AD/At 800/9 Amdt 2 Engine Mount (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/AT 800/9 Amdt 1 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.

Airtractor 800 Series Aeroplanes

AD/AT 800/9 Amdt 2 Engine Mount 7/2008

Applicability:

All Model AT-802 and AT-802A aircraft, serial numbers 0001 through 0227.

Requirement:

For all aircraft with less than 5,000 total hours time in service that do not have gussets installed on the engine mount in accordance with Snow Engineering Co. Service Letter (SL) No. 253 Revision A, dated 16 October 2007, Snow Engineering Co. SL No. 253 Revision B, dated 30 November 2007, or Snow Engineering Co. SL No. 253 Revision C, dated 17 April 2008:

1.    Visually inspect the engine mount as follows:

Inspect in accordance with Snow Engineering Co. Service Letter (SL) No. 253, revised 22 January 2007, Snow Engineering Co. SL No. 253 Revision A, dated 16 October 2007, Snow Engineering Co. SL No. 253 Revision B, dated 30 November 2007, or Snow Engineering Co. SL No. 253 Revision C, dated 17 April 2008.

2.    Where crack damage is detected during any Requirement 1 inspection, repair and modify the engine mount by installing gussets in accordance with Snow Engineering Co. SL No. 253 Revision B, or Snow Engineering Co. SL No. 253 Revision C.  This modification terminates the Requirement 1 repetitive inspections.

3.    Unless already accomplished in accordance with Requirement 2, inspect, repair if cracked, and modify the engine mount by installing gussets in accordance with Snow Engineering Co. SL No. 253 Revision B, or Snow Engineering Co. SL No. 253 Revision C. at the compliance time(s) specified in the compliance section of this Directive.  This modification terminates the Requirement 1 repetitive inspections.

4.    The Requirement 3 modification may be delayed, provided the following is accomplished in accordance with the service information provided in Snow Engineering Co. Service Letter (SL) No. 253, revised 22 January 2007, Snow Engineering Co. SL No. 253 Revision A, dated 16 October 2007,Snow Engineering Co. SL No. 253 Revision B, or Snow Engineering Co. SL No. 253 Revision C:

Initially inspect upon reaching the applicable compliance time in Requirement 3.a. or 3.b., unless accomplished within the last 100 hours time in service;

Repetitively inspect thereafter at intervals not to exceed 100 hours time in service; and,

If cracks are detected during any inspection, before further flight, repair the cracked part and install the gussets.

Note 1:  As a terminating action to the Requirement 1 inspections, the gussets modification may be installed before detecting cracks or reaching the times specified above provided an inspection assures the area is crack free before installing the gussets.

Note 2:  FAA AD 2008-10-12 Amdt 39-15518 refers.

Compliance:

1.    Initially before the aircraft reaches a total of 1,300 hours time in service or within 100 hours time in service after 30 August 2007, whichever occurs later.  Inspect thereafter at intervals not to exceed 300 hours time in service.

2.    Before further flight.

3.    At whichever of the following times occurs later:

a.     Before the aircraft reaches 5,000 hours total time in service; or,

b.    Within 100 hours time in service after 3 July 2008.

4.    Until 30 April 2009, at which time the modification must be incorporated.

The compliance time for Requirement 1 remains unchanged by this issue of the Directive.

This Amendment becomes effective on 3 July 2008.

Background:

The FAA received reports of cracked engine mounts.  Such cracking, unless detected and corrected, could result in failure of the engine mount and possible separation of the engine from the aircraft.

Amendment 1 is issued in response to a new FAA AD which was prompted by reports of two Model AT-802A aircraft with cracked engine mounts below the initial compliance time.  The FAA has determined that the initial inspection is required when the aircraft reaches a total of 1,300 hours time in service.

David Villiers
Delegate of the Civil Aviation Safety Authority

23 May 2008