Special Conditions: Northwest Aerospace Technologies, Inc (NAT), Boeing Model 787-9 Airplane; Installation of High Wall Suites

SUPPLEMENTARY INFORMATION:

Background

NAT has applied for an amended supplemental type certificate for the installation of suites in the passenger cabin in Boeing Model 787-9 series airplanes. The Boeing Model 787-9 airplane, currently approved under Type Certificate No. T00021SE, is a twin-engine transport category airplane, with a maximum seating capacity for 420 passengers, and a maximum take-off weight of 553,000 pounds.

Type Certification Basis

Under the provisions of 14 CFR 21.101, NAT must show that the Boeing Model 787-9 airplane, as changed, continues to meet the applicable provisions of the regulations listed in Type Certificate No. T00021SE 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 ( i.e.,14 CFR part 25) do not contain adequate or appropriate safety standards for the Boeing Model 787-9 airplane 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 applicant apply for a supplemental type certificate to modify any other model included on the same type certificate 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, the Boeing Model 787-9 airplane 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

The Boeing Model 787-9 airplane will incorporate the following novel or unusual design feature:

Single-passenger suites with high walls that diminish occupant's awareness of their surroundings in emergency situations. These suites are considered a novel design for transport category airplanes and were not considered when applicable airworthiness standards were created.

Discussion

For the Model 787-9 airplane, NAT has proposed a customer option for the installation of six high wall suites (HWS) arranged in two rows of three suites each in a 1-1-1 configuration. The characteristics of this HWS design are unique such that the suite walls are higher than conventional mini-suites with partial height surroundings. While the walls for these suites do not extend fully up from the floor to the ceiling, such as those found in traditional “high wall” suites, their wall height of 60 inches is greater than the eye level of a 5th percentile female, impeding visual awareness and egress. These suites are also not remote from the main cabin (such as overhead crew rests). Additionally, the design of these suites is novel in the inclusion of berths that are accessible to the occupant of the suite during flight, unlike previous high wall suite designs.

Part 25 in its current form does not have regulations that address suite installations in the cabin with walls of height that reduce occupant visibility and situational awareness.

Due to the novel design features of these HWS, suitable passenger alerting, supplemental oxygen, and firefighting equipment and procedures are needed for this configuration to ensure occupant awareness in emergency situations. Furthermore, the proposed suite design necessitates the development of additional special conditions, including, but not limited to crew procedures for managing hazards and suite occupants, as well as maintaining cabin-egress route dimensions after deformation of the walls and seats.

The 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.

Discussion of Comments

The FAA issued Notice of Proposed Special Conditions No. 25-24-03-SC for the Boeing Model 787-9 series airplane, which was published in the Federal Register on August 6, 2024 (89 FR 63845).

The FAA received three comments from Boeing.

Boeing requests to change the description of the suites to remove the single criterion of impending visual awareness and egress of a 5th percentile female. Instead, Boeing requests FAA to use multifaceted criteria ( i.e., oxygen masks, smoke detection, and firefighting), which would categorize the suites as mini-suites instead of high wall suites. Boeing further asserts that a height of 60 inches to demarcate between high wall suites and mini-suites is not consistent with industry, FAA, or European Union Aviation Safety Agency (EASA) practice. The FAA disagrees that the proposed suites are mini-suites. These suites are described as high wall suites because the height of the walls, in this case 60 inches, exceeds the eye height of shorter stature occupants such that they are unable to see the emergency exits from within the suites, which increases safety risk associated with actions expected of the occupants in an emergency. This description is consistent with the FAA Grant of Exemption 17635B, issued to The Boeing Company for high wall suites installed on Model 777 airplanes which states, “In most previous approvals, the low-wall mini-suite door did not obscure the passenger's view of the airplane's emergency exit. However, in this case, the high walls create long corridors that could obscure view of the emergency exits, and impede the overall egress capability of the cabin, creating a new safety risk.” This description is also consistent with discussion of high wall suites at industry meetings where the FAA has maintained the position discussed in the noted exemption.

Boeing also proposes to change the discussion section regarding part 25 which states that part 25 does not specifically address suites with walls that reduce occupant visibility and situational awareness. Boeing asserts that commercial aircraft commonly include architectural elements that are addressed by existing regulations that may also potentially reduce visibility and situational awareness. The FAA infers that Boeing is maintaining that existing regulations already address suites with high walls, and the FAA disagrees with Boeing's comment. While current regulations are sufficient to address a high wall architectural element such as a partition, they do not address the safety risk posed by surrounding an occupant with high walls. The discussion section is intended to convey that part 25 did not previously consider safety factors associated with high walls surrounding seats that were previously installed in an open seating environment. Among these factors is the safety risk associated with walls that diminish visibility of emergency exits and awareness of emergency conditions, which must be addressed by special conditions.

