80-20-03 FOKKER-VFW B.V.: Amendment 39-3923. Applies to Model F-27 series airplanes, serial numbers 10105 through 10248, which have incorporated Fokker Service Bulletin F27/61- 9(G6), serial numbers 10249 through 10518, except for airplanes which have Fokker Service Bulletin F27/61-10(G7) incorporated, and serial numbers 10519 through 10553, certificated in all categories.
Compliance is required as indicated, unless already accomplished.
To prevent propeller auto-feathering caused by inadvertent potential being introduced into the propeller auto-feathering circuit, accomplish the following:
(a) Within the next 500 hours time in service after the effective date of this AD, for airplane serial numbers 10105 through 10248 if Fokker Service Bulletin F27/61-9(G6) has been incorporated, and for airplane serial numbers 10249 through 10518 if Fokker Service Bulletin F27/61-10(G7) has not been incorporated, rework the cockpit floor and wiring in the receptacles, replace, route, and connect new wiring, and finish shielding in accordance with paragraph 2, "Accomplishment Instructions," General and Part I of Fokker Service Bulletin F27/61-29, revision 2, dated March 1, 1979, or an FAA-approved equivalent.
(b) Within the next 500 hours time in service after the effective date of this AD for airplane serial numbers 10249 through 10518 except for airplanes which have Fokker Service Bulletin F27/61-10(G7) incorporated, install new shielded wires between the engine firewall and the partial pressure bulkhead in accordance with Fokker Service Bulletin F27/61-35 dated March 23, 1979, or an FAA-approved equivalent.
(c) Within the next 500 hours time in service after the effective date of this AD, for airplane serial numbers 10519 through 10553, rework the cockpit floor and wiring in the receptacles, replace, route, and connect new wiring, and finish shielding in accordance with paragraph 2, "Accomplishment Instructions," General and Part II of Fokker Service Bulletin F27/61-29, revision 2, dated March 1, 1979, or an FAA-approved equivalent.
(d) If an equivalent means of compliance is used in complying with paragraphs (a), (b), or (c) of this AD, that equivalent must be approved by the Chief, Aircraft Certification Staff, AEU-100, Europe, Africa, and Middle East Office, FAA, c/o American Embassy, Brussels, Belgium.
NOTE: There is a typographical error on page 4 of Fokker Service Bulletin F27/61-29, revision 2, dated March 1, 1979. Aircraft serial numbers 10150 to 10248 inclusive listed in the first column of the replacement wire table should be changed to read 10105 to 10248 inclusive.
This amendment becomes effective October 22, 1980.