AD/B737/130 Amdt 2 Rudder PCU Displacement Tests (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/B737/130 Amdt 1 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.

Boeing 737 Series Aeroplanes

AD/B737/130 Amdt 2 Rudder PCU - Displacement Tests 10/2005

Applicability:

All Model B737 series aircraft.

Requirement:

1.    Perform a displacement test on the secondary slide in the dual servo valve in the rudder PCU in accordance with Boeing Alert Service Bulletin 737-27A1221 Revision 1 dated January 28, 1999 (Model 737-100, -200, -300, -400 and -500 series) or in accordance with Boeing Alert Service Bulletin 737-27A1222, Revision 1, dated January 28, 1999 (Model 737-600, -700 and -800 series).

2.    Subject to the test in Requirement 1 proving negative (valve fails test), replace the valve assembly in accordance with Boeing Alert Service Bulletin
737-27A1221 Revision 1 dated January 28, 1999 (Model 737-100, -200, -300,
-400 and -500 series) or in accordance with Boeing Alert Service Bulletin
737-27A1222, Revision 1, dated January 28, 1999 (Model 737-600, -700 and
-800 series), and repeat test.

3.    Do not install on any aircraft any main rudder PCU having P/N 65-44861-12 and serial number 3509A or lower or, any PCU having P/N 65C37053-(XX) (Model 737-100, -200, -300, -400 and -500 series) or PCU having P/N 251A301-(XX) and serial number 0299 or lower (Model 737-600, -700 and -800 series) unless the PCU nameplate has been vibro-engraved with the letter “C” following the serial number.

Accomplishment of the requirements of AD/B737/201 (FAA AD 2002-20-07) constitutes terminating action for the requirements of this Directive.

Note 1:  Subsequent serial numbers greater than those listed in Requirement 3 are displacement tested as part of the certified production process and do not require the letter “C” to be vibro-engraved.

Note 2:  FAA AD 99-11-05 Amendment 39-11175 issued December 7, 1999 refers and corrects FAA AD 99-11-05 dated 24 May 1999.

Compliance:

1.    Initial Test.

a.     Model 737-100, -200, -300, -400 and -500 series aeroplanes the test must be completed within 16 months time in service from 12 August 1999.  Thereafter, repeat the displacement test at intervals not exceeding 24,000 flight hours.

b.    For aeroplanes equipped with a PCU having P/N 65-44861-12 and serial number 3509A or lower or P/N 65C37053-(XX), the test must be completed within 16 months time in service from 12 August 1999.  Thereafter, repeat the displacement test at intervals not exceeding 24,000 flight hours.

c.     For Model 737-600, -700 and -800 aeroplanes having line numbers 1 through 222 inclusive that are equipped with PCU’s having P/N 251A301-(XX) and serial number 299 or lower, conduct the test within 16 months time in service from 12 August 1999.  Thereafter, repeat the displacement test at intervals not exceeding 24,000 flight hours.

d.    For all other aeroplanes, conduct the test prior to the accumulation of 24,000 total flight hours or within 30 days from the effective date of this Directive, whichever is the later.  Thereafter, repeat the displacement test at intervals not exceeding 24,000 flight hours.

2.    Prior to further flight.

3.    After 30 November 2000. 

The compliance times remain unchanged by this issue.

This Amendment becomes effective on 29 September 2005.

Background:

As part of the rudder system improvement programme, this Directive was introduced to detect cracks in the secondary slide in the dual concentric servo valve of the rudder PCU.  This Directive reflects a Country of Origin Airworthiness Directive.

Amendment 1 reflected a number of corrections to the original directive mandated by the Country of Origin AD.

Amendment 2 is issued in response to FAA AD 2002-20-07, which requires incorporation of a new rudder control system; which when incorporated, supersedes the requirements of AD 99-11-05, the Requirement document of this Directive.

The original issue of this Airworthiness Directive became effective on 12 August 1999.

David Punshon
Delegate of the Civil Aviation Safety Authority

19 August 2005