in an MRH sleeve that
investigation determined was a fatigue crack that had initiated from a
corrosion pit located in an area with chipped paint. This condition, if
not addressed, could result in failure of an MRH sleeve, loss of a main
rotor blade, and subsequent loss of the helicopter.
    Accordingly, EASA AD 2022-0130-E requires initial one-time detailed
visual inspections of MRH sleeve P/N 332A31-3071-00 and depending on
the results, follow-on repetitive inspections and corrective actions.

FAA's Determination

    These helicopters have been approved by EASA and are approved for
operation in the United States. Pursuant to the FAA's bilateral
agreement with the European Union, EASA has notified the FAA about the
unsafe condition described in its emergency AD. The FAA is issuing this
AD after evaluating all known relevant information and determining that
the unsafe condition described previously is likely to exist or develop
on other helicopters of the same type design.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Airbus Helicopters Emergency Alert Service
Bulletin No. 62A017, Revision 0, dated June 30, 2022, which applies to
Model EC225LP and EC725AP helicopters. This service information
specifies procedures for one-time detailed visual inspections of a
certain area (identified as ``Specific area'' in Figure 3 of the
service information) of MRH sleeve P/N 332A31-3071-00. Depending on the
one-time inspection results, this service information specifies
procedures for follow-on inspections, which include eddy current
inspections, and chemical stripping and fluorescent penetrant
inspections; and corrective actions, which include applying primer and
paint protection, removing corrosion, applying a protective coating,
contacting Airbus Helicopters for corrective action, and removing and
returning the MRH sleeve to Airbus Helicopters.
    This service information is reasonably available because the
interested parties have access to it through their normal course of
business or by the means identified in the ADDRESSES section.

AD Requirements

    This AD requires visually inspecting the ``Specific area'' of each
MRH sleeve P/N 332A31-3071-00 for flaking and paint touch-up. If there
is any flaking or paint touch-up, this AD requires visually inspecting
the ``Specific area'' of the MRH sleeve for a crack.
    As a result of the visual inspection, if there is a crack, this AD
requires removing the MRH sleeve from service and installing an
airworthy part. If there is not a crack, this AD requires an inspector
with a certain qualification using high-frequency eddy current (HFEC)
to inspect the ``Specific area'' of the MRH sleeve for a crack.
    As a result of the HFEC, if there is a crack, this AD requires
removing the MRH sleeve from service and installing an airworthy part.
If there is not a crack, this AD requires chemically stripping and
fluorescent penetrant inspecting (FPI) the ``Specific area'' of the MRH
sleeve for corrosion.
    As a result of the FPI, if there is corrosion, this AD requires
removing the corrosion by hand and repeating the FPI of each affected
area to inspect for corrosion, and depending on the subsequent results,
removing the MRH sleeve from service and installing an airworthy part;
or drying the MRH sleeve, applying a protective coating, primer, and
paint protection, and having an inspector with a certain qualification
using HFEC repetitively inspect the ``Specific area'' of the MRH sleeve
for a crack. If there is a crack, this AD requires removing the MRH
sleeve from service and installing an airworthy part. However, if the
corrosion cannot be removed by hand, this AD requires removing the MRH
sleeve from service and installing an airworthy part or repairing the
MRH sleeve in accordance with a certain approved method.
    As a result of the first FPI, if there is no corrosion, this AD
requires applying primer and paint protection.
    As an option to the first FPI and its follow-on actions, if there
is not a crack, this AD allows applying primer and paint protection or,
for any areas with flaking paint, applying only varnish instead of
primer and paint protection on each flaking paint area; and having an
inspector with a certain qualification using HFEC to repetitively
inspect the ``Specific area'' of the MRH sleeve for a crack. If there
is a crack, this AD requires removing the MRH sleeve from service and
installing an airworthy part.
    This AD also prohibits installing an MRH sleeve unless specified
one-time visual inspections have been accomplished.

Differences Between This AD and the EASA AD

    If there is corrosion in an MRH sleeve, EASA AD 2022-0130-E
requires contacting Airbus Helicopters for approved repair
instructions, whereas this AD requires removing the MRH sleeve from
service or repairing the MRH sleeve in accordance with a certain
approved method.

