[Federal Register Volume 87, Number 243 (Tuesday, December 20, 2022)]
[Proposed Rules]
[Pages 77749-77763]
[FR Doc No: 2022-27445]

========================================================================
Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.

========================================================================

Federal Register / Vol. 87, No. 243 / Tuesday, December 20, 2022 /
Proposed Rules

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 21

[Docket No. FAA-2022-1548]

Airworthiness Criteria: Special Class Airworthiness Criteria for
the Archer Aviation Inc. Model M001 Powered-Lift

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed airworthiness criteria.

-----------------------------------------------------------------------

SUMMARY: The FAA announces the availability of, and requests comments
on, the proposed airworthiness criteria for the Archer Aviation Inc.
(Archer) Model M001 powered-lift. This document proposes airworthiness
criteria the FAA finds to be appropriate and applicable for the
powered-lift design.

DATES: The FAA must receive comments by January 19, 2023.

ADDRESSES: Send comments identified by docket number FAA-2022-1548
using any of the following methods:
     Federal eRegulations Portal: Go to http://www.regulations.gov and follow the online instructions for sending your
comments electronically.
     Mail: Send comments to Docket Operations, M-30, U.S.
Department of Transportation (DOT), 1200 New Jersey Avenue SE, Room
W12-140, West Building Ground Floor, Washington, DC 20590-0001.
     Hand Delivery of Courier: Take comments to Docket
Operations in Room W12-140 of the West Building Ground Floor at 1200
New Jersey Avenue SE, Washington, DC, between 8 a.m. and 5 p.m., Monday
through Friday, except Federal holidays.
     Fax: Fax comments to Docket Operations at<PHONE_NUMBER>.
    Privacy: The FAA will post all comments it receives, without
change, to http://www.regulations.gov, including any personal
information the commenter provides. Using the search function of the
docket website, anyone can find and read the electronic form of all
comments received into any FAA docket, including the name of the
individual sending the comment (or signing the comment for an
association, business, labor union, etc.). DOT's complete Privacy Act
Statement can be found in the Federal Register published on April 11,
2000 (65 FR 19477-19478), as well as at http://DocketsInfo.dot.gov.
    Docket: Background documents or comments received may be read at
http://www.regulations.gov at any time. Follow the online instructions
for accessing the docket or go to the Docket Operations in Room W12-140
of the West Building Ground Floor at 1200 New Jersey Avenue SE,
Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday,
except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Anthony Primozich, Center for Emerging
Concepts and Innovation (CECI) Branch, AIR-650, Policy and Innovation
Division, Aircraft Certification Service, Federal Aviation
Administration, 2200 S 216th Street, Des Moines, WA 98198-6547;
telephone and fax<PHONE_NUMBER>; email [email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites interested people to take part in the development
of proposed airworthiness criteria for the Archer Model M001 powered-
lift by sending written comments, data, or views. Please identify the
Archer Model M001 and Docket No. FAA-2022-1548 on all submitted
correspondence. The most helpful comments reference a specific portion
of the airworthiness criteria, explain the reason for a recommended
change, and include supporting data.
    Except for Confidential Business Information as described in the
following paragraph, and other information as described in 14 CFR
11.35, the FAA will file in the docket all comments received, as well
as a report summarizing each substantive public contact with FAA
personnel concerning these proposed airworthiness criteria. Before
acting on this proposal, the FAA will consider all comments received on
or before the closing date for comments. The FAA will consider comments
filed late if it is possible to do so without incurring delay. The FAA
may change these airworthiness criteria based on received comments.

Confidential Business Information

    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 notice 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 notice, 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 notice. Submissions
containing CBI should be sent to the individual listed under For
Further Information Contact. Any commentary that the FAA receives that
is not specifically designated as CBI will be placed in the public
docket for this notice.

Background

    On March 30, 2022, Archer applied for a type certificate for the
Model M001 powered-lift. The Archer Model M001 powered-lift has a
maximum gross takeoff weight of 6,500 lbs. and is capable of carrying a
pilot and four passengers. The aircraft has a high-wing and V-tail \1\
configuration with fixed tricycle landing gear. The aircraft uses 12
electric engines powered by onboard batteries for propulsion instead of
conventional air and fuel combustion. Six engines with five-bladed
variable-pitch propellers are mounted on the forward edge of the main
wing, three to each side, which are capable of tilting to provide both
vertical and forward thrust. The other six electric engines drive two-
bladed fixed-pitch propellers and are mounted on the aft edge of the
main wing, three to each side; they are fixed in place to provide only
vertical thrust. The aft-mounted engines operate only during thrust-
borne or semi-thrust-

borne flight; in wing-borne forward flight, these engines are switched
off and the propellers are faired in line with the aircraft fuselage.
The aircraft structure and propellers are constructed of composite
materials. The Archer Model M001 powered-lift is intended to be used
for part 91 and part 135 operations, with a single pilot onboard, under
visual flight rules.
---------------------------------------------------------------------------

    \1\ A V-Tail aircraft design incorporates two slanted tail
surfaces instead of the horizontal and vertical fins of a
conventional aircraft empennage. The two fixed tail surfaces of a V-
Tail act as both horizontal and vertical stabilizers and each has a
moveable flight-control surface referred to as a ruddervator.
---------------------------------------------------------------------------

Discussion

    Because the FAA has not yet established powered-lift airworthiness
standards in 14 CFR, the FAA type certificates powered-lift as special
class aircraft. Under the procedures in 14 CFR 21.17(b), the
airworthiness requirements for special class aircraft are the portions
of the requirements in 14 CFR parts 23, 25, 27, 29, 31, 33, and 35
found by the FAA to be appropriate and applicable to the specific type
design and any other airworthiness criteria found by the FAA to provide
an equivalent level of safety to the existing standards. This notice
announces the applicable regulations and other airworthiness criteria
developed, under Sec.  21.17(b), for type certification of the Archer
Model M001 powered-lift.
    The Archer Model M001 powered-lift has characteristics of both a
rotorcraft and an airplane. It is designed to function as a helicopter
for takeoff and landing and as an airplane cruising at higher speeds
than a helicopter during the en-route portion of flight operations.
Accordingly, the Archer Model M001 powered-lift proposed airworthiness
criteria contain standards from parts 23, 33, and 35 as well as other
proposed airworthiness criteria specific for a powered-lift with
electric engines.
    For the existing regulations that are included without
modification, these proposed airworthiness criteria include all
amendments to the existing part 23, 33, and 35 airworthiness standards
in effect as of the application date of March 30, 2022. These are part
23, amendment 23-64, part 33, amendment 33-34, and part 35, amendment
35-10.
    The Archer Model M001 powered-lift proposed airworthiness criteria
also include new performance-based criteria consisting of part 23
standards at amendment 23-64, modified as necessary to capture the
powered-lift's transitional flight modes. The FAA developed these
criteria because no existing standard captures the powered-lift's
transitional flight modes. The proposed criteria also contain
definitions specific for a powered-lift, such as flight modes,
configurations, speeds, and terminology. Additionally, electric-engine
and related propeller airworthiness criteria are proposed. The new
requirements specific to the Archer Model M001 powered-lift use an
``AM1.xxxx'' section-numbering scheme.
    The FAA selected and designed the particular airworthiness criteria
proposed in this notice for the following reasons:

Aircraft-Level Requirements

    The proposed installation requirements for cockpit voice and flight
data recorders remain unchanged from the normal category airplane
airworthiness standards in part 23. The proposed requirement to prepare
Instructions for Continued Airworthiness accounts for the applicant's
option to install type certificated engines and propellers or to seek
approval of the engines and propellers under the aircraft type
certificate.

General

    The proposed airworthiness criteria include new or modified
definitions to explain the unique capabilities and flight phases of the
Archer Model M001 powered-lift and the meaning of certain terms used in
regulations that have been incorporated by reference. In the event of a
loss of engine power, airplanes and rotorcraft inherently have the
ability to glide or autorotate, respectively. Although the aircraft may
sustain damage, the ability to glide or autorotate allows the aircraft
to reasonably protect the occupants. However, not all powered-lift have
these capabilities. To address this, the FAA proposes a definition for
``continued safe flight and landing,'' unique for the Archer Model M001
powered-lift, that modifies language from the existing definition in
Sec.  23.2000; the FAA also proposes a new definition for ``controlled
emergency landing'' to capture the level of performance the Archer
Model M001 powered-lift must meet, equivalent to a glide or
autorotation.
    In addition, because many of the proposed airworthiness criteria
are performance-based, like the regulations found in part 23, the FAA
has proposed to adopt Sec.  23.2010 by reference, which would require
that the means of compliance used to comply with these proposed
airworthiness criteria be accepted by the Administrator. Because no
powered-lift consensus standards are currently accepted by the
Administrator, the means of compliance for the Archer Model M001
powered-lift will be accepted through the issue paper process.\2\
---------------------------------------------------------------------------

    \2\ See Order 8110.112A, Standardized Procedures for Usage of
Issue Papers and Development of Equivalent Levels of Safety
Memorandums.
---------------------------------------------------------------------------

Flight

    Although part 23 replaced prescriptive design requirements with
performance-based rules that are more easily adaptable to new and novel
technology, these performance-based rules were written for
conventionally configured airplanes equipped with reversible flight
controls for fixed-wing takeoff and landing operations. To accommodate
Archer's ability to engage in vertical takeoff and landing operations,
these proposed airworthiness criteria adopt language from parts 27 and
29, where appropriate, with changes to allow for safe operation of the
powered-lift below the stall speed of the wing. The FAA developed
proposed criteria to address the integration of alternating sources of
lift: thrust-borne, semi-thrust-borne, and wing-borne. While the FAA
has experience certifying indirect flight-control systems such as fly-
by-wire systems, Archer's design uses a unique, integrated flight- and
propulsion-control system that requires new airworthiness criteria.
    In addition, the FAA proposes a new AM1.2105, which incorporates
all of Sec.  23.2105 and adds criteria in new paragraphs (f) and (g).
Proposed AM1.2105(f) and (g) would ensure the pilot is capable of
executing a controlled emergency landing in the event of a loss of
power or thrust, whether by the aircraft's ability to glide or
autorotate, or through an equivalent means that reasonably protects
occupants.

