Federal Register / Vol. 89, No. 240 / Friday, December 13, 2024 / Rules and Regulations 100727 

rest compartment in the event of a fire 

in the cargo compartment. 

19. Means must be provided to 

prevent access into the Class C cargo 

compartment during all airplane 

operations and to ensure that the 

maintenance door is closed during all 

airplane flight operations. 

20. All enclosed stowage 

compartments within the crew rest that 

are not limited to stowage of emergency 

equipment or airplane-supplied 

equipment (e.g., bedding) must meet the 

design criteria given in the table below. 

As indicated by the table below, this 

special condition does not address 

enclosed stowage compartments greater 

than 200 ft3 in interior volume. The inflight accessibility of very large, 

enclosed stowage compartments and the 

subsequent impact on the 

crewmembers’ ability to effectively 

reach any part of the compartment with 

the contents of a hand fire extinguisher 

will require additional fire protection 

considerations similar to those required 

for inaccessible compartments such as 

Class C cargo compartments. 

Fire protection features 

Stowage compartment interior volumes 

Less than 25 ft3 25 ft3 to 57 ft3 57 ft3 to 200 ft3

Materials of Construction 1 ............. Yes ................................................ Yes ................................................ Yes. 

Detectors 2 ...................................... No ................................................. Yes ................................................ Yes. 

Liner 3 ............................................. No ................................................. No ................................................. Yes. 

Locating Device 4 ........................... No ................................................. Yes ................................................ Yes. 

1 Material: The material used to construct each enclosed stowage compartment must at least be fire resistant and must meet the flammability

standards established for interior components per the requirements of § 25.853. For compartments less than 25 ft3 in interior volume, the design 

must ensure the ability to contain a fire likely to occur within the compartment under normal use. 2 Detectors: Enclosed stowage compartments equal to or exceeding 25 ft3 in interior volume must be provided with a smoke or fire detection 

system to ensure that a fire can be detected within a one-minute detection time. Flight tests must be conducted to show compliance with this requirement. Each system (or systems) must provide: 

(a) A visual indication in the flight deck within one minute after the start of a fire; 

(b) An aural warning in the crew rest compartment; and 

(c) A warning in the main passenger cabin. This warning must be readily detectable by a flight attendant, taking into consideration the positioning of flight attendants throughout the main passenger compartment during various phases of flight. 3 Liner: If it can be shown that the material used to construct the stowage compartment meets the flammability requirements of a liner for a 

Class B cargo compartment, then no liner would be required for enclosed stowage compartments equal to or greater than 25 ft3 in interior volume but less than 57 ft3 in interior volume. For all enclosed stowage compartments equal to or greater than 57 ft3 in interior volume but less than 

or equal to 200 ft3, a liner must be provided that meets the requirements of § 25.855 at Amendment 25–60 for a class B cargo compartment. 4 Location Detector: Crew rest areas which contain enclosed stowage compartments exceeding 25 ft3 interior volume and which are located 

away from one central location such as the entry to the crew rest area or a common area within the crew rest area would require additional fire 

protection features and/or devices to assist the firefighter in determining the location of a fire. 

Issued in Kansas City, Missouri, on 

December 9, 2024. 

Patrick R. Mullen, 

Manager, Technical Policy Branch, Policy and 

Standards Division, Aircraft Certification 

Service. 

[FR Doc. 2024–29432 Filed 12–12–24; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. FAA–2024–2387; Special 

Conditions No. 25–871–SC] 

Special Conditions: Airbus Models 

A321 neo ACF and A321 neo XLR; 

Single-Occupant Oblique Seats With 

Pretensioner Restraint Systems 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final special conditions; request 

for comments. 

SUMMARY: These special conditions are 

issued for the Airbus Model A321 neo 

ACF and A321 neo XLR airplanes. 

These airplanes have a novel or unusual 

design feature when compared to the 

state of technology envisioned in the 

airworthiness standards for transport 

category airplanes. This design feature 

incorporates oblique (side-facing) 

passenger seats which may include a 3- 

point restraint system with 

pretensioner. These oblique seats may 

be installed at an angle of 18 to 45 

degrees to the aircraft centerline and 

have surrounding furniture that 

introduces occupant and loading 

concerns. The applicable airworthiness 

regulations do not contain adequate or 

appropriate safety standards for this 

design feature. These special conditions 

contain the additional safety standards 

that the Administrator considers 

necessary to establish a level of safety 

equivalent to that established by the 

existing airworthiness standards. 

