AD/DHC-8/133 Amdt 1 Main Landing Gear System (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/DHC-8/133 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.

Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes

AD/DHC-8/133 Amdt 1 Main Landing Gear System 13/2007 TX

Applicability:

Bombardier Inc. DHC-8 aircraft, Models 400, 401 and 402, serial numbers 4001, 4003 and subsequent.

Requirement:

1.    General Visual Inspection of the Main Landing Gear System:

       Perform a general visual inspection of the left hand and right hand main landing gear system in accordance with Bombardier DHC-8 Series 400 Maintenance Requirements Manual (PSM 1-84-7), Part 1 (Maintenance Review Board Report), tasks Z700-03E (left hand) and Z700-04E (right hand) and rectify any discrepancy found.

2.    General Visual Inspection of the Main Landing Gear Retract Actuator Jam Nut:

a.     Perform a general visual inspection of the left hand and right hand main landing gear retract actuator jam nut to ensure the wire lock is in place and the nut is secured.  If the wire lock is not in place or the jam nut is not secured, accomplish Bombardier Repair Drawing (RD) 8/4-32-059 Issue 5 or later approved revision.

b.    Repeat the actions detailed in Requirement 2.a. of this AD.

3.    Detailed Visual Inspection of the Main Landing Gear Retract Actuator:

a.     Perform a detailed visual inspection and any required action(s) in accordance with Bombardier RD 8/4-32-059 Issue 5 or later approved revision.

b.    Repeat the actions detailed in Requirement 3.a. of this AD.

Respective inspections performed in accordance with earlier issues of RD 8/4-32-059 satisfy the actions detailed in Requirements 2 and 3 of this AD.

If the visual inspection of the piston (p/n 46570-1/-3) threads and thread relief area for evidence of corrosion in accordance with RD 8/4-32-059 Rev. NC was performed without using borescope or 10X magnification mirror, a one time deferral for up to 500 landings is permissible to complete the inspection of the piston using borescope or 10X magnification mirror.

4.    Reporting Requirement:

       Report any discrepancies found during any of the above inspections to Bombardier Technical Help Desk and to CASA via the SDR reporting system.

Ferry Flight:

To permit the ferry of an aircraft to a location where the inspection requirements of this directive can be accomplished, adhere to the following procedures and limitations:

Flight Crew Limitations and Procedures:

A.   Ferry Flight with gear extended and pinned.

B.    Landing to be conducted at a minimum descent rate.

C.   Minimize braking on landing.

D.   Flight to be conducted per Aircraft Operating Manual (AOM) Section 4.8.

E.    Essential crew only on board.

F.    Flight in known or forecast icing condition is prohibited.

Maintenance Procedures:

(i)    Inspect the left hand and right hand main landing gear retract actuator jam nut to ensure the wire lock is in place and the nut is secure.

(ii)   Perform the general visual inspections as defined in accordance with Bombardier All Operators Message No. 236 Rev A or later revisions.

(iii)  If items 1 and 2 results are satisfactory, insert main landing gear ground lock pins and lockwire in place.

(iv) Ensure the nose landing gear ground lock is engaged.

Note: Transport Canada AD CF-2007-20 R1 dated 11 October 2007 refers.

Compliance:

1.    Remains unchanged as detailed in the original issue of this AD as: Before further flight after 14 September 2007 (the effective date of the original issue of this AD), unless previously accomplished.

2a.  Remains unchanged as detailed in the original issue of this AD as: Before further flight after 14 September 2007, unless previously accomplished.

2b.  At intervals not to exceed 250 landings or one month from the effective date of this AD.

3a.  Remains unchanged as detailed in the original issue of this AD as: For aircraft main landing gear retract actuator (p/n 46550-7 or 46550-9) that have accumulated 8,000 or more landings or in service for more than 4 years since new, whichever occurs first at 14 September 2007 - before further flight after 14 September 2007.

       For aircraft main landing gear retract actuator (p/n 46550-7 or 46550-9) that have accumulated between 4,000 to 7,999 landings or in service between 2 to 4 years since new at 14 September 2007 - Within 500 flight hours or 3 months after the effective date of this AD, whichever occurs first.

       For aircraft main landing gear retract actuator (p/n 46550-7 or 46550-9) that have accumulated less than 4,000 landings or less than 2 years service in service since new, at 14 September 2007 - Prior to reaching 4,500 landings or 27 months in service new, whichever occurs first.

3b.  At intervals not to exceed 2,000 landings or one calendar year from the effective date of this AD.

4.    Within 7 days after each inspection.

This Amendment becomes effective on 2 November 2007.

Background:

The original issue of this AD was in response to two reported cases of main landing gear collapse. Main landing gear collapse may result in an unsafe landing of the aircraft.

This amendment changes the compliance time by introducing calendar periods and repetitive inspections until such time that a terminating action becomes available.

The original issue of this AD became effective on 14 September 2007.

David Punshon
Delegate of the Civil Aviation Safety Authority

26 October 2007