Justification for Immediate Adoption and Determination of the Effective
Date

    Section 553(b)(3)(B) of the Administrative Procedure Act (APA) (5
U.S.C. 551 et seq.) authorizes agencies to dispense with notice and
comment procedures for rules when the agency, for ``good cause,'' finds
that those procedures are ``impracticable, unnecessary, or contrary to
the public interest.'' Under this section, an agency, upon finding good
cause, may issue a final rule without providing notice and seeking
comment prior to issuance. Further, section 553(d) of the APA
authorizes agencies to make rules effective in less than thirty days,
upon a finding of good cause.
    An unsafe condition exists that required the immediate adoption of
Emergency AD 2022-14-51, issued on July 1, 2022, to all known U.S.
owners and operators of these helicopters. The FAA found that the risk
to the flying public justified waiving notice and comment prior to
adoption of this rule because failure of an affected part could result
in loss of the helicopter and injury to its occupants and persons on
the ground. In light of this, the initial actions required by this AD
must be accomplished before further flight and certain follow-on
actions required by this AD must be accomplished within 15 hours time-
in-service or 3 months, whichever occurs first after accomplishing the
initial actions. These compliance times are shorter than the time
necessary for the public to comment and for publication of the final
rule. These conditions still exist, therefore, notice and opportunity
for prior public comment are impracticable and contrary to the public
interest pursuant to 5 U.S.C. 553(b)(3)(B).
    In addition, the FAA finds that good cause exists pursuant to 5
U.S.C. 553(d) for making this amendment effective in less than 30 days,
for the same reasons the FAA found good cause to forego notice and
comment.

Comments Invited

    The FAA invites you to send any written data, views, or arguments
about this final rule. Send your comments to an address listed under
ADDRESSES. Include ``Docket No. FAA-2022-0878; Project Identifier MCAI-
2022-00873-R'' at the beginning of your comments. The most helpful
comments reference a specific portion of the final rule, explain the
reason for any recommended change, and include supporting data. The FAA
will consider all comments received by the closing date and may amend
this final rule because of those comments.
    Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
https://www.regulations.gov, including any personal information you
provide. The agency will also post a report summarizing each
substantive verbal contact received about this final rule.

Confidential Business Information

    CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this AD contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this AD, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as ``PROPIN.'' The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this AD. Submissions containing CBI should be sent to Kristi
Bradley, Program Manager, COS Program Management Section, Operational
Safety Branch, Compliance & Airworthiness Division, FAA, 10101 Hillwood
Pkwy., Fort Worth, TX 76177; telephone<PHONE_NUMBER>; email
[email protected]. Any commentary that the FAA receives which is
not specifically designated as CBI will be placed in the public docket
for this rulemaking.

Regulatory Flexibility Act

    The requirements of the Regulatory Flexibility Act (RFA) do not
apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt
a rule without prior notice and comment. Because the FAA has determined
that it has good cause to adopt this rule without prior notice and
comment, RFA analysis is not required.

Costs of Compliance

    The FAA estimates that this AD affects 33 helicopters of U.S.
Registry. Labor rates are estimated at $85 per work-hour. Based on
these numbers, the FAA estimates the following costs to comply with
this AD.
    Visually inspecting an affected MRH sleeve for flaking and paint
touch-up takes about 0.5 work-hour for an estimated cost of $43 per MRH
sleeve and up to $7,095 for the U.S. fleet (with up to five affected
MRH sleeves per helicopter).
    If required, visually inspecting each MRH sleeve for a crack takes
about 0.5 work-hour for an estimated cost of $43 per MRH sleeve.
Accomplishing an HFEC takes about 0.5 work-hour for an estimated cost
of $43 per MRH sleeve, per inspection cycle. Chemically stripping and
accomplishing an FPI takes about 8 work-hours for an estimated cost of
$680 per MRH sleeve, per inspection cycle.
    Removing corrosion and applying protective coating, primer, and
paint protection takes a minimal amount of time and parts cost a
nominal amount. Replacing an MRH sleeve takes about 4 work-hours and
parts cost about $102,371 for an estimated cost of $102,711 per MRH
sleeve. The FAA has no way of determining the costs pertaining to any
necessary repairs that are required to be done with an approved method.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. Subtitle VII: Aviation Programs,
describes in more detail the scope of the Agency's authority.
    The FAA is issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701: General requirements.
Under that section, Congress charges the FAA with promoting safe flight
of civil aircraft in air commerce by prescribing regulations for
practices, methods, and procedures the Administrator finds necessary
for safety in air commerce. This regulation is within the scope of that
authority because it addresses an unsafe condition that is likely to
exist or develop on products identified in this rulemaking action.

