AD 82-15-04 ACTIVE

82-15-04 FOKKER B.V.: Amendment 39-4418. Applies to Model F28 Series 1000 and 4000 airplanes certificated in all categories, serial numbers as indicated below. Note: Some serial numbers listed may actually be 2000, 3000, 5000, or 6000 airplanes that are not presently eligible for U.S. certification. Those serial numbers may be disregarded insofar as this AD is concerned.

1. Unless already accomplished, accomplish the following within the time specified in each paragraph below after the effective date of this AD.

A. Applies to F28 airplanes S/N 11003-11064 and 11991-11993 inclusive. Compliance required within six months after the effective date of this AD. Install an inspection window in the passenger door per Fokker Service Bulletin F28/52-43, Part IV, dated April 16, 1974.

B. Applies to F28 airplanes S/N 11003-11070, 11072-11074, and 11991- 11993 inclusive. Compliance required within six months after the effective date of this AD. Replace sliding pins inthe passenger door per Fokker Service Bulletin F28/52-44 dated April 9, 1974.

C. Applies to F28 airplanes S/N 11021-11062 and 11991-11993 inclusive for the rear cargo door and 11003-11062 and 11991-11993 inclusive for the front and center cargo doors. Compliance required within six months after the effective date of this AD. Install the improved switch operating mechanism in the rear, forward, and center cargo door rabbets per Parts I & II of Fokker Service Bulletin F28/52-49, Revision 1, dated March 1, 1976.

D. (1) Applies to F28 airplanes S/N 11003-11081 and 11991-11993 inclusive. Compliance required within six months after the effective date of this AD. Install a reinforced safety catch and stop assembly on the front cargo door and the center cargo door, if installed, per Part I of Fokker Service Bulletin F28/52-51 dated September 3, 1974.

(2) Applies to F28 airplanes S/N 11021-11052, 11054-11061 and 11063-11076 inclusive, and S/N 11078, 11079, and 11191-11193 inclusive. Compliance required within six months after the effective date of this AD. Install a new safety catch and stop assembly on the rear cargo door per Part II of the service bulletin.

E. Applies to F28 airplanes S/N 11003-11081 and 11991-11993 inclusive. Compliance required within 500 flight hours time in service after the effective date of this AD. Inspect the cargo door locking mechanism per Fokker Service Bulletin F28/52-53 dated May 10, 1974.

F. Applies to F28 airplanes S/N 11003-11020 inclusive. Compliance required within 500 flight hours time in service after the effective date of this AD. Inspect and adjust the cargo door lock warning and locking mechanism for correct functioning per Fokker Service Bulletin F28/52-54 dated July 1, 1974.

G. Applies to F28 airplanes S/N 11003-11081 and 11991-11993 inclusive. Compliance required within the next 500 flight hours time in service after the effective date of this AD. Inspect the cargo door latching mechanism and adjust, if necessary, per Fokker Service Bulletin F28/52-56 dated July 26, 1974.

H. Applies to F28 airplanes S/N 11003-11020 inclusive. Compliance required within the next 500 flight hours time in service after the effective date of this AD. Install a safety catch on the rear cargo door per Fokker Service Bulletin F28/52-61 dated May 21, 1975.

I. Applies to F28 airplanes S/N 11003-11110 and 11991-11993 inclusive. Compliance required within the next 500 flight hours time in service after the effective date of this AD. Modify the shape of the secondary guide rails at fuselage station 3870 (if in post SB F28/52- 55, Part I Configuration) and at station 4610 per Fokker Service Bulletin F28/52-66 dated April 12, 1976.

J. Applies to F28 airplanes S/N 11003-11112, 11115, 11116, 11120, and 11991-11993. Compliance required within the next 500 flight hours time in service after the effective date of this AD. Modify the actuating mechanism of the cargo door lock warning switches per Fokker Service Bulletin F28/52-80, Revision 1, dated October 23, 1978.

K. Applies to F28 airplanes forward and center cargo doors - S/N 11003- 11081, 11991-11993, and 11082-11101 inclusive if S/B F28/52-51 has been incorporated; rear cargo door - S/N 11053, 11062, 11077, 11080, and 11081 if S/B F28/52-51 has been incorporated and S/N 11090-11093, 11108-11112, and 11114-11116 inclusive, and S/N 11118, 11120-11124, and 11126-11128 inclusive, S/N 11130, 11133, 11135, and 11138-11141 inclusive. Compliance required within the next 500 flight hours time in service after the effective date of this AD. Reinforce the cargo door locking handle access panels per Fokker Service Bulletin F28/52-81 dated October 1, 1977.

L. Applies to F28 airplanes S/N 11003-11016 inclusive. Compliance required within 500 flight hours time in service after the effective date of this AD. Reinforce the speed brake accumulator brackets per Fokker Service Bulletin F28/53-4dated May 19, 1970.

M. Applies to F28 airplanes S/N 11003-11020 inclusive and S/N 11991. Compliance required within 500 flight hours time in service after the effective date of this AD. Install a plastic separation screen and add ventilation provisions per Fokker Service Bulletin F28/53-21 dated October 11, 1971.