DATES: This action is effective on Airbus 

S.A.S. on December 13, 2024. Send 

comments on or before January 27, 

2025. 

ADDRESSES: Send comments identified 

by Docket No. FAA–2024–2387 using 

any of the following methods: 

• Federal eRegulations Portal: Go to 

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 or 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 9 

a.m. and 5 p.m., Monday through 

Friday, except Federal holidays. 

• Fax: Fax comments to Docket 

Operations at 202–493–2251. 

Docket: Background documents or 

comments received may be read at 

www.regulations.gov at any time. 

Follow the online instructions for 

accessing the docket or go to 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: 

Shannon Lennon, Cabin Safety Section, 

AIR–624, Technical Policy Branch, 

Policy and Standards Division, Aircraft 

Certification Service, Federal Aviation 

Administration, 2200 South 216th 

Street, Des Moines, Washington 98198; 

telephone (206) 231–3209; fax (206) 

231–3827; email Shannon.Lennon@

faa.gov. 

SUPPLEMENTARY INFORMATION: The 

substance of these special conditions 

has been published in the Federal 


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Register for public comment in several 

prior instances with no substantive 

comments received. Therefore, the FAA 

finds, pursuant to 14 CFR 11.38(b), that 

new comments are unlikely, and notice 

and comment prior to this publication 

are unnecessary. 

Privacy 

Except for Confidential Business 

Information (CBI) as described in the 

following paragraph, and other 

information as described in title 14, 

Code of Federal Regulations (14 CFR) 

11.35, the FAA will post all comments 

received without change to 

www.regulations.gov, including any 

personal information you provide. The 

FAA will also post a report 

summarizing each substantive verbal 

contact received about these special 

conditions. 

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 these special 

conditions contain commercial or 

financial information that is customarily 

treated as private, that you actually treat 

as private, and that is relevant or 

responsive to these special conditions, 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 the 

indicated comments will not be placed 

in the public docket of these special 

conditions. Send submissions 

containing CBI to the individual listed 

in the FOR FURTHER INFORMATION

CONTACT section above. Comments the 

FAA receives, which are not specifically 

designated as CBI, will be placed in the 

public docket for these special 

conditions. 

Comments Invited 

The FAA invites interested people to 

take part in this rulemaking by sending 

written comments, data, or views. The 

most helpful comments reference a 

specific portion of the special 

conditions, explain the reason for any 

recommended change, and include 

supporting data. 

The FAA will consider all comments 

received by the closing date for 

comments. The FAA may change these 

special conditions based on the 

comments received. 

Background 

On September 23, 2024, Airbus S.A.S. 

applied for an amendment to Type 

Certificate No. (TC no.) A28NM to 

include new Models A321 neo ACF and 

A321 neo XLR airplanes. Airbus Model 

A321 neo ACF and Model A321 neo 

XLR airplanes, which are derivatives of 

the Model A321 currently approved 

under TC no. A28NM, are twin-engine 

transport category airplanes with a 

maximum passenger capacity of 244. 

The maximum takeoff weight of the 

Airbus Model A321 neo ACF is 

approximately 213,848 pounds, while 

the Airbus Model A321 neo XLR has a 

maximum takeoff weight of 

approximately 222,667 pounds. 

Type Certification Basis 

Under the provisions of title 14, Code 

of Federal Regulations (14 CFR) 21.101, 

Airbus S.A.S must show that Models 

A321 neo ACF and A321 neo XLR 

airplanes, as changed, continue to meet 

the applicable provisions of the 

regulations listed in TC No. A28NM, or 

the applicable regulations in effect on 

the date of application for the change, 

except for earlier amendments as agreed 

upon by the FAA. 

If the Administrator finds that the 

applicable airworthiness regulations 

(e.g., 14 CFR part 25) do not contain 

adequate or appropriate safety standards 

for the Airbus Models A321 neo ACF 

and A321 neo XLR airplanes because of 

a novel or unusual design feature, 

special conditions are prescribed under 

the provisions of § 21.16. 