Powerplant

    Part 23 (amendment 23-64) addresses electric propulsion, but only
for conventionally configured airplanes that use propulsion for forward
thrust. Archer's new and novel design uses a distributed propulsion
system to provide forward thrust, lift, and control. While some of
these design features can be addressed by existing airworthiness
standards in parts 23 and 27, other features require the development of
new airworthiness criteria. The proposed airworthiness criteria address
the following unique and novel powerplant installation features:
     multi-engine isolation in a distributed propulsion system,
     simplified control of distributed propulsion,
     integration of a propulsion system into aircraft flight
controls, and

     energy-system crashworthiness associated with vertical
takeoff and landing capability.
    The proposed airworthiness criteria in AM1.2405 combine engine and
propeller control functions from Sec. Sec.  23.2405 and 23.2425, and
revise the application to capture all powerplant control functions
including engine control, propeller control, and nacelle rotation.
Energy system airworthiness criteria in proposed AM1.2430 would include
a requirement to address energy system crashworthiness to capture the
intent of Sec.  27.952 and would delete requirements specific to liquid
fuel systems. The powerplant fire-protection airworthiness criteria in
proposed AM1.2440 would replace prescriptive language from Sec.
23.2440 for designated fire zones, with generalized fire-zone language
to address all powerplant-related fire threats. Electric propulsion
systems introduce new fire threats from high-voltage electrical power
and battery systems. Designated fire zones assume a kerosene-based fire
threat, which is inconsistent with fire threats from electric
powerplant installations. These proposed criteria are intended to allow
for safe operation of the powered-lift using an all-electric
distributed propulsion system for thrust-borne, semi-thrust-borne, and
wing-borne flight.

Structures

    The flight and ground loads for powered-lift are generally
comprised of three types of flight configurations: vertical,
transition, and forward. The proposed airworthiness criteria are not
taken solely from the forward-flight requirements of part 23 (for
airplanes) or the vertical-flight requirements of part 27 (for
rotorcraft). Powered-lift also rely on a transitional type of lift,
which may include a combination of forward and vertical flight loads.
The aerodynamic flow field around the powered-lift during transitional
type of lift can be considerably different from what is traditionally
observed during forward and vertical flight. In some flight
configurations, the powered-lift may experience a combination of
forward and vertical flight loads (forces). In other configurations,
the aircraft may undergo a completely new type of aerodynamic flow
field, not experienced during strictly forward or vertical flight.
Traditional existing airworthiness standards do not adequately
represent the aerodynamic loads, used for structural design, of a
powered-lift. Therefore, the FAA finds that additional airworthiness
criteria are necessary for structural design. The FAA created AM1.2200
and AM1.2225 by revising Sec. Sec.  23.2200 and 23.2225 to address the
powered-lift structural design envelope. The FAA created AM1.2240 by
revising Sec.  23.2240 to remove level 4 airplane requirements, because
the Archer Model M001 powered-lift is not a level 4 airplane.
    In addition, the FAA proposes a new AM1.2320, which incorporates
all of Sec.  23.2320 except for Sec.  23.2320(b). Proposed AM1.2320(b)
contains a new bird strike requirement specific for the applicant's
design. The FAA recognizes the threat from bird strikes in the
environment in which these aircraft are intended to operate is more
severe than the environment that rotorcraft or part 23 fixed-wing
aircraft operate in today. The Archer Model M001 powered-lift has
inherent design features and expected operations that potentially
expose the aircraft to a higher probability of impact with birds.
    The Archer Model M001 powered-lift will operate at altitudes
similar to rotorcraft, and the FAA expects it will cruise at airspeeds
that are the same as or greater than rotorcraft. However, the FAA
expects the Archer Model M001 powered-lift will spend less time in
hover compared to rotorcraft, increasing high-speed flight time. The
FAA also recognizes that the Archer Model M001 powered-lift will be
much quieter than conventional helicopter turboshaft engines and
rotors. As a result, birds will have fewer cues to the existence of the
vehicle due to quiet approach environments.
    All of these factors combined increase the aircraft's exposure to
birds. Accordingly, the FAA proposes a more comprehensive bird strike
requirement for the Archer Model M001 powered-lift. As cited in the
Aviation Rulemaking Advisory Committee (ARAC) Rotorcraft Bird Strike
Working Group (RBSWG) report,\3\ an analysis of bird strike threats
against rotorcraft showed the median bird size for birds involved in
damaging strikes was 1.125 kg (2.5 lb). Based on that research, the FAA
proposes a bird impact size of 1.0 kg (2.2-lb), consistent with
rotorcraft industry testing. The applicant must perform an evaluation
at the aircraft level to determine what parts of the aircraft are
exposed to potential bird strikes.
---------------------------------------------------------------------------

    \3\ ARAC RBSWG Report, Rev. B, May 8, 2019, page 15, Section
``Bird Mass'' (ARAC RBSWG Report), https://www.faa.gov/regulations_policies/rulemaking/committees/documents/index.cfm/document/information?documentID=3964.
---------------------------------------------------------------------------

    The FAA also proposes a requirement for bird deterrence devices to
reduce the potential for bird strikes. Research, testing, and use of
bird-deterrence technology has shown to be effective in reducing bird
strikes.\4\ Alerting birds to the presence of the aircraft allows birds
to avoid striking the aircraft. Bird deterrence systems may include,
for example, light technology to aid birds in detecting and avoiding
the aircraft.
---------------------------------------------------------------------------

    \4\ ARAC RBSWG Report, pages 48-50.
---------------------------------------------------------------------------

Electric Engines

    The electric engines proposed for installation on the Archer Model
M001 powered-lift use electric power instead of air-and-fuel combustion
to propel the aircraft. These electric engines are designed,
manufactured, and controlled differently than aircraft engines that
operate using aviation fuel. These engines are built with an electric
motor, a controller, and a high-voltage system that draws energy from
electrical storage or generating systems. The engines in the Archer
Model M001 powered-lift are devices that convert electrical energy into
mechanical energy; electric current flowing through wire coils in the
motor produces a magnetic field that interacts with magnets on the
rotating armature shaft. The controller is a system that consists of
two main functional elements: the motor controller and an electric-
power inverter to drive the motor associated with an electric engine.
The high-voltage system is a combination of wires, power-conditioning
components, and connectors that couple an energy source to an electric
engine, associated motor, and a controller.
    The technology required to provide energy through these high-
voltage and high-current electronic components introduces potential
hazards that do not exist in aircraft engines that operate using
aviation fuel. For example, high-voltage transmission lines,
electromagnetic fields, magnetic materials, and high-speed electrical
switches form the electric engine's physical properties. Operating at
these high power levels also exposes the electric engines to potential
failures, which could adversely affect safety, and that are not common
to aircraft engines that operate using aviation fuel.

Propellers

    Part 35 contains airworthiness standards to ensure that uninstalled
propellers meet the minimum level of safety that the FAA deems
acceptable. Part 35 requirements are appropriate for propellers that
are installed on conventional airplanes, type certificated under part
23 or part 25, that have construction and blade-pitch actuation methods
typically found on such airplanes.

    Emerging electric-powered and hybrid electric-powered aircraft,
especially electric powered-lift that are intended for ``air taxi''
type operations in and near urban areas and capable of vertical and
short takeoff and landing, often feature propellers designed for both
horizontal thrust and vertical lift. In addition, propeller blade-pitch
actuation for such aircraft typically is performed electrically, and is
more extensively integrated into the aircraft's propulsion and flight-
control system compared to conventional airplanes type certificated
under part 23 or part 25.
    Propellers are integral parts of a variety of airplane propulsion
systems and, until the advent of electric engines, have been subjected
to the forces of fossil-fuel-powered reciprocating and turbine
combustion engines. Electric engines present different considerations
due to the increased torque and potentially higher revolutions per
minute.
    The most basic requirement, for all conventional part 23 and 25
aircraft as well as the Archer Model M001 powered-lift, is to reduce
the risk of propeller failure or release of debris to the occupants and
critical aircraft structures and components to an acceptable level.
Features and characteristics of propellers must ensure that they are
safe for the certification application requested.
    These proposed airworthiness criteria would require functional
engine demonstrations, including feathering, negative torque, negative
thrust, and reverse-thrust operations, as appropriate, using a
representative propeller. The applicant may conduct these
demonstrations as part of the endurance and durability demonstrations.

Applicability

    These airworthiness criteria, established under the provisions of
Sec.  21.17(b), are applicable to the Archer Model M001 powered-lift.
Should Archer wish to apply these airworthiness criteria to other
powered-lift models, it must submit a new application for a type
certificate.

The Proposed Airworthiness Criteria

    The FAA proposes to establish the following airworthiness criteria
for type certification of the Archer Model M001 powered-lift. The FAA
proposes that compliance with the following criteria will provide an
equivalent level of safety to existing rules.

Aircraft-Level Requirements

Sec.  23.1457  Cockpit voice recorders.

    (a) through (g) [Applicable to Model M001]

Sec.  23.1459  Flight data recorders.

    (a) through (e) [Applicable to Model M001]

AM1.1529 Instructions for Continued Airworthiness

    The applicant must prepare Instructions for Continued Airworthiness
(ICA), in accordance with Appendices A, A1, and A2, that are acceptable
to the Administrator. ICA for the aircraft, engines, and propellers may
be shown in a single aircraft ICA manual if the engine and propeller
approvals are sought through the aircraft certification program.
Alternatively, the applicant may provide individual ICA for the
aircraft, engines, and propellers. The instructions may be incomplete
at the time of type certification if a program exists to ensure their
completion prior to delivery of the first aircraft, or issuance of a
standard certificate of airworthiness, whichever occurs later.

