Commonwealth legislation

AD/HS 748/9 - Auto Feather Micro Switch Operating Levers

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Commonwealth

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legislative instrument

Plain English Summary

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This AD requires owners/operators of British Aerospace HS 748 aeroplanes (without modification 6909) to inspect the fork ends of the auto-feather micro‑switch levers per Jetstream Mandatory Service Bulletin HS748-76-15 Revision 4, initially within 1,000 hours TIS from 5 Jan 1995 and repeating every 1,000 hours until mod 6909 is installed.

The inspections address reported cracking that could prevent propeller auto‑feathering after an engine failure; CASA mandates compliance and operators bear inspection and repair costs or may fit the modification to end recurring checks.

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AD/HS 748/9 - Auto Feather Micro Switch Operating Levers

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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British Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes

AD/HS 748/9 Auto Feather Micro Switch Operating Levers 1/95

Applicability: All HS 748 series aircraft not incorporating modification 6909.

Requirement: Action in accordance with Revision 4 of Jetstream Aircraft Ltd Mandatory SB HS748-76-15.

Note: UK CAA AD 0132 refers.

Compliance: Within 1000 hours time in service from 5 January 1995. Thereafter, reinspect at intervals not exceeding 1000 hours time in service until modification 6909 has been incorporated.

Background: Cracks in the fork end of the levers which actuate the auto feather inhibiting micro switches, located on the engine sub frame, have been reported. In the event of a failed micro switch being followed by an engine failure, propeller auto feathering will not take place.

Source text

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

1 AD/HS 748/9 - Auto Feather Micro Switch Operating Levers