Commonwealth legislation

AD/AT/18 - Parking Brake Valve

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legislative instrument

Plain English Summary

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This AD mandates replacing certain Gerdes (A-850-5) or Cleveland (60-9) parking-brake valves on specified Airtractor models with Scott P/N 4500A-2, per Snow Engineering Service Letter #76, because lever slippage in flight has caused landing overturns. It affects owners/operators of listed AT‑250/300/400/500 series aircraft not already fitted with the Scott valve, who must complete the swap at the next maintenance release after 31 May 1997 or by 31 Dec 1997 and bear parts and labor costs.

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AD/AT/18 - Parking Brake Valve

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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Airtractor AT-300, 400 and 500 Series Aeroplanes

AD/AT/18 Parking Brake Valve 5/97

Applicability: All model AT-250, AT-300, AT-301, AT-302, AT-400, AT-400A, AT-401, AT-402,

AT-501 and AT-502 series aircraft not fitted with Scott P/N 4500A-2 parking brake valve.

Requirement: Unless previously carried out, replace Gerdes P/N A-850-5 or Cleveland P/N 60-9, as applicable, parking brake valve with Scott P/N 4500A-2 parking brake valve in accordance with Snow Engineering Co. Service Letter #76, dated December 12, 1988.

Note: FAA AD 96-24-08 Amdt 39-9833 refers.

Compliance: At next scheduled maintenance release issue after 31 May 1997, or by 31 December 1997, whichever occurs first.

This Airworthiness Directive becomes effective on 24 April 1997.

Background: Advice has been received that during flight the parking brake valve lever can slip from the OFF to the ON position and has caused several aircraft to overturn when landing.

Source text

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

1 AD/AT/18 - Parking Brake Valve