AIRWORTHINESS DIRECTIVE
CAA-AD-1-019/98
Date of issue: March 19, 1998
AIRCRAFT - WING FLAPS - REPLACEMENT OF SUPPORT STRAP
Applicability: SAAB SF 340A -004 through -159, SAAB 340B-160 through -384, -386 through -404, ~406 through -408, -410 through -413
Note: Please note that the flap assemblies are interchangeable and it is possible that different flap assemblies have been mixed on the aircraft because of replacement during service.
Effective date: March 20, 1998
Compliance : Required as indicated in SAD AD 1-117R1
Remarks: This Airworthiness Directive supersedes and cancels CAA-AD-3-059/97. 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 324086, fax: 420 2 364112.
Ing. Pavel MATOUŠEK
Director of Airworthiness Division CAA CZ
AIRWORTHINESS DIRECTIVE NO: 1-117R1
LUFTFARTSVERKET, Aviation Safety Department
Swedish Airworthiness Directives (SAD) SAD No 1-117R1 - Cancels SAD 1-117
Section 1. Swedish Manufactured Aeronautical Products
AIRCRAFT TYPE: SAAB SF 340A and SAAB 340B
SERIAL No’s SAAB SF 340A -004 through -159
AFFECTED: SAAB 340B-160 through -384, -386 through -404, ~406 through -408, -410 through -413
Note: Please note that the flap assemblies are interchangeable and it is possible that different flap assemblies have been mixed on the aircraft because of replacement during service.
SUBJECT: Wings - Flaps - Replacement of Support Strap
BACKGROUND: During a scheduled inspection (16000 flight inspection) of the flap structure on one aircraft it was found that the forward lower spar cap had cracked at WS 142. The crack was discovered in the radius of the spar cap extending in spanwise direction. During the repair of the spar it was also revealed that the support strap (both UH and R/H flap) connecting the flap actuator fitting to the forward spar web at STA 142 was cracked. Cracked flap support straps can in long terms lead to further damages of the flap structure. This will result in extensive and time consuming repairs or ultimately lead to jammed flaps. Inspection and installation of a new support strap made of steel will prevent this.
REFERENCE DOCUMENTS: Saab Aircraft AB Service Bulletin SAAB 340-57-033 revision 02 dated 29 January,1998.
ACTIONS: Perform inspection and actions described in Saab Aircraft AB Service Bulletin SAAB 340-57-033 revision 02 dated 29 January 1998 or later revision.
COMPLIANCE TIME: The modification has to be performed not later than the latest opportunity of the following two alternatives:
1 At the next scheduled structural inspection of the flap, refer to the MRB report.
2 Wthin 3000 flights after effective date of this SAD
Visual Inspection: For flaps that have accumulated more than 16 000 flights (inspection threshold in the MRB) an external and internal visual inspection has to be performed within 1500 flights after release of this SAD unless the flap has been modified within that period.
Examples:
EFFECTIVE DATE: 2 March, 1998