Regulatory Findings

    This AD will not have federalism implications under Executive Order
13132. This AD will not have a substantial direct effect on the States,
on the relationship between the national Government and the States, or
on the distribution of power and responsibilities among the various
levels of government.
    For the reasons discussed, I certify that this AD:
    (1) Is not a ``significant regulatory action'' under Executive
Order 12866, and
    (2) Will not affect intrastate aviation in Alaska.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.

The Amendment

    Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701.

Sec.  39.13   [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness
directive:

2022-14-51 Airbus Helicopters: Amendment 39-22124; Docket No. FAA-
2022-0878; Project Identifier MCAI-2022-00873-R.

(a) Effective Date

    The FAA issued Emergency Airworthiness Directive (AD) 2022-14-51
on July 1, 2022, directly to affected owners and operators. As a
result of such actual notice, that AD was effective for those owners
and operators on the date it was provided. This AD contains the same
requirements as that emergency AD and, for those who did not receive
actual notice, is effective on August 3, 2022.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Airbus Helicopters Model EC225LP helicopters,
certificated in any category, with main rotor hub (MRH) sleeve part
number 332A31-3071-00 installed.

(d) Subject

    Joint Aircraft Service Component (JASC) Code: 6200, Main Rotor
System.

(e) Unsafe Condition

    This AD was prompted by a report of a cracked MRH sleeve. The
FAA is issuing this AD to detect corrosion or cracking in an MRH
sleeve. The unsafe condition, if not addressed, could result in
failure of an MRH sleeve, loss of a main rotor blade, and subsequent
loss of the helicopter.

(f) Compliance

    Comply with this AD within the compliance times specified,
unless already done.

(g) Required Actions

    (1) Before further flight after the effective date of this AD,
visually inspect the ``Specific area'' of each MRH sleeve as
depicted in Figure 3 of Airbus Helicopters Emergency Alert Service
Bulletin No. 62A017, Revision 0, dated June 30, 2022 (ASB 62A017),
for flaking and paint touch-up.
    (2) As a result of the actions required by paragraph (g)(1) of
this AD, if there is no flaking or paint touch-up, no further action
is required. If there is any flaking or paint touch-up, before
further flight, visually inspect the ``Specific area'' of the MRH
sleeve as depicted in Figure 3 of ASB 62A017 for a crack.
    (3) As a result of the actions required by paragraph (g)(2) of
this AD, if there is a crack, before further flight, remove the MRH
sleeve from service and replace it with an airworthy part. If there
is not a crack, within 15 hours time-in-service (TIS) or 3 months,
whichever occurs first after accomplishing the actions required by
paragraph (g)(1) of this AD, use high-frequency eddy current (HFEC)
to inspect the ``Specific area'' of the MRH sleeve as depicted in
Figure 3 of ASB 62A017 for a crack. This HFEC inspection must be
accomplished by a Level II or III inspector certified in the eddy
current fault detection method in the Aeronautics Sector according
to the EN4179 or NAS410 standard.
    (4) As a result of the actions required by paragraph (g)(3) of
this AD, if there is a crack, before further flight, remove the MRH
sleeve from service and replace it with an airworthy part. If there
is not a crack, before further flight, chemically strip and
fluorescent penetrant inspect (FPI) the ``Specific area'' of the MRH
sleeve as depicted in Figure 3 of ASB 62A017 for corrosion.
    (i) If there is corrosion as a result of the actions required by
the introductory text of paragraph (g)(4) of this AD, before further
flight, accomplish the actions required by paragraph (g)(4)(i)(A) or
(B) of this AD.
    (A) Remove the corrosion by hand using 120-grit abrasive cloth,
followed by 400-grit abrasive cloth. After removing the corrosion,
perform an FPI of each affected area to inspect for corrosion, and
accomplish the actions required by paragraph (g)(4)(i)(A)(1) or (2)
of this AD.
    (1) If there is corrosion, before further flight, remove the MRH
sleeve from service and replace it with an airworthy part or repair
it in accordance with a method approved by the Manager, General
Aviation & Rotorcraft Section, International Validation Branch, FAA;
or European Union Aviation Safety Agency (EASA); or Airbus
Helicopters' EASA Design Organization Approval (DOA). If approved by
the DOA, the approval must include the DOA-authorized signature.
    (2) If there is no corrosion, before further flight, completely
dry the MRH sleeve and apply a protective coating, primer, and paint
protection. Following application, within 15 hours TIS and
thereafter at intervals not to exceed 15 hours TIS, use HFEC to
inspect the ``Specific area'' of the MRH sleeve as

