E6-9819. Special Conditions: Boeing Model 777-200 Series Airplanes; Forward Lower Lobe Crew Rest Compartment (CRC)

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed special conditions.

SUMMARY:

This action proposes special conditions for the Boeing Model 777-200 series airplanes. These airplanes, modified by Aerocon Engineering Company (AEC), will have a novel or unusual design feature associated with a forward lower lobe crew rest compartment (CRC). The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These proposed 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:

We must receive your comments by August 7, 2006.

ADDRESSES:

You must mail two copies of your comments to: Federal Aviation Administration, Transport Airplane Directorate, Attn: Rules Docket (ANM-113), Docket No. NM347, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. You may deliver two copies to the Transport Airplane Directorate at the above address. You must mark your comments: Docket No. NM347. You can inspect comments in the Rules Docket weekdays, except Federal holidays, between 7:30 a.m. and 4 p.m.

FOR FURTHER INFORMATION CONTACT:

Jayson Claar, FAA, Airframe/Cabin Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft Certification Service, 1601 Lind Avenue, SW., Renton, Washington, 98055-4056; telephone [phone]; facsimile [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite interested people to take part in this rulemaking by sending written comments, date, or views. The most helpful comments reference a specific portion of the proposed special conditions, explain the reason for any recommended change, and include supporting data. We ask that you send us two copies of written comments.

We will file in the docket all comments we receive, as well as a report summarizing each substantive public contact with FAA personnel concerning these proposed special conditions. You can inspect the docket before and after the comment closing date. If you wish to review the docket in person, go to the address in the ADDRESSES section of this preamble between 7:30 a.m. and 4 p.m., weekdays, except Federal holidays.

We will consider all comments we receive on or before the closing date for comments. We will consider comments filed late if it is possible to do so without incurring expense or delay. We may make changes to these proposed special conditions based on the comments we receive.

If you want the FAA to acknowledge receipt of your comments on this proposal, include with your comments a pre-addressed, stamped postcard on which the docket number appears. We will stamp the date on the postcard and mail it back to you.

Background

On March 10, 2005, Aerocon Engineering Company (AEC) applied for a supplemental type certificate to permit installation of a CRC in Boeing 777-200 series airplanes.

The CRC will be located under the passenger cabin floor in the forward cargo compartment of Boeing Model 777-200 series airplanes. It will be the size of three standard airfreight containers, combined, and will be removable from the cargo compartment. The CRC will be occupied in flight but not during taxi, takeoff, or landing. No more than ten crewmembers at a time will be permitted to occupy it. The CRC will have a smoke detection system, a hand held fire extinguishing system, and an oxygen system.

The CRC will be accessed from the main deck via a “stairhouse.” The floor within the stairhouse has a hatch that leads to stairs which occupants use to descend into the CRC. This hatch locks automatically in the open position when fully opened. In addition, there will be an emergency hatch which opens directly into the main passenger cabin area. The CRC also has a maintenance access/ground loading door. This door is intended to be used to allow maintenance personnel and cargo handlers to enter the CRC from the cargo compartment when the airplane is not in flight.

Type Certification Basis

Under the provisions of § 21.101, AEC must show that Boeing Model 777-200 series airplanes, as changed, continue to meet (1) the applicable provisions of the regulations incorporated by reference in Type Certificate No. T00001SE or (2) the applicable regulations in effect on the date of application for the change. The regulations incorporated by reference in the type certificate are commonly referred to as the “original type certification basis.” The regulations incorporated by reference in Type Certificate No. T00001SE are as follows:

The certification basis for Boeing Model 777-200 series airplanes is 14 CFR part 25, as amended by Amendments 25-1 through 25-82, except for § 25.571(e)(1) which remains at Amendment 25-71, with exceptions. Refer to Type Certificate No. T00001SE, as applicable, for a complete description of the certification basis for this model, including certain special conditions that are not relevant to these proposed special conditions.

If the Administrator finds that the applicable airworthiness regulations (i.e., 14 CFR part 25) do not contain adequate or appropriate safety standards for Boeing Model 777-200 series airplanes because of a novel or unusual design feature, special conditions are prescribed under the provisions of § 21.16.

