Commonwealth legislation

AD/SF340/25 Amdt 1 - Vertical Stabilizer Top Closure Rib

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Commonwealth

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legislative instrument

Plain English Summary

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This airworthiness directive requires operators of SAAB SF340 aeroplanes with serial numbers SF340A‑031–159 and SF340B‑160–194 to inspect and then modify the vertical stabilizer top closure rib following SAAB service bulletins (SAAB 340‑55‑022 Rev 1 and 340‑55‑023). Inspections start at 500 flight hours after 16 May 1991 and recur per the bulletin; the modification (terminating action) must be completed by 1 August 1992.

The directive is intended to prevent fatigue cracks that could cause fin–rudder jamming; aircraft operators and maintenance organisations bear the inspection, modification and scheduling costs.

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AD/SF340/25 Amdt 1 - Vertical Stabilizer Top Closure Rib

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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SAAB SF340 Series Aeroplanes

AD/SF340/25

Amdt 1

Vertical Stabilizer Top Closure Rib 12/91

Applicability: All model SF340 with Serial Nos SF340A-031 through 159 and Serial Nos SF340B- 160 through 194.

Requirement: Inspect and modify the vertical stabilizer top closure rib in accordance with the Technical Requirements of SAAB Scania AB Service Bulletins, SAAB 340-55-022 Revision 1 dated 27 February 1990, and SAAB 340-55-023 dated 1 October 1990.

Note: Swedish Airworthiness Directive No 1-036, Revision A. refers.

Compliance: Inspect upon achieving 500 hours in service after 16 May 1991, as required by the previous issue of this Directive; and then at intervals not exceeding those in SAAB Service Bulletins 340-55-022 Revision 1.

Modify in accordance with SAAB Service Bulletin 340-55-023 before 1 August 1992.

Background: Fatigue cracks in the vertical stabilizer top closure rib could lead to friction and ultimate jamming between the fin and rudder. This amendment calls up Revision A of the Requirement Document, which makes terminating action mandatory.

Source text

Sourced from the Federal Register of Legislation (legislation.gov.au), CC BY 4.0.

1 AD/SF340/25 Amdt 1 - Vertical Stabilizer Top Closure Rib