Bell 212 N1079U

Summary

On 17 January 2003 at about 02:52 local time, a Bell 212 registered N1079U, operated by National Science Foundation, was involved in an accident near McMurdo Station, Antarctica. 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

17 January 2003 at 02:52

Classification

Accident

Location

McMurdo Station, Antarctica

Coordinates

-77.8333, 166.6000

Aircraft

Bell 212

Registration

N1079U

Category

Helicopter

Engines

2

Operator

National Science Foundation

Operating rule

Public Use

Purpose of flight

Public Use

Phase of flight

Not recorded

Route

McMurdo Station → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ANC03GA023

2 people were seriously injured.

The pilot's continued operation of the helicopter with an unstable external load, which resulted in damage to the cargo hook assembly, adjacent throttle controls, and subsequent loss of engine power, precipitating an emergency descent and impact with terrain. Factors associated with the accident were the load oscillations, and the separation of the fuel crossover lines.

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

Read the full NTSB narrative

The public use helicopter was lifting a 20' by 14' by 6" thick platform, weighing about 1250 pounds, on a 100 foot long line. The airline transport pilot had successfully lifted and transported three similar platforms with the accident helicopter just before the accident flight, although he had difficulty controlling the load on two flights, and landed to check the helicopter for damage after the third flight. On the accident flight, the pilot reported a severe jolt to the airframe while the helicopter was approximately 200' AGL, and the load was approximately 100' AGL, followed by an immediate loss of engine power. Ground witnesses noted that the platform swung from right to left, fore and aft, and rose vertically several times. The platform rose one final time, and "slammed down" on the long line, breaking the platform in half. Witnesses said they then saw white vapor coming from the helicopter, the load was jettisoned, and the helicopter descended very rapidly, impacting on a frozen lake. Postaccident examination of the engines disclosed no evidence of any preimpact mechanical anomalies. An inspection of the external cargo hook and its support structure in the belly of the helicopter, revealed a sheared bolt at the top of the hook support assembly, which allowed the assembly to move and change shape. Witness marks indicate that the hook assembly overrode its container ring, and struck the fuel crossover lines, throttle control bell cranks for both engines, and the throttle position push/pull tubes. Both fuel crossover lines were pulled from their respective fuel tanks, and the throttle position bell cranks were found in the engine idle cutoff position, with the crossover lines crushed against them.

Quoted verbatim from the NTSB record.