In addition to the applicable airworthiness regulations and special conditions, Boeing Model 777-200 series airplanes must comply with the fuel vent and 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 § 11.19, under § 11.38 and they become part of the type certification basis under § 21.101.

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 or similar novel or unusual design feature, or should any other model already included on the same type certificate be modified to incorporate the same or similar novel or unusual design feature, the proposed special conditions would also apply to the other model under § 21.101.

Novel or Unusual Design Features

While the installation of a CRC is not a new concept for large transport category airplanes, each CRC has unique features based on design, location, and use on the airplane. The CRC is novel in terms of part 25 in that it will be located below the passenger cabin floor in the forward cargo compartment of Boeing Model 777-200 series airplanes. Due to the novel or unusual features associated with the installation of a CRC, special conditions are considered necessary to provide a level of safety equal to that established by the airworthiness regulations incorporated by reference in the type certificates of these airplanes. These proposed special conditions do not negate the need to address other applicable part 25 regulations.

Operational Evaluations and Approval

These proposed special conditions specify requirements for design approvals (i.e., type design changes and supplemental type certificates) of CRCs administered by the FAA's Aircraft Certification Service. Prior to operational use of a CRC, the FAA's Flight Standards Service, Aircraft Evaluation Group (AEG), must evaluate and approve the “basic suitability” of the CRC for occupation by crewmembers. If an operator wishes to utilize a CRC as “sleeping quarters,” the CRC must undergo an additional operational evaluation and approval. The CRC would be evaluated for compliance to §§ 121.485(a) and 121.523(b), with Advisory Circular 121-31, Flight Crew Sleeping Quarters and Rest Facilities, providing one method of compliance to these operating regulations.

To obtain an operational evaluation, the type design holder must contact the AEG within the Flight Standards Service which has operational approval authority for the project. In this instance, it is the Seattle AEG. The type design holder must request a “basic suitability” evaluation or a “sleeping quarters” evaluation of the crew rest. The type design holder may make these requests concurrently with the demonstration of compliance with these special conditions.

The results of these evaluations will be documented in the Boeing Model 777-200 Flight Standardization Board (FSB) Report Appendix. In discussions with their FAA Principal Operating Inspector (POI), individual operators may reference these standardized evaluations as the basis for an operational approval, in lieu of an on-site operational evaluation.

An operational re-evaluation and approval will be required for any changes to the approved CRC configuration, if the changes affect procedures for emergency egress of crewmembers, other safety procedures for crewmembers occupying the CRC, or training related to these procedures. The applicant for any such change is responsible for notifying the Seattle AEG that a new crew rest evaluation is required.

All instructions for continued airworthiness (ICAW), including service bulletins, must be submitted to the Seattle AEG for approval acceptance before the FAA issues its approval of the modification.

Discussion of Proposed Special Conditions No. 9 and 12

The following clarifies how proposed Special Condition No. 9 should be understood relative to the requirements of § 25.1439(a):

Amendment 25-38 modified the requirements of § 25.1439(a) by adding, “In addition, protective breathing equipment must be installed in each isolated separate compartment in the airplane. Including upper and lower lobe galleys, in which crewmember occupancy is permitted during flight for the maximum number of crewmembers expected to be in the area during any operation.” The CRC is an isolated separate compartment, so § 25.1439(a) is applicable. However, the § 25.1439(a) PBE requirements for isolated separate compartments are not appropriate because the CRC is novel and unusual in terms of the number of occupants.

In 1976 when Amendment 25-38 was adopted, small galleys were the only isolated compartments that had been certificated. Two crewmembers were the maximum expected to occupy those galleys.

These proposed special conditions address a CRC, which can accommodate up to ten crewmembers. This large number of occupants in an isolated compartment was not envisioned at the time Amendment 25-38 was adopted. It is not appropriate for all occupants to don PBE in the event of a fire because the first action should be to leave the confined space unless the occupant is fighting the fire. Taking the time to don the PBE would prolong the time for the emergency evacuation of the occupants and possibly interfere with efforts to extinguish the fire.

