Commonwealth legislation

AD/F50/68 - Lower Cowling By-Pass Duct Opening

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Commonwealth

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legislative instrument

Plain English Summary

4/10 complexity

Requires certain serial‑numbered Fokker F.27 Mk.050 (F50) aeroplanes to have the engine by‑pass duct air‑outlet physically modified per Fokker Service Bulletin F50‑71‑041 within three months of 12 Oct 1995. CASA issued the AD to reduce in‑flight engine power fluctuations from ice ingestion. Affected aircraft operators must schedule and pay for the mandated work; the directive prescribes the manufacturer’s procedure and does not provide quantified benefits, costs, or alternative compliance options.

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AD/F50/68 - Lower Cowling By-Pass Duct Opening

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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Fokker F50 (F27 Mk 50) Series Aeroplanes

AD/F50/68 Lower Cowling By-Pass Duct Opening 11/95

Applicability: Fokker Aircraft B.V. Model F.27 Mk.050 series, serial numbers as listed in the requirement document.

Requirement: Modify the air outlet opening of the engine by-pass duct in accordance with Fokker

S.B. F50-71-041 dated 10 November 1993.

Note: Dutch AD BLA 1995-065 (A) dated 30 June 1995 also refers.

Compliance: Required within the next three (3) calendar months after the 12 October 1995, unless accomplished previously.

Background: There have been a number of in-flight power fluctuations in the service experience of the Fokker Model F.27 Mk.050 series aircraft. In certain weather conditions ice can build up in the engine air intake leading to a loss of engine power as a result of ice ingestion.

This Directive mandates the by-pass duct modification to reduce the possibility of ingestion of ice into the engine.

Source text

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

1 AD/F50/68 - Lower Cowling By-Pass Duct Opening