Remarks: Where applicable, the requirements of this AD must be integrated into the Aircraft's Logbook(s). Address inquiries concerning this AD to: Civil Aviation Authority, Airworthiness Division, Ruzyne Airport, 160 08 Prague 6, Czech Republic, tel.: 420 2 33320922, fax: 420 2 20562270.

(formerly Fokker Aircraft B.V.)

Model F.27 series

RLD Type Certificate Nr.: A22F

Recently, RLD have received a report from an F.27 "Friendship" operator concerning the discovery of a cracked wing-to-fuselage attachment fitting. There are four such fittings on the wing front- and rear spars, two on each spar on both sides of the fuselage. This particular fitting was located at Wing STA.1040, on the rear spar RH side. Subsequent investigation revealed that the cracking had resulted from stress corrosion. Subject fittings are manufactured from 7079-T6 aluminium, which is known to be sensitive to this type of corrosion. The affected aircraft had been inspected and modified in accordance with Fokker Service Bulletin (SB) F27/57-54 some eight (8) years prior to the cracked fitting being found.

Since an unsafe condition has been identified that may exist or develop on other aircraft of the same type design, this Airworthiness Directive (BLA) requires a one-time inspection of the affected wing-to-fuselage fittings (see Figure 1 of this directive) and the reporting of all findings to the present Type Certificate holder. RLD considers this directive to be a precautionary measure and further requirements may follow.

Applicability: Fokker Aircraft B.V. Model F.27 Mk.100 through Mk.700 series (except Mk.500RF), serial numbers 10102 and 10105 through 10582

Effective date: June 1, 1999

Compliance: Required as indicated, unless accomplished previously.

(a) Within the next 6 months after the effective date of this directive, inspect the wing-to-fuselage fittings in accordance with the Accomplishment Instructions of STORK Fokker SB F27/57-77 dated April 1, 1999 or a later RLD-approved revision;

(b) Within ten (10) calendar days after the inspection as required by paragraph (a) of this directive, report all findings to Fokker Services B.V., address indicated below.

Note : STORK Fokker Services' Technical and Operational Notice (TON) 27.018 (Ref. TS99.53471) dated April 1, 1999 also pertains to this subject.

- Operators of the affected aircraft may obtain copies of the referenced service information upon request directly from Fokker Services B.V., Technical Services Dept., P.O.Box 231, 2150 AE Nieuw-Vennep, The Netherlands; telephone (31) 252-627-350 facsimile (31) 252-627-211.

- Compliance with this AD must be recorded in the proper Aircraft Log Book(s).

- Where applicable, the requirements of this AD must be integrated into the aircraft's Maintenance Schedule.