20 June-19 July 2019

880
Broken rocker shaft assembly. (611953904 )
Piston
LYCOMING O540 F1B5 –  ATA 8520 RECIPROCATING ENGINE POWER SECTION – BUSHING – UNSERVICEABLE. DR 611953836
During scheduled maintenance, a loose connecting rod bushing was discovered upon cylinder removal IAW Lycoming 630A. All remaining connecting rods overhauled.
LYCOMING O320 D2J –  ATA 7322 FUEL CONTROL/RECIPROCATING ENGINES – CARBURETTOR – SCREW MISSING. DR 611953866
Whilst the aircraft was on short finals, reduced power slightly at around 250 ft, as the power was reduced, engine failed, windmilling to a stop.

After landing, attempted to taxi into the parking area, however engine stopped three times between exiting runway and reaching the parking area. Managed to restart engine on each occasion. Preliminary finding showed Idle screw missing from Carburettor assembly.

Overhauled Carburettor fitted, Engine runs carried out, Idle and Idle Mixture adjustments carried out and aircraft released to service.

LYCOMING O235 L2C –  ATA 8520 RECIPROCATING ENGINE POWER SECTION – PISTON ENGINE – FIRE. DR 611953891
Black smoke seen coming out of lower cowling on engine start. Suspected over prime. Engine inspected for fire damage, Minor amount of black soot cleaned up. Engine started O.K. Engine runs carried out.
CONTINENTAL TSIO520 VB –  ATA 8550 RECIPROCATING ENGINE INTERNAL OIL SYSTEM  – PISTON ENGINE – CONTAM OIL. DR 611953895
Metal in engine oil filter found. Engine removed and sent to engine shop.
CONTINENTAL TSIO520 –  ATA 8550 RECIPROCATING ENGINE INTERNAL OIL SYSTEM – OIL FILTER – CONTAM OIL. DR 611953901
Filter found contaminated during scheduled maintenance. Investigations are continuing.
LYCOMING O320 B2C –  ATA 8520 RECIPROCATING ENGINE POWER SECTION – ROCKER BOSS – BROKEN. DR 611953904
Broken rocker shaft assembly. Cylinder assembly replaced.
 
CONTINENTAL TSIO520 –  ATA 7810 ENGINE COLLECTOR/TAILPIPE/NOZZLE  – Exhaust Stack – LEAKING. DR 611953907
During a scheduled inspection of the LH and RH Engine exhaust system (IAW AD-C400-43 A8 Req 1), Engineers noted that the RH Engine – Inboard exhaust stack slip joint showed evidence of leakage. Defective exhaust stack was removed and replaced with a serviceable item.

Exhaust stack slip joint worn to limits and no longer sealing Exhaust Gases. Exhaust Stack has been in service for 1518.5 FH. It is not considered unusual for leakage to be detected in an exhaust of this age.

LYCOMING O540 F1B5 –  ATA 8520 RECIPROCATING ENGINE POWER SECTION  – EXHAUST VALVE – LEAKING. DR 611953908
Cylinder found to have low compression during a scheduled maintenance check. Was unable to achieve compression result after engine ground run. Result maximum 50 psi over 80 psi.

Root cause: Leaking exhaust valve /seat.

LYCOMING O320 J2A –  ATA 8520 RECIPROCATING ENGINE POWER SECTION  – CYLINDER – LOW COMPRESSION. DR 611953909
Cylinder had low compression during a scheduled maintenance. Was unable to achieve acceptable compression results. Further ground runs c/o with no improvement. Results 30/80 psi.
LYCOMING O360 J2A –  ATA 8510 RECIPROCATING ENGINE FRONT SECTION – FILTER – DETERIORATED. DR 611953921
Aircraft experienced partial loss of power in flight, requiring an emergency landing.

Root cause: Upon inspection, it was found that the Bracket Air Filter had disintegrated and partially blocked the carburettor venturi.
The part in question was installed brand new from a sealed packet the day before the incident. The shelf life had one year remaining. The only thing different was that the part had been stored in hot conditions (in a non airconditioned shed in summer). Potentially this led to a breakdown of the foam.