Bell 47G-3B-1 N48020

Summary

On 1 December 2002 at about 21:10 local time, a Bell 47G-3B-1 registered N48020, operated by Bureau of Land Managment, was involved in an accident near Panaca, Nevada, United States. One person was 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

1 December 2002 at 21:10

Classification

Accident

Location

Panaca, Nevada, United States

Coordinates

37.7903, -114.4250

Aircraft

Bell 47G-3B-1

Registration

N48020

Category

Helicopter

Engines

1

Operator

Bureau of Land Managment

Operating rule

Part 91: General Aviation

Purpose of flight

Public Use

Phase of flight

Not recorded

Route

Caliente → Panaca

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

LAX03TA043

Nobody was injured.

separation of the no. 6 cylinder intake valve head from the valve stem, which resulted in a loss of engine power. The mechanism responsible for the valve failure is unknown.

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

Read the full NTSB narrative

The helicopter experienced a loss of engine power and landed hard during an autorotation, severing the tail boom. The number 6 cylinder's intake valve separated, with the valve's head wedged in the intake valve seat bore. Removal of the rocker box cover on that cylinder revealed that the spring retainer was broken into numerous pieces. The piston head showed over 15 impressions consistent in dimension to that of the valve head. After examining the number 6 cylinder, a metallurgist determined that the valve failed in between the intake valve head and the valve stem.

Quoted verbatim from the NTSB record.