This section of the FEDERAL REGISTER

contains regulatory documents having general

applicability and legal effect, most of which

are keyed to and codified in the Code of

Federal Regulations, which is published under

50 titles pursuant to 44 U.S.C. 1510.

The Code of Federal Regulations is sold by

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Rules and Regulations Federal Register

86713 

Vol. 89, No. 211 

Thursday, October 31, 2024 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 21 

[Docket No. FAA–2022–1726] 

Airworthiness Criteria: Special Class 

Airworthiness Criteria for the 

AgustaWestland Philadelphia 

Corporation Model AW609 PoweredLift 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Issuance of final airworthiness 

criteria. 

SUMMARY: The FAA announces the 

special class airworthiness criteria for 

the AgustaWestland Philadelphia 

Corporation (AWPC) Model AW609 

powered-lift. This document sets forth 

the airworthiness criteria the FAA finds 

to be appropriate and applicable for the 

powered-lift design. 

DATES: These airworthiness criteria are 

effective December 2, 2024. 

FOR FURTHER INFORMATION CONTACT: 

Richard C Snyder, Certification 

Coordination Section, AIR–613, Policy 

and Standards Division, Aircraft 

Certification Service, 10101 Hillwood 

Parkway, Fort Worth, TX 76177; 

telephone and fax 817–222–4486; email 

richard.c.snyder@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Background 

The AWPC Model AW609 is a twoengine powered-lift with a maximum 

weight of 17,500 lbs., and a capacity of 

two crew and nine passengers. The 

aircraft has two ‘‘proprotors’’ instead of 

propellers or rotors. The AW609 design 

is a direct descendant of the Bell 

Helicopter Model BA609 certification 

project, which had design origins from 

the experimental Bell XV–15 aircraft. 

The FAA issued a notice of proposed 

airworthiness criteria for the AW609 

powered-lift, which published in the 

Federal Register on June 9, 2023 (88 FR 

37805). 

After several changes of applicants, 

on February 15, 2012, AgustaWestland 

Tilt-Rotor Company, now AWPC, 

applied for a type certificate for the 

Model AW609. Under 14 CFR 21.17(c), 

an application for type certification is 

effective for three years, unless the FAA 

approves a longer period. Section 

21.17(d) provides that, where a type 

certificate has not been issued within 

the time limit established under 

§ 21.17(c), the applicant may file for an 

extension and update the designated 

applicable regulations in the type 

certification basis. Since the project was 

not certificated within the established 

time limit, the FAA approved a series of 

requests for extension by AWPC with 

the most recent request submitted on 

February 22, 2024. If the application 

extension is approved, the date of the 

updated type certification basis will 

change from March 31, 2021, to March 

31, 2024. 

Discussion 

Powered-lift are type certificated as 

special class aircraft because the FAA 

has not yet established powered-lift 

airworthiness standards as a separate 

part of subchapter C of 14 CFR. Under 

the procedures in § 21.17(b), the 

airworthiness requirements for special 

class aircraft are the portions of the 

requirements in 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. These final 

airworthiness criteria announce the 

applicable regulations and other 

airworthiness criteria developed for 

type certification of the Model AW609 

powered-lift under § 21.17(b). 

The 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 enroute portion of 

flight operations. Accordingly, the 

Model AW609 certification basis 

contains standards from parts 23, 25, 

and 29, as well as other airworthiness 

criteria specific for a powered-lift. 

This certification basis includes parts 

23, 25, and 29 airworthiness standards. 

These are part 23 at amendment 23–62, 

part 25 at amendment 25–135 (except 

§ 25.903(a) at amendment 25–140 and 

§ 25.1517 at amendment 25–86), and 

part 29 at amendment 29–55 (except 

§ 29.1353 at amendment 29–59). The 

certification basis incorporates by 

reference existing transport category 

airplane and rotorcraft standards, one 

normal category airplane standard, 

Category A rotorcraft standards, 

optional Category B rotorcraft standards, 

and criteria for operation under 

instrument flight rules. Flight into 

known icing conditions (FIKI) is not 

being sought with the current 

certification; however, FIKI is included 

in these airworthiness criteria for future 

certifications. 