depicted in Figure 3 of ASB 62A017 for a crack. This HFEC inspection
must be accomplished by a Level II or III inspector certified in the
eddy current fault detection method in the Aeronautics Sector
according to the EN4179 or NAS410 standard. If there is a crack,
before further flight, remove the MRH sleeve from service and
replace it with an airworthy part. Accomplishment of the HFEC
inspections with no detected cracks after 75 hours TIS since
applying the coating, primer, and paint protection constitutes a
terminating action for the repetitive inspections required by this
paragraph.
    (B) If the corrosion cannot be removed by hand as specified in
paragraph (g)(4)(i)(A) of this AD, before further flight, remove the
MRH sleeve from service and replace it with an airworthy part or
repair it in accordance with a method approved by the Manager,
General Aviation & Rotorcraft Section, International Validation
Branch, FAA; or EASA; or Airbus Helicopters' EASA DOA. If approved
by the DOA, the approval must include the DOA-authorized signature.
    (ii) If there is no corrosion as a result of the actions
required by the introductory text of paragraph (g)(4) of this AD,
before further flight, apply primer and paint protection.
    (5) As an option to the actions required by paragraph (g)(4) of
this AD, if there is not a crack, accomplish the actions required by
paragraphs (g)(5)(i) and (ii) of this AD.
    (i) Before further flight, apply primer and paint protection. If
there is any area with flaking paint, you may apply only varnish
instead of primer and paint protection on each flaking paint area.
    (ii) Within 15 hours TIS after accomplishing the actions
required by paragraph (g)(5)(i) of this AD and thereafter at
intervals not to exceed 15 hours TIS, HFEC inspect the ``Specific
area'' of the MRH sleeve as depicted in Figure 3 of ASB 62A017 for a
crack. This HFEC inspection must be accomplished by a Level II or
III inspector certified in the eddy current fault detection method
in the Aeronautics Sector according to the EN4179 or NAS410
standard. If there is a crack, before further flight, remove the MRH
sleeve from service and replace it with an airworthy part.
    (6) As of the effective date of this AD, do not install an MRH
sleeve identified in paragraph (c) of this AD on any helicopter
unless the actions required by paragraphs (g)(1) and (2) of this AD
have been accomplished.

(h) Special Flight Permits

    A special flight permit may be issued in accordance with 14 CFR
21.197 and 21.199 provided that there are no passengers onboard and
there is no crack or corrosion in an MRH sleeve.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, International Validation Branch, FAA, has the
authority to approve AMOCs for this AD, if requested using the
procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19,
send your request to your principal inspector or local Flight
Standards District Office, as appropriate. If sending information
directly to the manager of the International Validation Branch, send
it to the attention of the person identified in paragraph (j)(1) of
this AD. Information may be emailed to: [email protected].
    (2) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the local flight standards district office/certificate holding
district office.

(j) Related Information

    (1) For more information about this AD, contact Kristi Bradley,
Program Manager, COS Program Management Section, Operational Safety
Branch, Compliance & Airworthiness Division, FAA, 10101 Hillwood
Pkwy., Fort Worth, TX 76177; telephone<PHONE_NUMBER>; email
[email protected].
    (2) The subject of this AD is addressed in EASA Emergency AD
2022-0130-E, dated June 30, 2022. You may view the EASA AD at
https://www.regulations.gov in Docket No. FAA-2022-0878.