Special conditions are initially 

applicable to the model for which they 

are issued. Should the type certificate 

for that model be amended later to 

include any other model that 

incorporates the same novel or unusual 

design feature, or should any other 

model already included on the same 

type certificate be modified to 

incorporate the same novel or unusual 

design feature, these special conditions 

would also apply to the other model 

under § 21.101. 

In addition to the applicable 

airworthiness regulations and special 

conditions, Airbus Models A321 neo 

ACF and A321 neo XLR airplanes must 

comply with the exhaust-emission 

requirements of 14 CFR part 34 and the 

noise-certification requirements of 14 

CFR part 36. 

The FAA issues special conditions, as 

defined in 14 CFR 11.19, in accordance 

with § 11.38, and they become part of 

the type certification basis under 

§ 21.101. 

Novel or Unusual Design Features 

Airbus Models A321 neo ACF and 

A321 neo XLR airplanes will 

incorporate a novel or unusual design 

feature: single occupant oblique (sidefacing) passenger seats that may include 

a 3-point restraint system with 

pretensioner. These oblique seats may 

be installed at an angle of 18 to 45 

degrees relative to the aircraft centerline 

and have surrounding furniture that 

introduces occupant and loading 

concerns. 

Discussion 

Title 14, Code of Federal Regulations 

(14 CFR) 25.785(d) requires that each 

occupant of a seat that makes more than 

an 18 degree angle with the vertical 

plane containing the airplane centerline 

must be protected from head injury by 

a safety belt and an energy absorbing 

rest that will support the arms, 

shoulders, head, and spine, or by a 

safety belt and shoulder harness that 

will prevent the head from contacting 

any injurious object. 

The proposed Airbus Model A321 neo 

ACF and A321 neo XLR seat 

installations are novel in that the 

current requirements do not adequately 

address protection of the occupant’s 

neck and spine for seating 

configurations that are positioned at 

angles greater than 18 degrees up to and 

including 45 degrees from the airplane 

centerline. The installation of passenger 

seats at angles of 18 to 45 degrees to the 

airplane centerline is unique due to the 

seat/occupant interface with the 

surrounding furniture that introduces 

occupant alignment/loading concerns 

with or without the installation of a 3- 

point or airbag restraint systems. The 

existing special conditions for Airbus 

Model A321 neo ACF series airplane 

oblique seat installations (Special 

Conditions No. 25–779–SC) also do not 

address oblique seats with 3-point 

restraint systems equipped with 

pretensioners. Therefore, in order to 

provide a level of safety equivalent to 

that afforded to occupants of forward 

and aft facing seating, additional 

airworthiness standards in the form of 

new special conditions are necessary. 

The FAA has been conducting and 

sponsoring research on appropriate 

injury criteria for oblique (side-facing) 

seat installations. To reflect current 

research findings, the FAA issued 

Policy Statement PS–AIR–25–27, 

‘‘Technical Criteria for Approving SideFacing Seats,’’ dated July 11, 2018, 

which defines injury criteria for oblique 

seats. 

FAA-sponsored research has found 

that an un-restrained flailing of the 


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Federal Register / Vol. 89, No. 240 / Friday, December 13, 2024 / Rules and Regulations 100729 

upper torso, even when the pelvis and 

torso are nearly aligned, can produce 

serious spinal and torso injuries. At 

lower impact severities, even with 

significant misalignment between the 

torso and pelvis, these injuries did not 

occur. Tests with an FAA H–III 

anthropomorphic test dummy (ATD) 

have identified a level of lumbar spinal 

tension corresponding to the no-injury 

impact severity. This level of tension is 

included as a limit in the special 

conditions. The spine tension limit 

selected is conservative with respect to 

other aviation injury criteria since it 

corresponds to a no-injury loading 

condition. 

Other restraint systems, in lieu of 

single lap belt restraint systems have 

been used to comply with the occupant 

injury criteria of § 25.562(c)(5). For 

instance, shoulder harnesses have been 

widely used on flight-attendant seats, 

flight-deck seats, in business jets, and in 

general-aviation airplanes to reduce 

occupant head injury in the event of an 

emergency landing. Special conditions, 

pertinent regulations, and published 

guidance exist that relate to other 

restraint systems. However, the use of 

pretensioners in the restraint system on 

transport category airplane seats to 

comply with the occupant injury criteria 

of § 25.562(c)(5) is a novel design. 