N. Applies to F28 airplanes S/N 11003 through 11037 and 11991 through 11994. Compliance required within 500 hours time in service after the effective date of this AD. Inspect for cracks and rework if necessary the speedbrake attach hinge fitting per Fokker Service Bulletin F28/53-26, Revision 1, dated January 2, 1975.

O. (1) Applies to F28 airplanes S/N 11020-11055, 11057-11061, and 11063-11071 inclusive, and S/N 11073, 11075, 11078, and 11991-11993 inclusive. Compliance required within 500 hours time in service after the effective date of this AD and at intervals of 250 flight hours thereafter until the modification in paragraph 2 has been carried out.Inspect the PLI washers in the rear cargo compartment latch brackets for correct installation per Part I of Fokker Service Bulletin F28/53-54, Revision 3, dated October 11, 1976. If one or more washers per latch fitting are incorrectly installed, proceed with paragraph 2 of this AD within the next ten hours time in service.

(2) Applies to F28 S/N 11020-11090 inclusive, 11092, and 11991- 11993 inclusive. Compliance required within the next 1000 hours time in service after the effective date of this AD or within ten hours time in service if required by paragraph O.(1), above. Install MS washers and bolts in the cargo door latch fittings per the service bulletin.

(3) Applies to F28 airplanes S/N 11003-11055, 11057-11061, and 11063-11071 inclusive, and S/N 11073, 11075, 11078, and 11991-11993 inclusive. Compliance required within the next 500 hours time in service after the effective date of this AD. Install MS washers and shorter bolts in the forward and center cargo doorlatch fittings per the service bulletin.

P. Applies to F28 airplanes S/N 11003-11091 and 11991-11993 inclusive. Compliance required within 500 hours time in service after the effective date of this AD. To ensure the proper torquing of the MS 21250 bolts in the main entry door latch fittings, replace the dural washers with MS 20002 washers per Part V of Fokker Service Bulletin F28/51-10, Revision 1, dated July 11, 1975.

Q. Applies to F28 airplanes S/N 11003-11025 inclusive and S/N 11991, 11992, and 11994. Compliance required within 500 flight hours after the effective date of this AD. To prevent stringer cracks, install connecting angles in the stabilizer torsion box at rib station 3800 per Fokker Service Bulletin F28/55-8, Revision 1, dated October 16, 1972.

R. Applies to F28 airplanes S/N 11003-11064 and 11991-11993 inclusive. Compliance required within six months after the effective date of this AD. To ensure proper functioning of the horizontal stabilizer hinge bearings, inspect the bearings per Part I of Fokker Service Bulletin F28/55-14, Revision 1, dated March 15, 1974. If relative rotation does not occur between the bearings ball and the outer ring, modify the hinge bearing installation per Part II of the service bulletin within nine months of the inspection. If relative rotation does occur between the ball and the outer ring, the Part II modification must be accomplished within two years after the effective date of this AD.

S. Applies to F28 airplanes S/N 11003-11020, 11022-11025, and 11991- 11993 inclusive. Compliance required within six months after the effective date of this AD. To prevent stress corrosion cracks, install bronze bushings in the stabilizer hinge brackets per Fokker Service Bulletin F28/55-17 dated October 27, 1975.

T. Applies to F28 airplanes as follows: S/N 11003-11145 inclusive and S/N 11147, 11150, 11151, 11991, and 11992. Compliance required within six months after the effective date of this AD. To prevent the loss of the stabilizer hinge bolts if the nut has backed off, install an additional retaining device per Fokker Service Bulletin F28/55-21 dated May 19, 1980.

U. Applies to F28 airplanes S/N 11003-11038, 11040, and 11991-11994 inclusive. Compliance required within six weeks after the effective date of this AD. Balance the aileron servo tabs per Fokker Service Bulletin F28/57-33, Revision 1, dated February 24, 1972.

V. Applies to F28 airplanes S/N 11003-11123 inclusive, 11126, 11991, and 11992 which have accumulated 15,000 landings. Compliance required within two months after the effective date of this AD. To detect cracks in wing rear spar brackets, inspect per Fokker Service Bulletin F28/57-58, Revision 3, dated October 9, 1979. Repair cracks in accordance with the service bulletin.

W. Applies to F28 airplanes S/N 11003-11123 inclusive and S/N 11126, 11991, and 11992. Compliance required within six months after the effective date ofthis AD. To minimize the chance of cracking bracket lugs, install chromium plated bolts and bronze bushings and inspect left-hand and right-hand rear spar bracket lugs per Fokker Service Bulletin F28/57-59 dated July 25, 1979. Repair cracked lugs in accordance with the service bulletin.

X. Applies to F28 airplanes S/N 11111-11145 inclusive and S/N 11147, 11148, 11150, and 11151. Compliance required within three months after the effective date of this AD. To prevent performance deterioration, reseal the butt straps and boundary layer fences on the wing leading edge sections per Fokker Service Bulletin F28/57-61 dated April 14, 1980.

2. Alternate means of compliance with this AD which provide an equivalent level of safety may be used when approved by the Chief, Seattle Area Aircraft Certification Office, FAA Northwest Mountain Region.

3. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of inspections and/or modifications required by this AD.

The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1).

This amendment becomes effective August 23, 1982.