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20051114028189I

Incident
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FAA incident report · Lancar Lancairivpt · Harlowton, MT · November 14, 2005

FAA Aviation Safety Information Portal

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Date
November 14, 2005 · 09:05 local
Place
Harlowton, MT
Phase of flight
Normal Cruise
Operating rules
General operating rules (Part 91)
Aircraft
N83RR
Reported as
Lancar Lancairivpt
Reported engine
WALTER M601E11
People aboard
1
Fatal injuries
0
Pilot’s flight hours
3,500 total75 in this make and model80 in the last 90 days

From the FAA’s Accident/Incident Data System (AIDS), through its Aviation Safety Information Portal, as reported. The NTSB investigates accidents separately, and its record of an accident is the fuller one. The aircraft is matched to the registry by N-number and event date, checked against the reported make and model; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

What happened

The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.

(-23) On 11/14/05 at approximately 0900 MDT, aircraft N83RR, a lance air iv-p, departed helena, Montana (hln) with an IFR flight plan enroute to gary Indiana (gyy), with only the pilot on board. About 15 to 20 minutes into the flight, cruising at FL250, the pilot noticed the engine oil pressure started to drop. The pilot slowly brought the engine power back to idle and feathered the propeller. He declared an emergency and was cleared to descend and land at wheatland county airport, Harlowton, Montana (hwq). The aircraft landed without incident. The walter engine was disassembled and inspected by a walter technician. Investigation found that the front oil scavenge had failed. The failure of the pump was caused by a piece of magnesium left over from the casting or machining process that apparently didn't get cleaned out of the front gearbox prior to assembly. It appears that the piece of metal lodged in the scavenge pump causing it to fail. When the pump failed, the engine oil accumulated in the front gearbox, thereby starving the rear gearbox of engine oil. The engine's primary oil pump is driven from the rear gearbox, so as the oil accumulated up front, there was minimal oil left to circulate through the primary oil pump resulting in loss of oil pressure. A FAA form 8010-4 malfunction or defect report will be submitted by the engine manufacturer. This incident is considered closed.

As the FAA filed it

(-23) ON 11/14/05 AT APPROXIMATELY 0900 MDT, AIRCRAFT N83RR, A LANCE AIR IV-P, DEPARTED HELENA, MONTANA (HLN) WITH AN IFR FLIGHT PLAN ENROUTE TO GARY INDIANA (GYY), WITH ONLY THE PILOT ON BOARD. ABOUT 15 TO 20 MINUTES INTO THE FLIGHT, CRUISING AT FL250, THE PILOT NOTICED THE ENGINE OIL PRESSURE STARTED TO DROP. THE PILOT SLOWLY BROUGHT THE ENGINE POWER BACK TO IDLE AND FEATHERED THE PROPELLER. HE DECLARED AN EMERGENCY AND WAS CLEARED TO DESCEND AND LAND AT WHEATLAND COUNTY AIRPORT, HARLOWTON, MONTANA (HWQ). THE AIRCRAFT LANDED WITHOUT INCIDENT. THE WALTER ENGINE WAS DISASSEMBLED AND INSPECTED BY A WALTER TECHNICIAN. INVESTIGATION FOUND THAT THE FRONT OIL SCAVENGE HAD FAILED. THE FAILURE OF THE PUMP WAS CAUSED BY A PIECE OF MAGNESIUM LEFT OVER FROM THE CASTING OR MACHINING PROCESS THAT APPARENTLY DIDN'T GET CLEANED OUT OF THE FRONT GEARBOX PRIOR TO ASSEMBLY. IT APPEARS THAT THE PIECE OF METAL LODGED IN THE SCAVENGE PUMP CAUSING IT TO FAIL. WHEN THE PUMP FAILED, THE ENGINE OIL ACCUMULATED IN THE FRONT GEARBOX, THEREBY STARVING THE REAR GEARBOX OF ENGINE OIL. THE ENGINE'S PRIMARY OIL PUMP IS DRIVEN FROM THE REAR GEARBOX, SO AS THE OIL ACCUMULATED UP FRONT, THERE WAS MINIMAL OIL LEFT TO CIRCULATE THROUGH THE PRIMARY OIL PUMP RESULTING IN LOSS OF OIL PRESSURE. A FAA FORM 8010-4 MALFUNCTION OR DEFECT REPORT WILL BE SUBMITTED BY THE ENGINE MANUFACTURER. THIS INCIDENT IS CONSIDERED CLOSED.