NYC95LA130

The flight was at 6,000 ft when the engine started to vibrate and lose power. The pilot set up for a forced landing at an airport. The vibration increased and the power loss continued. Oil started to cover the windshield, and the pilot found it necessary to slip to see ahead which further reduced his airspeed and altitude. The airplane landed 1/4 mile short of the runway in trees. Examination of engine found the crankshaft had failed on the front face of the number 2 crank pin. Metallurgical examination revealed fracture features typical of a fatigue crack that originated below the surface.

On May 31, 1995, at 1735 eastern daylight time, a Piper PA- 32-260, N16354, was destroyed during a forced landing in Ashland, Virginia. The private pilot was not injured. Visual meteorological conditions prevailed, and the flight, which had departed Emporia, Virginia, at 1700, was operated on an Instrument Flight Rules (IFR) flight plan under 14 CFR Part 91.

In the NTSB Accident Report, the pilot stated:

...At 6000 [feet] routine flight until vibration started with some loss of power...The vibration and power loss worsened...I was unable to maintain altitude and speed, but the airport looked "makeable". Unfortunately a large amount of oil then appeared from the cowling and covered the windshield. This was about 4000 ft, and 8 miles. I had to start slipping to see forward and each time the drag slowed the plane and caused altitude loss. The vibration and power loss worsened, until about 3/4 mile short of the runway the engine stopped. I was close to stall speed so I put the nose down and tried to restart the engine. This failed. I could not make the runway so I slipped to see forward and saw a stand of small trees and aimed for them. Close in I shut off the fuel, magnetos, electrics, and opened the door. About 50 yds out I saw power lines and nosed under them, then pulled the flaps, raised the nose and mushed into the trees.

The FAA reported that the airplane came to rest about 1/4 mile from the approach end of runway 16. Both wings and the fuselage were bent.

Examination of the engine found a hole on the top, next to the number 2 cylinder. No oil was found in the engine. During engine disassembly, the crankshaft was found fractured at the forward crossover check of the number 2 crank pin.

According to the NTSB Metallurgical Report, # 96-5:

...fracture revealed features typical of a fatigue crack that originated...approximately 0.05 inch below the forward radius surface...Fatigue propagation was...through at least 75 % of the rod journal cross section. The remaining portion of the fractures was damaged by post-fracture mechanical contact which obliterated the original fracture features.

...Rockwell superficial hardness testing performed on the nitride surface of the #2 main journal produced an average hardness of 70HR30N, which was above the specified minimum hardness.

...The nitride case and core hardness were within the specified depth and hardness range, respectively...The microstructure contained no metallurgical anomalies.

...Energy dispersive X-ray spectroscopic analysis of the section produced a spectrum consistent with the composition of a 4300 series steel.