1AD/CON/56 Amdt 1 - Number Two Crankcase Main Bearing Integrity

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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Teledyne Continental Motors Piston Engines

AD/CON/56

Amdt 1

Number Two Crankcase Main Bearing Integrity 1/90

Applicability: TSIO 520BE engines S/N 528001 through 528337 as fitted to Piper PA46-310P Malibu aircraft listed by serial number in Piper SB 913A.

Requirement: 1. Inspect crankcase for end play in accordance with TCM SB M89-14 Section A,

2. Carry out thru-bolt torque check in accordance with TCM SB M89-14 Section B,

3. Inspect number two crankcase main bearing in accordance with TCM SB M89-14 Section C.

Note: The repetitive checks and inspections detailed in Requirements No. 1 and No. 3 may be discontinued following disassembly of the crankcase assembly to a depth sufficient to inspect the crankcase mating flanges for evidence of fretting, and new bearings are installed.

Compliance: 1. Prior to further flight and thereafter at intervals not to exceed 25 hours time in service.

2. Unless previously accomplished within 10 hours time in service prior to issue of CAO 105 AD/PA46/16; prior to further flight.

3. Prior to further flight and thereafter at intervals not to exceed 200 hours time in service.

Background: This Directive has been amended to include a terminating action. Advice from the manufacturer indicates, loss of thru-bolt torque results in fretting of the crankcase mating flanges and possible migration of the number two main bearing. Until that fretting is addressed, the integrity of the number two main bearing is suspect and repetitive inspections as detailed in TCM SB M89-14 is justified.