AD/B737/189 - Rudder Feel and Centering Unit (Cth)

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

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Boeing 737 Series Aeroplanes

AD/B737/189 Rudder Feel and Centering Unit 11/2002 DM

Applicability: Model 737-600, -700, -700C, -800, and -900 series aircraft, line numbers 948 through 1108.

Requirement: Action in accordance with the technical requirements of FAA AD 2002-16-23 Amdt 39-12862.

Note: Boeing Alert Service Bulletin 737-27A1259 refers.

Compliance: Within 10 days after 4 September 2002 for the initial requirement. Thereafter as specified in the Requirement document, with a revised effective date of 4 September 2002.

This Airworthiness Directive becomes effective on 4 September 2002.

Background: The FAA has received reports of low rudder pedal forces caused by a broken inner spring in the rudder feel and centring unit on some new generation Model 737 aircraft. Investigation of the broken springs revealed an incorrect process used on a specific batch of inner springs. In the event that both the inner and outer springs fail, the pedal feel and centring forces will be lost. This condition, if not corrected, could result in pilot- induced oscillation and consequent loss of control of the aircraft.