1AD/B737/116 Amdt 1 - Yaw Damper and Rudder Power Control Unit Wiring Change

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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Boeing 737 Series Aeroplanes

AD/B737/116

Amdt 1

Yaw Damper and Rudder Power Control Unit Wiring Change

6/99

Applicability: All Boeing 737 -300, -400 and -500 model aircraft up to and including line position 2907.

Requirement: 1. Install new wiring and associated hardware for a new yaw damper and pressure reducer bypass valve in accordance with Boeing Service Bulletin (SB) 737-22- 1124 Revision 1 dated 25 March 1999.

Note: FAA AD 97-14-03 Amdt 39-10060 refers.

Compliance: 1. The original compliance of ‘No later than 26 March 2002’ remains unchanged.

This Amendment becomes effective on 17 June 1999.

Background: The FAA issued AD 97-14-03 to prevent both excessive rudder authority resulting in reduced controllability of the aircraft as well as malfunctions of the yaw damper system which could cause sudden uncommanded yawing of the aircraft and consequent injury to passengers and crewmembers. Boeing responded with the issue of SB 737-22-1124, detailing the installation of new wiring for the proposed hardware changes which will be the subject of another AD.

This amendment limits the applicability and introduces revised wiring requirements.

The original issue of this Airworthiness Directive became effective on 26 March 1998.