Bell 206B III N16733

Summary

On 8 January 1989 at about 21:27 local time, a Bell 206B III registered N16733, operated by Avman Inc, was involved in an accident near Park City, Utah, 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

8 January 1989 at 21:27

Classification

Accident

Location

Park City, Utah, United States

Coordinates

40.6409, -111.4901

Aircraft

Bell 206B III

Registration

N16733

Category

Helicopter

Engines

1

Operator

Avman Inc

Operating rule

Part 91: General Aviation

Purpose of flight

Other Work Use

Phase of flight

Not recorded

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

DEN89LA059

Nobody was injured.

THE SELECTION OF AN UNSUITABLE LANDING SITE BY THE PILOT, RESULTING IN TAIL ROTOR CONTACT WITH THE TERRAIN AND SHEARING OF THE TAIL ROTOR DRIVESHAFT.

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

Read the full NTSB narrative

THE COMMERCIAL PLT FLEW A RESCUE TEAM TO A MOUNTAIN AVALANCHE AREA. THE TEAM DEPLANED AND DURING THE UNLOADING PROCEDURE THE HELICOPTER SETTLED BACKWARDS INTO LOOSE SNOW. THE PLT ADDED COLLECTIVE PITCH AND ATTEMPTED TO HOVER. AS THE HELICOPTER LEFT THE GROUND, AN UNCOMMANDED RIGHT SPIN BEGAN. THE PLT PERFORMED A HOVERING AUTOROTATION 30 FEET AWAY FROM THE GROUND PERSONNEL. AT TOUCHDOWN THE TAIL BOOM ENTERED DEEP SNOW AND THE ACFT CAME TO REST NOSE HIGH. THE PLT DISCOVERED THE TAIL ROTOR SHAFT HAD BROKEN FORWARD OF THE TAIL ROTOR GEAR BOX. A POST ACCIDENT INVESTIGATION SHOWED EVIDENCE THAT THE TAIL ROTOR BLADES ENTERED LOOSE SNOW AND WERE SUBJECTED TO RAPID DECELERATION. THE SHAFT HAD SHEARED UNDER APPLIED TORQUE.

Quoted verbatim from the NTSB record.