Ad/Convair/27 - Drag Strut Shearbolt (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.

Kelowna Flightcraft (General Dynamics/Convair) Series Aeroplanes

AD/CONVAIR/27 Drag Strut Shearbolt 11/2006

Applicability:

GENERAL DYNAMICS Models 340/440 aeroplanes, including those converted to Turbo-propeller power.

Requirement:

To detect cracks originating at the shearbolt bore in the drag strut, and prevent possible failure of the landing gear, accomplish the following:

1.    Non-Modified Struts (See Definitions, below).

(a)   Perform a disassembly inspection of the nose landing gear, left hand, upper drag strut for crack development in the area of the clutch plate to strut shear bolt attach hole per General Dynamics Service Bulletin 640(340) S.B.
No. 32-8, dated 10 August 1973, or later FAA-approved revisions, and modify the strut per Part III of the Bulletin.

(b)   If no cracks are found, repeat the inspection in Requirement 1(a) above.

(c)   If cracks are located, replace the drag strut with new or serviceable parts of the same type design.

2.    Modified or New Struts (See Definitions, below).

(a)   Perform a disassembly inspection of the nose landing gear, left hand upper drag strut in the area of the clutch plate to strut shear bolt attach hole as specified in General Dynamics Service Bulletin No. 32-8, or later FAA-approved revisions.

(b)   If no cracks are found, repeat the inspection in Requirement 2(a), above.

(c)   If cracks are found, replace the drag strut with new or serviceable part of the same type design.

Definitions:

Non-Modified Struts - This is an original configuration strut, which has not been modified by previous Service Engineering Reports or by Service Bulletin No.
32-8.

Modified Struts - This includes all struts modified by previous SER's No.
15-4-340-38/440-38 and 15-4-340-44A/440-44A or by Part III of Service Bulletin No. 32-8 that have not been modified per Part IV of Service Bulletin
No. 32-8.

New Struts - Part Number 340-7310231-1 struts that have not been reworked per Part IV of Service Bulletin No. 32-8.

Note:  FAA AD 73-19-11 Amdt 39-1736 refers.

Compliance:

1.    (a)   Within 1200 landings after the effective date of this A.D., unless already accomplished within the last 4800 landings prior to this A.D.

1.    (b)   On or before 20,000 landings following modification per Requirement 1.(a) and at intervals not to exceed 6000 landings thereafter, until the strut has been modified in accordance with the provisions of Part IV, Service Bulletin No. 32-8, or later FAA-approved revisions.

1.    (c)   The various configurations and the re-inspection requirements are:

(i)    If new or previously modified struts are used for replacement, which do not have the modifications of Part IV, Service Bulletin No. 32-8 incorporated, perform an initial inspection on or before 20,000 landings from time of replacement and at intervals not to exceed 6000 landings thereafter.

(ii)   If previously modified parts are used for replacement that have a subsequent rework accomplished per Part IV of Service Bulletin No.
32-8, perform an initial inspection on or before 20,000 landings following each rework, and at intervals not to exceed 6000 landings thereafter.

(iii)  Struts repaired per Part II of the Service Bulletin No. 32-8, or later
FAA-approved revisions, will be inspected at intervals not to exceed 6000 landings following the repair.

2.    (a)   After the effective date of this AD, on or before the accumulation of 26,000 landings on a new or modified part, or 6000 additional landings, whichever occurs later.

2.    (b)   At intervals not to exceed 6000 landings until the strut has been modified in accordance with the provisions of Part IV, Service Bulletin No. 32-8, or later FAA-approved revisions.

2.    (c)   The various configurations and the re-inspection requirements are:

(i)    If new or previously modified struts are used for replacement, which do not have the modifications of Part IV, Service Bulletin No. 32-8 incorporated, perform an initial inspection on or before 20,000 landings from time of replacement and at intervals not to exceed 6000 landings thereafter.

(ii)   If previously modified parts are used for replacement that have a subsequent rework accomplished per Part IV of Service Bulletin No.
32-8, perform an initial inspection on or before 20,000 landings following each rework, and at intervals not to exceed 6000 landings thereafter.

(iii)  Struts repaired per Part II of the Service Bulletin No. 32-8, or later
FAA-approved revisions, will be inspected at intervals not to exceed 6000 landings following the repair.

This Airworthiness Directive becomes effective on 26 October 2006.

Background:

The intent of this AD is to detect cracks originating at the shearbolt bore in the drag strut, and prevent possible failure of the landing gear.

James Coyne
Delegate of the Civil Aviation Safety Authority

13 September 2006