The certification basis also includes 

new criteria unique to the powered-lift 

design, designated as tiltrotor (TR) 

criteria. Many of these TR criteria 

consist of modified part 25 or 29 

standards. Some include criteria that 

combine existing parts 23, 25, and 29 

standards, as the maximum weight of 

the Model AW609 exceeds the weight 

for normal category rotorcraft and most 

part 23 category airplanes, but its 

passenger seating is less than that of a 

transport category airplane or a 

transport category rotorcraft. The FAA 

also developed TR criteria because no 

existing standard captures the poweredlift’s transitional flight modes (during 

flight, the powered-lift nacelle rotates 

the proprotor system from providing 

vertical lift to horizontal propulsion). 

The TR criteria also contain definitions 

specific for the powered-lift, such as 

flight modes, configurations, speeds, 

and terminology (‘‘flaperon’’ instead of 

‘‘aileron’’ or ‘‘flap;’’ ‘‘proprotor’’ instead 

of ‘‘rotor’’ or ‘‘propeller’’). 

For example, while existing parts 25 

and 29 standards for passenger 

emergency exits include a size 

classification (types I, II, III, IV) 

depending on the passenger seating 

capacity and other factors, the 

certification basis has a TR with criteria 

for the specific type of passenger 

emergency exit that is part of the design 

of the Model AW609. Another example 

involves fatigue evaluation. Part 25 

contains requirements such as a limit of 

validity (LOV) on airframe fatigue for 

pressurized fuselages, which are not in 

part 29. Instead, fatigue evaluation in 

part 29 includes a composite structures 

fatigue rule, due to the more extreme 

fatigue environment of rotorcraft. For 

small airplanes, part 23, amendment 


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23–48, added a composite airframe 

evaluation requirement for bonded 

joints, which is included in agency 

compliance guidance for parts 25 and 29 

but not required by a specific regulation 

(the safety requirement is complied with 

through other broad existing regulations 

in those parts). Since the Model AW609 

has a pressurized fuselage, the FAA 

developed TR criteria to include the 

LOV requirement. The certification 

basis incorporates by reference the part 

29 composite rotorcraft structures 

fatigue rule, TR criteria to include the 

composite bonding requirements from 

part 23, as well as TR criteria to include 

fatigue requirements for elastomeric 

primary structural elements. The new 

requirements specific to the AWPC 

Model AW609 in the proposed 

airworthiness criteria used a ‘‘TR.xxxx’’ 

section-numbering scheme. 

Summary of Changes From the 

Proposed Airworthiness Criteria 

Based on comments received, these 

final airworthiness criteria reflect the 

following changes, in addition to others 

as explained in more detail in the 

Discussion of Comments section: 

• Added § 29.1547 to the final 

airworthiness criteria for the case where 

a magnetic compass is installed. 

• Revised these final airworthiness 

criteria to provide clarification on future 

certification for FIKI conditions. 

• Clarified statements about TR.45 

applicability. 

• Revised proposed TR.575 to 

account for the unique nature and 

operating environment of elastomeric 

principle structural elements (PSEs). 

• Updated § 25.775 to clarify that the 

reference to § 25.335(a) is replaced with 

TR.335(a) for the purposes of these 

airworthiness criteria. 

• Did not include § 25.875 and 

updated TR.875 in these final 

airworthiness criteria to prevent 

confusion between the terms propeller 

and proprotor, thereby combining 

proposed TR.875 and § 25.875, which 

call out requirements for buffeting, 

proprotor (propeller), and other rotating 

components. Accordingly, TR.875 in 

these final airworthiness criteria 

addresses both proposed TR.875 and 

§ 25.875. 

• Revised the incorporation by 

reference of § 29.1521 to reflect that the 

reference to § 29.1509(c) is replaced 

with TR.1509(c) since § 29.1509 is not 

part of the type certification basis for the 

Model AW609. 

• Specified the amendment level for 

§ 25.1517 to be 25–86. 

• Revised these airworthiness criteria 

to remove § 25.1353 and include 

§ 29.1353 at amendment 29–59 for 

electrical wiring protection due to 

recent amendments to part 29. 

