Bell 206 L-1 N2138Y

Summary

On 23 March 2001 at about 20:20 local time, a Bell 206 L-1 registered N2138Y, operated by EMS AirService of New York, Inc, was involved in an accident near Seneca Falls, New York, United States. 2 people were on board and 2 were seriously injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

23 March 2001 at 20:20

Classification

Accident

Location

Seneca Falls, New York, United States

Coordinates

42.9600, -76.8267

Aircraft

Bell 206 L-1

Registration

N2138Y

Category

Helicopter

Engines

1

Operator

EMS AirService of New York, Inc

Operating rule

Part 91: General Aviation

Purpose of flight

Positioning

Phase of flight

Not recorded

Route

Canadaigua → Marcellus

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

NYC01LA088

2 people were seriously injured.

the loss of a bolt in a Thomas coupling on the tail rotor drive shaft, for undetermined reasons, during climb, while operating over unsuitable terrain.

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

Read the full NTSB narrative

The Bell 206 L-1 helicopter was on a positioning flight. While in cruise flight, the pilot added power for a slow climb, and experienced multiple "bangs" and yawing. He reduced power, determined that he had lost tail rotor thrust, and set up for a precautionary landing in a wooded area. Upon touchdown, the helicopter rolled over. A bolt was found missing from the Thomas coupling located between the aft end of the aft short shaft, and the foward segment of the tail rotor drive shaft. In addition, the bracket for the forward hanger bearing was fractured. Metallurgical examination of the flange from the Thomas coupling with the missing bolt, revealed thread imprint marks on the inside of the bolt hole bore, and lipped material at the edge of the bolt hole bore. The hanger bearing mount had failed in overstress with no evidence of progressive cracking. The helicopter had been operated for 15.2 hours since the Thomas coupling had been disassembled and put back together. The mechanic reported that he had reused the bolts and self-locking nuts, and tightened them to the proper torque. The missing nut and bolt were not recovered. A check of the FAA database for SDRs revealed no other occurrences in the preceding 5 years.

Quoted verbatim from the NTSB record.