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.

Kelowna Flightcraft (General Dynamics/Convair) Series Aeroplanes


AD/CONVAIR/14

Main Landing Gear Beam Webs

5/2006
 
Applicability:
Model 340 and 440 aircraft, and all such model aircraft converted to turbopropeller power.
Requirement:
1.    Inspect main landing gear (MLG) beam webs part number (P/N) 340-1650551-7, -8, -53, and -54 for crack indications in the upper flange radius area by dye penetrant inspection procedures, in accordance with General Dynamics 640 (340D) Service Bulletin No. 57-3, dated 17 April 1970. 2.    If no cracks are detected, repeat the Requirement 1 inspection. 3.    If cracks are detected during any Requirement 1 inspection, accomplish one of the following: a.     If MLG beam web cracking exceeds 7-inches total length and/or extends more than 2-inches forward or aft of the P/N 340-8510109 MLG trunnion fitting, replace the beam web before further flight. b.    If MLG beam web cracking is less than 2.75-inches long and orientated in a wing chordwise direction along the web flange bend radius, either: (i)    Stop-drill the crack in accordance with Section 2.(B)(3) of SB No. 57-3, and reinspect for further crack propagation at intervals not to exceed 50 hours time in service until the beam is reinforced in accordance with Requirement 4 or replaced in accordance with Requirement 3.a.; or, (ii)   Replace the beam web. 4.    If cracks are between 2.75-inches and 7-inches in length and do not extend more than 2-inches forward or aft of the P/N 340-8510109 MLG trunnion fitting, either replace the beam web or stop-drill and reinforce the beam web in accordance with Section 2.(B)(4) of SB No. 57-3.  If the beam web is stop-drilled and reinforced, it must be reinspected for further crack propagation, until the beam web is replaced. Cracks propagating beyond a stop-drill hole may be stop-drilled again providing the crack length remains within the above stated limits. Note:  FAA AD 70-12-01 Amdt 39-1000 refers.
 
Compliance:
1.    Unless the initial inspection is already accomplished, within 50 hours time in service after 11 May 2006 unless accomplished within the last 450 hours time in service. 2.    At intervals not to exceed 500 hours time in service. 3.    Before further flight. 3.b. (i)    Reinspect at intervals not to exceed 50 hours time in service, until reinforcement or replacement. 4.    Reinspect at intervals not to exceed 500 hours time in service, until beam web is replaced.
 
This Airworthiness Directive becomes effective on 11 May 2006.
Background:
The FAA requires inspection for cracks, and if necessary, replacement of the main landing gear beam webs.
David Villiers
Delegate of the Civil Aviation Safety Authority 29 March 2006