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the
incorporation by reference of the service information listed in this
paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do
the actions required by this AD, unless the AD specifies otherwise.
    (i) Airbus Helicopters Emergency Alert Service Bulletin No.
62A017, Revision 0, dated June 30, 2022.
    (ii) [Reserved]
    (3) For Airbus Helicopters service information identified in
this AD, contact Airbus Helicopters, 2701 North Forum Drive, Grand
Prairie, TX 75052; telephone<PHONE_NUMBER> or<PHONE_NUMBER>; fax
(972) 641-3775; or at https://www.airbus.com/helicopters/services/technical-support.html.
    (4) You may view this service information at the FAA, Office of
the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room
6N-321, Fort Worth, TX 76177. For information on the availability of
this material at the FAA, call<PHONE_NUMBER>.
    (5) You may view this service information that is incorporated
by reference at the National Archives and Records Administration
(NARA). For information on the availability of this material at
NARA, email: [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on July 8, 2022.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2022-15387 Filed 7-14-22; 4:15 pm]
BILLING CODE 4910-13-P


QUESTIONS FOR TRAVELING SCREEN MANUFACTURERS Received from Trent Gathright on 9/ 11/ 2002.

REPLACING COARSE MESH TRAVELING SCREENS WITH FINE MESH TRAVELING SCREENS The following questions inquire about replacing coarse mesh traveling screens with fine mesh traveling screens. Note that replacement screens will have fish baskets for use with a return system. If you perform this kind of work, please answer the following questions:

The following questions cover the breadth of information being sought but admittedly are somewhat extensive. Those shown in non bold print are generally require brief or quality responses and are intended to be discussed over the phone. Questions in bold print may require research and may best be presented in a follow up context.

General 1. In consultations and/ or projects, how often do you encounter site conditions at existing intakes where the existing screens cannot be readily accessed via crane?

In approximately 25 years of experience, we see +/ 40 % of the Traveling Screens that are housed in buildings that require the dis assembly of the screens prior to removal. Therefore, these are not " readily accessible" for immediate removal. This is of course a rough estimate.

2. What range of screen mesh opening sizes do you consider to be " fine mesh?" When facilities examine and/ or select finer mesh to reduce entrainment, what is the most common mesh size? Are there any differences in the fine mesh sizes commonly evaluated and/ or selected for new intakes versus existing intake retrofits?

The old common " rule of thumb" for the mesh size of traveling screens is ½ the diameter of the condenser tube, therefore 97% of existing " Thru Flow" type traveling screens contain 3/ 8" square opening mesh. We consider anything between ½ " to ¼ " opening to be coarse mesh and 3/ 16" and smaller to be " fine" mesh. We have retrofitted a number of screens with 1/ 8" opening both on fish handling and none fish handling. I personally performed a number of experiments in 1983 to 1986 on the result of Fish as they encounter traveling band screens. This was the first work actually observing fish " underwater" through ports in the sides of the flume. The results conclude that " smooth" top mesh ( woven wire mesh pressed flat on the upstream side to provide a smooth surface to prevent descaling) with a slotted opening typically 1/ 8" wide x ½ " tall. Many screens with 3/ 8" and ¼ " square openings are just large enough to allow juvenile fish to become lodged in the mesh opening. New intakes are typically retrofitted with 1/ 8" x ½ " Smooth Top mesh if fish handling is required, ( based on the work performed by Fletcher & Gathright). 3. What is the range and typical spacing between multiple screen units at most existing intakes? In other words how wide are the columns/ walls at the screen location? How close can they be, if space limitation is an issue? How much of the well width does the screen panel cover?

Typical spacing between screens is normally +/ 2' 6" due to the civil works wall between adjacent cells. The screens overlap above deck by +/ 1' 0" thus allowing approx. 1' 6" between most Thru Flow Band Screens. Dual Flow Conversion screens eliminate this clearance problem. We will discuss this in greater detail later. The most common width channel is 11' 2" ( although there are wider and narrower installations) thus allowing a 10' 0" effective width Thru Flow. The frame of the screen fits into guide slots embedded in the civil walls and contains the chain tracks. Each side frame absorbs approx. 7" thus the rule of thumb is that the effective width of a screen is normally 1' 2" less than the channel width.

4. How practical is it to replace screen panels only, versus replacing the entire mechanical unit? When finer mesh is required, how practical or common is it to replace screen panels only? What is the deciding factor? What are the relative cost savings compared to replacing the entire screen unit?

