Federal Aviation
Administration      

MMEL Policy Letter 87 Revision 10

Date:

Aug 10, 2010

To:

All Region Flight Standards Division Managers
All Aircraft Evaluation Group Managers

From:

Manager, Air Transportation Division, AFS-200

Reply to Attn of:

Manager, Technical Programs Branch, AFS-260

SUBJECT:

Flight Data Recorder (FDR)

MMEL CODE:

31 (INDICATING / RECORDING SYSTEMS)

REFERENCE:

 

PL-87, Revision 9, dated March 8, 2010

PL-87, Revision 8, dated October 7, 2005

PL-87, Revision 7, dated September 15, 2004

PL-87, Revision 6, dated November 25, 2002

PL-87, Revision 5, dated July 23, 2001

PL-87, Revision 4, dated October 05, 2000
PL-87, Revision 3, dated November 20, 1999
PL-87, Revision 2, dated September 23, 1998
PL-87, Revision 1, dated February 15, 1997
PL-87, Original, dated January 27, 1997
PL-29, Revision 1, dated March 29, 1991

 

 

 

 

PURPOSE:

The purpose of this policy letter is to provide standardized Master Minimum Equipment List (MMEL) requirements for the Flight Data Recorder (FDR) on air carrier aircraft.

 

DISCUSSION:

Revision 10: Expands and clarifies the sub category for air carrier and commercial certificate holders.

 

Revision 9: Revised relief for required FDR parameters by allowing only up to three parameters to be inoperative.

 

Revision 8: Revised PL 87 is to clarify MMEL relief for those air carriers who have a Flight Recorder System installed and when not required by FAR.  The number required is changed from “1” to “-” for the C category MMEL item.

 

Revision 7: Revised PL 87 to provide additional MMEL relief for operators other than holders of an air carrier or commercial operator certificate.

 

Revision 6: Clarifies relief provisions existing for systems when modified with an installed Combined Voice and Flight Data Recorder (CVFDR).

 

Revision 5: Revises policy letter provisos to include the intent of the policy letter narrative concerning FDR failure after pushback or repair attempt.

 

Revision 4 contains inoperative parameters to be repaired under a hard time requirement. It also clarified the term "designated airport" and “FDR inoperative dispatch”.

 

Revision 3 clarifies the intent of the policy stated in Revision 2 by adding an item for FAR required parameters similar to the existing item for parameters not required by Title 14 Code of Federal Regulations (14 CFR).

 

Revision 2 clarifies the intent of policy letter 87, revision 1, and provides for continued use of an FDR with missing required parameters.

 

Revision 1 reformats policy letter 87 with no change to policy.

 

This policy letter was revised in March 1991 as a result of National Transportation Safety Board (NTSB) Safety Recommendation A-90-74, which requested the Federal Aviation Administration (FAA) to require more stringent repair interval criteria for inoperative Cockpit Voice Recorder (CVR) and FDR systems. Each system was assigned a category A repair interval, and the related proviso specified repairs be made within three flight days. The policy granting MMEL relief for the FDR provided the CVR remained operational remained in effect.

 

NTSB Safety Recommendation A-96-46 subsequently requested the FAA to further reexamine this policy to ensure that flight with an inoperative FDR is permitted only until the aircraft's first arrival at a suitable repair facility, but not to exceed three days.

 

Recent 14 CFR changes and requirements have placed greater emphasis on FDR functionality and access to additional parameters. However, the loss of parameters (failures), both those required by 14 CFR and those not required by 14 CFR, is not apparent to the flight crew due to the lack of a visible flight deck indication. The operational status of these parameters is identified by maintenance program procedures. Therefore, relief for these parameters is now specified as Category A and must be repaired within the intervals specified by the MMEL.

 

In order to maintain maximum FDR capability, if it is determined that a parameter is missing, every effort should be made to continue to record all available parameters rather than considering the complete flight data recorder inoperative per MMEL.

 

POLICY:  

The following separate policy has been established for the FDR so that flight with an inoperative recorder is minimized. The FDR system continues to be assigned a Category A repair interval and repairs remain required to be made within three flight days.

 

It is the intent of this policy to ensure that flight with an inoperative FDR is permitted only until the aircraft arrives at a designated airport. The operator will designate airport(s) which have FDR repair capabilities in their respective Minimum Equipment List (MEL). These airport(s) may differ from normal maintenance facilities.

 

In cases where FDR failure occurs after pushback but prior to takeoff at a designated airport, continued operation of the aircraft is allowed to the next designated airport.

 

In cases where repair is attempted but not successful, the aircraft may be dispatched on a flight or series of flights to the next designated airport. When a repair attempt is not successful, repair must be accomplished at the next designated airport.

 

On aircraft that have been modified with a CVFDR, where CVFDR replaces the stand alone CVR and adds redundant FDR functionality, failure of either the Digital Flight Data Recorder (DFDR), or FDR function of CVFDR, does not invoke the need to make stops for repairs at designated airports and can be deferred at the "C" category. Only when all recording is lost, dual FDR failure occurs, or failure of the digital Flight Data Acquisition Unit, does the "A" category relief need be imposed.

 

The following standard MMEL proviso and repair category is adopted to provide standardization among all MMELs.

 

31 INDICATING /     RECORDING SYSTEMS

Repair Interval

Number Installed

Number Required for Dispatch

Remarks or Exceptions

FLIGHT DATA RECORDER (FDR) INSTALLED FOR A HOLDER OF AN AIR CARRIER OR COMMERCIAL OPERATOR CERTIFICATE

XX-X Flight Data Recorder
 (FDR) System

 
 

        Includes FDR function of Combined Voice and Flight Data Recorder (CVFDR)

C

-

-

Any in excess of those required by FAR may be inoperative.

 

A

 

-

 

0

 

May be inoperative provided:

a)            Cockpit Voice Recorder (CVR) operates normally,

b)            Airplane is not dispatched from a designated airport as listed in the operator’s MEL unless:

  1. The FDR failure occurs after pushback but prior to takeoff, or
  2. The FDR repair was attempted but not successful.

c)            In those cases where repair is attempted but not successful, the aircraft may be dispatched on a flight or series of flights until the next designated airport where repair must be accomplished prior to dispatch, and

d)            Repairs are made within three flight days.

FDR Recording Parameters required by FAR

A

-

-

Up to three (3) recording parameters may be inoperative provided:

a)              Cockpit Voice Recorder (CVR) operates normally, and

b)              Repairs are made within 20 calendar days.

FDR Recording Parameters not required by FAR

A

-

-

May be inoperative provided repairs are made prior to the completion of the next heavy maintenance visit.

 

FLIGHT DATA RECORDER (FDR) INSTALLED FOR AN OPERATOR OTHER THAN A HOLDER OF AN AIR CARRIER OR COMMERCIAL OPERATOR CERTIFICATE

 

XX-X Flight Data Recorder
(FDR) System

C

-

1

Any in excess of those required by FAR may be inoperative.

 

A

-

0

May be inoperative provided repairs are made in accordance with applicable FARs.

 

 

 

 

 

Each Flight Operations Evaluation Board (FOEB) Chairman should apply this Policy to affected MMELs through the normal FOEB process.

 

 

 

 

John Duncan Manager,

Air Transportation Division, AFS-200