In regard to proposed Special Condition No. 12, the FAA considers that during the 1-minute smoke detection time, penetration of a small quantity of smoke from this forward lower lobe CRC design into an occupied area on this airplane configuration would be acceptable based upon the limitations placed in these proposed special conditions. The FAA determination considers that the proposed special conditions place sufficient restrictions in the quantity and type of material allowed in crew carry-on bags that the threat from a fire in this remote area would be equivalent to that experienced on the main cabin.

Applicability

As discussed above, these proposed special conditions are applicable to Boeing Model 777-200 series airplanes as modified by the AEC forward lower lobe CRC. Should AEC apply at a later date for a change to the supplemental type certificate to include another model listed on the same type certificate data sheet, incorporating the same or similar novel or unusual design feature, these special conditions would apply to that model as well.

Conclusion

This action affects only certain novel or unusual design features on the Boeing Model 777-200 series airplanes. It is not a rule of general applicability, and it affects only the applicant which applied to the FAA for approval of these features on the airplane.

List of Subjects in 14 CFR Part 25

• Aircraft
• Aviation safety
• Reporting and recordkeeping requirements

The authority citation for these proposed special conditions is as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.

The Proposed Special Conditions

Accordingly, the Federal Aviation Administration (FAA) proposes the following special conditions as part of the type certification basis for the Boeing Model 777-200 series airplanes, modified by Aerocon Engineering Company.

1. Occupancy of the forward lower lobe crew rest compartment (CRC) is limited to the total number of installed bunks and seats in each compartment. There must be an approved seat or Berth able to withstand the maximum flight loads when occupied for each occupant permitted in the CRC. The maximum occupancy is ten in the CRC.

(a) There must be appropriate placard(s) displayed in a conspicuous place at each entrance to the CRC to indicate:

(1) The maximum number of occupants allowed;

(2) That occupancy is restricted to crewmembers who are trained in the evacuation procedures for the CRC;

(3) That occupancy is prohibited during taxi, take-off and landing;

(4) That smoking is prohibited in the CRC;

(5) That hazardous quantities of flammable fluids, explosives, or other dangerous cargo are prohibited from the CRC; and

(6) That stowage in the CRC must be limited to emergency equipment, airplane-supplied equipment (e.g., bedding), and crew personal luggage; cargo or passenger baggage is not allowed.

(b) There must be at least one ashtray located conspicuously on or near the entry side of any entrance to the CRC.

(c) There must be a means to prevent passengers from entering the compartment in the event of an emergency or when no flight attendant is present.

(d) There must be a means for any door installed between the CRC and passenger cabin to be capable of being quickly opened from inside the compartment, even when crowding occurs at each side of the door.

(e) For all doors installed in the evacuation routes, there must be a means to preclude anyone from being trapped inside the compartment. If a locking mechanism is installed, it must be capable of being unlocked from the outside without the aid of special tools. The lock must not prevent opening from the inside of the compartment at any time.

2. There must be at least two emergency evacuation routes, each of which can be used by each occupant of the CRC to rapidly evacuate to the main cabin. The exit door/hatch for each route must be able to be closed for the main cabin after evacuation. In addition—

(a) The routes must be located with one at each end of the compartment, or with two having sufficient separation within the compartment and between the routes to minimize the possibility of an event (either inside or outside of the CRC) rendering both routes inoperative.

(b) The routes must be designed to minimize the possibility of blockage, which might result from fire, mechanical or structural failure, or persons standing on top of or against the escape route. If an evacuation route utilizes an area where normal movement of passengers occurs, it must be demonstrated that passengers would not impede egress to the main deck. If a hatch is installed in an evacuation route, the point at which the evacuation route terminates in the passenger cabin should not be located where normal movement by passengers or crew occurs (main aisle, cross aisle, passageway or galley complex). If such a location cannot be avoided, special consideration must be taken to ensure that the hatch or door can be opened when a person, the weight of a ninety-fifth percentile male, is standing on the hatch or door. The use of evacuation routes must not be dependent on any powered device. If there is low headroom at or near an evacuation route, provisions must be made to prevent or to protect occupants (of the CRC) from head injury.

