Enstrom F-28F N8622U

Summary

On 25 July 1998 at about 22:00 local time, a Enstrom F-28F registered N8622U was involved in an accident near Skwentna, Alaska, United States. 2 people were 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

25 July 1998 at 22:00

Classification

Accident

Location

Skwentna, Alaska, United States

Coordinates

61.9299, -151.7295

Aircraft

Enstrom F-28F

Registration

N8622U

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Part 135: Air Taxi & Commuter

Purpose of flight

Unknown

Phase of flight

Not recorded

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ANC98LA109

Nobody was injured.

A loss of engine power due to a fractured number three cylinder intake manifold flange, and the pilot's inability to maintain the proper rate of descent during the autorotation flare. A contributing factor associated with the accident was the downwind (tailwind) landing condition.

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

Read the full NTSB narrative

The certificated commercial helicopter pilot was conducting a salmon survey for the State of Alaska, Department of Fish & Game. This operation required him to hover the helicopter over the stream while the passenger, a wildlife biologist employed by the State of Alaska, noted the number of fish. The pilot stated that while in a hover above the stream, he felt a slight vibration followed by a partial loss of engine power. He said that while hover taxiing the helicopter to a suitable landing area, the engine continued to lose power, and he was forced to make a downwind autorotation. He said that as the helicopter touched down, the main rotor blades flexed downward, and struck the tail boom. The helicopter's tail boom, and tail rotor gearbox sustained substantial damage. The operator reported that during a postaccident inspection of the engine, a fractured intake manifold flange was discovered on the number three cylinder assembly.

Quoted verbatim from the NTSB record.