SUBPART A--General

AM1.2000 Applicability and Definitions

    (a) These airworthiness criteria prescribe airworthiness standards
for the issuance of a type certificate, and changes to that type
certificate, for the Archer Aviation Inc. Model M001 powered-lift.
    (b) For purposes of these airworthiness criteria, the following
definitions apply:
    (1) Continued safe flight and landing means an aircraft is capable
of continued controlled flight and landing, possibly using emergency
procedures, without requiring exceptional pilot skill or strength.
    (2) Phases of flight means ground operations, takeoff, climb,
cruise, descent, approach, hover, and landing.
    (3) Source of lift means one of three sources of lift: thrust-
borne, wing-borne, and semi-thrust-borne. Thrust-borne is defined as
when the powered-lift is maneuvering in the vertical plane and lift is
predominately from downward thrust. Wing-borne is defined as when the
powered-lift is maneuvering in the horizontal plane and lift is
predominately from fixed airfoil surfaces. Semi-thrust-borne is the
combination of thrust-borne and wing-borne, where both forms of lift
are applied.
    (4) Loss of power/thrust means a condition when the aircraft can no
longer provide the commanded power or thrust required for continued
safe flight and landing.
    (5) Controlled emergency landing means the pilot is capable of
choosing the direction and area of touchdown, and the aircraft is
capable of reasonably protecting occupants. Upon landing, some damage
to the aircraft may be acceptable.
    (c) Terms used in the part 23 provisions that are adopted in these
airworthiness criteria are interpreted as follows:
    ``Airplane'' means ``aircraft.''
    ``This part'' means ``these airworthiness criteria.''

Sec.  23.2010  Accepted means of compliance.

    (a) through (b) [Applicable to Model M001]

SUBPART B--Flight Performance

Sec.  23.2100  Weight and center of gravity.

    (a) through (c) [Applicable to Model M001]

AM1.2105 Performance Data

    (a) Unless otherwise prescribed, an aircraft must meet the
performance requirements of this subpart in still air and standard
atmospheric conditions.
    (b) Unless otherwise prescribed, the applicant must develop the
performance data required by this subpart for the following conditions:
    (1) Airport altitudes from sea level to 10,000 feet (3,048 meters);
and
    (2) Temperatures above and below standard day temperature that are
within the range of operating limitations, if those temperatures could
have a negative effect on performance.
    (c) The procedures used for determining takeoff and landing
performance must be executable consistently by pilots of average skill
in atmospheric conditions expected to be encountered in service.
    (d) Performance data determined in accordance with paragraph (b) of
this section must account for losses due to atmospheric conditions,
cooling needs, installation losses, downwash considerations, and other
demands on power sources.
    (e) The hovering ceiling, in and out of ground effect, must be
determined over the ranges of weight, altitude, and temperature, if
applicable.
    (f) Continued safe flight and landing must be possible from any
point within the flight envelope following a critical loss of thrust
not shown to be extremely improbable.
    (g) The aircraft must be capable of a controlled emergency landing,
after loss of power or thrust, by gliding or

autorotation, or an equivalent means, to mitigate the risk of loss of
power or thrust.

AM1.2110 Minimum Safe Speed

    The applicant must determine the aircraft minimum safe speed for
each flight condition encountered in normal operations, including
applicable sources of lift and phases of flight, to maintain controlled
safe flight. The minimum safe speed determination must account for the
most adverse conditions for each flight configuration.

AM1.2115 Takeoff Performance

    (a) The applicant must determine takeoff performance accounting for
flight envelope and obstacle safety margins.
    (b) The applicant must determine takeoff performance accounting for
any loss of thrust not shown to be extremely improbable.

AM1.2120 Climb Requirements

    (a) The applicant must demonstrate minimum climb performance at
each weight, altitude, and ambient temperature within the operating
limitations using the procedures published in the flight manual.
    (b) The applicant must demonstrate minimum climb performance
accounting for any loss of thrust not shown to be extremely improbable.

AM1.2125 Climb Information.

    (a) The applicant must determine climb performance at each weight,
altitude, and ambient temperature within the operating limitations
using the procedures published in the flight manual.
    (b) The applicant must determine climb performance accounting for
any loss of thrust not shown to be extremely improbable.

AM1.2130 Landing

    The applicant must determine the following, for standard
temperatures at critical combinations of weight and altitude within the
operational limits:
    (a) The landing performance, assuming approach paths applicable to
the aircraft.
    (b) The approach, transition if applicable, and landing speeds,
configurations, and procedures, which allow a pilot of average skill to
land within the published landing performance consistently and without
causing damage or injury, and which allow for a safe transition to the
balked landing conditions of these airworthiness criteria, accounting
for the minimum safe speed.

FLIGHT CHARACTERISTICS

AM1.2135 Controllability

    (a) The aircraft must be controllable and maneuverable, without
requiring exceptional piloting skill, alertness, or strength, within
the operating envelope--
    (1) At all loading conditions for which certification is requested;
    (2) During all phases of flight while using applicable sources of
lift;
    (3) With likely flight-control or propulsion-system failure;
    (4) During configuration changes;
    (5) In all degraded flight-control-system operating modes not shown
to be extremely improbable; and
    (6) In thrust-borne operation, and must be able to land safely in
wind velocities from zero to a wind limit appropriate for the aircraft
from any azimuth angle.
    (b) The applicant must determine critical control parameters, such
as limited-control power margins, and if applicable, account for those
parameters in developing operating limitations.
    (c) It must be possible to make a smooth change from one flight
condition to another (changes in configuration, and in source of lift
and phase of flight) without exceeding the approved flight envelope.

AM1.2140 Trim

    (a) The aircraft must maintain lateral and directional trim without
further force upon, or movement of, the primary flight controls or
corresponding trim controls by the pilot, or the flight-control system,
under normal phases of flight while using applicable sources of lift in
cruise.
    (b) The aircraft must maintain longitudinal trim without further
force upon, or movement of, the primary flight controls or
corresponding trim controls by the pilot, or the flight-control system,
under the following conditions:
    (1) Climb.
    (2) Level flight.
    (3) Descent.
    (4) Approach.
    (c) Residual control forces must not fatigue or distract the pilot
during normal operations of the aircraft and likely abnormal or
emergency operations, including loss of thrust not shown to be
extremely improbable on multi-engine aircraft.

AM1.2145 Stability

    (a) Aircraft not certified for aerobatics must exhibit stable
characteristics in normal operations and after likely failures of the
flight and propulsion control system.
    (b) No aircraft may exhibit any divergent longitudinal stability
characteristic so unstable as to increase the pilot's workload or
otherwise endanger the aircraft and its occupants.

AM1.2150 Minimum Safe Speed Flight Characteristics, Minimum Safe Speed
Warning, and Spins.

    (a) The aircraft must have controllable minimum safe speed flight
characteristics in straight flight, turning flight, and accelerated
turning flight with a clear and distinctive minimum safe speed warning
that provides sufficient margin to prevent inadvertent slowing below
minimum safe speed.
    (b) Aircraft not certified for aerobatics must not have a tendency
to inadvertently depart controlled flight from thrust asymmetry after a
critical loss of thrust.
    (c) Aircraft certified for aerobatics that include spins must have
controllable stall characteristics and the ability to recover within
one and one-half additional turns after initiation of the first control
action from any point in a spin, not exceeding six turns or any greater
number of turns for which certification is requested, while remaining
within the operating limitations of the aircraft.
    (d) Spin characteristics in aircraft certified for aerobatics that
includes spins must recover without exceeding limitations and may not
result in unrecoverable spins--
    (1) With any typical use of the flight or engine-power controls; or
    (2) Due to pilot disorientation or incapacitation.

Sec.  23.2155  Ground and water handling characteristics.

    [Applicable to Model M001]

Sec.  23.2160  Vibration, buffeting, and high-speed characteristics.

    (a) [Applicable to Model M001]
    (b) through (d) [Not applicable to Model M001]

AM1.2165 Performance and Flight Characteristics Requirements for Flight
in Atmospheric Icing Conditions

    (a) An applicant who requests certification for flight in
atmospheric icing conditions must show the following in the icing
conditions for which certification is requested:
    (1) Compliance with each requirement of this subpart, except those
applicable to spins and any that must be demonstrated at speeds in
excess of--
    (i) 250 knots calibrated airspeed (CAS);
    (ii) VMO/MMO or VNE; or

    (iii) A speed at which the applicant demonstrates the airframe will
be free of ice accretion.
    (2) The means by which minimum safe speed warning is provided to
the pilot for flight in icing conditions and non-icing conditions is
the same.
    (b) The applicant must provide a means to detect icing conditions
for which certification is not requested and show the aircraft's
ability to avoid or exit those icing conditions.
    (c) The applicant must develop an operating limitation to prohibit
intentional flight, including takeoff and landing, into icing
conditions for which the aircraft is not certified to operate.

