Squawk Box

December 2018 Issue




Turbochargers

The following information is derived from the FAA’s Service Difficulty Reports and Aviation Maintenance Alerts.

Cessna 402b Utiliner/Businessliner
Blown Seals

During descent, pilot noted oil streaking back from top engine cowl louvers, then dropping oil pressure. Pilot conducted precautionary shutdown and feathered propeller. Pilot continued descent and landed at destination without issue. Maintenance removed cowling and found oil appearing to come from the turbocharger (p/n 4066109025) area. Further investigation revealed oil bypassing the seals on the turbo.

Part total time: Unknown


Diamond DA40 Diesel
Cracked Bearing Flange

During a scheduled inspection, the turbocharger bearing flange was found cracked in two places where it meets the turbocharger turbine, allowing exhaust gas to “jet” over the top of the turbocharger. Other failures have been found in our fleet as well. No known cause or recommendations at this time.

Part total time: 101.0 hours


Diamond DA40 Diesel
Seized Turbocharger

Student pilot was in cruise flight when the aircraft engine suddenly started to lose power. The pilot failed to restore power and performed an emergency landing to a dirt field, without damage or injury. Examination revealed the turbocharger (p/n E4A41100000) had seized.

Part total time: 516.0 hours


Piper PA-31-350 Navajo Chieftain
Leaking Bearing

During routine inspection, the left tailpipe was found to have burnt oil on it. The tailpipe was removed for further investigation, and burnt oil was visible in the turbocharger (p/n LW12463) around the turbine bearing. Due to this oil leak, the turbocharger was removed and replaced.

Part total time: 682.0 hours


Piper PA-31-350 Navajo Chieftain
Seized Turbocharger

Crew landed at home base and informed maintenance the right engine was burning oil and not developing full power. Inspection revealed seized turbocharger (p/n 4091709001). Turbocharger was replaced and engine run. No further defect found.

Part total time: Unknown


Piper PA-46-350P Malibu Mirage
Seized Turbocharger

Pilot reported loss of power, followed by pressurization loss, during climb. Engine ran well, but power was limited to 19 inches manifold pressure instead of 35. Examination revealed right turbocharger (p/n 46C19839M) had seized. Unable to determine any external cause of failure.

Part total time: 837.0 hours

Turbocharger