(c) Emergency evacuation procedures, including the emergency evacuation of an incapacitated occupant from the CRC, must be established. All of these procedures must be transmitted to all operators for incorporation into their training programs and appropriate operational manuals.

(d) There must be a limitation in the Airplane Flight Manual or other suitable means requiring that crewmembers be trained in the use of evacuation routes.

3. There must be a means for the evacuation of an incapacitated person (representative of a 95th percentile male) from the CRC to the passenger cabin floor. The evacuation must be demonstrated for all evacuation routes. A flight attendant or other crewmember (a total of one assistant within the CRC) may provide assistance in the evacuation. Additional assistance may be provided by up to three persons in the main passenger compartment. For evacuation routes having stairways, the additional assistants may descend down to one half the elevation change from the main deck to the lower deck compartment, or to the first landing, whichever is higher.

4. The following signs and placards must be provided in the CRC:

(a) At least one exit sign, located near each exit, meeting the requirements of § 25.812(b)(1)(i) at Amendment 25-58, except that a sign with reduced background area of no less than 5.3 square inches (excluding the letters) may be utilized, provided that it is installed such that the material surrounding the exit sign is light in color (e.g., white, cream, light beige). If the material surrounding the exit sign is not light in color, a sign with a minimum of a one-inch wide background border around the letters would also be acceptable;

(b) An appropriate placard located near each exit defining the location and the operating instructions for each evacuation route;

(c) Placards must be readable from a distance of 30 inches under emergency lighting conditions; and

(d) The exit handles and evacuation path operating instruction placards must be illuminated to at least 160 micro lamberts under emergency lighting conditions.

5. There must be a means in the event of failure of the aircraft's main power system, or of the normal CRC lighting system, for emergency illumination to be automatically provided for the CRC.

(a) This emergency illumination must be independent of the main lighting system.

(b) The sources of general cabin illumination may be common to both the emergency and the main lighting systems if the power supply to the emergency lighting system is independent of the power supply to the main lighting system.

(c) The illumination level must be sufficient for the occupants of the CRC to locate and transfer to the main passenger cabin floor by means of each evacuation route.

(d) The illumination level must be sufficient with the privacy curtains in the closed position for each occupant of the CRC to locate a deployed oxygen mask.

6. There must be means for two-way voice communications between crewmembers on the flightdeck and occupants of the CRC. There must also be public address (PA) system microphones at each flight attendant seat required to be near a floor level exit in the passenger cabin per § 25.785(h) at Amendment 25-51. The PA system must allow two-way voice communications between flight attendants and the occupants of the CRC, except that one microphone may serve more than one exit provided the proximity of the exits allows unassisted verbal communication between seated flight attendants.

7. There must be a means for manual activation of an aural emergency alarm system, audible during normal and emergency conditions, to enable crewmembers on the flightdeck and at each pair of required floor level emergency exits to alert occupants of the CRC of an emergency situation. Use of a public address or crew interphone system will be acceptable, provided an adequate means of differentiating between normal and emergency communications is incorporated. The system must be powered in flight for at least ten minutes after the shutdown or failure of all engines and auxiliary power units (APU) or the disconnection or failure of all power sources which are dependent on the continued operation of the engines and APUs.

8. There must be a means, readily detectable by seated or standing occupants of the CRC, which indicates when seat belts should be fastened. In the event there are no seats, at least one means must be provided to cover anticipated turbulence (e.g., sufficient handholds). Seat belt type restraints must be provided for berths and must be compatible for the sleeping attitude during cruise conditions. There must be a placard on each berth requiring that seat belts must be fastened when occupied. If compliance with any of the other requirements of these special conditions is predicated on specific head location, there must be a placard identifying the head position.