SUBPART C--Structures

AM1.2200 Structural Design Envelope

    The applicant must determine the structural design envelope, which
describes the range and limits of aircraft design and operational
parameters for which the applicant will show compliance with the
requirements of this subpart. The applicant must account for all
aircraft design and operational parameters that affect structural
loads, strength, durability, and aeroelasticity, including:
    (a) Structural design airspeeds, landing-descent speeds, and any
other airspeed limitation at which the applicant must show compliance
to the requirements of this subpart. The structural design airspeeds
must--
    (1) Be sufficiently greater than the minimum safe speed of the
aircraft to safeguard against loss of control in turbulent air; and
    (2) Provide sufficient margin for the establishment of practical
operational limiting airspeeds.
    (b) Design maneuvering load factors not less than those, which
service history shows, may occur within the structural design envelope.
    (c) Inertial properties including weight, center of gravity, and
mass moments of inertia, accounting for--
    (1) Each critical weight from the aircraft empty weight to the
maximum weight; and
    (2) The weight and distribution of occupants, payload, and fuel.
    (d) Characteristics of aircraft control systems, including range of
motion and tolerances for control surfaces, high lift devices, or other
moveable surfaces.
    (e) Each critical altitude up to the maximum altitude.
    (f) Engine-driven lifting-device rotational speed and ranges, and
the maximum rearward and sideward flight speeds.

Sec.  23.2205  Interaction of systems and structures.

    [Applicable to Model M001]

Structural Loads

Sec.  23.2210  Structural design loads.

    (a) through (b) [Applicable to Model M001]

Sec.  23.2215  Flight load conditions.

    (a) through (c) [Applicable to Model M001]

Sec.  23.2220  Ground and water load conditions.

    [Applicable to Model M001]

AM1.2225 Component loading conditions

    The applicant must determine the structural design loads acting on:
    (a) Each engine mount and its supporting structure such that both
are designed to withstand loads resulting from--
    (1) Powerplant operation combined with flight gust and maneuver
loads; and
    (2) For non-reciprocating powerplants, sudden powerplant stoppage.
    (b) Each flight control and high-lift surface, their associated
system and supporting structure resulting from--
    (1) The inertia of each surface and mass balance attachment;
    (2) Flight gusts and maneuvers;
    (3) Pilot or automated system inputs;
    (4) System induced conditions, including jamming and friction; and
    (5) Taxi, takeoff, and landing operations on the applicable
surface, including downwind taxi and gusts occurring on the applicable
surface.
    (c) A pressurized cabin resulting from the pressurization
differential--
    (1) From zero up to the maximum relief pressure combined with gust
and maneuver loads;
    (2) From zero up to the maximum relief pressure combined with
ground and water loads if the aircraft may land with the cabin
pressurized; and
    (3) At the maximum relief pressure multiplied by 1.33, omitting all
other loads.
    (d) Engine-driven lifting-device assemblies, considering loads
resulting from flight and ground conditions, as well limit input torque
at any lifting-device rotational speed.

Sec.  23.2230  Limit and ultimate loads.

    (a) through (b) [Applicable to Model M001]

Structural Performance

Sec.  23.2235  Structural strength.

    (a) through (b) [Applicable to Model M001]

AM1.2240 Structural Durability

    (a) The applicant must develop and implement inspections or other
procedures to prevent structural failures due to foreseeable causes of
strength degradation, which could result in serious or fatal injuries,
or extended periods of operation with reduced safety margins. Each of
the inspections or other procedures developed under this section must
be included in the Airworthiness Limitations Section of the
Instructions for Continued Airworthiness, required by AM1.1529.
    (b) For pressurized aircraft:
    (1) The aircraft must be capable of continued safe flight and
landing following a sudden release of cabin pressure, including sudden
releases caused by door and window failures.
    (2) For aircraft with maximum operating altitude greater than
41,000 feet, the procedures developed for compliance with paragraph (a)
of this section must be capable of detecting damage to the pressurized
cabin structure before the damage could result in rapid decompression
that would result in serious or fatal injuries.
    (c) The aircraft must be designed to minimize hazards to the
aircraft due to structural damage caused by high-energy fragments from
an uncontained engine or rotating machinery failure.

Sec.  23.2245  Aeroelasticity.

    (a) through (b) [Applicable to Model M001]

Design

Sec.  23.2250  Design and construction principles.

    (a) through (e) [Applicable to Model M001]

Sec.  23.2255  Protection of structure.

    (a) through (c) [Applicable to Model M001]

Sec.  23.2260  Materials and processes.

    (a) through (g) [Applicable to Model M001]

Sec.  23.2265  Special factors of safety.

    (a) through (c) [Applicable to Model M001]

Structural Occupant Protection

Sec.  23.2270  Emergency conditions.

    (a) through (e) [Applicable to Model M001]

SUBPART D--Design and Construction

AM1.2300 Flight-control systems

    (a) The applicant must design flight-control systems to:

    (1) Operate easily, smoothly, and positively enough to allow proper
performance of their functions; and
    (2) Protect against likely hazards.
    (b) The applicant must design trim systems, if installed, to:
    (1) Protect against inadvertent, incorrect, or abrupt trim
operation; and
    (2) Provide a means to indicate--
    (i) The direction of trim control movement relative to aircraft
motion;
    (ii) The trim position with respect to the trim range;
    (iii) The neutral position for lateral and directional trim; and
    (iv) The range for takeoff for all applicant-requested center of
gravity ranges and configurations.
    (c) In addition to paragraph (a) and (b) of this section, for
indirect flight-control systems:
    (1) A means must be provided to indicate to the flightcrew any
significant changes or degradation to the handling or operational
characteristics of the aircraft during normal and abnormal system
operation; and
    (2) Features that protect the aircraft against loss of control,
structural damage, or exceeding critical limits must be designed such
that--
    (i) The onset characteristics of each protection feature is smooth
and appropriate for the phase of flight and type of maneuver;
    (ii) There are no adverse flight characteristics in aircraft
response to flight-control inputs, unsteady atmospheric conditions, and
other likely conditions, including simultaneous limiting events; and
    (iii) The aircraft is capable of continued safe flight and landing
following failures not shown to be extremely improbable throughout the
approved flight envelope and expected operational conditions.

Sec.  23.2305  Landing gear systems.

    (a) through (c) [Applicable to Model M001]

Sec.  23.2310  Buoyancy for seaplanes and amphibians.

    (a) through (b) [Applicable to Model M001]

Occupant System Design Protection

Sec.  23.2315  Means of egress and emergency exits.

    (a) through (b) [Applicable to Model M001, including the ditching
exclusion in (a)(1)]

AM1.2320 Occupant Physical Environment.

    (a) The applicant must design the aircraft to:
    (1) Allow clear communication between the flightcrew and
passengers;
    (2) Protect the pilot and flight controls from propellers; and
    (3) Protect the occupants from serious injury due to damage to
windshields, windows, and canopies.
    (b) The aircraft must be capable of continued safe flight and
landing after a bird strike with a 2.2-lb (1.0 kg) bird. In addition,
the aircraft design must include bird deterrence devices to reduce the
potential for bird strikes.
    (c) The aircraft must provide each occupant with air at a
breathable pressure, free of hazardous concentrations of gases, vapors,
and smoke during normal operations and likely failures.
    (d) If a pressurization system is installed in the aircraft, it
must be designed to protect against:
    (1) Decompression to an unsafe level; and
    (2) Excessive differential pressure.
    (e) If an oxygen system is installed in the aircraft, it must--
    (1) Effectively provide oxygen to each user to prevent the effects
of hypoxia; and
    (2) Be free from hazards in itself, in its method of operation, and
its effect upon other components.

Fire and High Energy Protection

Sec.  23.2325  Fire protection.

    (a)(1), (a)(2), (b) through (d), (f)(1), and (g) through (h)
[Applicable to Model M001]
    (a)(3), (e), and (f)(2) [Not applicable to Model M001]

AM1.2330 Fire Protection in Fire Zones and Adjacent Areas.

    (a) Flight controls, engine mounts, and other flight structures
within or adjacent to fire zones must be capable of withstanding the
effects of a fire.
    (b) Engines in a fire zone must remain attached to the aircraft in
the event of a fire.
    (c) In fire zones, terminals, equipment, and electrical cables used
during emergency procedures must perform their intended function in the
event of a fire.

AM1.2335 Lightning and Static Electricity Protection.

    (a) The aircraft must be protected against catastrophic effects
from lightning.
    (b) The aircraft must be protected against hazardous effects caused
by an accumulation of electrostatic charge.

SUBPART E--Powerplant

AM1.2400 Powerplant Installation.

    (a) For the purpose of this subpart, the aircraft powerplant
installation must include each component necessary for propulsion,
which affects propulsion safety, or provides auxiliary power to the
aircraft.
    (b) Each aircraft engine and propeller must have a type certificate
or be approved under the aircraft type certificate using standards
found in subparts H and I.
    (c) The applicant must construct and arrange each powerplant
installation to account for--
    (1) Likely operating conditions, including foreign-object threats;
    (2) Sufficient clearance of moving parts to other aircraft parts
and their surroundings;
    (3) Likely hazards in operation including hazards to ground
personnel; and
    (4) Vibration and fatigue.
    (d) Hazardous accumulations of fluids, vapors, or gases must be
isolated from the aircraft and personnel compartments and be safely
contained or discharged.
    (e) Powerplant components must comply with their component
limitations and installation instructions or be shown not to create a
hazard.

AM1.2405 Power or Thrust Control Systems.

    (a) Any power or thrust control system, reverser system, or
powerplant control system must be designed so no unsafe condition
results during normal operation of the system.
    (b) Any single failure or likely combination of failures or
malfunctions of a power or thrust control system, reverser system, or
powerplant control system must not prevent continued safe flight and
landing of the aircraft.
    (c) Inadvertent flightcrew operation of a power or thrust control
system, reverser system, or powerplant control system must be
prevented, or if not prevented, must not prevent continued safe flight
and landing of the aircraft.
    (d) Unless the failure of an automatic power or thrust control
system is extremely remote, the system must--
    (1) Provide a means for the flightcrew to verify the system is in
an operating condition;
    (2) Provide a means for the flightcrew to override the automatic
function; and
    (3) Prevent inadvertent deactivation of the system.

Sec.  23.2410  Powerplant installation hazard assessment.