It is of course more practical to only replace the mesh unless it involves fish handling. The old method typically referred to as a " Ristroph" screen literally adds a bucket ( like a house gutter) to the bottom lifting shelf of each basket ( panel). However this method has been well proven that it SIGNIFICANTLY adds to fish mortality. The " bucket" not only absorbs mesh room but creates a vortex in the bucket that slams the juvenile fish against the mesh again and again eventually leading to mortality. We therefore created a NEW basket design that converts the structural cross members ( i. e. basket rails) into a hydraulically stabilized area that actually attracts the juvenile fish as they get close the screen. The old method caused fish to avoid the screens due to the vortex in the bucket as all fish have an inherent " pressure sensitive live" that runs longitudinally along their body. Thus they react quickly to changes in pressure. The new method creates a sheltered zone that they seek and are therefore quickly removed form the intake. This new method is referred to as S. I. M. P. L. E. TM ( Stabilized Integrated Marine Protective Lifting Environment) developed by this author and his associate engineer. Although a screen may be retro fitted, this would include all new baskets, extending the height of the head section to accommodated fish sprays, changing the housings to accommodate fish sprays and fish troughs, a larger drive to accommodate the unbalanced load, etc  therefore the only thing typically salvaged is the frame and head shaft or about 25% of the cost of a new screen. It is therefore recommended that NEW screens be installed vs. retro fitting.

5. Can wedge wire type screen panels be used on traveling screens?

Yes wedge wire can be used but this is cost prohibitive vs. using Smooth Top mesh. Wedge wire is about 3 times more expensive than regular mesh and 2 times more expensive than smooth top mesh. 6. What problems may be encountered in replacing coarse mesh with fine mesh traveling screens ( either screen panel only or entire unit). What are the typical solutions? Specifically,  Problems with collection of additional debris?  Problems with increase in through screen velocity?  Other problems ( describe)

 Debris collection is actually increased although some minor problems are encountered with debris in the fish troughs if filamentatious algae is encountered.

 The " Through screen velocity" can be reduced slightly with a Thru Flow type screen and often greatly with a Dual Flow Conversion screen. Both would utilize the S. I. M. P. L. E. basket that increases basket percent open area.

 Typical solutions the replacement of the entire screens with a prior study of the most common debris encountered.

7. Can replacement of through flow with dual flow ( double entry single exit) screens be used to increase screen area and thus reduce through screen velocities and reduce impingement?

Yes. We have provided a number of Dual Flow Conversion Fish Handling Band Screens ( Dunkirk, Medicine Hat, Barking Reach) to reduce velocity. The effective width of the screens can be increased as the panels ( baskets) are parallel to the channel vs. perpendicular. Normally the deck opening parallel to the channel is only +/ 5' 4" but the deck is typically a concrete walk way only about 1' 0" thick and can be easily removed by cutting to allow for a DFC.

8. What is the % open space for typical coarse mesh traveling screens ( e. g., 3/ 8 inch) that were evaluated and/ or installed at power plant intakes in the past? If not known, what is a typical wire gauge? What is the % open space for different sized fine mesh screens?

Typically 67.9 percent open area ( opening)^ 2 / ( opening + wire dia.)^ 2. The most common is 3/ 8" square with 14 Ga. ( 0.080" diameter wire).

9. Are you aware of any recent retrofit installations where the system capacity or flow volume was not increased, yet substantial civil/ structural modifications were necessary? If so: NO, not on retro fits. The only reductions we have seen are on new installations where the velocity is limited.  What was done and why?  What was the facility name and location?  What were costs or who can we contact for cost information? Equipment Costs 10. EPA previously obtained 1999 costs for single entry single exit traveling screens with the structural component made of carbon steel coated with epoxy paint and screens made of 304 stainless steel, with non metallic baskets. Can you provide delivered equipment costs for comparable ( freshwater) fine mesh ( using most common mesh size from above) screen units with widths in the range of 5, 10, 14  15 ft and well depths in the range of 10, 25, 50, 75, & 100ft? The 1999 traveling screen costs included:  Non metallic fish handling panels  Spray systems  Fish trough  Housings and transitions  Continuous operating features  Drive unit  Frame seals  Engineering Budget Prices for Fish Handling Thru Flow Band Screens Application: Fresh Water ( Primarily Epoxy Coated Carbon Steel with Stainless Steel Mesh and Fasteners) Effective Width ( ft.) Depth ( ft) 5' 0" 10' 0" 14' 0"