Addition of Position Light TRs 

After the FAA issued the notice of 

proposed airworthiness criteria for 

public comment, AWPC presented a 

forward left and right position light 

design that would not meet the 

prescriptive regulatory requirements 

defined under §§ 29.1385–29.1395. In 

general terms, the existing requirements 

define the use of a single left and a 

single right forward-looking position 

light. Due to the AW609 configuration, 

AWPC proposed using multiple light 

sources for each forward position light 

providing lighting at a level comparable 

to the part 29 lighting requirements. The 

FAA developed TR.1385, TR.1387, 

TR.1389, TR.1391, TR.1393, and 

TR.1395 to establish the same level of 

safety to §§ 29.1385, 29.1387, 29.1389, 

29.1391, 29.1393, and § 29.1395 to 

address the non-traditional 

configuration of the AW609 poweredlift’s position lights. These TRs 

modified the language in certain part 29 

sections to allow for a group of forward 

position lights to be installed on each 

side of the aircraft. 

Discussion of Comments 

The FAA received responses from six 

commenters including: Overair, Inc 

(Overair), Parker Lord Corporation 

(Parker Lord), Advanced Air Mobility 

Institute, Transport Canada, and two 

individual commenters. 

Subpart A—General 

The FAA proposed criteria that 

adopted existing and developed 

definitions and abbreviations 

specifically for the Model AW609 

powered-lift under subpart A. The FAA 

received and reviewed comments from 

Transport Canada and Overair regarding 

subpart A of the proposed airworthiness 

criteria. 

Transport Canada requested the FAA 

revise TR.10(c) to use the phrase 

‘‘flightdeck’’ instead of ‘‘cockpit’’ for 

consistency with TR.1322. The FAA 

concurs and has revised TR.10(c) to use 

the term ‘‘flightdeck.’’ 

Transport Canada requested the FAA 

revise TR.11 by adding a statement that 

abbreviations in these criteria apply in 

addition to the abbreviations in 14 CFR 

1.2. The FAA does not agree with 

Transport Canada’s request because 14 

CFR part 1.2 abbreviations are 

applicable unless specifically addressed 

as not being applicable in the 

certification basis. 

Overair stated that ‘‘VMIN’’ as defined 

in TR.11(c) and ‘‘minimum safe speed’’ 

as defined in other previously issued 

powered-lift special class airworthiness 

criteria would cause confusion between 

the two terms. The FAA disagrees with 

Overair. The airworthiness criteria for 

the AW609 are a special class 

certification basis and as such, the 

requirements are specific for this aircraft 

rather than generally applicable. In 

addition, the development of the 

AW609 certification basis predates the 

use of performance-based rules, which 

is the approach generally used for other 

special class powered-lift or similar 

aircraft. 

Subpart B—Flight 

The FAA proposed criteria that 

adopted existing regulations from 

subpart B of parts 23, 25, and 29, as well 

as developed criteria specifically for the 

Model AW609 powered-lift . Subpart B 

covers a wide range of flight criteria 

including performance, controllability, 

trim, stability, and stalls. 

The FAA received and reviewed 

comments from Overair regarding 

subpart B of the proposed airworthiness 

criteria. 

Overair requested the FAA clarify the 

safety intent of TR.45 related to the 

hovering ceiling given the differences in 

airworthiness criteria proposed for 

different powered-lift types. The FAA 

acknowledges Overair’s request. TR.45 

is general performance for Category A 

aircraft. The FAA developed these 

airworthiness criteria for the AW609 for 

guaranteed performance that would 

integrate all aircraft flight modes 

defined in TR.10 and HTR.45 including 

hover. TR Appendix H—Category B 

Performance defines Category B 

performance and HTR.45 addresses 

general performance determination. 

Overair requested the FAA justify the 

climb performance identified in TR.67. 

Specifically, Overair requested the FAA 

explain why § 29.67(a)(1) was not 

adopted for the first takeoff segment and 

explain the rationale for adopting part 

25 fixed-wing OEI minimum climb 

gradient criteria for this powered-lift 

special class aircraft. Finally, Overair 

inquired whether these performance 

requirements will provide the same 

level of safety when operating out of 

heliports and/or vertiports. 

The FAA acknowledges Overair’s 

comment. The FAA determined 

§ 29.67(a)(1), which establishes climb 

performance at 200 ft, was inappropriate 

for a transport category powered-lift 

such as the AW609. In addition, the 

FAA did not adopt part 25 fixed-wing 

OEI climb requirements for the AW609. 