    (a) through (c) [Applicable to Model M001]

Sec.  23.2415  Powerplant ice protection.

    (a) through (b) [Applicable to Model M001]

AM1.2425 Powerplant Operational Characteristics

    (a) Each installed powerplant must operate without any hazardous
characteristics during normal and emergency operation within the range
of operating limitations for the aircraft and the engine.
    (b) The design must provide for the shutdown and restart of the
powerplant in flight within an established operational envelope.

AM1.2430 Energy Systems

    (a) Each energy system must--
    (1) Be designed and arranged to provide independence between
multiple energy-storage and supply systems, so that failure of any one
component in one system will not result in loss of energy storage or
supply of another system;
    (2) Be designed to prevent catastrophic events due to lightning
strikes, taking into account direct and indirect effects on the
aircraft where the exposure to lightning is likely;
    (3) Provide the energy necessary to ensure each powerplant and
auxiliary power unit functions properly in all likely operating
conditions;
    (4) Provide the flightcrew with a means to determine the total
useable energy available and provide uninterrupted supply of that
energy when the system is correctly operated, accounting for likely
energy fluctuations;
    (5) Provide a means to safely remove or isolate the energy stored
in the system from the aircraft; and
    (6) Be designed to retain energy under all likely operating
conditions and to minimize hazards to occupants following an emergency
landing or otherwise survivable impact (crash landing).
    (7) [Reserved]
    (b) Each energy-storage system must--
    (1) Withstand the loads under likely operating conditions without
failure; and
    (2) Be isolated from personnel compartments and protected from
hazards due to unintended temperature influences.
    (3) [Reserved]
    (4) [Reserved]
    (c) Each energy-storage refilling or recharging system must be
designed to--
    (1) Prevent improper refilling or recharging; and
    (2) [Reserved]
    (3) Prevent the occurrence of hazard to the aircraft or to persons
during refilling or recharging.

Sec.  23.2435  Powerplant induction and exhaust systems.

    (a) through (b) [Applicable to Model M001]

AM1.2440 Powerplant Fire Protection

    There must be means to isolate and mitigate hazards to the aircraft
in the event of a powerplant-system fire or overheat in operation.

SUBPART F--Equipment

Sec.  23.2500  Airplane level systems requirements.

    (a) through (b) [Applicable to Model M001]

Sec.  23.2505  Function and installation.

    [Applicable to Model M001]

Sec.  23.2510  Equipment, systems, and installations.

    (a) through (c) [Applicable to Model M001]

AM1.2515 Electrical- and Electronic-System Lightning Protection

    (a) Each electrical or electronic system that performs a function,
the failure of which would prevent the continued safe flight and
landing of the aircraft, must be designed and installed such that--
    (1) The function at the aircraft level is not adversely affected
during and after the time the aircraft is exposed to lightning; and
    (2) The system recovers normal operation of that function in a
timely manner after the aircraft is exposed to lightning unless the
system's recovery conflicts with other operational or functional
requirements of the system.
    (b) For an aircraft approved for operation under instrument flight
rules (IFR), each electrical and electronic system that performs a
function, the failure of which would significantly reduce the
capability of the aircraft or the ability of the flightcrew to respond
to an adverse operating condition, must be designed and installed such
that the system recovers normal operation of that function in a timely
manner after the aircraft is exposed to lightning.

Sec.  23.2520  High-intensity Radiated Fields (HIRF) protection.

    (a) through (b) [Applicable to Model M001]

Sec.  23.2525  System power generation, storage, and distribution.

    (a) through (c) [Applicable to Model M001]

Sec.  23.2530  External and cockpit lighting.

    (a) through (e) [Applicable to Model M001]

Sec.  23.2535  Safety equipment.

    [Applicable to Model M001]

AM1.2540 Flight in Icing Conditions

    An applicant who requests certification for flight in icing
conditions must show the following in the icing conditions for which
certification is requested:
    (a) The ice protection system provides for safe operation; and
    (b) The aircraft design must provide protection from slowing to
less than the minimum safe speed when the autopilot is operating.

Sec.  23.2545  Pressurized systems elements.

    [Applicable to Model M001]

Sec.  23.2550  Equipment containing high-energy rotors.

    [Applicable to Model M001]

SUBPART G--Flightcrew Interface and Other Information

AM1.2600 Flightcrew Interface

    (a) The pilot compartment, its equipment, and its arrangement to
include pilot view, must allow each pilot to perform their duties for
all sources of lift and phases of flight and perform any maneuvers
within the operating envelope of the aircraft, without excessive
concentration, skill, alertness, or fatigue.
    (b) The applicant must install flight, navigation, surveillance,
and powerplant controls and displays, as needed, so qualified
flightcrew can monitor and perform defined tasks associated with the
intended functions of systems and equipment, without excessive
concentration, skill, alertness, or fatigue. The system and equipment
design must minimize flightcrew errors, which could result in
additional hazards.

Sec.  23.2605  Installation and operation.

    (a) through (c) [Applicable to Model M001]

Sec.  23.2610  Instrument markings, control markings, and placards.

    (a) through (c) [Applicable to Model M001]

AM1.2615 Flight, Navigation, and Powerplant Instruments

    (a) Installed systems must provide the flightcrew member who sets
or monitors parameters for the flight, navigation, and powerplant, the
information necessary to do so during each source of lift and phase of
flight. This information must--
    (1) Be presented in a manner that the crewmember can monitor the
parameter and determine trends, as needed, to operate the aircraft; and

    (2) Include limitations, unless the limitations cannot be exceeded
in all intended operations.
    (b) Indication systems that integrate the display of flight or
powerplant parameters to operate the aircraft, or are required by the
operating rules of title 14, chapter I, must--
    (1) Not inhibit the primary display of flight or powerplant
parameters needed by any flightcrew member in any normal mode of
operation; and
    (2) In combination with other systems, be designed and installed so
information essential for continued safe flight and landing will be
available to the flightcrew in a timely manner after any single failure
or probable combination of failures.

AM1.2620 Aircraft Flight Manual

    The applicant must provide an Aircraft Flight Manual that must be
delivered with each aircraft.
    (a) The Aircraft Flight Manual must contain the following
information--
    (1) Aircraft operating limitations;
    (2) Aircraft operating procedures;
    (3) Performance information;
    (4) Loading information; and
    (5) Other information that is necessary for safe operation because
of design, operating, or handling characteristics.
    (b) The portions of the Aircraft Flight Manual containing the
information specified in paragraphs (a)(1) through (a)(4) of this
section must be approved by the FAA in a manner specified by the
Administrator.

SUBPART H--Electric Engine Requirements

Sec.  33.5  Instruction manual for installing and operating the engine.

    (a) through (c) [Applicable to Model M001]

Sec.  33.7  Engine ratings and operating limitations.

    (a) [Applicable to Model M001]
    (b) through (d) [Not applicable to Model M001]

AM1.2702 Engine Ratings and Operating Limits

    Ratings and operating limits must be established and included in
the type certificate data sheet based on:
    (a) Shaft power, torque, rotational speed, and temperature for:
    (1) Rated takeoff power;
    (2) Rated maximum continuous power; and
    (3) Rated maximum temporary power and associated time limit.
    (b) Duty Cycle and the rating at that duty cycle. The duty cycle
must be declared in the type certificate data sheet.
    (c) Cooling fluid grade or specification.
    (d) Power-supply requirements.
    (e) Any other ratings or limitations that are necessary for the
safe operation of the engine.

Sec.  33.8  Selection of engine power and thrust ratings.

    (a) through (b) [Applicable to Model M001]

Sec.  33.15  Materials.

    (a) through (b) [Applicable to Model M001]

Sec.  33.17  Fire protection.

    (a) through (g) [Applicable to Model M001]

AM1.2704 Fire Protection.

    High-voltage electrical wiring interconnect systems must be
protected against arc faults. Non-protected electrical wiring
interconnects must be analyzed to show that arc faults do not cause a
hazardous engine effect.

AM1.2705 Durability.

    The engine design and construction must minimize the development of
an unsafe condition of the engine between maintenance intervals,
overhaul periods, or mandatory actions described in the applicable ICA.

Sec.  33.21  Engine cooling.

    [Applicable to Model M001]

AM1.2706 Engine Cooling

    If cooling is required to satisfy the safety analysis as described
in AM1.2717, the cooling-system monitoring features and usage must be
documented in the engine installation manual.

Sec.  33.23  Mounting attachment and structure.

    (a) through (b) [Applicable to Model M001]

Sec.  33.25  Accessory attachments.

    [Applicable to Model M001]

AM1.2709 Overspeed

    (a) A rotor overspeed must not result in a burst, rotor growth, or
damage that results in a hazardous engine effect, as defined in
AM1.2717(d)(2). Compliance with this paragraph must be shown by test,
validated analysis, or a combination of both. Applicable assumed rotor
speeds must be declared and justified.
    (b) Rotors must possess sufficient strength with a margin to burst
above certified operating conditions and above failure conditions
leading to rotor overspeed. The margin to burst must be shown by test,
validated analysis, or a combination thereof.
    (c) The engine must not exceed the rotor-speed operational
limitations that could affect rotor structural integrity.

Sec.  33.28  Engine control systems.

