NTSB Factual Report

On July 9, 2004, at 1130 central daylight time, a Cessna 340A, N60PP, received substantial damage on impact with terrain during approach to Mason City Municipal (MCW), Mason City, Iowa. The pilot shut down the right engine after a loss of right engine oil pressure and landed short of runway 35. Instrument meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 business flight was operating on an instrument flight rules (IFR) flight plan. The commercial pilot reported no injuries. The flight originated from Goshen Municipal Airport, Goshen, Indiana, and was en route to MCW.

The pilot stated that while en route to his destination at 16,000 feet, he noticed a "slight drop" in oil pressure on the right engine and "immediately" requested a lower altitude so that he could descend to visual meteorological conditions. He initially received a clearance to 14,000 feet and then to 10,000 feet, which put him "in good visual conditions."

The oil pressure continued to drop "very slowly," and he determined he could "easily" make it to his destination. He received clearance to descend to 4,000 feet where he had MCW in sight and cancelled his IFR flight plan. He still had oil pressure, and he configured the airplane for landing. On short final, the oil pressure dropped to zero. He shutdown the right engine and was not able to get the propeller feathered. The pilot stated that the airplane experienced a hard landing and was able to taxi clear of the runway. The airplane was towed to a fixed base operator.

Inspection of the accident site by the Federal Aviation Administration revealed that the airplane touched down about 7 feet short of runway 35. The right propeller was not in the feathered position.

The airplane was recovered by Myers Aviation, Oshkosh, Wisconsin, where the right engine, a Teledyne Continental Motors, TSIO-520-ND, serial number R-228402-R, was inspected by an airframe and power plant mechanic. The mechanic reported that the right engine oil quantity was "just over 4 quarts." He added 3 more quarts in order to perform a ground run of the engine and investigate the oil pressure problem. The ground run revealed that the oil pressure was normal, the oil temperature was normal, the cylinder head temperature was normal, and the magneto check was normal. He did not run the engine past 1,700 rpm in order to avoid a propeller strike due to a flat landing gear strut.

The mechanic stated that during removal of the engines and wings, he noticed that the vacuum line and wing boot deice lines were "full" of oil. He removed the right engine oil filter and no metal was noted. He checked the right engine turbocharger and found that it was "seized-up." The right engine driven vacuum pump was identified by the mechanic as a Pesco 207, type B-12, part number 207-JA, serial number DG-22308. The pump data tag listed "Pump Eng'R'Ng Service Corp., Cleveland, Ohio. The mechanic stated that this pump was "full" of oil, the pump drive shaft was sheared, and the pump contained an internal oil separator.

Examination of the turbocharger bearings and shaft did not show evidence of blue colored discoloration. The turbocharger bearings and shaft displayed evidence of circumferential wear consistent with normal operation.

NTSB Probable Cause

The proper touchdown point not obtain/maintained by the pilot following a single-engine approach to landing. Contributing factors were the vacuum pump oil leak, the low oil pressure of the propeller control system, and the unfeathered propeller.