Piper PA-24 N6764P

Summary

On 29 October 2004 at about 00:09 local time, a Piper PA-24 registered N6764P was involved in an accident near Buffalo Grove, Illinois, United States. One person was on board and one was seriously injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

29 October 2004 at 00:09

Classification

Accident

Location

Buffalo Grove, Illinois, United States

Nearest airport

Palwaukee Muni (PWK)

Coordinates

42.1683, -87.9344

Aircraft

Piper PA-24

Registration

N6764P

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Wheeling → Evansville

Aircraft damage

Substantial

Weather

IMC

Light

Night/Dark

NTSB number

CHI05LA019

1 person was seriously injured.

Fatigue fracture of the engine crankshaft during initial climb after takeoff resulting in a complete loss of engine power. Contributing factors were the trees and the highway.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The airplane was substantially damaged during a forced landing following a complete loss of engine power during initial climb after takeoff. The pilot reported that approximately 10 minutes after takeoff, when the flight was about 3,000 feet mean sea level, he heard a "loud bang followed by extreme vibrations of the aircraft." The pilot executed a forced landing on a four-lane highway about 4 miles north of the departure airport. He noted, "While flaring to land a car turned in front of me. I avoided the car, however, the left wing started clipping trees." The airplane came to rest on the highway median. A post-accident inspection of the engine determined that the crankshaft had failed aft of the number 2 main bearing journal. Metallurgical examination of the crankshaft fracture surface revealed crack arrest marking (beach marks) indicative of fatigue cracking. Fatigue initiation was at the surface of the main bearing journal slightly forward of the aft radius. The adjacent journal surface was roughened and discolored with multiple longitudinally oriented parallel cracks (ladder cracks) in the surface. Magnified examination found that the fatigue fracture originated at one of the ladder cracks and grew aft through about 75 percent of the crank cheek before the crankshaft failed. The other journals showed some circumferential scratches and light wear. However, none showed the high level of surface damage exhibited by the fractured main journal. According to the maintenance logbook, the engine had accumulated 3,109.8 hours total time and 876.8 hours since overhaul.

Quoted verbatim from the NTSB record.