    (b)(1)(i), (b)(1)(iii), and (b)(1)(iv) [Applicable to Model M001]
    (a), (b)(1)(ii), (b)(2) through (m) [Not applicable to Model M001]

AM1.2710 Engine Control Systems

    (a) Applicability.
    These requirements apply to any system or device that is part of
the engine type design that controls, limits, monitors, or protects
engine operation and is necessary for the continued airworthiness of
the engine.
    (b) Engine control.
    The engine control system must ensure the engine does not
experience any unacceptable operating characteristics or exceed its
operating limits, including in failure conditions where the fault or
failure results in a change from one control mode to another, from one
channel to another, or from the primary system to the back-up system,
if applicable.
    (c) Design assurance.
    The software and complex electronic hardware, including
programmable logic devices, must be--
    (1) Designed and developed using a structured and systematic
approach that provides a level of assurance for the logic commensurate
with the hazard associated with the failure or malfunction of the
systems in which the devices are located; and
    (2) Substantiated by a verification methodology acceptable to the
Administrator.
    (d) Validation.
    All functional aspects of the control system must be substantiated
by test, analysis, or a combination thereof, to show that the engine
control system performs the intended functions throughout the declared
operational envelope.
    (e) Environmental limits.
    Environmental limits that cannot be adequately substantiated by
endurance demonstration, validated analysis, or a combination thereof
must be demonstrated by the system and component tests in AM1.2727.
    (f) Engine control system failures.
    The engine control system must--
    (1) Have a maximum rate of Loss of Power Control (LOPC) that is
suitable for the intended aircraft application;
    (2) When in the full-up configuration, be single fault tolerant, as
determined by the Administrator, for electrical, electrically
detectable, and electronic failures involving LOPC events;

    (3) Not have any single failure that results in hazardous engine
effects; and
    (4) Not have any likely failures or malfunctions that lead to local
events in the intended aircraft application.
    (g) System-safety assessment.
    The applicant must perform a system-safety assessment. This
assessment must identify faults or failures that affect normal
operation, together with the predicted frequency of occurrence of these
faults or failures. The intended aircraft application must be taken
into account to assure the assessment of the engine control system
safety is valid.
    (h) Protection systems.
    The engine control devices and systems' design and function,
together with engine instruments, operating instructions, and
maintenance instructions, must ensure that engine operating limits will
not be exceeded in-service.
    (i) Aircraft-supplied data.
    Any single failure leading to loss, interruption, or corruption of
aircraft-supplied data (other than power command signals from the
aircraft), or aircraft-supplied data shared between engine systems
within a single engine or between fully independent engine systems,
must--
    (1) Not result in a hazardous engine effect, as defined in
AM1.2717(d)(2), for any engine installed on the aircraft; and
    (2) Be able to be detected and accommodated by the control system.
    (j) Engine control system electrical power.
    (1) The engine control system must be designed such that the loss,
malfunction, or interruption of the control system electrical power
source will not result in a hazardous engine effect, as defined in
AM1.2717(d)(2), the unacceptable transmission of erroneous data, or
continued engine operation in the absence of the control function. The
engine control system must be capable of resuming normal operation when
aircraft-supplied power returns to within the declared limits.
    (2) The applicant must identify and declare, in the engine
installation manual, the characteristics of any electrical power
supplied from the aircraft to the engine control system for starting
and operating the engine, including transient and steady-state voltage
limits, or electrical power supplied from the engine to the aircraft
via energy regeneration, and any other characteristics necessary for
safe operation of the engine.

Sec.  33.29  Instrument connection.

    (a), (e), and (g) [Applicable to Model M001]
    (b) through (d) and (h) [Not applicable to the Model M001]

AM1.2711 Instrument Connection

    (a) In addition, as part of the system-safety assessment of
AM1.2710(g) and AM1.2733(g), the applicant must assess the possibility
and subsequent effect of incorrect fit of instruments, sensors, or
connectors. Where practicable, the applicant must take design
precautions to prevent incorrect configuration of the system.
    (b) The applicant must provide instrumentation enabling the
flightcrew to monitor the functioning of the engine cooling system
unless evidence shows that:
    (1) Other existing instrumentation provides adequate warning of
failure or impending failure;
    (2) Failure of the cooling system would not lead to hazardous
engine effects before detection; or
    (3) The probability of failure of the cooling system is extremely
remote.

AM1.2712 Stress Analysis

    (a) A mechanical, thermal, and electromagnetic stress analysis must
show a sufficient design margin to prevent unacceptable operating
characteristics and hazardous engine effects.
    (b) Maximum stresses in the engine must be determined by test,
validated analysis, or a combination thereof, and must be shown not to
exceed minimum material properties.

AM1.2713 Critical and Life-Limited Parts

    (a) The applicant must show, by a safety analysis or means
acceptable to the Administrator, whether rotating or moving components,
bearings, shafts, static parts, and non-redundant mount components
should be classified, designed, manufactured, and managed throughout
their service life as critical or life-limited parts.
    (1) Critical part means a part that must meet prescribed integrity
specifications to avoid its primary failure, which is likely to result
in a hazardous engine effect as defined in AM1.2717(d)(2).
    (2) Life-limited parts may include but are not limited to a rotor
and major structural static part, the failure of which can result in a
hazardous engine effect due to low-cycle fatigue (LCF) mechanism or any
LCF-driven mechanism coupled with creep, or other failure mode. A life
limit is an operational limitation that specifies the maximum allowable
number of flight cycles that a part can endure before the applicant
must remove it from the engine.
    (b) In establishing the integrity of each critical part or life-
limited part, the applicant must provide to the Administrator the
following three plans for approval: an engineering plan, a
manufacturing plan, and a service-management plan, as defined in Sec.
33.70.

AM1.2714 Lubrication System

    (a) The lubrication system must be designed and constructed to
function properly between scheduled maintenance intervals in all flight
attitudes and atmospheric conditions in which the engine is expected to
operate.
    (b) The lubrication system must be designed to prevent
contamination of the engine bearings and lubrication system components.
    (c) The applicant must demonstrate by test, validated analysis, or
a combination thereof, the unique lubrication attributes and functional
capability of paragraphs (a) and (b) of this section.

AM1.2715 Power Response

    The design and construction of the engine, including its control
system, must enable an increase--
    (a) From the minimum power setting to the highest rated power
without detrimental engine effects;
    (b) From the minimum obtainable power while in flight, and while on
the ground, to the highest rated power within a time interval
determined to be safe for aircraft operation; and
    (c) From the minimum torque to the highest rated torque without
detrimental engine or aircraft effects, to ensure aircraft structural
integrity or aircraft aerodynamic characteristics are not exceeded.

AM1.2716 Continued Rotation

    If the design allows any of the engine main rotating systems to
continue to rotate after the engine is shut down while in-flight, this
continued rotation must not result in hazardous engine effects, as
specified in AM1.2717(d)(2).

Sec.  33.75  Safety analysis.

    (a)(1) through (a)(2), (d), (e), and (g)(2) [Applicable to Model
M001]
    (a)(3) through (c), (f), (g)(1), and (g)(3) [Not applicable to
Model M001]

AM1.2717 Safety Analysis

    (a) The applicant must comply with Sec.  33.75(a)(2) using the
failure definitions in paragraph (d) of this section.
    (b) If the failure of such elements is likely to result in
hazardous engine effects, then the applicant may show compliance by
reliance on the prescribed integrity requirements such as Sec.  33.15,
AM1.2709, AM1.2713, or combinations thereof, as applicable. The failure
of such elements and associated

prescribed integrity requirements must be stated in the safety
analysis.
    (c) The applicant must comply with Sec.  33.75(d) and (e) using the
failure definitions in paragraph (d) of this section.
    (d) Unless otherwise approved by the Administrator, the following
definitions apply to the engine effects when showing compliance with
this condition:
    (1) A minor engine effect does not prohibit the engine from meeting
its type-design requirements and the intended functions in a manner
consistent with Sec.  33.28(b)(1)(i), (b)(1)(iii), and (b)(1)(iv), and
the engine complies with the operability requirements such as AM1.2715,
AM1.2725, and AM1.2731, as appropriate.
    (2) The engine effects in Sec.  33.75(g)(2) are hazardous engine
effects with the addition of:
    (i) Electrocution of the crew, passengers, operators, maintainers,
or others; and
    (ii) Blockage of cooling systems that are required for the engine
to operate within temperature limits.
    (3) Any other engine effect is a major engine effect.
    (e) The intended aircraft application must be taken into account to
assure that the analysis of the engine system safety is valid.

AM1.2718 Ingestion

    (a) Ingestion from likely sources (foreign objects, birds, ice,
hail) must not result in hazardous engine effects defined by
AM1.2717(d)(2), or unacceptable power loss.
    (b) Rain ingestion must not result in an abnormal operation such as
shutdown, power loss, erratic operation, or power oscillations
throughout the engine operating range.
    (c) If the design of the engine relies on features, attachments, or
systems that the installer may supply, for the prevention of
unacceptable power loss or hazardous engine effects following potential
ingestion, then the features, attachments, or systems must be
documented in the engine installation manual.
    (d) Ingestion sources that are not evaluated must be declared in
the engine installation manual.

AM1.2719 Liquid Systems

    (a) Each liquid system used for lubrication or cooling of engine
components must be designed and constructed to function properly in all
flight attitudes and atmospheric conditions in which the engine is
expected to operate.
    (b) If a liquid system used for lubrication or cooling of engine
components is not self-contained, the interfaces to that system must be
defined in the engine installation manual.
    (c) The applicant must establish by test, validated analysis, or a
combination of both, that all static parts subject to significant gas
or liquid pressure loads will not:
    (1) Exhibit permanent distortion beyond serviceable limits or
exhibit leakage that could create a hazardous condition when subjected
to normal and maximum working pressure with margin.
    (2) Exhibit fracture or burst when subjected to the greater of
maximum possible pressures with margin.
    (d) Compliance with paragraph (c) of this section must take into
account:
    (1) The operating temperature of the part;
    (2) Any other significant static loads in addition to pressure
loads;
    (3) Minimum properties representative of both the material and the
processes used in the construction of the part; and
    (4) Any adverse physical geometry conditions allowed by the type
design, such as minimum material and minimum radii.
    (e) Approved coolants and lubricants must be listed in the engine
installation manual.