Finally, Boeing proposes to remove conditions 1, 2, 3, 4, 6, and 7, which are associated with high wall suites, and place condition 5 which relates to berths, in an exemption regarding mini-suites. The FAA disagrees with Boeing's proposal since the suites in question are not mini-suites but high wall suites. Furthermore, incorporating beds into the suites requires conditions specific to decompression alerting and maintaining availability of supplemental oxygen for bed occupants to mitigate the safety risk associated with diminished situational awareness.

The special conditions are adopted as proposed.

Applicability

As discussed above, these special conditions are applicable to the Boeing Model 787-9 airplane. Should Northwest Aerospace Technologies, Inc apply at a later date for a supplemental type certificate to modify any other model included on Type Certificate No. T00021SE to incorporate the same novel or unusual design feature, these special conditions would apply to that model as well.

Under standard practice, the effective date of final special conditions would be 30 days after the date of publication in the Federal Register . However, as the certification date for the Boeing Model 787-9, as modified by Northwest Aerospace Technologies, Inc., is imminent, the FAA finds that good cause exists to make these special conditions effective upon publication.

Conclusion

This action affects only a certain novel or unusual design feature on one model of airplane. It is not a rule of general applicability and affects only the applicant who applied to the FAA for approval of these features on the airplane.

Authority Citation

The authority citation for these special conditions is as follows:

Authority: 49 U.S.C. 106(f), 106(g), 40113, 44701, 44702, 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 Boeing Model 787-9 series airplanes, as modified by NAT.

The suites must have the following features:

1. A supplemental oxygen system with the following:

a. Oxygen masks for each seat and berth installed in the suite that meet the same 14 CFR part 25 regulations as the supplemental oxygen system for the main passenger-cabin occupants.

b. An aural and visual alert system to warn occupants and to indicate the need to don oxygen masks in the event of decompression. The aural alert must activate concurrently with the deployment of the oxygen masks in the main passenger cabin and must be loud enough to be heard and clearly understood from each suite berth and seat location.

c. When an occupant needs to locate and don a deployed oxygen mask, sufficient levels of lighting to perform this task must be automatically activated within the suite.

d. Automatic presentation of oxygen for occupants lying in the berth.

e. If a chemical oxygen generator is used as the oxygen supply source, the suite oxygen installation must meet §§ 25.795(d) and 25.1450 at amendment 25-138 or higher.

2. The design approval holder must provide operating procedures to move suite occupants when smoke is present, or firefighting is occurring near or in the suites, for incorporation into the operator's training programs and appropriate operational manuals:

a. A limitation must be included in the airplane flight manual (AFM) requiring that crewmembers be trained in the operating procedures related to the suites.

3. The design of each suite, and the location of the firefighting equipment where suites are installed, must allow the crewmembers to conduct effective firefighting in the suite. For a manual, hand-held extinguishing system (designed as the sole means to fight a fire) for the suite:

a. A limitation must be included in the AFM requiring that crewmembers be trained in the firefighting procedures.

b. Each suite design must allow crewmembers equipped for firefighting to have unrestricted access to all parts of the suite compartment.

4. Approved procedures describing the methods for searching the suite compartment for fire sources must be established. These procedures should include a drawing or photo clearly indicating the location of the stowage drawer and other potential sources of smoke ( e.g., the monitor). They must be transmitted to the operator for incorporation into their training programs and appropriate operations manuals.

5. If a berth is installed, occupancy of each suite is limited to a single passenger.

a. Each berth installed in the suite must incorporate a safety belt that meets § 25.785(f).

b. Each berth must be placarded to indicate the appropriate orientation of the occupant's head direction.

c. Each berth cushion must meet § 25.853(c).

6. If waste-disposal receptacles are fitted in the suite, the suite must be equipped with an automatic fire-extinguishing system that meets the performance requirements of § 25.854(b).

7. The design of each suite must:

a. Maintain minimum main aisle(s), cross aisle(s), and passageway(s) required by 14 CFR part 25 requirements when subjected to the ultimate inertia forces listed in § 25.561(d).

b. Prevent structural failure or deformation of components that could block access to the available evacuation routes ( e.g., seats, doors, contents of stowage compartments, etc.).

8. In addition to the requirements of § 25.562 for seat systems, which are occupiable during taxi, takeoff, and landing, the suite structure must be designed for the additional loads imposed by the seats as a result of the conditions specified in § 25.562(b).

[FR Doc. 2024-23936 Filed 10-16-24; 8:45 am]

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