10 $ 69,648 $ 87,453 $ 100,732 Approx. HP 3/ 4 1 3 20 $ 89,028 $ 109,202 $ 123,622 Approx. HP 1 2 5 30 $ 108,408 $ 135,251 $ 166,961 Approx. HP 2 5 7.5 40 $ 127,788 $ 153,688 $ 178,154 Approx. HP 3 7.5 10 50 $ 151,500 $ 222,853 $ 249,921 Approx. HP 5 10 15 60 $ 170,880 $ 256,415 $ 290,556 Approx. HP 7.5 15 20 Budget Prices for Fish Handling Thru Flow Band Screens Application: Brackish Water ( Primarily 316 Stainless Steel with Stainless Steel Mesh and Fasteners) Effective Width ( ft.) Depth ( ft) 5' 0" 10' 0" 14' 0"

10 $ 137,903 $ 182,226 $ 213,436 20 $ 176,275 $ 227,544 $ 261,937 30 $ 214,648 $ 281,822 $ 353,765 40 $ 253,020 $ 320,239 $ 377,482 50 $ 299,970 $ 464,359 $ 529,547 60 $ 338,342 $ 534,291 $ 615,647 If we are unable to obtain updated costs we may use the ENR Construction Cost Index which results in a capital cost increase of 9% when updating 1999 costs to July 2002. Do you feel that this reasonably reflects the actual changes over this period?

Yes as we normally use an inflation rate of 2.5% so 3% over 3 years is a good number.

11. What equipment materials do you recommend ( or are commonly selected) for corrosive environments, such as brackish and saltwater? What is the most common material selected for saltwater environments?  Carbon Steel with epoxy coating ( freshwater) This is also very common for sea water with sacrificial zinc anodes for the frames and even the basket frames.  304 Stainless Steel   Never for brackish as 304 does not stand up to chlorides.  316 Stainless Steel  Most of the plate material is now dual certified as 316L, which is used to prevent crevice crack corrosion from the carbides that would normally surface with plain 316. Of course the non welded items such as the mesh and fasteners would be 316SS.  70/ 30 Copper Nickel   Once in 25 years for an Alaskan project.  90/ 10 Copper Nickel Very rarely.  Other ( Describe) For warm seawater ( i. e. countries closer to the equator) it now common to see requirements for 316Ti ( 316 with Titanium) as well as 317 SS. 12. Can you provide equipment costs of this corrosion resistant equipment or provide relative equipment cost difference compared to freshwater unit, such as a cost factor or percent increase?

See the above chart for brackish / seawater applications.

13. What water bodies are experiencing problems with Zebra mussels and how much extra are the equipment costs for special alloy construction or comparable materials?

Zebra mussels are fresh water mollusks that came over from Russia ships and were discharged into the Great Lakes via the ships bilge water. These are now common in every water body that connects to the Great Lakes. They do not like warm temperatures yet but they are adapting and moving down the Mississippi. There are paints with musselcides ( i. e. copper based paints) that supposedly will kill mussels but they last so long before being rendered ineffective. This is too general of a question to give you a quantitative answer. We suggest incorporating debris filters just upstream of the condensers to prevent macrofouling as mussel larvae are to fine to screen out at the raw water intake.

14. If you indicated replacing screen panels only is practical, can you provide estimates of the costs for replacing the panels only, including both equipment and installation? NOT only is this not practical it would also not be functional.

15. Please provide a description of installation methods and typical costs for screen units, and whether you perform such services including differences for wet versus dry installation. Also discuss relative cost of removal and disposal of existing screens ( are the costs minimal?).

Can you provide us with a list of benefits that Brackett Green will receive for providing this information free of charge ?

Screen change out varies from site to site based on the screen effective width, depth, is it in door or out door, how close can you get a crane, does it have to come out in pieces, etc  but at the end of the day the average, typical, cost for removing the old screen and installing a new screen is +/ $ 45,000 per channel ( or per well).

16. Are there any special considerations for nuclear facilities ( e. g., does screen framing need to be stronger and more resistant to collapse) and how do the special considerations affect equipment selection, costs and/ or performance? Are there any other situations where similar requirements are common? Can you provide an equipment cost factor for selecting screens that meet these requirements versus typical non nuclear installations?

