Engine Wear

SDR # 20120228023

SDR submitted:

Metal was found in the oil filter during a 50 hour inspection. Follow-up inspections were conducted in accordance with Lycoming Service Instruction-1492d. The aeroplane was ground run for 30 minutes - no metal found in filter.

The aeroplane was flown for one hour and the oil filter was again removed for inspection. Metal was again found in the filter and the engine was then removed for inspection and overhaul.

Engine components (lifter bodies) showing wear

* Engine components (lifter bodies) showing wear

Transport Canada Comments:
When an aeroplane engine shows signs of wear outside of what would be considered normal, questions must be asked as to the cause. If a reasonable explanation cannot determine the cause of the fault, teardown or overhaul is often the only choice.

Good job by the maintenance team for following up after the ground runs even though the engine appeared to be operating normally. This is a good example of due diligence and following manufacturer’s instruction (SI -1492d). Had the engine been allowed to continue to operate, a potentially serious situation such as complete engine failure was likely to have occurred.

Cracked Starter Causing Oil Loss / Engine Shutdown

SDR # 20111004005

SDR submitted:

While en route, the crew noticed a low oil quantity indication of 2 quart for the #1 engine. The oil pressure and temperatures were reported to be normal for the next 40 minutes when the quantity dropped to zero and pressure dropped to minimum values. The low oil pressure warning for the number 1 engine annunciated. The flight crew shut down the number 1 engine and the aeroplane landed.

Maintenance found that the number 1 engine starter sustained significant fracture damage to the housing assembly. With the CFM56 shared oil with the starter it is suspected that this was the exit point for the engine oil. Using recorded data, it was confirmed that the oil pressure limitations were not exceeded. Maintenance actions and engine runs carried out as per the aircraft maintenance manual and the aeroplane was released for service.

Cracked starter 

* Cracked starter

Transport Canada Comments:
The exact cause of the failure is not known, however the overhaul report stated that the ‘Failed gear housing allowed oil loss, ultimately causing an in flight shut down. 

Cracked Anti-Ice Fitting Affecting Engine Performance

SDR # 20111118014

SDR submitted:

The engine would not develop full power at altitude. Maintenance discovered that a fitting on the anti-ice shield was cracked, affecting the p2t2 sensor. This caused the single red-line (SRL) computer to control the exhaust gas temperature (EGT) incorrectly. The fitting was replaced and the aeroplane was returned to service. No further incidents were reported by flight crew.

Cracked anti-ice fitting 

* Cracked anti-ice fitting

Transport Canada Comments:
Good job troubleshooting this potentially difficult snag! 

Broken Propeller Bearing Race

SDR # 20111122004

SDR submitted:

During the replacement of the aeroplane’s left propeller actuator, the engineer noticed that the #1 blade outer race located inside the propeller hub was broken. A visual inspection of the #1 blade outer race revealed plating missing on the lower section of the race near the fracture point and bearing marks along the race. Fragments of metal were also observed at the fracture point, standing straight as if the race was magnetized. The remaining blades were removed and the #4 blade outer race was found with a small area of plating missing a nd bearing marks along the race. The propeller hub is currently being replaced. Similar damages were reported a few weeks previously on the right propeller of the same aeroplane. The hub assembly has been shipped to a repair station for a detailed inspection/evaluation.

Cracked bearing race 

* Cracked bearing race

Transport Canada Comments:
Well done by the engineer who discovered this discrepancy. 

It is important to conduct area inspections when carrying out line maintenance tasks especially with high time components.

Improper Use Of Tooling Causing In Flight Shutdown

SDR # 20111201009

SDR submitted:

Pilot reports that after takeoff at approx 1200 Feet, during clean up of the flight deck configuration, the #2 engine fuel auxiliary pump was selected off. Approximately 5 to 10 seconds after the pump was selected off, the engine began to surge with an associated fuel pressure master caution light and then the engine failed. The pilot returned to base.

Maintenance found a protective cap inside a flex line going to the Fuel Metering Unit.

Fuel line disconnected from fitting 

* Fuel line disconnected from fitting

Improper plug blocking fuel line 

* Improper plug blocking fuel line

Plug after removal

* Plug after removal

Transport Canada Comments:
Improper use of various tooling including protective caps can cause many problems such as blocked pitot/static ports, weight on wheel configuration problems as well as damaged structure or components. Instructions for correct tool use must be followed at all times including ensuring that the tool is in proper condition. Any warning devices or flags to remind maintainers to remove the tool prior to maintenance release must also be in place and intact.

Engine Control Service Information Letter

Diamond DA-20C1
SDR # 20121114002

SDR submitted:

On final approach, the engine would not respond to throttle input. The engine was shut-down with the mixture lever cut-off and the aeroplane landed short of the paved runway in the grass. There was no injury to the crew or passengers and no physical damage to the aeroplane. A post-flight inspection revealed damage to the splines on throttle body lever-to-cable hook-up.

Fuel Metering Unit 

* Top of Engine
** Fuel Metering Unit (Ref)
*** Throttle control arm
**** Lock Nut
***** Throttle Component Shaft

Fuel Injector (Ref)

* Fuel Injector (Ref)
** Mixture Component Shaft
*** Mixture Control Arm
**** Lock Nut

Transport Canada Comments:
Diamond Aircraft has released Service Information Letter 20C1-006 which describes inspection and maintenance of both the throttle and mixture control arms. It is important that operators inspect their aeroplanes in accordance with these instructions. 

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