Pretensioner technology involves a 

step-change in loading experienced by 

the occupant for impacts below and 

above that at which the device deploys, 

because activation of the shoulder 

harness, at the point at which the 

pretensioner engages, interrupts uppertorso excursion. Such excursion could 

result in the head-injury criteria (HIC) 

being higher at an intermediate impact 

condition than that resulting from the 

maximum impact condition 

corresponding to the test conditions 

specified in § 25.562. See condition 7 in 

these special conditions. 

The ideal triangular maximumseverity pulse is defined in Advisory 

Circular (AC) 25.562–1B, ‘‘Dynamic 

Evaluation of Seat Restraint Systems 

and Occupant Protection on Transport 

Airplanes’’. For the evaluation and 

testing of less-severe pulses for purposes 

of assessing the effectiveness of the 

pretensioner setting, a similar triangular 

pulse should be used with acceleration, 

rise time, and velocity change scaled 

accordingly. The magnitude of the 

required pulse should not deviate below 

the ideal pulse by more than 0.5g until 

1.33 t1 is reached, where t1 represents 

the time interval between 0 and t1 on 

the referenced pulse shape, as shown in 

AC 25.562–1B. This is an acceptable 

method of compliance to the test 

requirements of the special conditions. 

Additionally, the pretensioner might 

not provide protection, after actuation, 

during secondary impacts. Therefore, 

the case where a small impact is 

followed by a large impact should be 

addressed. If the minimum deceleration 

severity at which the pretensioner is set 

to deploy is unnecessarily low, the 

protection offered by the pretensioner 

may be lost by the time a second, larger 

impact occurs. 

Conditions 1 through 7 address 

occupant protection in consideration of 

the oblique-facing seats. Conditions 8 

through 10 ensure that the pretensioner 

system activates when intended and 

protects a range of occupants under 

various accident conditions. Conditions 

11 through 16 address maintenance and 

reliability of the pretensioner system, 

including any outside influences on the 

mechanism, to ensure it functions as 

intended. 

These special conditions contain the 

additional safety standards that the 

Administrator considers necessary to 

establish a level of safety equivalent to 

that established by the existing 

airworthiness standards. 

Applicability 

As discussed above, these special 

conditions are applicable to the Airbus 

Model A321 neo ACF and Model A321 

neo XLR airplanes. Should Airbus 

S.A.S. apply at a later date for a change 

to the type certificate to include another 

model incorporating the same novel or 

unusual design feature, or should any 

other model already included on the 

same type certificate be modified to 

incorporate the same novel or unusual 

design feature, these special conditions 

would apply to that model as well. 

Conclusion 

This action affects only a certain 

novel or unusual design feature on one 

model series of airplanes. It is not a rule 

of general applicability. 

List of Subjects in 14 CFR Part 25 

Aircraft, Aviation safety, Reporting 

and recordkeeping requirements. 

Authority Citation 

The authority citation for these 

special conditions is as follows: 

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

44701, 44702, and 44704. 

The Special Conditions 

Accordingly, pursuant to the 

authority delegated to me by the 

Administrator, the following special 

conditions are issued as part of the type 

certification basis for the Airbus Model 

A321 neo ACF and A321 neo XLR series 

airplanes. 

In addition to the requirements of 

§ 25.562, passenger seats installed at an 

angle between 18 degrees and 45 

degrees from the aircraft centerline must 

meet the following conditions: 

1. Body-to-Wall and Body-toFurnishing Contact: 

If a seat is installed aft of a structure 

(e.g., interior wall or furnishings) that 

does not provide a homogenous contact 

surface for the expected range of 

occupants and yaw angles, then 

additional analysis and tests may be 

required to demonstrate that the injury 

criteria are met for the area that an 

occupant could contact. For example, if, 

in addition to a pretensioner restraint 

system, an airbag device is present, 

different yaw angles could result in 

different airbag-device performance, 

then additional analysis or separate tests 

may be necessary to evaluate 

performance. 

