AD/F28/82 - Fuel Boost Pump Wiring
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
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Fokker F28 Series Aeroplanes
AD/F28/82 Fuel Boost Pump Wiring 1/2000 DM
Applicability: Model F.28 Mk.1000 through Mk.4000 series aeroplanes.
Requirement: 1. Perform a one time review of the aeroplane Maintenance Logs in accordance with Part 1 of the Accomplishment Instructions of Fokker Service Bulletin (SB) F28/28-046 dated 1 September 1999.
2. If, either during the Requirement 1 review or during subsequent service of the aeroplane, reports are found of resettable or non-resettable tripping of the Fuel Boost Pump circuit breakers, perform corrective actions in accordance with Part 2 of the Accomplishment Instructions of SB F28/28-046 dated 1 September 1999.
3. Check for signs of fuel leakage from the Boost Pump wiring conduits in accordance with Part 1 of the Accomplishment Instructions of SB F28/28-046 dated 1 September 1999.
4. If, during the Requirement 3 inspection or any other inspection, fuel leakage is found from the Boost Pump wiring conduit on the rear spar of the wing, perform corrective action in accordance with Part 2 of the Accomplishment Instructions of SB F28/28-046 dated 1 September 1999.
5. Replace the existing three single wires inside the Boost Pump metal conduit with three twisted wires, protected by a Polyamide braided wire sleeve in accordance with Part 3 of the Accomplishment Instructions of SB F28/28-046 dated 1 September 1999.
Accomplishment of Requirement 5 is considered terminating action for Requirements 1, 2 and 3.
Note 1: Netherlands AD 1999-114 (A) refers.
Compliance: 1. Within 30 days after the effective date of this Directive.
2. Within the ten days following the occurrence.
Note 2: During the ten days subsequent to the report of resettable or non-resettable circuit breaker tripping, operation with an unserviceable boost pump is only allowed provided that the boost pump circuit breaker is pulled and secured. Both the circuit breaker and the boost pump switch are to be placarded as ‘INOPERATIVE’.
MMEL item 28-22-1 and the relevant Operating Procedure also pertain to this subject.
3. Within 30 days after the effective date of this Directive and thereafter at intervals not to exceed 90 days.
4. Before further flight.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
5. In accordance with the following table:
| Aircraft hours total time in service on the effective date of this Directive | Compliance period after the effective date of this Directive |
|---|---|
| equal to or exceeding 40,000 | one year |
| less than 40,000 | two years |
This Airworthiness Directive becomes effective on 8 December 1999.
Background: The Fokker B.V. Fuel System Safety Programme investigation of the boost pump wiring on Fokker F28 aeroplanes revealed that the boost pump wiring insulation layers can be damaged during installation/removal and/or chafing of the wiring. Additionally, signs of arcing between the wiring and the conduit was detected in two boost pump wiring metal conduits located in the collector tank.
This Directive requires a one time review of aircraft maintenance documentation, repetitive checks for signs of fuel leakage from the boost pump wiring conduits inside the Main Landing Gear strut bays and corrective action as necessary. The Directive also requires eventual replacement of the existing three single wires in the boost pump metal conduit.