Rather, the FAA established different 

takeoff flight paths for ground-level 

heliports under TR.59 and elevated 

heliports under TR.60 that do not exist 


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under part 25. The takeoff flight path 

under TR.59 and TR.69 utilizes the 

performance established under TR.67 to 

ensure positive engine out climb 

performance from the surface to 1500 ft 

above ground level, for different 

segments. 

Overair requested the FAA clarify 

why a stall speed has been adopted for 

the AW609 as opposed to the 

‘‘minimum safe speed’’ in other 

powered-lift special class airworthiness 

criteria. The FAA acknowledges 

Overair’s comment. The AW609 is a 

§ 21.17(b) special class certification 

basis aircraft and the airworthiness 

criteria are specific to this aircraft. 

Unlike other § 21.17(b) powered-lift, the 

AW609 certification basis did not use 

performance-based criteria. There are 

differences between performance-based 

and prescriptive criteria. Conversionmode minimum safe speed is covered 

elsewhere in the AW609 airworthiness 

criteria; in the AW609 airworthiness 

criteria, airplane-mode (wing-borne) 

minimum safe speed is covered in 

TR.103, 201, 203, and 207. Conversionmode (Semi-thrust borne) minimum safe 

speed is covered in TR.38 and 143. 

While the airworthiness criteria for the 

AW609 may be different from the 

airworthiness criteria for other poweredlift, the safety intent is the same with 

regards to stall and minimum speeds. 

Overair requested the FAA explain 

why the wind velocity requirement, 

from all azimuths, has been increased 

from ‘‘at least 17 knots’’ in § 29.143(c) 

to 20 knots. The FAA acknowledges 

Overair’s comment. The AW609, as a 

special class aircraft, is a transport 

category aircraft and its certification 

basis includes appropriate requirements 

from both parts 25 and 29. Section 

25.237(a)(1) requires ‘‘a 90-degree cross 

component of wind velocity, 

demonstrated to be safe for takeoff and 

landing, . . . [that] must be at least 20 

knots . . .’’ The FAA determined that 

§ 29.143(c) and (d)’s requirements of at 

least 17 knots all azimuth capability 

could provide a controllability gap for 

the AW609 when attempting to land or 

takeoff; as such the FAA adopted 20 

knots to maintain consistency with 

transport aircraft requirements for 

specific applicability to the AW609. 

This approach is consistent with the 

draft ‘‘Interim Airworthiness Criteria for 

Powered-Lift Transport Category 

Aircraft,’’ dated July 1988. 

The FAA received several comments 

from Overair on the topics of flight 

performance and characteristics, and 

Overair requested an explanation as to 

why the FAA adopted older, nonperformance-based criteria. The FAA 

establishes the minimum safety 

standards without dictating designs. 

Manufacturers are free to choose the 

design strategy that suits their poweredlift, as long as these designs meet a 

minimum accepted safety standard. 

The FAA received multiple comments 

from Overair regarding the stability 

criteria proposed in TR.173 (static 

longitudinal stability), TR.175 

(demonstration of static longitudinal 

stability), and TR.177 (static lateraldirectional stability). Overair asked for 

clarification as to why proposed TR.173, 

TR.175, and TR.177 include stability 

requirements from the 1960’s instead of 

using recent special conditions for part 

25 aircraft equipped with a fullauthority electronic flight control 

system. Overair requested the FAA 

incorporate more current airworthiness 

standards for fly-by-wire technology 

into the AW609 certification basis. The 

FAA does not concur with Overair’s 

request to revise TR.173, TR.175, and 

TR.177 to incorporate recent special 

conditions for fly-by-wire technology. 

The recent fly-by-wire special 

conditions were considered in TR.173, 

TR.175, and TR.177. The commenter’s 

assumption, that the recent special 

conditions were not considered for the 

TRs, is incorrect. 

