Ad/Cessna 170/84 - Engine Mounting Brackets (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.

Cessna 170, 172, F172, FR172 and 175 Series Aeroplanes

AD/CESSNA 170/84 Engine Mounting Brackets 10/2008

Applicability:

Model 175 aircraft, serial numbers 55001 through 55703, manufactured 1958.

Model 175 aircraft, serial numbers 55704 through 56238, manufactured 1959.

Model 175 aircraft, serial numbers 28700A, 626, and 640, manufactured 1958 and 1959.

Model 175A aircraft, serial numbers 691, and 56239 through 56777 manufactured 1960.

Requirement:

1.    Check the aircraft logbook to determine if all four of the original engine mounting brackets have been replaced.  If it is positively determined that all four of the original engine mounting brackets have been replaced, no further action is required.

2.    If it cannot be positively determined that all four of the original engine mounting brackets have been replaced, inspect each of the upper and lower engine mounting brackets on both the left and right sides for cracks in accordance with Cessna Single Engine Service Bulletin SEB07-2 Revision 2, dated 18 June 2007, or later FAA approved revision.

3.    If cracks are found in any of the engine mounting brackets during any Requirement 2 inspection, replace the cracked engine mounting bracket(s) in accordance with Cessna Single Engine Service Bulletin SEB07-2 Revision 2, dated 18 June 2007, or later FAA approved revision.

Replacement of all four of the original engine mounting brackets terminates the repetitive inspection requirement of this Directive.

Note:  FAA AD 2008-15-06 Amdt 39-15618 refers.

Compliance:

1.    Within 30 days after 25 September 2008.

2.    Within 12 months after 25 September 2008.  If no cracks are found, repetitively inspect thereafter at intervals not to exceed 500 hours time in service; until all four of the original engine mounting brackets are replaced.

3.    Before further flight after the inspection in which cracks are found.

This Airworthiness Directive becomes effective on 25 September 2008.
Background:	The FAA received a report of the engine detaching from the firewall during landing on one of the affected aircraft.  This Directive requires repetitive inspections of originally installed engine mounting brackets.

David Villiers
Delegate of the Civil Aviation Safety Authority

11 August 2008