9. In lieu of the requirements specified in § 25.1439(a) at Amendment 25-38 that pertain to isolated compartments and to provide a level of safety equivalent to that which is provided occupants of a small isolated galley, the following equipment must be provided in the CRC:

(a) At least one approved hand-held fire extinguisher appropriate for the kinds of fires likely to occur;

(b) Two PBE devices approved to Technical Standard Order (TSO)-C116 or equivalent, suitable for fire fighting, or one PBE for each hand-held fire extinguisher, whichever is greater; and

(c) One flashlight.

Note:

Additional PBEs and fire extinguishers in specific locations, (beyond the minimum numbers prescribed in Special Condition No. 9) may be required as a result of any egress analysis accomplished to satisfy Special Condition No. 2(a).

10. A smoke or fire detection system (or systems) must be provided that monitors each occupiable area within the CRC, including those areas partitioned by curtains. Flight tests must be conducted to show compliance with this requirement. Each system (or systems) must provide:

(a) A visual indication to the flightdeck within one minute after the start of a fire;

(b) An aural warning in the CRC; 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.

11. The CRC must be designed such that fires within the compartment can be controlled without a crewmember having to enter the compartment, or the design of the access provisions must allow crewmembers equipped for fire fighting to have unrestricted access to the compartment. The time for a crewmember on the main deck to react to the fire alarm, to don the fire fighting equipment, and to gain access must not exceed the time for the compartment to become smoke-filled, making it difficult to locate the fire source.

12. There must be a means provided to exclude hazardous quantities of smoke or extinguishing agent originating in the CRC from entering any other compartment occupied by crewmembers or passengers. This means must include the time periods during the evacuation of the CRC and, if applicable, when accessing the CRC to manually fight a fire. Smoke entering any other compartment occupied by crewmembers or passengers when the access to the CRC is opened, during an emergency evacuation, must dissipate within five minutes after the access to the CRC is closed. Hazardous quantities of smoke may not enter any other compartment occupied by crewmembers or passengers during subsequent access to manually fight a fire in the CRC (the amount of smoke entrained by a firefighter exiting the CRC through the access is not considered hazardous). During the 1-minute smoke detection time, penetration of a small quantity of smoke from the CRC into an occupied area is acceptable. Flight tests must be conducted to show compliance with this requirement.

If a built-in fire extinguishing system is used in lieu of manual fire fighting, then the fire extinguishing system must be designed so that no hazardous quantities of extinguishing agent will enter other compartments occupied by passengers or crew. The system must have adequate capacity to suppress any fire occurring in the CRC, considering the fire threat, volume of the compartment and the ventilation rate.

13. There must be a supplemental oxygen system equivalent to that provided for main deck passengers for each seat and berth in the CRC. The system must provide an aural and visual warning to warn the occupants of the CRC to don oxygen masks in the event of decompression. The warning must activate before the cabin pressure altitude exceeds 15,000 feet. The aural warning must sound continuously for a minimum of five minutes or until a reset push button in the CRC is depressed. Procedures for crew rest occupants to follow in the event of decompression must be established. These procedures must be transmitted to the operators for incorporation into their training programs and appropriate operational manuals.

14. The following requirements apply to CRCs that are divided into several sections by the installation of curtains or partitions:

(a) To warn sleeping occupants, there must be an aural alert that can be heard in each section of the CRC and that accompanies automatic presentation of supplemental oxygen masks. A visual indicator that occupants must don an oxygen mask is required in each section where seats or berths are not installed. A minimum of two supplemental oxygen masks is required for each seat or berth. There must also be a means by which the oxygen masks can be manually deployed from the flightdeck.

(b) A placard is required adjacent to each curtain that visually divides or separates, for privacy purposes, the CRC into small sections. The placard must require that the curtain remains open when the private section it creates is unoccupied.

(c) For each section of the CRC created by the installation of a curtain, the following requirements of these special conditions must be met both with the curtain open and with the curtain closed:

(1) Emergency illumination (Special Condition No. 5);

(2) Emergency alarm system (Special Condition No. 7);

(3) Seat belt fasten signal or return to seat signal as applicable (Special Condition No. 8); and

(4) The smoke or fire detection system (Special Condition No. 10).