Overair also inquired as to why 

proposed TR.181(a)(1) and TR.181(a)(2) 

(free and fixed position dynamic 

stability criteria, respectively) were 

included in the airworthiness criteria 

for an aircraft equipped with an 

irreversible electronic flight control 

system. Overair requested the FAA not 

adopt proposed TR.181(a)(1) and 

TR.181(a)(2) in the final airworthiness 

criteria. The FAA does not concur with 

Overair’s request to not adopt proposed 

TR.181(a)(1) and TR.181(a)(2) in the 

final airworthiness criteria. The FAA 

determined that evaluation of free and 

fixed flight control characteristics is 

necessary even if an aircraft has an 

irreversible electronic flight control 

system. 

Subpart C—Structure and Strength 

The FAA proposed criteria that 

adopted existing regulations from 

subpart C of parts 25 and 29, as well as 

developed criteria specifically for the 

AW609. Subpart C covers a wide range 

of strength criteria including flight 

loads, control surface loads, emergency 

landing conditions, and fatigue 

evaluations. The FAA received and 

reviewed comments from Parker Lord 

and one individual commenter. 

Parker Lord requested the FAA revise 

the definition of a Primary Structural 

Element (PSE). Parker Lord also 

recommended the FAA change the 

qualification and certification of 

elastomeric PSEs from physical and 

static strength attributes to material 

functionality and the dynamic response 

within the design requirements of the 

rotor system. The FAA agrees with 

Parker Lord’s requests and has revised 

the language in final TR.575 to use the 

designed dynamic response of the 

material as compliance criteria instead 

of traditional static loading, 

deformation, and fatigue for compliance 

criteria. 

An individual commenter suggested 

the AW609 may become unstable in a 

windmilling condition and may develop 

whirl flutter. The commenter stated the 

aircraft should be tested for stability in 

this situation and if necessary given 

procedures and limitations. The 

commenter also stated that if the system 

design prevents windmilling, there 

should be backup systems and 

procedures. FAA acknowledges the 

commenter’s concern. Windmilling 

impact on aircraft stability, including 

any impact on whirl flutter, is already 

evaluated under § 25.629 and TR.629, 

therefore, no additional changes are 

deemed necessary to those 

airworthiness criteria. 

Subpart D—Design and Construction 

The FAA proposed criteria that 

adopted existing regulations from 

subpart D of parts 25 and 29, as well as 

developed criteria specifically for the 

Model AW609 powered-lift. Subpart D 

covers a wide range of design and 

construction criteria including criteria 

covering rotors, control systems, landing 

gear, and personnel and cargo 

accommodations. 

The FAA received and reviewed 

comments from Overair and Transport 

Canada regarding subpart D of the 

proposed airworthiness criteria. 

Transport Canada requested the FAA 

specify which paragraphs of § 25.335 

and TR.335 the FAA is referring to in 

the reference to § 25.775 in the proposed 

airworthiness criteria. The FAA has 

revised the reference to § 25.775 in the 

final airworthiness criteria to indicate 

that § 25.335(a) is replaced with 

TR.335(a). 

Transport Canada requested the FAA 

add § 25.865 to the final airworthiness 

criteria because that regulation 

addresses fire protection requirements 

for the engine mounting structure and 

engine attachment points. The FAA 

does not agree with Transport Canada’s 

request. Section 29.861(a) is included in 

the final airworthiness criteria, and uses 

the term ‘‘structure,’’ which includes 

engine mounts as indicated by the 

example in the guidance material of AC 

29.861. As a result, compliance with 

§ 29.861(a) must also address engine 


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mounting structure and engine 

attachment points. Applying § 29.861(a) 

is sufficient for this powered-lift, and 

requiring compliance to § 25.865 is not 

necessary. AC 29–2C ‘‘Certification of 

Transport Category Rotorcraft’’ and AC 

29.861 ‘‘Fire Protection of Structure, 

Controls, and Other Parts’’ provide 

guidance for engine mounts and fire 

protection requirements. 

Transport Canada stated that § 25.867 

does not define clearly what surfaces to 

consider as ‘‘rear of the nacelles’’ and 

requested the FAA clarify the intent 

with a figure to define the envelope and 

boundaries radially and axially. The 

FAA does not agree with Transport 

Canada’s request to provide a figure as 

this figure is defined in the project 

specific methods of compliance to 

§ 25.867. 

