AD/Jetstream/95 Amdt 1 Steering Actuator Piston Rod Cracking (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/JETSTREAM/95 and issues the following AD under subregulation 39.001(1) of CASR 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.

British Aerospace BAe 3100 (Jetstream) Series Aeroplanes

AD/JETSTREAM/95 Amdt 1 Steering Actuator Piston Rod Cracking 3/2005

Applicability:

All British Aerospace HP 137 Mk1, Jetstream Series 200, 3100, and 3200 aircraft.

Requirement:

1.    For aircraft previously inspected in accordance with BAE Systems Service Bulletin (S/B) 32-JA020741:

a.     Recalculate the safe life limit for the piston rod in accordance with BAE Systems S/B 32-JA030644 dated 6 October 2003 or later approved revisions.

b.    Replace any steering jack with a where the piston rod does not meet the safe life limit as calculated in Requirement 1a of this Directive.

c.     Re-torque the piston rod eye-end in accordance with BAE Systems S/B 32-JA030644 later approved revisions.

2.    For aircraft that have not accomplished BAE Systems S/B 32-JA020741:

a.     Inspect the piston rod for cracking, measure the release torque and measure the tab washer deformation in accordance with Part 1 of the accomplishment instructions of BAE Systems S/B 32-JA030644 later approved revisions.

b.    Replace any steering jack with a where the piston rod is cracked.

c.     Calculate the safe life limit for the piston rod in accordance with BAE Systems S/B 32-JA030644 later approved revisions.

d.    Replace any steering jack with a where the piston rod does not meet the safe life limit as calculated in Requirement 2a of this Directive.

e.     Re-torque the piston rod eye-end in accordance with BAE Systems S/B 32-JA030644 later approved revisions.

3.    Prior to installation in an aeroplane inspect the steering jack piston rod and determine the safe life in accordance with paragraph 2 of the BAE Systems S/B 32-JA030644 or later approved revisions.

Note:  UK CAA AD G-2004-029 which supersedes 003-11-2002 refers.

Compliance:

For Requirement 1:  Unless previously accomplished, within 3 months from the effective date of this Directive.

For Requirement 2:  Within 2 months from the effective date of this Directive.

For Requirement 3:  From the effective date of this Directive.

This Amendment becomes effective on 17 March 2005.

Background:

The manufacturer has determined that the fatigue life of the subject component needed further revision.  This amendment details the requirements for recalculating the safe life of the subject component.

Cracks have been found in the steering jack piston rod adjacent to the eye-end.  This was caused by a high torque applied to the eye-end during assembly of the unit.  Severe cracking can lead to failure of the jack and loss of steering control.

The original issue of this Directive became effective 12 June 2003.

James Coyne
Delegate of the Civil Aviation Safety Authority

4 February 2005