Commonwealth legislation

AD/EMB-120/3 Amdt 1 - Autopilot Disengagement Logic

In ForceCTH

Jurisdiction

Commonwealth

Collection

legislative instrument

Plain English Summary

4/10 complexity

This airworthiness directive requires operators of Embraer EMB-120 aeroplanes to implement a modification to the autopilot disengagement logic so that pressing the “AP DISCONNECT” button removes power from the affected servo motor. It responds to a reported elevator trim runaway and imposes maintenance and inspection work (per Brazilian AD 91‑03‑02 R2) on aircraft owners/operators, who bear scheduling, parts and labour costs and must meet the specified compliance dates.

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Current sections

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AD/EMB-120/3 Amdt 1 - Autopilot Disengagement Logic

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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Embraer EMB-120 (Brasilia) Series Aeroplanes

AD/EMB-120/3

Amdt 1

Autopilot Disengagement Logic 12/91

Applicability: As detailed in the requirement document.

Requirement: Action in accordance with the technical requirements of Brazilian AD 91-03-02 R2.

Compliance: Parts I and II of the requirement document must be actioned in accordance with the original issue of this AD which required compliance within 300 hours time in service after 2 April 1991, or prior to 13 August 1991. Part III of the requirement document must be complied with prior to 31 December 1991.

Background: Advice has been received of an elevator trim runaway during descent which caused a deep pitch down of the aeroplane. As a result, the crew experienced great difficulty maintaining control of the aircraft. This AD introduces a modification which will allow the crew to quickly disconnect power from the affected servo motor by disengaging the autopilot when the “AP DISCONNECT” button is activated.

Note: Amendment 1 to this AD is issued to require compliance with Part III of Brazilian AD 91-03-02R2 which was introduced with Revision 2 to the Brazilian AD.

Source text

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

1 AD/EMB-120/3 Amdt 1 - Autopilot Disengagement Logic