Transport Canada requested a 

rationalization of the FAA’s exception 

of § 25.869(a)(3) from the proposed 

airworthiness criteria and requested the 

FAA include § 25.869(a)(3) in the final 

airworthiness criteria. Additionally, the 

commenter provided wording for 

§ 25.869(a)(3) from amendment 25–113 

even though the current amendment is 

25–123, which has different language. 

The FAA does not concur with 

Transport Canada’s request to include 

§ 25.869(a)(3) at either amendment level 

in the final airworthiness criteria as the 

airworthiness criteria already contain 

criteria such as § 29.1301, TR.1309, and 

§ 29.1353 that are intended to address 

the same requirements as those covered 

by the various part 25 wiring and EWIS 

requirements, including § 25.869(a)(3). 

Overair commented that the inclusion 

of both § 25.675(a) and § 29.675(a) in the 

proposed airworthiness criteria was 

confusing and requested the FAA not 

make § 25.675(a) applicable to the 

AW609 because § 29.675(a) is also 

applicable. The FAA does not concur 

with this request. Both regulations need 

to be included in the final airworthiness 

criteria because the AW609 operates in 

both helicopter and airplane modes 

including the conversion mode. The 

AW609 aircraft control is affected by 

rotor collective and cyclic pitch, 

conventional airplane control surfaces 

(elevator, flaperons), and nacelle tilt; 

traditional helicopter-type pilot controls 

in the cockpit provide aircraft control in 

pitch, roll, and yaw axes. 

Overair requested the FAA not adopt 

§ 25.875 from the proposed 

airworthiness criteria and reword 

TR.875 to prevent confusion. The FAA 

concurs with this request and has 

revised the final airworthiness criteria 

to not adopt § 25.875 and reworded 

TR.875 to reflect the use of ‘‘proprotors’’ 

instead and of propellers to reflect 

TR.10(o) terminology. 

Subpart E—Powerplant 

The FAA proposed criteria that 

adopted existing regulations from 

subpart E of parts 25 and 29, as well as 

developed criteria specifically for the 

Model AW609 powered-lift. Subpart E 

covers a wide range of powerplant 

criteria including rotor drive systems, 

fuel systems, oil systems, and cooling 

and exhaust systems. The FAA received 

and reviewed comments from Transport 

Canada and one individual commenter 

regarding subpart E of the proposed 

airworthiness criteria. 

Transport Canada requested the FAA 

revise proposed TR.963 to remove the 

phrase ‘‘for compliance with’’ and 

replace it with ‘‘in addition to.’’ FAA 

does not concur with Transport 

Canada’s request. The requested change 

would increase the testing requirements 

for flexible fuel tank bladders in a way 

that is not intended. 

Transport Canada requested the FAA 

rationalize the exception of § 25.1203(h) 

from the proposed airworthiness criteria 

and to include § 25.1203(h) in the final 

airworthiness criteria. The FAA does 

not concur with the request to include 

§ 25.1203(h) in the final airworthiness 

criteria as the airworthiness criteria 

already contain criteria such as 

§ 29.1301, TR.1309, and § 29.1353 that 

are intended to address similar 

requirements as those covered by the 

various part 25 EWIS requirements, 

including § 25.1203(h). 

The FAA received several comments 

with no specific requested changes to 

the proposed airworthiness criteria from 

an individual on several aspects 

regarding FIKI, icing protection, and 

inadvertent icing encounters. 

The commenter inquired as to 

whether the AW609 has any relief from 

the subpart E powerplant-related 

requirements of normal FIKI 

certification other than having no 

subpart B testing with ice shapes and 

the relief of limited exposure time. The 

commenter also inquired as to whether 

the flight manual limitation that ‘‘the 

pilot is prohibited from flight into 

known or forecast icing’’ reduces or 

eliminates any of the other subpart E 

requirements for the AW609 that are 

normally included in a FIKI 

certification. The FAA acknowledges 

the commenter’s questions: the 

powerplant icing requirements are 

applicable per TR.1093, regardless of 

the aircraft’s FIKI status. 

Subpart G—Operating Limitations and 

Information 

The FAA proposed criteria that 

adopted existing regulations from 

subpart G of parts 25 and 29, as well as 

developed criteria specifically for the 

Model AW609 powered-lift. Subpart G 

covers a wide range of operating 

limitations and information criteria 

including airspeed, markings and 

placards, indicators, and flight manuals. 

