Aviation Accident Summaries

Aviation Accident Summary NYC98LA015

SCOTTSVILLE, VA, USA

Aircraft #1

N2200J

Piper PA-32RT-300

Analysis

The pilot leveled off at his cruise altitude of 6,500 feet, the engine started to vibrate, and oil was observed leaking from the engine cowling. The vibration and oil flow increased in intensity, and the pilot shut the engine off, and performed a forced landing to a field. During the ground roll, the airplane struck a berm about 2 feet high. Examination of the engine revealed the number 2 connecting rod had failed between the wrist pin hole and crankshaft yoke. Metallurgical examination of the fracture found fatigue, and evidence of gauling in the area of the connecting rod bolt holes. Gauling was also found on the number 6 connecting rod bolt holes. According engine manufacturer, gauling could occur from high loading such as produced during overspeed or excessive manifold pressure operation. The operator reported the airplane was flown by company pilots on charter flights, and was also a rental airplane.

Factual Information

On October 20, 1997, about 1046 eastern daylight time, a Piper PA-32RT-300, N2200J, operated by Blue Ridge Air, was substantially damaged during a forced landing near Scottsville, Virginia. The certificated commercial pilot and passenger were not injured. Visual meteorological conditions prevailed for the charter flight that departed from Charlottesville, Virginia, about 1030. The flight was operated on a Visual Flight Rules (VFR) flight plan under 14 CFR Part 135, destined for Southern Pines, North Carolina. In the NTSB Pilot/Operator Aircraft Accident Report, the pilot stated: "...About 15 minutes into the flight, leveling off at a cruising altitude of 6,500 [feet] MSL. Severe engine vibration was noted along with oil leaking from the area of the oil door partially covering the windscreen." "An emergency was declared a decision to land off-airport was made. The single passenger on-board briefed, and a glide established...." In a follow-up telephone interview, the pilot reported that the departure and climb to cruise altitude were uneventful. As the airplane was leveled at 6,500 feet for cruise, the engine was vibrating more than normal, and oil was leaking from the area of the oil filler door on the engine cowling. The vibration continued, and increased in intensity, as did the amount of oil that was leaking from the engine cowling, and covering the windshield. A field was selected for a forced landing and the engine was secured, followed by shutting off the fuel and electrical power. On short final, a power line was observed and the pilot elected to go under it. After touchdown, the airplane struck a 2 foot high berm that had been obscured by vegetation, and not observed from the air. The nose and left main landing gear collapsed, and the airplane slide to stop. The occupants then exited the airplane. On-site examination of the airplane by an inspector from the Federal Aviation Administration (FAA) revealed two holes on the top of the engine case above the forward connecting rod. The Inspector reported that the forward connecting rod was separated from the crankshaft, and there was no evidence of distress on the forward connecting rod journal surface. The engine was disassembled on November 11, 1997. The number 2 connecting rod was broken mid-way between the crankshaft yoke and the piston wrist pin hole. Pieces of metal were found in the oil pump and oil screen. The number 2 and 6 connecting rods were forwarded to the Textron Lycoming Metallurgical Laboratory for further examination. According to their report # LN 11145, dated December 16, 1997: "...Examination of the [number 2] connecting rod fracture surface at the yoke revealed beach marks...initiating from the crankpin bore indicating the rod failed in fatigue and progressed toward the OD of the crankpin bore. The fatigue origin was too severely damaged to determine whether the fatigue initiated from a galled spot. However, galled spots were observed near the origin...Examination of the No.6 connecting rod crankpin bore also revealed galled spots in the vicinity of the connecting rod bolt hole areas...." According to Textron Lycoming Mandatory Service Bulletin No. 439A, Inspection of Connecting Rods for Fretting and/or Galling and Repair of Fretting: "...Galling...is caused by movement between the surfaces of the bearing insert and the connecting rod during periods of high loading such as is produced during overspeed or excessive manifold pressure operation...." According to the operator, the airplane was flown by company pilots on charter flights, and available to pilots at large as a rental airplane.

Probable Cause and Findings

improper engine operation by undetermined person(s) that initiated gauling on the connecting rod, and led to its subsequent failure.

 

Source: NTSB Aviation Accident Database

Get all the details on your iPhone or iPad with:

Aviation Accidents App

In-Depth Access to Aviation Accident Reports