.

Federal Aviation
Administration

MMEL Policy Letter 107, Revision 1

Date:

May 22, 2001

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:

MMEL Relief for Inoperative APU Generator

MMEL CODE:

24 (ELECTRICAL POWER)

REFERENCE:

PL-107, Revision Original, dated March 6, 2001, signed by Gregory L. Michael

PURPOSE:

The purpose of this policy letter is to provide standardized master minimum equipment list (MMEL) policy for inoperative auxiliary power unit (APU) generator(s).

DISCUSSION:

Revision 1 removes policy containing category and proviso.  APU generators are protected from electrical/mechanical failure by incorporation of several different safety features.  Some of these safety features are very sophisticated on newer APUs, while older units may have minimum protection from a failure. Several aircraft manufacturers have installed systems that will produce messages indicating whether the failure is electrical or mechanical.  Maintenance will be able to troubleshoot the system using company procedures.  MMEL (M) procedures may permit operation of the APU with the generator installed or removed.

POLICY:  

Flight Operation Evaluation Board (FOEB) chairman may allow relief for APU generator(s) provided the board considers the type of failure. The type of failure may dictate if the generator should be removed or remain installed for continued APU operation.

 

This policy should be applied to affected MMELs through the normal FOEB process.

 

 

 

Gary E. Davis for

Gregory L. Michael, Manager,

Air Transportation Division, AFS-200

 

 

 

 

 

PL-107 reformatted on November 6, 2008 with no change to content.