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/11

Main Windshield Lower
Longeron Splice Channel

5/2006
 
Applicability:
Model 340 and 440 aircraft, and all such model aircraft converted to turbopropeller power.
Requirement:
1.    Inspect the main windshield lower longeron splice channel part number (P/N) 340-3110113-15 for cracks in accordance with General Dynamics 640 (340D) Service Bulletin (SB) No. 53-3, dated 24 April 1970. 2.    If no cracks are detected, repeat the Requirement 1 inspection. 3.    If cracks are detected, either: a.     Replace the longeron splice channel P/N 340-3110113-15, and perform the Requirement 4 inspection; or, b      (i)    Install on the instrument panel in full view of the pilot and co-pilot, a placard limiting operation to a maximum of 18,000 feet above sea level. (ii)   Change the cabin pressure relief valve nominal setting to 3 psi. (iii)  Visually inspect the adjacent areas in accordance with SB No. 53-3 until the channel is replaced.  A cracked channel must be replaced with a new channel within 1,000 hours time in service from detection of the cracking.  Channel P/N 340-3110113-15 must be replaced before further flight if any cracking of the adjacent structure is detected during any repetitive inspection. The cabin pressure relief valve setting may be returned to normal and the placard removed from the instrument panel when the cracked channel is replaced.  Compliance with the Requirement 4 inspection intervals is required after replacing the channel. 4.    Normal inspection intervals may be resumed for a period of 10,000 hours time in service when a cracked channel is replaced with a new channel.  Inspect the channel for cracks in accordance with SB No. 53-3. Note:  FAA AD 70-13-02 Amdt 39-1016 refers.
 
Compliance:
1.    Unless the initial inspection is already accomplished, within 150 hours time in service after 11 May 2006 or before the accumulation of 10,000 hours time in service, whichever occurs later. 2.    Within 2,000 hours time in service after the initial inspection, and thereafter at intervals not to exceed 2,000 hours time in service. For Requirements 3.a. and 3.b:  Before further flight. For Requirement 3.b.(iii):  At intervals not to exceed 150 hours time in service until the channel is replaced. 4.    Before the accumulation of 10,000 hours time in service after replacement of the channel and thereafter at intervals not to exceed 2,000 hours time in service.
 
This Airworthiness Directive becomes effective on 11 May 2006.
Background:
The FAA requires inspections to detect cracks in the main windshield lower longeron splice channel.  Undetected cracking could result in failure of the windshield support structure and consequent loss of pressurisation.
David Villiers
Delegate of the Civil Aviation Safety Authority 29 March 2006