14 August—18 September 2017

778

ROLLS ROYCE RB211 972 84–ATA 7261 TURBINE ENGINE OIL SYSTEM–OIL TUBE–LEAKING. DR 611750499
Engine #1 oil leak reported. Leak was traced to tube IPC 79-22-48-02/300 that required replacement. After maintenance, leak check carried out during idle ground run and was found satisfactory.

ALLISON 250 C30P–ATA 7240 TURBINE ENGINE COMBUSTION SECTION–COMBUSTION CASE–CRACKED. DR 611750563
Outer combustion case found cracked near fuel nozzle boss. Crack (110 mm) initiated only on outer layer and no air leak at this stage. Item replaced with serviceable item.

PRATT AND WHITNEY PT6A 67B–ATA 7261 TURBINE ENGINE OIL SYSTEM–Oil filler tube assembly–Clip broken. DR 611750604
During pre-flight inspection, nothing unusual was detected with the dip stick, but at the end of the flight, oil was visible on the fuselage side. Opening the cowling showed the dip stick to be halfway out. Oil level after shut down was 0.3; it was reported in the maintenance release as 0.5 from the previous flight. It was established that dip stick oil filler tube assy locking clip was broken. Oil filler tube assy replaced.

GENERAL ELECTRIC CF6 80E1 A3–ATA 7320 FUEL CONTROLLING SYSTEM–TUBE–CRACKED AND LEAKING. DR 611750605
Running fuel leak tracing back to cracked I/B VBV actuator rod end tube was witnessed from # 2 engine drain mast. Tube was disconnected from actuator. Engine was replaced as per company convenience. The type certificate holder/OEM has been notified. This is a known failure mode, and GE has released modification service bulletin SB 73-0128 to address the issue.

LYCOMING ALF502R 5–ATA 7260 TURBINE ENGINE ACCESSORY DRIVE–Tower Shaft–DISCONNECTED. DR 611750618
After take-off, #1 engine failed as confirmed by roll and associated yawing moment. Relevant memory items and checklists completed. After landing, no damage noted in engine inlet and exhaust. Engine change carried out. During this process, access gained to the failed engine accessory gearbox tower shaft and it was discovered that the retainer holding the tower shaft in position had become dislodged from its secured position allowing the tower shaft to drop and disconnect from its drive spline. Once the tower shaft was no longer driving the accessory gearbox, FCU among other items stopped providing fuel and the engine rolled back.

GENERAL ELECTRIC CT7 9B–ATA 7210 TURBINE ENGINE REDUCTION GEAR–Prop Gear Box–FAILED INSPECTION. DR 611750622
During inspection against GE SB 72-0531, propeller gearbox S/N: IHI001XX failed inspection due fretting wear leaving the propeller shaft flange under the minimum thickness IAW GECT7 MM Ch72-10-00. No corrosion was found at the dowel pin area. PGB was removed from service and replaced.

GARRETT TPE331 1–ATA 7510 ENGINE ANTI-ICING SYSTEM–GASKET–DAMAGED. DR 611750627
R/H engine fire light illuminated temporarily after take-off. Defect was traced to blown engine anti-ice shield gasket. Investigations are continuing for possible amendments to AMP calling for detailed inspections. OEM and engine overhaul shop is also being consulted.

GENERAL ELECTRIC CF6 80E1 A3–ATA 7320 FUEL CONTROLLING SYSTEM–Fuel Supply Tube–CRACKED AND LEAKING. DR 611750652
During cruise, a discrepancy in fuel was observed, with the destination fuel prediction reducing. The fuel used vs fuel remaining showed unaccounted fuel loss. Once descending, left engine was shut down as per the checklist and a PAN declared. Once the engine was shut down, fuel leak appeared to cease. An uneventful single engine landing was carried out. Engineering inspection found a cracked VBV fuel tube that was subsequently replaced. GE SB 73-0128 introduces four reworked VSV/VBV fuel tubes to prevent cracking. Failure of pre-mod SB 73-0128 VSV/VBV fuel tubes is a known world fleet issue. As best practice for either the pre- or post-mod configuration GE also recommend, to check the clamping locations are neutralised during tube disturbance/installation during maintenance and ensure that the tube ends line up without any preload.

GENERAL ELECTRIC CT7 8A–ATA 7300 ENGINE FUEL AND CONTROL–FADEC–FAULTY. DR 611750653
Master caution, FADEC 1 FAULT and FADEC 2 FAULT lights illuminated. Fault code provided by the crew in chapter 45 of the AMM indicated FADEC channel B data is stale and cannot be trusted. FADEC fault was cleared on shutdown of one engine. Engineers tested system and cleared defect.

LYCOMING ALF502R 5–ATA 7321 FUEL CONTROL/TURBINE ENGINES –FILTER–clogged. DR 611750672
After take-off, engine #2 fuel filter clogged light illuminated. Aircraft returned to departing base and filter element (partially clogged) was replaced. Filter was sent for analysis and results are awaited.

ROLLS ROYCE TAY650 65015–ATA 7250 TURBINE ENGINE TURBINE SECTION–ROTOR BLADE–DAMAGED. DR 611750680
On take-off after 400 ft, received an amber caution associated with alert ‘Engine vibration Hi #2’, procedure carried out. Small reduction of thrust on #2 was required to bring vibration within limits.  Engineering inspection of the aircraft found HPT blades damaged. Engine change decided and ongoing.

GARRETT TPE331 1–ATA 7810 ENGINE COLLECTOR/TAILPIPE/NOZZLE–SHROUD–CRACKED. DR 611750681
During scheduled phase 2 inspection, a 4-cm crack was noticed in the LH engine exhaust shroud P/N 3101582-7. The duct was removed & inspected IAW EMM 72-50-05 confirming the 4-cm crack on the outer duct body. Moreover, inner weld joining the outer shell was found to be cracked through approximately 270 degrees or 3/4’s of the weld. The exhaust duct was replaced with a serviceable item.

PRATT AND WHITNEY PT6A 114A–ATA 7321 FUEL CONTROL/TURBINE ENGINES–FCU–Failed on fitment. DR 611750735
After overhauled FCU fitment, engine began to experience hung starts (30-40% Ng) and fuel flow fluctuations. OEM and overhaul facility informed. New FCU fitted, engine ground tests carried out satisfactory.

CFM CFM56 7B 24–ATA 7321 FUEL CONTROL/TURBINE ENGINES–HMU–SUSPECT FAULTY. DR 611750761
On approach, as thrust was increased, #2 eng N1 observed low coupled with high EGT (not outside limits). Moreover #2 eng control master caution was presented. Approach continued with idle thrust on #2 eng. Engine operation normal during all other flight phases. During the course of troubleshooting, HMU was replaced, investigation is in progress.

PRATT AND WHITNEY PT6A 27–ATA 7261 TURBINE ENGINE OIL SYSTEM–FILTER–CONTAM OIL. DR 611750773
Metal debris located in oil filter. Source was traced to a failed circlip on back of rear RGB housing, allowing coupling to rub on bronze bush. Engine currently being reassembled at approved overhaul facility.

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