The FAA received and reviewed 

comments from Transport Canada 

regarding subpart G of the proposed 

airworthiness criteria. 

Transport Canada requested the FAA 

revise the reference to § 25.1585(a)(8) in 

§ 25.1517 to read ‘‘§ 25.1585(a)(3)’’ and 

explained that § 25.1585(a)(8) does not 

exist.’’ The FAA acknowledges 

Transport Canada’s request; however, 

the reference to § 25.1585(a)(8) is 

correct. The FAA revised the final 

airworthiness criteria to indicate that 

the criteria includes § 25.1517, Rough 

air speed, VRA is at amendment 25–86, 

which contains (a)(8). 

Transport Canada requested the FAA 

revise the reference to § 29.1509 and 

TR.1509 in § 29.1521 to include the 

appropriate paragraphs. The FAA 

concurs and revised the reference to 

§ 29.1509 and TR.1509 to indicate that 

paragraph (c) is the appropriate 

paragraph. 

Transport Canada requested the FAA 

add ‘‘§ 29.1547 Magnetic direction 

indicator. (a)–(d) [Applicable to 

AW609]’’ to the airworthiness criteria 

and, if the FAA agrees, then also add a 

reference to § 29.1547 in TR.1501(b). 

The FAA concurs with adding § 29.1547 

to these final airworthiness criteria and 

notes that § 29.1327 is the requirement 

for a magnetic compass and § 29.1547 is 

the requirement for a calibration card if 

a compass is installed. In lieu of a 

magnetic compass, § 25.1303 and 

TR.1303 allow for direction indicators 

(gyroscopically stabilized, magnetic or 

non-magnetic). 

General Comments 

The FAA received comments on the 

proposed criteria that were not specific 

to any subpart from The Advanced Air 

Mobility Institute, Transport Canada, 

and one individual commenter. 

Transport Canada made several 

comments concerning the structure and 

formatting of the airworthiness criteria 

document. Transport Canada further 

stated that the airworthiness criteria as 

written references many requirements 

instead of writing the actual text for the 

airworthiness criteria. Transport Canada 

suggested the FAA write the actual text 

for airworthiness criteria throughout the 


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document to make explicit the text 

agreed to when these airworthiness 

criteria are finalized. The FAA 

disagrees, because the 14 CFR 

regulations listed in the airworthiness 

criteria for the AW609 are incorporated 

into the criteria by referencing the 

existing rule. 

Transport Canada stated that the 

formula in proposed TR.725 Limit drop 

test, paragraph (d), is incomplete. The 

FAA disagrees with Transport Canada. 

The formula is correctly stated in the 

proposed criteria, and matches the 

formula suggested by the commenter. 

Transport Canada stated the heading 

for proposed TR.103 Stall SPEED is 

incorrect and that the term ‘‘SPEED’’ 

should be lower case and in bold text. 

The FAA agrees with Transport Canada 

and has corrected the heading in TR.103 

in the final airworthiness criteria. 

Transport Canada requested the FAA 

explain why §§ 25.1701–25.1733 for an 

EWIS were not included in the 

proposed airworthiness criteria and 

requested the FAA add §§ 25.1701– 

25.1733. The FAA does not concur with 

Transport Canada’s request to include 

§§ 25.170–25.1753 in the final 

airworthiness criteria as the FAA 

updated the final airworthiness criteria 

to replace § 25.1353 with § 29.1353 due 

to the recent addition of amendment 

29–59 which introduced a part 29 safety 

target for electrical wiring. The final 

airworthiness criteria also contain 

§ 29.1301, and TR.1309 which, in 

addition to § 29.1353, address similar 

requirements to those covered by the 

referenced part 25 EWIS and energy 

storage requirements. 

Transport Canada requested the FAA 

clarify whether part 34, Fuel Venting 

and Exhaust Emission Requirements For 

Turbine Engine Powered Airplanes, is 

applicable to the AW609, either to the 

engine or aircraft, as fuel venting can be 

influenced by the engine’s installation 

effects. The FAA acknowledges 

Transport Canada’s concern. The 

AW609 uses the PT6C–67A, which is a 

turboshaft engine. Part 34 does not 

apply to turboshaft engines. As long as 

the AW609 continues to use a turboshaft 

engine, part 34 will not be applicable. 

