Ad/DHC-8/133 - Main Landing Gear System (Cth)

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 39.001(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 Main Landing Gear System 11/2007 TX

Applicability:

Bombardier Inc. DHC-8 aircraft, Models 400, 401 and 402, serial numbers 003 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:

       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.

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

       Perform a detailed visual inspection in accordance with Bombardier
RD 8/4-32-059.

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 Emergency AD CF-2007-20 dated 12 September 2007 refers.

Compliance:

1.    Before further flight after the effective date of this AD, unless previously accomplished.

2.    Before further flight after the effective date of this AD, unless previously accomplished.

3.    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 after the effective date of this AD - before further flight after the effective date of this AD.

       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, whichever occurs first - Within 500 flight hours after the effective date of this AD.

4.    Within 7 days after each inspection.

This Airworthiness Directive becomes effective on 14 September 2007.
Background:	Two recent cases of main landing gear collapse have been reported.  Main landing gear collapse may result in an unsafe landing of the aircraft.

Charles Lenarcic
Delegate of the Civil Aviation Safety Authority

13 September 2007