Federal Aviation
Administration

MMEL Policy Letter (PL) 95, Revision 2

Date:

January 15, 2012

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:

VHF Communications MMEL Requirements

MMEL CODE:

23 (COMMUNICATIONS)

REFERENCE:

PL-95, Revision 1, dated March 20, 2002

PL-95, Original, dated August 15, 1997

PL-17, Original, dated August 30, 1985

14 CFR 91.126, 91.127, 91.129, 91.130, 91.131, 91.135, 91.205, 91.511

121.345, 121.347, 121.349, 121.351, 125.203, 129.17, 135.161, 135.165

PURPOSE:

To establish standardized Master Minimum Equipment List (MMEL) relief for VHF communications equipment.

DISCUSSION:

Revision 2 omits the Global Change (GC) designation for this PL.  Refer to PL-59 for post-GC policy.

Revision 1 deletes the High Frequency (HF) relief from this PL.  Policy for HF MMEL relief is currently addressed in Policy Letter 106, Titled "High Frequency MMEL Requirements."

In the past, many MMELs stated, As required by FAR, with no other qualifications for various communications Systems.  However, safety can be impacted if an aircraft is dispatched with an inoperative communication system that is powered by an emergency bus and subsequent in-flight events require the flightcrew to switch to emergency power.  Thus relief should not be permitted if that communications system or component is powered by an emergency bus.  In addition, subordinate components such as Frequency Transfer Lights, Frequency Transfer Switches, etc. should be listed as part of the MMEL relief, if appropriate.

POLICY:

MMEL communications relief should not be permitted if the communications system or component is powered by an emergency bus, or equivalent, and is required to accomplish an emergency procedure.  While there are significant differences in electrical power distribution between various airplanes, the following MMEL example is intended to provide general communications system guidance to Flight Operations Evaluation Boards (FOEB).  It should be customized, as appropriate, for each airplane type.

 

23 (COMMUNICATIONS)

Repair Interval

Number Installed

Number Required for Dispatch

Remarks or Exceptions

23-X

Communications Systems (VHF and UHF)

D

-

-

Any in excess of those required by CFR may be inoperative provided it is not powered by the Emergency AC Bus, Emergency DC Bus, Battery Bus, Battery Direct Bus, or the DC Transfer Bus and not required for emergency procedures.

1)

VHF Communication Control Panels

 

 

 

 

 

a)  Frequency Transfer Light

C

-

0

 

 

b)  Frequency Transfer Switch

C

-

0

 

 

c)  Frequency Selector Knob

C

-

2

 

 

d)  Frequency Indication

C

-

2

 

 

 

Each FOEB Chairperson should apply this Policy to affected MMELs through the normal FOEB process.

 

 

 

 

 

John S. Duncan

Manager, Air Transportation Division