2. Neck Injury Criteria: 

The seating system must protect the 

occupant from experiencing serious 

neck injury. In addition to a 

pretensioner restraint system, if an 

airbag device also is present, the 

assessment of neck injury must be 

conducted with the airbag device 

activated, unless there is reason to also 

consider that the neck injury potential 

would be higher for impacts below the 

airbag-device deployment threshold. 

(a) The Nij (calculated in accordance 

with 49 CFR 571.208) must be below 

1.0, where Nij = Fz/Fzc + My/Myc, and 

Nij critical values are: 

(1) Fzc = 1530 lbs. for tension 

(2) Fzc = 1385 lbs. for compression 

(3) Myc = 229 lb-ft in flexion 

(4) Myc = 100 lb-ft in extension 

(b) In addition, peak Fz must be below 

937 lbs. in tension and 899 lbs. in 

compression. 

(c) Rotation of the head about its 

vertical axis relative to the torso is 

limited to 105 degrees in either 

direction from forward facing. 

(d) The neck must not impact any 

surface that would produce 

concentrated loading on the neck. 

3. Spine and Torso Injury Criteria: 

(a) The lumbar spine tension (Fz) 

cannot exceed 1,200 lbs. 

(b) Significant concentrated loading 

on the occupant’s spine, in the area 

between the pelvis and shoulders 

during impact, including rebound, is 

not acceptable. During this type of 

contact, the interval for any rearward (X 

direction) acceleration exceeding 20g 

must be less than 3 milliseconds as 

measured by the thoracic 

instrumentation specified in 49 CFR 

part 572, subpart E, filtered in 

accordance with SAE International 


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100730 Federal Register / Vol. 89, No. 240 / Friday, December 13, 2024 / Rules and Regulations 

(SAE) recommended practice J211/1, 

‘‘Instrumentation for Impact Test-Part 1- 

Electronic Instrumentation.’’ 

(c) The occupant must not interact 

with the armrest or other seat 

components in any manner significantly 

different than would be expected for a 

forward-facing seat installation. 

4. Pelvis Criteria: 

Any part of the load-bearing portion 

of the bottom of the ATD pelvis must 

not translate beyond the edges of the 

seat bottom seat-cushion supporting 

structure. 

5. Femur Criteria: 

Axial rotation of the upper leg (about 

the Z-axis of the femur per SAE 

Recommended Practice J211/1) must be 

limited to 35 degrees from the nominal 

seated position. Evaluation during 

rebound does not need to be considered. 

6. ATD and Test Conditions: 

Longitudinal tests conducted to 

measure the injury criteria above must 

be performed with the FAA Hybrid III 

ATD, as described in SAE 1999–01– 

1609, ‘‘A Lumber Spine Modification to 

the Hybrid III ATD for Aircraft Seat 

Tests.’’ The tests must be conducted 

with an undeformed floor, at the mostcritical yaw cases for injury, and with 

all lateral structural supports (e.g. 

armrests or walls) installed. 

Note: The applicant must demonstrate that 

the installation of seats via plinths or pallets 

meets all applicable requirements. 

Compliance with the guidance contained in 

policy memorandum PS–ANM–100–2000– 

00123, ‘‘Guidance for Demonstrating 

Compliance with Seat Dynamic Testing for 

Plinths and Pallets,’’ dated February 2, 2000, 

may be applied. 

7. Head Injury Criteria: 

The HIC value must not exceed 1000 

at any condition at which the 

pretensioner does or does not deploy, 

up to the maximum severity pulse that 

corresponds to the test conditions 

specified in § 25.562. Tests must be 

performed to demonstrate this, taking 

into account any necessary tolerances 

for deployment. 

When an airbag is present in addition 

to the pretensioner restraint system, and 

the anthropomorphic test dummy (ATD) 

has no apparent contact with the seat/ 

structure but has contact with the 

airbag, a HIC unlimited score in excess 

of 1000 is acceptable provided the 

HIC15 score (calculated in accordance 

with 49 CFR 571.208) for the contact is 

less than 700. ATD head contact with 

the seat or other structure, through the 

airbag, or contact subsequent to contact 

with the airbag, requires a HIC value 

that does not exceed 1000. 

