AD/B747/63 - APU Fuel Drain System (Cth)

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES

Boeing 747 Series Aeroplanes

AD/B747/63 APU Fuel Drain System 6/88

Applicability: B747 aeroplanes line numbers:

i) 1-153, 156 and 157 on which Boeing SB 747-49-2021 has been incorporated, and

ii) 154, 155, 158-678, 680 and 682-684.

Requirement: 1. Inspect the APU fuel supply line for leaks in accordance with Boeing 747 Maintenance Manual Section 28-25-00 page 601, dated 25 August 1987.

2. Modify the APU fuel line drain system, fuel pump drain, and turbine drain assembly in accordance with Boeing Service Bulletin 747-49-2051 dated 5 November 1987.

Note: FAA AD 88-05-07 Amdt 39-5867 refers.

Compliance: 1. Unless already accomplished, within 30 days after 16 June 1988 and thereafter at intervals not to exceed 30 days until modified in accordance with Para 2 of the Requirement. If leakage is detected, rectify before further flight.

2. Prior to 31 December 1990.

Note: Modification iaw SB 747-49-2051 constitutes terminating action for the repetitive inspection requirements.

Background: An overseas operator has reported finding fuel in the forward cargo compartment and in several of the overwing floor beam bays. The fuel originated from a leak in the APU engine fuel pump seal which pressurized the fuel line shroud and passed into the aircraft through an improperly installed coupling on the shroud. This Directive has been issued to eliminate a potential fire hazard.