Nuclear sites can vary from what is termed as " C" class or Commercial class, which are normal screens for an intake that is not seismically qualified. When " Q" class screens are required for seismically qualified intakes, the screen price can be as much as 50% more just because of the Quality control required for tractability. 17. Would converting to fine mesh screens have a significant effect on O& M costs? If so how much and why?

Yes it would have an impact as the screens would most likely operate under a higher differential thereby wearing out the chain quicker.

Construction Duration 18. When replacing existing screen units ( or screen panels only), approximately how long would the intake bay and/ or pumping unit need to be shut down?

In theory only 1 3days but in actuality this would normally have to be done during an outage to accommodate the new troughing, piping, etc  so we would suggest a 2 week turnaround depending on if old screens had to be removed.

Testing 19. Once the new screens are installed, what kind of performance testing is typically required? Is this often part of the package if you perform installation? What are typical costs and how do these costs compare to other construction/ equipment costs? What factors affect the costs?

The answer to this depends on whether you are referring to performance of fish recovery or just screen operability. Normally a fish screen has to be reviewed for one year to properly account for all of the indigenous species migrating past the intake.

Testing the screens for operability after installation is often in our package but normally only consists of 1 to 3 days of field service to make recommendations on adjusting the sprays, leveling the head shaft, checking gaskets, etc

ADDING FISH HANDLING AND RETURN The following questions inquire about adding a fish handling and return system to an intake with traveling screens where no fish return existed before. This can involve either retrofitting existing screens with fish handling features or putting in new screening units. In either case, the questions also focus on the costs and technical aspects of the addition of a fish return sluice/ conduit ( and possibly fish pumps).

20. Do you sell fish return retrofit systems for existing traveling screens? Yes. Can most existing screens be retrofitted without replacing the entire unit? No, most cannot but some can. We would estimate that maybe 30% of existing sites could upgrade without replacing the entire unit. Many sites could all into this but it is economically logical to do this as the parts and modifications required approach 60 to 70% of the cost of a new machine, then enter the warranty issue into the picture and most clients opt for a new screen. When is it more practical/ economical to replace the whole screening unit? 70% of the time. What are the costs for adding fish buckets, spray systems and troughs either in relation to other costs cited or for equipment sizes described earlier? 35 40 %. How much would the addition of fish buckets only reduce cost over replacing entire screen unit? Not acceptable.

21. How do you determine the design flow volume for the fish return conduit? Based on velocity. Generally, what proportion of the intake flow is diverted to the fish return? Impossible to quantify as the same width machine would require the same fish spray water but the depth could be 2 to 3 times greater.

22. Do you design, provide, or install fish return equipment such as pumps and return conduit? We can supply the fish return troughs. If so:  How are the return pipes/ flume configured and sized? Per site.  Is there a minimum diameter to accommodate large fish? Large fish are not the object but the pipe must handle the water volume.  What are typical slopes and velocities? 1/ 16" per foot to 1/ 8" per foot. Velocity can be state specific based on getting the fish out of the trough.  If pipes are used, do they tend to flow full? No.  What materials of construction are used for fish return conduits ( fiberglass)? Fiberglass.

23. EPA Survey data show few existing traveling screen return systems use fish pumps. Under what circumstances would fish pumps be necessary? Would not recommend them.

24. Do you have any cost data to share for adding fish return systems, especially fish pumps and return conduits? In general, what are typical equipment and installation unit costs for the conduit and support structure for return flows associated with intakes with capacities of 5,000 GPM to 500,000 GPM? If not available, who should we contact for more information? Fish return systems would run +/ $ 25,000 depending on how many screens and how far they had to discharge.

25. What is the typical range of return conduit lengths? 75 to 150 feet. How does water body type influence return conduit length? If it is tidal, it must discharge both directions. For example, do lengths tend to be shorter for non tidal rivers and streams? Longer.

26. Would there be any difference in intake downtime when adding fish handling features compared to downtime for screen replacement? Yes because of the additional piping, controls, troughs, etc  for the fish handling screens. For normal screen replacement, we have done these in as little as 12 hours each.

27. What additional O& M cost would be associated with a fish return system besides the operation of the screens? Fish spray wash water only as it is really a passive conduit.

28. The total average water required for a fish screen including the debris spray, inside fish spray, outside fish spray and trough make up water is 74.5 GPM per foot of effective width. ( not the 40 to 50 quoted during our telecon).