Airworthiness Directive · Amendment 39-18602 · Fuel
Fokker Services B.V. Airplanes
This AD applies to Fokker Services B.V. Model F.28 Mark 1000, 2000, 3000, and 4000 airplanes, certificated in any category, all serial numbers.
We are adopting a new airworthiness directive (AD) for all Fokker Services B.V. Model F.28 Mark 1000, 2000, 3000, and 4000 airplanes. This AD was prompted by a design review that revealed insufficient measures were taken to ensure the correct locking of the attachments of the fuel quantity tank units (FQTUs) in each wing tank. When an FQTU becomes loose, this could lead to insufficient clearance between the FQTU and the adjacent tank structure or other metal parts, and under certain conditions, create an ignition source inside the wing fuel vapor space. This AD requires modifying the FQTUs by applying sealant to cover the nuts, washers, and stud ends at the FQTU attachments in each main wing tank. This AD also requires revising the maintenance or inspection program, as applicable, by incorporating a fuel airworthiness limitation item and a critical design configuration control limitation (CDCCL). We are issuing this AD to prevent an ignition source in the wing fuel tank vapor space, which could result in a wing fuel tank explosion and consequent loss of the airplane.
At the next scheduled opening of the fuel tanks after the effective date of this AD, but no later than 84 months after the effective date of this AD, modify the FQTU in each main wing tank by applying sealant to cover the nuts, washers, and stud ends of the FQTU attachments, and do an inspection for leakage of the tank access panels, in accordance with the Accomplishment Instructions of Fokker Service Bulletin SBF28-28-054, Revision 1, dated January 9, 2014; and the information in Fokker Manual Change Notification—Maintenance Documentation MCNM-F28-037, Rev 1, dated January 9, 2014. If any fuel leakage is found, before further flight, reapply the sealant, in accordance with the Accomplishment Instructions of Fokker Service Bulletin SBF28-28-054, Revision 1, dated January 9, 2014; and the information in Fokker Manual Change Notification—Maintenance Documentation MCNM-F28-037, Rev 1, dated January 9, 2014.
Before further flight after completing the modification specified in paragraph (g) of this AD, or within 30 days after the effective date of this AD, whichever occurs later: Revise the airplane maintenance or inspection program, as applicable, by incorporating the fuel airworthiness limitation item and critical design configuration control limitation (CDCCL) specified in paragraph 1.L.(1)(c) of Fokker Service Bulletin SBF28-28-054, Revision 1, dated January 9, 2014. The initial compliance times for these tasks are at the latest of the times specified in paragraphs (h)(1), (h)(2), and (h)(3) of this AD.
(1) At the applicable time specified in Fokker Service Bulletin SBF28-28-050, Revision 3, dated December 11, 2014.
(2) Before further flight after completing the modification specified in paragraph (g) of this AD.
(3) Within 30 days after the effective date of this AD.
After accomplishing the revision required by paragraph (h) of this AD, no alternative actions (e.g., inspections), intervals, or CDCCLs may be used unless the actions, intervals, or CDCCLs are approved as an alternative method of compliance (AMOC) in accordance with the procedures specified in paragraph (k)(1) of this AD.
