Bell 206B N5016G

Summary

On 4 August 1998 at about 14:45 local time, a Bell 206B registered N5016G was involved in an accident near Lucerne Valley, California, 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

4 August 1998 at 14:45

Classification

Accident

Location

Lucerne Valley, California, United States

Coordinates

34.5191, -116.8795

Aircraft

Bell 206B

Registration

N5016G

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Positioning

Phase of flight

Not recorded

Route

Riverside → Flagstaff

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

LAX98LA256

Nobody was injured.

The failure of the mechanic who installed the engine to follow proper procedures by insuring the proper torque to the oil output line, resulting in a loose fitting, oil loss and subsequent bearing failure.

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

Read the full NTSB narrative

The pilot had been flying for about 25 minutes when he noticed that the oil pressure gauge and torque gauge were fluctuating. He initiated an approach to a precautionary landing spot on an asphalt pad. About 150 feet agl, the engine quit and the pilot autorotated to touch down on a paved road. The main rotor blades severed the tail boom aft of the horizontal stabilizer. The engine had received some maintenance work and had been reinstalled in the helicopter the night before the accident, at which time the pilot performed a test run and leak check of the engine, with no noted discrepancies. The pilot further stated that the engine had been running normally until the fluctuation of the oil pressure and torque gauges. During an examination of the engine, the oil output line was connected, but loose, and oil was seen dripping from the fitting area. Oil was observed over most of the fuselage and underneath the engine. There was approximately 1 pint of oil found in the sump. Further teardown of the engine revealed that the number 8 bearing was destroyed and no oil was found throughout the lubrication system. The Bell Helicopter maintenance manual specifies a torque value for the fitting on the oil output line; however, the mechanic who installed the engine reported that he did not use a torque wrench to tighten the line because he would have had to remove some other lines to get to it and he was in a hurry.

Quoted verbatim from the NTSB record.