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Federal Aviation Administration
Washington, DC

MMEL Policy Letter 79, Revision 9

Date:                                          12/05/2017

To:                                             Manager, Aircraft Evaluation Division (AFS-100)
     All Aircraft Evaluation Group Managers

From:                                        Manager, Air Transportation Division (AFS-200)

Reply to Attn of:                       Manager, New Program Implementation Branch (AFS-240)

SUBJECT:                       Passenger Seat Relief

MMEL CODE:                        25 (EQUIPMENT/FURNISHINGS)

REFERENCE:                         PL-79, Revision 8, dated March 12, 2012
    PL-79, Revision 7, dated December 01, 2009
    PL-79, Revision 6, dated August 04, 2008
    PL-79, Revision 5, dated June 01, 2007
    PL-79, Revision 4, dated June 10, 2005
    PL-79, Revision 3, dated September 15, 2004
    PL-79, Revision 2, dated March 01, 2001
    PL-79, Revision 1, dated August 15, 1997
    PL-79, Original, dated November 14, 1995

PURPOSE:

The purpose of this Policy Letter is to provide guidance to FOEB Chairmen for relief associated with aircraft passenger seats and their components.

DISCUSSION:

Revision 9: This revision addresses new seat technology and provides guidance to FOEB Chairmen for current and future passenger seat configurations related to MMEL relief.

Revision 8: Revised Passenger Seat(s); added subsystem 4: Seat Belt Air Bag Restraint System: Passenger Seats, whose positions were certified with airbags using the Head-Injury Criteria (HIC) requirements per 14 CFR part 25, 25.562, may not be used if the air bags are inoperable. A seat with an inoperable airbag may be used if the seat position was not certificated using HIC and there is no change to the functionality of the seat belt restraint system.

Revision 7: Revised to provide operator guidance for passenger seat deferrals with seat cushions removed.

Revision 6: Revised the repair category for second set of “Recline Mechanism” provisos from repair category C to D. Removed the (M) from the second set of “Recline Mechanism” provisos when a seat is immovable in the full upright position (seat is already immovable and no maintenance is required). Revised repair category for “Armrest” proviso from repair category C to D. Added an (M) to the existing “Armrest” proviso with a recline mechanism because the seat must be secured in the upright position. Added a second set of provisos to the “Armrest” relief for an armrest without a recline mechanism.

Revision 5: Revised repair category for passenger seats from repair category C to D. Added an (M) to the existing proviso for the recline mechanism. Added a second set of provisos with an (M) to the “Recline Mechanism” when a seat is immovable in the full upright position.

Revision 4: Revised subitem 3) “Armrest”. The (O) was deleted from the proviso, and proviso a) and b) titles were changed from “Seat” to “Armrest”. Proviso c) was added for an armrest with a recline mechanism.

Revision 3: Added “Armrest” as subitem 3.

Revision 2: Changed the repair category to C to comply with the PL-52, Revision 3 (Category D Policy Letter).

Revision 1: Reformatted the Policy Letter with no change to policy.

POLICY:

The following MMEL provisos and repair categories are provided for passenger seat components related to the safe egress from an aircraft and seats being in the certified taxi, takeoff, and landing (TTL) position. The items listed are basic to most fleet types; new technology and seat development will result in each FOEB Chairman having to evaluate new relief based on the two primary requirements of having unrestricted emergency egress and the seat being in the TTL position.

Items not related to emergency egress or TTL could be addressed through the operator’s approved NEF program provided they can be justified using the NEF process and can be secured or removed to provide unrestricted emergency egress.

MMEL TABLE KEY
SYSTEM & SEQUENCE NO.
ITEM
1. REPAIR CATEGORY
2. NUMBER INSTALLED
3. NUMBER REQUIRED FOR DISPATCH
4. REMARKS OR EXCEPTIONS

25. EQUIPMENT/FURNISHINGS

 

Sequence No.

Item

1

2

3

4

Change Bar

25-XX

Passenger Seats

 

 

 

 

 

1)

Passenger Seats
(Includes all Configurations and Locations)

D

-

-

May be inoperative provided:

a)   Seat does not restrict access to any emergency exit, egress route, or main aisle, and

b)   The affected seat(s) is blocked and placarded “DO NOT OCCUPY”.

NOTE 1: A seat with an inoperative seat belt or shoulder harness is considered inoperative.

NOTE 2: Affected seat(s) may include the seat(s) behind and/or adjacent outboard seats.

NOTE 3: Inoperative seats do not affect the required number of Flight Attendants.

 

2)

Positioning Controls for Taxi, Takeoff, and Landing (TTL)
(Mechanical and/or Electrical)

D

-

-

(M) May be inoperative and seat occupied provided seat is secured in the taxi, takeoff, and landing (TTL) position.

 

 

 

D

-

-

May be inoperative and seat occupied provided seat is immovable in the taxi, takeoff, and landing (TTL) position.

 

3)

Under Seat Baggage Restraining System

C

-

-

(O) May be inoperative provided:

a)   Baggage is not stowed under seat with inoperative restraining system,

b)   Associated seat is placarded “DO NOT STOW BAGGAGE UNDER THIS SEAT”, and

c)   Procedures are established to alert Cabin Crew of inoperative restraining system.

 

4)

Armrests

 

 

 

 

 

a)

With Seat Positioning Controls for Taxi, Takeoff, and Landing (TTL) and/or Other Controls

D

-

-

(M) May be inoperative or missing and seat occupied provided:

a)   Armrest does not restrict access to any emergency exit, egress route, or main aisle, and

b)   If Armrest with seat control is missing or removed, seat is secured in taxi, takeoff, and landing (TTL) position.

 

b)

Without Seat Positioning Controls for Taxi, Takeoff, and Landing (TTL) and/or Other Controls

D

-

-

May be inoperative or missing and seat occupied provided it does not restrict access to any emergency exit, egress route, or main aisle.

 

5)

Seat Belt/Air Bag Restraint Systems

 

 

 

 

 

a)

Seat Belt/Air Bags Required by 14 CFR

D

-

-

May be inoperative provided affected seat is blocked and placarded “DO NOT OCCUPY”.

 

b)
***

Seat Belt/Air Bags Not Required by 14 CFR

D

-

-

(M) May be inoperative or disconnected provided seat belt operates normally.

 

Each Flight Operations Evaluation Board (FOEB) Chair should review the specific aircraft configuration(s) and apply this policy to affected MMELs through the normal FOEB process.

ORIGINAL SIGNED by

/s/ Stephen C. Moates for

Manager, Air Transportation Division