AM1.2720 Vibration Demonstration

    (a) The engine must be designed and constructed to function
throughout its normal operating range of rotor speeds and engine output
power, including defined exceedances, without inducing excessive stress
in any of the engine parts because of vibration and without imparting
excessive vibration forces to the aircraft structure.
    (b) Each engine design must undergo a vibration survey to establish
that the vibration characteristics of those components that may be
subject to induced vibration are acceptable throughout the declared
flight envelope and engine operating range for the specific
installation configuration. The possible sources of the induced
vibration that the survey must assess are mechanical, aerodynamic,
acoustical, or electromagnetic. This survey must be shown by test,
validated analysis, or a combination thereof.

AM1.2721 Overtorque

    When approval is sought for a transient maximum engine overtorque,
the applicant must demonstrate by test, validated analysis, or a
combination thereof, that the engine can continue operation after
operating at the maximum engine overtorque condition without
maintenance action. Upon conclusion of overtorque tests conducted to
show compliance with this subpart, or any other tests that are
conducted in combination with the overtorque test, each engine part or
individual groups of components must meet the requirements of AM1.2729.

AM1.2722 Calibration Assurance

    Each engine must be subjected to calibration tests to establish its
power characteristics and the conditions both before and after the
endurance and durability demonstrations specified in AM1.2723 and
AM1.2726.

AM1.2723 Endurance Demonstration

    (a) The applicant must subject the engine to an endurance
demonstration, acceptable to the Administrator, to demonstrate the
engine's limit capabilities.
    (b) The endurance demonstration must include increases and
decreases of the engine's power settings, energy regeneration, and
dwellings at the power settings or energy regeneration for durations
that produce the extreme physical conditions the engine experiences at
rated performance levels, operational limits, and at any other
conditions or power settings that are required to verify the limit
capabilities of the engine.

AM1.2724 Temperature Limit

    The engine design must demonstrate its capability to endure
operation at its temperature limits plus an acceptable margin. The
applicant must quantify and justify to the Administrator the margin at
each rated condition. The demonstration must be repeated for all
declared duty cycles and associated ratings, and operating
environments, that would impact temperature limits.

AM1.2725 Operation Demonstration

    The engine design must demonstrate safe operating characteristics,
including but not limited to power cycling, starting, acceleration, and
overspeeding throughout its declared flight envelope and operating
range. The declared engine operational characteristics must account for
installation loads and effects.

AM1.2726 Durability Demonstration

    The engine must be subjected to a durability demonstration to show
that each part of the engine has been designed and constructed to
minimize any unsafe condition of the system between overhaul periods or
between engine replacement intervals if the

overhaul is not defined. This test must simulate the conditions in
which the engine is expected to operate in-service, including typical
start-stop cycles.

AM1.2727 System and Component Tests

    The applicant must show that systems and components will perform
their intended functions in all declared environmental and operating
conditions.

AM1.2728 Rotor Locking Demonstration

    If shaft rotation is prevented by locking the rotor(s), the engine
must demonstrate:
    (a) Reliable rotor locking performance;
    (b) Reliable unlocking performance; and
    (c) That no hazardous engine effects, as specified in
AM1.2717(d)(2), will occur.

AM1.2729 Teardown Inspection

    The applicant must comply with either paragraph (a) or (b) of this
section as follows:
    (a) Teardown evaluation.
    (1) After the endurance and durability demonstrations have been
completed, the engine must be completely disassembled. Each engine
component and lubricant must be within service limits and eligible for
continued operation in accordance with the information submitted for
showing compliance with AM1.1529.
    (2) Each engine component having an adjustment setting and a
functioning characteristic that can be established independent of
installation on or in the engine must retain each setting and
functioning characteristic within the established and recorded limits
at the beginning of the endurance and durability demonstrations.
    (b) Non-Teardown evaluation.
    If a teardown is not performed for all engine components, then the
life limits for these components and lubricants must be established
based on the endurance and durability demonstrations and documented in
the Instructions for Continued Airworthiness in accordance with
AM1.1529.

AM1.2730 Containment

    The engine must provide containment features that protect against
likely hazards from rotating components as follows--
    (a) The design of the case surrounding rotating components must
provide for the containment of the rotating components in the event of
failure, unless the applicant shows that the margin to rotor burst
precludes the possibility of a rotor burst.
    (b) If the margin to rotor burst shows that the case must have
containment features in the event of failure, the case must provide for
the containment of the failed rotating components. The applicant must
define by test, validated analysis, or a combination thereof, and
document in the engine installation manual, the energy level,
trajectory, and size of fragments released from damage caused by the
rotor failure, and that pass forward or aft of the surrounding case.

AM1.2731 Operation With a Variable-Pitch Propeller

    The applicant must conduct functional demonstrations including
feathering, negative torque, negative thrust, and reverse thrust
operations, as applicable, with a representative propeller. These
demonstrations may be conducted in a manner acceptable to the
Administrator as part of the endurance, durability, and operation
demonstrations.

AM1.2732 General Conduct of Tests

    (a) Maintenance of the engine may be made during the tests in
accordance with the service and maintenance instructions submitted in
compliance with AM1.1529.
    (b) The applicant must subject the engine or its parts to
maintenance and additional tests that the Administrator finds necessary
if--
    (1) The frequency of the service is excessive;
    (2) The number of stops due to engine malfunction is excessive;
    (3) Major repairs are needed; or
    (4) Replacement of a part is found necessary during the tests or
due to the teardown inspection findings.
    (c) Upon completion of all demonstrations and testing specified in
these airworthiness criteria, the engine and its components must be--
    (1) Within serviceable limits;
    (2) Safe for continued operation; and
    (3) Capable of operating at declared ratings while remaining within
limits.

AM1.2733 Engine Electrical Systems

    (a) Applicability.
    Any system or device that provides, uses, conditions, or
distributes electrical power, and is part of the engine type design,
must provide for the continued airworthiness of the engine and maintain
electric engine ratings.
    (b) Electrical systems.
    The electrical system must ensure the safe generation and
transmission of power, electrical load shedding, and the engine does
not experience any unacceptable operating characteristics or exceed its
operating limits.
    (c) Electrical-power distribution.
    (1) The engine electrical-power distribution system must be
designed to provide the safe transfer of electrical energy throughout
the electrical power plant. The system must be designed to provide
electrical power so that the loss, malfunction, or interruption of the
electrical power source will not result in a hazardous engine effect,
as defined in AM1.2717(d)(2).
    (2) The system must be designed and maintained to withstand normal
and abnormal conditions during all ground and flight operations.
    (3) The system must provide mechanical or automatic means of
isolating a faulted electrical-energy generation or storage device from
affecting the safe transmission of electric energy to the electric
engine.
    (d) Protection systems.
    The engine electrical devices and systems must interrupt
transmission of electrical power when power conditions exceed design
limits.
    (1) The engine electrical system must be designed such that the
loss, malfunction, or interruption of the electrical power source will
not result in a hazardous engine effect, as defined in AM1.2717(d)(2).
    (2) The applicant must identify and declare, in the engine
installation manual, the characteristics of any electrical power
supplied from the aircraft to the engine, or electrical power supplied
to the aircraft from the engine from energy regeneration, systems for
starting and operating the engine, including transient and steady-state
voltage limits, and any other characteristics necessary for safe
operation of the engine.
    (e) Environmental limits.
    Environmental limits that cannot be adequately substantiated by
endurance demonstration, validated analysis, or a combination thereof
must be demonstrated by the system and component tests in AM1.2727.
    (f) Electrical-system failures.
    The engine electrical system must--
    (1) Have a maximum rate of Loss of Power Control (LOPC) that is
suitable for the intended aircraft application;
    (2) When in the full-up configuration, be single fault tolerant, as
determined by the Administrator, for electrical, electrically
detectable, and electronic failures involving LOPC events;
    (3) Not have any single failure that results in hazardous engine
effects; and
    (4) Not have any likely failure or malfunction that leads to local
events in the intended aircraft application.
    (g) System-safety assessment.
    The applicant must perform a system-safety assessment. This
assessment must

identify faults or failures that affect normal operation, together with
the predicted frequency of occurrence of these faults or failures. The
intended aircraft application must be taken into account to assure the
assessment of the engine system safety is valid.

SUBPART I--Propeller Requirements

AM1.2805 Propeller Ratings and Operating Limitations

    Propeller ratings and operating limitations must be established by
the applicant and approved by the Administrator, including ratings and
limitations based on the operating conditions and information specified
in this subpart, as applicable, and any other information found
necessary for safe operation of the propeller.

Sec.  35.7  Features and characteristics.

