# Presentation: 428180

## International Aircraft Materials Fire Test Working Group

**Special Conditions for Passenger Airplanes, Seats with Non-Traditional, Large Non-Metallic Panels**

- IAMFTWG Niagara Falls

- Tim Marker, FAA Technical Center

- June 17, 2008

## Example: Notice 25-06-13-SC for 737 airplanes, although

- FAA intends to issue Special Conditions for all transport
- category airplane types with more than 19 passengers.

## History

- 1980’s, research on postcrash cabin fire; development of 2 new standards,
- one for seat cushion flammability, another for large surface area interior panels.

- Heat release rate corollary to postcrash fire survival time.  Materials that comply
- with the new standard extend survival time by approximately 2 minutes.

- At the time these new standards were being written, the application of the heat
- release and smoke emission requirements to seats was investigated.

- It was determined that the overall effect on survivability was negligible, therefore
- the requirements did not address seats.  One primary reason seats were excluded
- was because of the recently-adopted standards for flammability of seat cushions
- would greatly inhibit involvement of the seats.

## Background

- August 8, 2005, Boeing applied for a design change to Type Certificate
- No. A16WE for installation of seats that include non-traditional, large,
- non-metallic panels in Boeing Model 737-700 series airplanes.

- Type Certificate No. A16WE does not require seats to meet the more
- stringent flammability standards required of large, non-metallic panels
- in the cabin interior.

- At the time applicable Rules were written, seats were designed with a
- metal frame covered by fabric, not with large, non-metallic panels.  Seats
- also met the recently adopted oil burner test for cushions.

- With seats designed mostly of fabric and metal, their contribution to a
- cabin fire had been minimized and not considered a threat.

- For these reasons, seats did not need to be tested to the HRR and
- smoke emission requirements.

## Background

- non-metallic panels.  Taken in total, the surface area of these panels is on the
- same order as the sidewall and overhead stow bin interior panels.

- To provide the level of passenger protection intended by the airworthiness
- standards, these non-traditional, large, non-metallic panels in the cabin must
- meet the standards of Title 14 CFR, Part 25, Appendix F, parts IV and V.

## Example of Seat with Non-Traditional Large, Non-Metallic Panel

## Example of Seat with Non-Traditional Large, Non-Metallic Panel

## Example of Seat with Non-Traditional Large, Non-Metallic Panel

## Example of Seat with Non-Traditional Large, Non-Metallic Panel

## Memorandum 97-112-39, Guidance for Flammability

- Testing of Seat/Console Installations, Oct 17, 1997

- Memo issued when it became clear that seat designs were evolving to include
- large, non-metallic panels with surface areas that would impact survivability
- during a cabin fire event, comparable to partitions or galleys.

- Memo noted that large surface area panels must comply with heat release and
- smoke emission requirements, even if they were attached to a seat.  In the
- absence of this policy, the use of panels on seat structures would have been a
- loophole in the airworthiness standards that would result in an unacceptable
- decrease in survivability during a cabin fire event.

## Definition of Non-Traditional, Large, Non-Metallic Panel

- A non-traditional, large, non-metallic panel is defined as a panel with _exposed_
- surface areas greater than 1.5 square feet installed per seat place.

- The panel may consist of either a single component or multiple components in
- a concentrated area.

- Examples of seat parts where these non-traditional panels are installed include,
- but are not limited to: seat backs, seat bottoms, leg/foot rests, kick panels, back
- shells, credenzas, and associated furniture.

- Examples of traditional _exempted_ parts of the seat include: Arm caps, armrest
- close-outs such as end bays and armrest-styled center consoles, food trays,
- video monitors, and shrouds.

## Clarification of “Exposed”

- senger cabin in the traditional sense, plus those panels enveloped such as
- by a dress cover.

- Traditional fabrics or leathers currently used on seats are excluded from these
- special conditions.  Non-traditional, large, non-metallic panels covered with
- traditional fabrics or leathers will be tested without their coverings or covering
- attachments.

## Final Rule at Amendment 25-83

- Final Rule at Amendment 25-83 clarified the definition of minimum panel size:
- “It is not possible to cite a specific size that will apply in all installations; however,
- as a general rule, components with exposed surface areas of one square foot or
- less may be considered small enough that they do not have to meet the new
- standards.  Components with exposed surface areas greater than two square
- feet may be considered large enough that they do have to meet the new
- standards.  Those with exposed surface areas greater than one square foot, but
- less than two square feet, must be considered in conjunction with the areas of
- the cabin in which they are installed before a determination can be made”.

## Final, Special Conditions

- ...the following special conditions are issued as part of the type certification basis
- for Boeing Model 737 series airplanes.

- Except as provided in paragraph 3 of these special conditions, compliance with
- Title 14 FR part 25, Appendix F, parts IV and V, heat release and smoke emission,
- is required for seats that incorporate non-traditional, large, non-metallic panels that
- may either be a single component or multiple components in a concentrated area
- in their design.

- 2. The applicant may designate up to and including 1.5 square feet of non-traditional
- non-metallic panel material per seat place that does not have to comply with special
- condition 1, above.  A triple seat assembly may have a total of 4.5 square feet
- excluded on any portion of the assembly (e.g., outboard seat place 1 square foot,
- middle 1 square foot, and inboard 2.5 square feet).

## Final, Special Conditions

- Appendix F, parts IV and V, when installed in compartments that are not otherwise
- required to meet these requirements.  Examples include:
- a. Airplanes with passenger capacities of 19 or less,
- b. Airplanes that do not have Sec. 25.853, Amendment 25-61 or later, in their
- certification basis and are not subject to the requirements of 14 CFR 121.312,
- c. Airplanes exempted from Sec. 25.853, Amendment 25-61 or later.

- 4. Only airplanes associated with new seat certification programs applied for after
- the effective date of these special conditions will be affected by the requirements
- in these special conditions.  Previously certificated interiors on the existing airplane
- fleet and follow-on deliveries of airplanes with previously certificated interiors are
- not affected.