Transport Canada requested the FAA 

clarify whether part 38, Airplane Fuel 

Efficiency Certification is applicable to 

the AW609. The AW609 certification 

basis precedes the promulgation of 14 

CFR part 38, and thus part 38 is not 

applicable to the AW609. 

The Advanced Air Mobility Institute 

recommended the FAA update and 

expand the airworthiness criteria for the 

Model AW609 powered-lift to require 

the implementation of a mandatory 

safety management system (SMS), 

designated as TR criteria. The FAA does 

acknowledge the value of 

implementation of a proactive SMS 

system. However, implementation of 

SMS is beyond the scope of this present 

effort to designate the applicable 

airworthiness criteria for this poweredlift. 

Applicability 

These airworthiness criteria, 

established under the provisions of 

§ 21.17(b), are applicable to the AWPC 

Model AW609 powered-lift. Should 

AWPC apply at a later date for a change 

to the type certificate to include another 

model, these airworthiness criteria 

would apply to that model as well, 

provided the FAA finds them 

appropriate in accordance with the 

requirements of subpart D to part 21. 

Conclusion 

This action affects only certain 

airworthiness criteria for the AWPC 

Model AW609 powered-lift. It is not a 

standard of general applicability. 

Authority Citation 

The authority citation for these 

airworthiness criteria is as follows: 

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

44701–44702, 44704. 

Airworthiness Criteria 

Pursuant to the authority delegated to 

me by the Administrator, the following 

airworthiness criteria are issued as part 

of the type certification basis for the 

AgustaWestland Philadelphia 

Corporation Model AW609 powered-lift. 

You may view the final airworthiness 

criteria on the internet at 

www.regulations.gov in Docket No. 

FAA–2022–1726. 

Issued in Kansas City, Missouri, on 

October 25, 2024. 

Patrick R. Mullen, 

Manager, Technical Policy Branch, Policy and 

Standards Division, Aircraft Certification 

Service. 

[FR Doc. 2024–25238 Filed 10–30–24; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2024–1004; Project 

Identifier AD–2023–01058–R; Amendment 

39–22866; AD 2024–20–07] 

RIN 2120–AA64 

Airworthiness Directives; Various 

Helicopters 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: The FAA is adopting a new 

airworthiness directive (AD) for various 

helicopters modified by certain 

supplemental type certificates (STCs) 

that approve the installation of an 

emergency float kit or an emergency 

float with a liferaft kit. This AD was 

prompted by the results of an accident 

investigation and subsequent reports of 

difficulty pulling the emergency float kit 

activation handle installed on the pilot 

cyclic. This AD requires repetitively 

inspecting the pull force on the float 

activation handle and for certain model 

helicopters, this AD also requires and 

replacing certain part-numbered float 

inflation reservoirs (reservoirs) and pull 

cable assemblies (cables) with other 

part-numbered reservoirs and cables. 

Finally, this AD prohibits installing 

certain part-numbered reservoirs and 

cables on specific helicopters. The FAA 

is issuing this AD to address the unsafe 

condition on these products. 

DATES: This AD is effective December 5, 

2024. 

The Director of the Federal Register 

approved the incorporation by reference 

of certain publications listed in this AD 

as of December 5, 2024. 

ADDRESSES: 

AD Docket: You may examine the AD 

docket at regulations.gov under Docket 

No. FAA–2024–1004; or in person at 

Docket Operations between 9 a.m. and 

5 p.m., Monday through Friday, except 

Federal holidays. The AD docket 

contains this final rule, any comments 

received, and other information. The 

address for Docket Operations is U.S. 

Department of Transportation, Docket 

Operations, M–30, West Building 

Ground Floor, Room W12–140, 1200 

New Jersey Avenue SE, Washington, DC 

20590. 

Material Incorporated by Reference: 

• For Dart Aerospace material 

identified in this AD, contact Dart 

Aerospace, LTD., 1270 Aberdeen Street, 

Hawkesbury, ON, K6A 1K7, Canada; 

phone: 1–613–632–5200; fax: 1–613– 

632–5246; website: dartaero.com. 


lotter on DSK11XQN23PROD with RULES1