(d) Crew rest compartments visually divided to the extent that evacuation could be affected must have exit signs that direct occupants to the primary stairway exit. The exit signs must be provided in each separate section of the CRC, and must meet the requirements of § 25.812(b)(1)(i) at Amendment 25-58. An exit sign with reduced background area as described in Special Condition No. 4(a) may be used to meet this requirement.

(e) For sections within a CRC that are created by the installation of a partition with a door separating the sections, the following requirements of these special conditions must be met both with the door open and with the door closed:

(1) There must be a secondary evacuation route from each section to the main deck, or alternatively, it must be shown that any door between the sections has been designed to preclude anyone from being trapped inside the compartment. Removal of an incapacitated occupant within this area must be considered. A secondary evacuation route from a small room designed for only one occupant for short time duration, such as a changing area or lavatory, is not required. However, removal of an incapacitated occupant within this area must be considered.

(2) Any door between the sections must be shown to be openable when crowded against, even when crowding occurs at each side of the door.

(3) There may be no more than one door between any seat or berth and the primary stairway exit.

(4) There must be exit signs in each section meeting the requirements of § 25.812(b)(1)(i) at Amendment 25-58 that direct occupants to the primary stairway exit. An exit sign with reduced background area as described in Special Condition No. 4(a) may be used to meet this requirement.

(5) Special Conditions No. 5 (emergency illumination), No. 7 (emergency alarm system), No. 8 (fasten seat belt signal or return to seat signal as applicable) and No. 10 (smoke or fire detection system) must be met both with the door open and with the door closed.

(6) Special Conditions No. 6 (two-way voice communication) and No. 9 (emergency fire fighting and protective equipment) must be met independently for each separate section except for lavatories or other small areas that are not intended to be occupied for extended periods of time.

15. Where a waste disposal receptacle is fitted, it must be equipped with a built-in fire extinguisher designed to discharge automatically upon occurrence of a fire in the receptacle.

16. Materials (including finishes or decorative surfaces applied to the materials) must comply with the flammability requirements of § 25.853 at Amendment 25-72. Mattresses must comply with the flammability requirements of § 25.853(b) and (c) at Amendment 25-72.

17. All lavatories within the CRC are required to meet the same requirements as those for a lavatory installed on the main deck except with regard to Special Condition No.10 for smoke detection.

18. When a CRC is installed or enclosed as a removable module in part of a cargo compartment or is located directly adjacent to a cargo compartment without an intervening cargo compartment wall, the following apply:

(a) Any wall of the module (container) forming part of the boundary of the reduced cargo compartment, subject to direct flame impingement from a fire in the cargo compartment and including any interface item between the module (container) and the airplane structure or systems, must meet the applicable requirements of § 25.855 at Amendment 25-72.

(b) Means must be provided so that the fire protection level of the cargo compartment meets the applicable requirements of § 25.855 at Amendment 25-72, § 25.857 at Amendment 25-60 and § 25.858 at Amendment 25-54 when the module (container) is not installed.

(c) Use of each emergency evacuation route must not require occupants of the CRC compartment to enter the cargo compartment in order to return to the passenger compartment.

(d) The aural warning in Special Condition No. 7 must sound in the CRC.

19. Means must be provided to prevent access into the Class C cargo compartment during all airplane flight operations and to ensure that the maintenance door is closed during all airplane flight operations.

20. All enclosed stowage compartments within the CRC 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 ft ³ in interior volume. The in-flight 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.

Stowage Compartment Interior Volumes

Fire protection features	Less than 25 ft 3	25 ft 3 to 57 ft 3	57 ft 3 to 200 ft 3
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 ft 3 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 ft 3 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 flightdeck within one minute after the start of a fire;
(b) An aural warning in the CRC; 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 ft 3 in interior volume but less than 57 ft 3 in interior volume. For all enclosed stowage compartments equal to or greater than 57 ft 3 in interior volume but less than or equal to 200 ft 3, a liner must be provided that meets the requirements of § 25.855 at Amendment 25-72 for a class B cargo compartment.
4 Location Detector—Crew rest areas which contain enclosed stowage compartments exceeding 25 ft 3 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 Renton, Washington, on June 13, 2006.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.