    (a) through (b) [Applicable to Model M001]

AM1.2815 Safety Analysis

    (a) The applicant must:
    (1) Analyze the propeller system to assess the likely consequences
of all failures that can reasonably be expected to occur. This analysis
will take into account, if applicable:
    (i) The propeller system when installed on the aircraft. When the
analysis depends on representative components, assumed interfaces, or
assumed installed conditions, the assumptions must be stated in the
analysis.
    (ii) Consequential secondary failures and dormant failures.
    (iii) Multiple failures referred to in paragraph (d) of this
section, or that result in the hazardous propeller effects defined in
paragraph (g)(1) of this section.
    (2) Summarize those failures that could result in major propeller
effects or hazardous propeller effects defined in paragraph (g) of this
section, and estimate the probability of occurrence of those effects.
    (3) Show that hazardous propeller effects are not predicted to
occur at a rate in excess of that defined as extremely remote
(probability of 10-7 or less per propeller flight hour).
Because the estimated probability for individual failures may be
insufficiently precise to enable the applicant to assess the total rate
for hazardous propeller effects, compliance may be shown by
demonstrating that the probability of a hazardous propeller effect
arising from an individual failure can be predicted to be not greater
than 10-8 per propeller flight hour. In dealing with
probabilities of this low order of magnitude, absolute proof is not
possible, and reliance must be placed on engineering judgment and
previous experience, combined with sound design and test philosophies.
    (b) If significant doubt exists as to the effects of failures or
likely combination of failures, the Administrator may require
assumptions used in the analysis to be verified by test.
    (c) The primary failures of certain single propeller elements (for
example, blades) cannot be sensibly estimated in numerical terms. If
the failure of such elements is likely to result in hazardous propeller
effects, those elements must be identified as propeller critical parts.
For propeller critical parts, the applicant must meet the prescribed
integrity specifications of AM1.2816. These instances must be stated in
the safety analysis.
    (d) If reliance is placed on a safety system to prevent a failure
progressing to hazardous propeller effects, the possibility of a safety
system failure, in combination with a basic propeller failure, must be
included in the analysis. Such a safety system may include safety
devices, instrumentation, early warning devices, maintenance checks,
and other similar equipment or procedures.
    (e) If the safety analysis depends on one or more of the following
items, those items must be identified in the analysis and appropriately
substantiated.
    (1) Maintenance actions being carried out at stated intervals. This
includes verifying that items that could fail in a latent manner are
functioning properly. When necessary to prevent hazardous propeller
effects, these maintenance actions and intervals must be published in
the Instructions for Continued Airworthiness required under AM1.1529.
Additionally, if errors in maintenance of the propeller system could
lead to hazardous propeller effects, the appropriate maintenance
procedures must be included in the relevant propeller manuals.
    (2) Verification of the satisfactory functioning of safety or other
devices at pre-flight or other stated periods. The details of this
satisfactory functioning must be published in the appropriate manual.
    (3) The provision of specific instrumentation not otherwise
required. Such instrumentation must be published in the appropriate
documentation.
    (4) A fatigue assessment.
    (f) If applicable, the safety analysis must include, but not be
limited to, assessment of indicating equipment, manual and automatic
controls, governors and propeller-control systems, synchrophasers,
synchronizers, and propeller thrust reversal systems.
    (g) Unless otherwise approved by the Administrator and stated in
the safety analysis, the following failure definitions apply to
compliance with these airworthiness criteria.
    (1) The following are regarded as hazardous propeller effects:
    (i) The development of excessive drag.
    (ii) A significant thrust in the opposite direction to that
commanded by the pilot.
    (iii) The release of the propeller or any major portion of the
propeller.
    (iv) A failure that results in excessive unbalance.
    (2) The following are regarded as major propeller effects for
variable-pitch propellers:
    (i) An inability to feather the propeller for feathering
propellers.
    (ii) An inability to change propeller pitch when commanded.
    (iii) A significant uncommanded change in pitch.
    (iv) A significant uncontrollable torque or speed fluctuation.

AM1.2816 Propeller Critical Parts

    The integrity of each propeller critical part identified by the
safety analysis required by AM1.2815 must be established by:
    (a) A defined engineering process for ensuring the integrity of the
propeller critical part throughout its service life,
    (b) A defined manufacturing process that identifies the
requirements to consistently produce the propeller critical part as
required by the engineering process, and
    (c) A defined service-management process that identifies the
continued airworthiness requirements of the propeller critical part as
required by the engineering process.

Sec.  35.17  Materials and manufacturing methods.

    (a) through (c) [Applicable to Model M001]

Sec.  35.19  Durability.

    [Applicable to Model M001]

AM1.2821 Variable- and Reversible-Pitch Propellers

    (a) No single failure or malfunction in the propeller system will
result in unintended travel of the propeller blades to a position below
the in-flight low-pitch position. The extent of any intended travel
below the in-flight low-pitch position must be documented by the
applicant in the appropriate manuals. Failure of structural elements
need not be considered if the occurrence of such a failure is shown to
be extremely remote under AM1.2815.

    (b) For propellers incorporating a method to select blade pitch
below the in-flight low-pitch position, provisions must be made to
sense and indicate to the flightcrew that the propeller blades are
below that position by an amount defined in the installation
instructions. The method for sensing and indicating the propeller blade
pitch position must be such that its failure does not affect the
control of the propeller.

Sec.  35.22  Feathering propellers.

    (a) through (c) [Applicable to Model M001]

AM1.2823 Propeller Control System

    The requirements of this section apply to any system or component
that controls, limits, or monitors propeller functions.
    (a) The propeller control system must be designed, constructed and
validated to show that:
    (1) The propeller control system, operating in normal and
alternative operating modes and in transition between operating modes,
performs the functions defined by the applicant throughout the declared
operating conditions and flight envelope.
    (2) The propeller control system functionality is not adversely
affected by the declared environmental conditions, including
temperature, electromagnetic interference (EMI), high intensity
radiated fields (HIRF), and lightning. The environmental limits to
which the system has been satisfactorily validated must be documented
in the appropriate propeller manuals.
    (3) A method is provided to indicate that an operating mode change
has occurred if flightcrew action is required. In such an event,
operating instructions must be provided in the appropriate manuals.
    (b) The propeller control system must be designed and constructed
so that, in addition to compliance with AM1.2815:
    (1) No single failure results in a hazardous propeller effect; and
    (2) No likely failures or malfunctions lead to local events in the
intended aircraft installation.
    (c) Electronic propeller-control-system embedded software must be
designed and implemented by a method approved by the Administrator that
is consistent with the criticality of the performed functions and that
minimizes the existence of software errors.
    (d) The propeller control system must be designed and constructed
so that the failure or corruption of aircraft-supplied data does not
result in hazardous propeller effects.
    (e) The propeller control system must be designed and constructed
so that the loss, interruption, or abnormal characteristic of aircraft-
supplied electrical power does not result in hazardous propeller
effects. The power quality requirements must be described in the
appropriate manuals.

Sec.  35.24  Strength.

    [Applicable to Model M001]

Sec.  35.33  General.

    (a) through (c) [Applicable to Model M001]

Sec.  35.34  Inspections, adjustments, and repairs.

    (a) through (b) [Applicable to Model M001]

Sec.  35.35  Centrifugal load tests.

    (a) through (c) [Applicable to Model M001]

Sec.  35.36  Bird impact.

    [Applicable to Model M001]

Sec.  35.37  Fatigue limits and evaluation.

    (a) through (c) [Applicable to Model M001, except replace the
reference to Sec.  35.15 with AM1.2815, and the reference to ``Sec.
23.2400(c) or Sec.  25.907'' with AM1.2400(c)]

Sec.  35.38  Lightning strike.

    [Applicable to Model M001]

Sec.  35.39  Endurance test.

    (a) through (c) [Applicable to Model M001, except replace the
reference to ``part 33'' with ``these airworthiness criteria'']

AM1.2840 Functional Test

    The variable-pitch propeller system must be subjected to the
applicable functional tests of this section. The same propeller system
used in the endurance test of Sec.  35.39 must be used in the
functional tests and must be driven by a representative engine on a
test stand or on the aircraft. The propeller must complete these tests
without evidence of failure or malfunction. This test may be combined
with the endurance test for accumulation of cycles.
    (a) Governing and reversible-pitch propellers. Thirteen-hundred
complete cycles must be made across the range of forward pitch and
rotational speed. In addition, 200 complete cycles of control must be
made from lowest normal pitch to maximum reverse pitch. During each
cycle, the propeller must run for 30 seconds at the maximum power and
rotational speed selected by the applicant for maximum reverse pitch.
    (b) Feathering propellers. Fifty cycles of feather and unfeather
operation must be made.
    (c) An analysis based on tests of propellers of similar design may
be used in place of the tests of this section.

Sec.  35.41  Overspeed and overtorque.

    (a) through (b) [Applicable to Model M001]

Sec.  35.42  Components of the propeller control system.

    [Applicable to Model M001]

Sec.  35.43  Propeller hydraulic components.

    (a) through (b) [Applicable to Model M001]

Appendix A to Part 23--Instructions for Continued Airworthiness

    A23.1 through A23.3(g) and A23.4 [Applicable to Model M001]
    A23.3(h) [Not applicable to Model M001]

Appendix A1--Instructions for Continued Airworthiness (Electric Engine)

AAM1.2701 General

    (a) This appendix specifies requirements for the preparation of
Instructions for Continued Airworthiness for the engines as required
by AM1.1529.
    (b) The Instructions for Continued Airworthiness for the engine
must include the Instructions for Continued Airworthiness for all
engine parts.
    (c) The applicant must submit to the FAA a program to show how
the applicant's changes to the Instructions for Continued
Airworthiness will be distributed, if applicable.

A33.2 Format

    (a) through (b) [Applicable to Model M001]

A33.3 Content

    (a) and (b) [Applicable to Model M001]
    (c) [Not applicable to Model M001]

A33.4 Airworthiness Limitations Section

    (a) [Applicable to Model M001]
    (b) [Not applicable to Model M001]

Appendix A2--Instructions for Continued Airworthiness (Propellers)

AAM1.2801 General

    (a) This appendix specifies requirements for the preparation of
Instructions for Continued Airworthiness for the propellers as
required by AM1.1529.
    (b) The Instructions for Continued Airworthiness for the
propeller must include the Instructions for Continued Airworthiness
for all propeller parts.
    (c) The applicant must submit to the FAA a program to show how
changes to the Instructions for Continued Airworthiness made by the
applicant or by the manufacturers of propeller parts will be
distributed, if applicable.

A35.2 Format

    (a) through (b) [Applicable to Model M001]

A35.3 Content

    (a) through (b) [Applicable to Model M001]

A35.4 Airworthiness Limitations Section

    [Applicable to Model M001]

    Issued in Washington, DC, on December 12, 2022.
Victor W. Wicklund,
Acting Director, Policy and Innovation Division, Aircraft Certification
Service.
[FR Doc. 2022-27445 Filed 12-19-22; 8:45 am]
BILLING CODE 4910-13-P