Document ID: chunk:federal_register_of_legislation:F2009L02785:body:0:p2
Version: federal_register_of_legislation:F2009L02785
Segment Type: other
Provision Reference: 
Character Range: 2889–4932

Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to the equivalent Requirements of FAA AD 2001-11-08.

                4. MAWEA power supply P/N 285T0035-201 may not be installed on any aeroplane as a replacement part.
             Note 3:  FAA AD 2001-11-08 Amdt 39-12250 refers.
Compliance:  For Requirement 1 - Before every flight until the MAWEA power supply is replaced in accordance with Requirement 2 or Requirement 3.
             For Requirement 2 - Before further flight.
             For Requirement 3 - Within six months after the effective date of this Directive.
             For Requirement 4 - As of the effective date of this Directive.
             This Amendment becomes effective on 30 July 2009.
Background:  The FAA received a report advising that during a production test flight of a Model 747-400 series aeroplane the flight test crew noticed a power supply failure on the status page of the EICAS.  Investigation revealed the automatic bench test procedure for the MAWEA overstressed the 5.7 volt over-voltage clamp circuit which resulted in the failure of the circuit to protect the warning cards in the MAWEA.
             A slow failure of the MAWEA power supply could result in the gradual degradation of available visual, aural and tactile alerts which could result in flight crew not being aware of and not taking immediate or appropriate action in the event of an unsafe condition occurring.
             The original issue of this Directive required repetitive checks to detect failures of the MAWEA power supply and if necessary, corrective action.  The Directive also provided for an optional terminating action.
             This Amendment increased the applicability to include all 747-400 and 747-400F series aeroplanes with a P/N 285T0035-201 MAWEA power supply and made the terminating action mandatory.
             The original issue of this Directive became effective on 22 September 1999.

James Coyne
Delegate of the Civil Aviation Safety Authority

16 June 2009