8. Protection During Secondary 

Impacts: 

The pretensioner activation setting 

must be demonstrated to maximize the 

probability of the protection being 

available when needed, considering 

secondary impacts. 

9. Protection of Occupants Other than 

50th Percentile: 

Protection of occupants for a range of 

stature from a 2-year-old child to a 95th 

percentile male must be shown. For 

shoulder harnesses that include 

pretensioners, protection of occupants 

other than a 50th percentile male may 

be shown by test or analysis. In 

addition, the pretensioner must not 

introduce a hazard to passengers due to 

the following seat configurations: 

(a) The seat occupant is holding an 

infant. 

(b) The seat occupant is a child in a 

child-restraint device. 

(c) The seat occupant is a pregnant 

woman. 

10. Occupants Adopting the Brace 

Position: 

Occupants in the traditional brace 

position when the pretensioner activates 

must not experience adverse effects 

from the pretensioner activation. 

11. Inadvertent Pretensioner 

Actuation: 

(a) The probability of inadvertent 

pretensioner actuation must be shown 

to be extremely remote (i.e., average 

probability per flight hour of less than 

10¥7). 

(b) The system must be shown not 

susceptible to inadvertent pretensioner 

actuation as a result of wear and tear, or 

inertia loads resulting from in-flight or 

ground maneuvers likely to be 

experienced in service. 

(c) The seated occupant must not be 

seriously injured as a result of 

inadvertent pretensioner actuation. 

(d) Inadvertent pretensioner 

activation must not cause a hazard to 

the airplane, nor cause serious injury to 

anyone who may be positioned close to 

the retractor or belt (e.g., seated in an 

adjacent seat or standing adjacent to the 

seat). 

12. Availability of the Pretensioner 

Function Prior to Flight: 

The design must provide means for a 

crewmember to verify the availability of 

the pretensioner function prior to each 

flight, or the probability of failure of the 

pretensioner function must be 

demonstrated to be extremely remote 

(i.e., average probability per flight hour 

of less than 10¥7) between inspection 

intervals. 

13. Incorrect Seat Belt Orientation: 

The system design must ensure that 

any incorrect orientation (twisting) of 

the seat belt does not compromise the 

pretensioner protection function. 

14. Contamination Protection: 

The pretensioner mechanisms and 

controls must be protected from external 

contamination associated with that 

which could occur on or around 

passenger seating. 

15. Prevention of Hazards: 

The pretensioner system must not 

induce a hazard to passengers in case of 

fire, nor create a fire hazard, if activated. 

16. Functionality After Loss of Power: 

The system must function properly 

after loss of normal airplane electrical 

power, and after a transverse separation 

in the fuselage at the most critical 

location. A separation at the location of 

the system does not have to be 

considered. 

Issued in Kansas City, Missouri, on 

December 9, 2024. 

Patrick R. Mullen, 

Manager, Technical Policy Branch, Policy and 

Standards Division, Aircraft Certification 

Service. 

[FR Doc. 2024–29442 Filed 12–12–24; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 27 

[Docket No. FAA–2024–0875; Special 

Conditions No. 27–058–SC] 

Special Conditions: Skyryse, Robinson 

Helicopter Company Model R66 

Helicopter; Interaction of Systems and 

Structures 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final special conditions. 

SUMMARY: These special conditions are 

issued for the Robinson Helicopter 

Company (Robinson) Model R66 

helicopter. This helicopter, as modified 

by Skyryse, will have a novel or unusual 

design feature when compared to the 

state of technology envisioned in the 

airworthiness standards for normal 

category helicopters. This design feature 

is a novel control input and fly-by-wire 

(FBW) system. The applicable 

airworthiness regulations do not contain 

adequate or appropriate safety standards 

for this design feature. These special 

conditions contain the additional safety 

standards that the Administrator 

considers necessary to establish a level 

of safety equivalent to that established 

by the existing airworthiness standards. 

DATES: Effective December 13, 2024. 

FOR FURTHER INFORMATION CONTACT: 

Daniel Moore, Airframe Section, AIR– 

622, Technical Policy Branch, Policy 

and Standards Division, Aircraft 


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