Cessna 210L N2117S

Summary

On 14 June 2001 at about 14:37 local time, a Cessna 210L registered N2117S was involved in an accident near Key West, Florida, United States. 5 people were on board and one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

14 June 2001 at 14:37

Classification

Accident

Location

Key West, Florida, United States

Coordinates

24.5491, -81.7810

Aircraft

Cessna 210L

Registration

N2117S

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Key West → Grand Cayman

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

MIA01LA168

1 person had minor injuries.

The improper installation of the cylinders by other maintenance personnel for failure to assure that the cylinders were properly torqued resulting in fatigue crack in the crankshaft, and crankshaft failure. A finding in the investigation was fretting of both crankcase halves at several areas.

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

Read the full NTSB narrative

No discrepancies were noted during the preflight; the oil capacity was 9 quarts. Additionally, there was no report of an engine malfunction either during engine start, taxi, or during the engine run-up before takeoff. After takeoff following the first power reduction, the pilot later reported that the engine made a loud bang, and the rpm indicated zero though the propeller was rotating. Unable to return, she ditched the airplane and all occupants escaped. Examination of the engine revealed no crankshaft continuity to the accessory section. Disassembly of the engine revealed that the crankshaft was fractured at the No. 3 crankshaft cheek; metallurgical examination revealed fatigue. There was no bearing in the No. 2 main bearing position in the crankcases, pieces of it were found in the oil sump. Additionally, a bolt for the No. 2 cylinder connecting rod was fractured near the bolt head. Metallurgical examination of the bearing pieces and of the fractured connecting rod bolt revealed overstress on the undamaged fracture surfaces, and features consistent with bending shear separation, respectively. Metallurgical examination of the crankcase halves revealed brown to black deposists at all cylinder mounting surfaces; the deposits are consistent with corrosion and fretting products. Additionally, fretting and polishing were noted in several areas of both crankcase halves. The No. 2 main bearing saddle area was noted to be, "...severely damaged with large rolled edges formed at the forward and rear edges...." The engine was rebuilt by Teledyne Continental Motors, on August 23, 1988, and installed in the airplane on October 1, 1988. All cylinders were overhauled and installed on the engine on November 25, 1994; at that time the engine had accumulated a total time of approximately 986 hours since major overhaul. Between October 1, 1988, and November 25, 1994, oil samples for analysis were taken 10 times; the oil analysis reports were not located in the maintenance records and were not available from the facility that performed the analysis. There was no record of the repair and/or replacement of the Nos. 2 or 3 cylinders between the time the overhauled cylinders were installed in 1994, and the last entry in the logbook which was dated March 6, 2001. At the time of the accident, the engine had accumulated approximately 548 hours since the overhauled cylinders were installed.

Quoted verbatim from the NTSB record.