Beechcraft M35 N693V

Summary

On 3 June 2004 at about 17:15 local time, a Beechcraft M35 registered N693V was involved in an accident near Strafford, Missouri, United States. 2 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

3 June 2004 at 17:15

Classification

Accident

Location

Strafford, Missouri, United States

Coordinates

37.2444, -93.3869

Aircraft

Beechcraft M35

Registration

N693V

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Tell City → Tulsa

Aircraft damage

Substantial

Weather

VMC

NTSB number

CHI04LA144

Nobody was injured.

The improper installation of the cylinder during the engine overhaul which resulted in the fatigue failure of the cylinder studs and through-bolts and the subsequent separation of the cylinder. Factors associated with the accident were the fence and the guy wire which the airplane contacted during the forced landing.

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

Read the full NTSB narrative

The airplane collided with a fence and a guy wire during a forced landing following a loss of engine power. The pilot reported he was flying at 8,500 feet mean sea level when the number 2 cylinder departed the engine resulting in a total loss of engine power. He reported that with no airports within gliding distance, he elected to land in a farmer's field where the airplane contacted a fence and a guy wire. The number 2 cylinder and the left magneto were not located after the accident. Half of the crankcase, two fractured cylinder through-bolts, two cylinder through-bolt nuts with pieces of bolts inside, four cylinder hold down nuts with pieces of studs inside, a connecting rod cap with the connecting rod cap bolt, and a connecting rod nut were submitted for a metallurgical examination. The studs and through-bolts were arbitrarily numbered clockwise starting at the upper forward stud. All of the studs and through-bolts that were examined exhibited fatigue cracking with stud 3 exhibiting the largest fatigue region. A lip was observed on the surface of the crankcase which corresponded to the forward edge of the cylinder barrel flange, adjacent to the through-bolts. Linear marks aligned with the axis of the cylinder were observed at the aft side of the cylinder hole corresponding to sliding contact with the cylinder barrel skirt. Sectioning of studs 3 and 4 revealed cracks and/or rolling laps at the thread roots. On stud 4, many of the cracks extended radially then turned. Two studs were removed from cylinder #4 and one of them also displayed sharp thread radii and cracking. This cylinder did not fail. The engine was overhauled on July 6, 2000, at a tach time of 2440.33 hours. The engine had accumulated 194.03 hours since the overhaul.

Quoted verbatim from the NTSB record.