Airworthiness Directive · Amendment 39-11761 · Fokker Model F.28 Mark 1000, 2000, 3000, and 4000 Series Airplanes
Fokker Model F.28 Mark 1000, 2000, 3000, and 4000 Series Airplanes
Model F.28 Mark 1000, 2000, 3000, and 4000 series airplanes having serial numbers 11003 through 11241 inclusive and 11991 through 11994 inclusive, certificated in any category.
Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (f) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
This amendment adopts a new airworthiness directive (AD), applicable to certain Fokker Model F.28 Mark 1000, 2000, 3000, and 4000 series airplanes, that requires a one-time review of the maintenance records to determine if tripping of the fuel boost pump circuit breakers has been recorded, repetitive inspections to detect fuel leakage from the fuel boost pump wiring conduits, and corrective actions, if necessary. This amendment also requires replacement of the three single wires inside the metal conduit of the fuel boost pumps with new wires protected by a polyamide sleeve, which terminates the repetitive inspections. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent the fuel boost pump wiring from chafing, which could result in electrical arcing and a possible fuel tank ignition source.
To prevent the fuel boost pump wiring from chafing, which could result in electrical arcing and a possible fuel tank ignition source, accomplish the following:
(a) Within 30 days after the effective date of this AD, perform a one-time inspection of the maintenance records of the airplane to determine if tripping of the fuel boost pump circuit breakers has been reported within the last 30 days, in accordance with Part 1 of the Accomplishment Instructions of Fokker Service Bulletin SBF28/28-046, dated September 1, 1999.
(b) If resettable or unresettable tripping of the circuit breaker of the fuel boost pump is reported during the inspection required by paragraph (a) of this AD, or if such tripping is reported at any time subsequent to that inspection: Within 10 days after the date of the inspection or any occurrence, accomplish the applicable repair (including a resistance check and inspections of the wire and conduit for discrepancies), in accordance with Part 2 of the Accomplishment Instructions of Fokker Service Bulletin SBF28/28-046, dated September 1, 1999. If any discrepancy is detected during any inspection performed during the repair, prior to further flight, repair in accordance with the service bulletin.
(c) In the event of any resettable or unresettable tripping of the circuit breakers of the fuel boost pump as indicated in paragraph (b) of this AD, the airplane may be operated for a period not to exceed 10 days after the occurrence, provided the circuit breaker of the fuel boost pump and fuel boost pump switch have been properly deactivated and placarded for flightcrew awareness, in accordance with the FAA-approved Master Minimum Equipment List (MMEL).
(d) Within 30 days after the effective date of this AD, perform a general visual inspection to detect signs of fuel leakage from the wiring conduits of the fuel boost pumps, in accordance with Part 1 of the Accomplishment Instructions of Fokker Service Bulletin F28/28-046, dated September 1, 1999. If any fuel leakage is detected during the inspection, prior to further flight, isolate the fuel leak, and repair in accordance with Part 2 of the Accomplishment Instructions of the service bulletin. Thereafter, repeat the inspection at intervals not to exceed 90 days.
Note 2: For the purposes of this AD, a general visual inspection is defined as: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or drop-light, and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”
(e) Replace the existing three single wires (including inspections) inside the metal conduits of the fuel boost pumps with three twisted wires protected by a polyamide braided wire sleeve, in accordance with Part 3 of the Accomplishment Instructions of Fokker Service Bulletin F28/28-046, dated September 1, 1999, at the time specified in paragraph (e)(1) or (e)(2) of this AD, as applicable. If any discrepancy is detected during any inspection required by this paragraph, prior to further flight, repair in accordance with the service bulletin. Accomplishment of the actions required by this paragraph constitutes terminating action for the actions required by this AD.
(1) For airplanes that have accumulated less than 40,000 total flight hours as of the effective date of this AD: Within 2 years after the effective date of this AD.
(2) For airplanes that have accumulated 40,000 or more total flight hours as of the effective date of this AD: Within 1 year after the effective date of this AD.
