MBB BK-117-A1 N122LF

Summary

On 30 April 1997 at about 22:10 local time, a MBB BK-117-A1 registered N122LF, operated by Keystone Helicopters, was involved in an accident near Kane, Pennsylvania, United States. 4 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

30 April 1997 at 22:10

Classification

Accident

Location

Kane, Pennsylvania, United States

Coordinates

41.6591, -78.8007

Aircraft

MBB BK-117-A1

Registration

N122LF

Category

Helicopter

Engines

2

Operator

Keystone Helicopters

Operating rule

Part 91: General Aviation

Purpose of flight

Positioning

Phase of flight

Not recorded

Route

Bellefont → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

IAD97LA070

Nobody was injured.

The pilot's decision to perform a low airspeed vertical descent with a tailwind, which resulted in settling with power.

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

Read the full NTSB narrative

After a 30 minute flight to his destination, the pilot found the hospital helipad, which was about a 200 square foot area, with 40 foot high wires on the north side, and 35 to 50 feet high trees surrounding the rest of the area. A windsock indicated about 3 to 5 knots winds from the west/southwest. During the approach from the southwest, the pilot descended vertically to the helipad. The pilot attempted to stop the rate of descent with the airspeed below 10 knots. The helicopter shuttered with the application of additional power. The helicopter yawed right, and 'the additional collective pitch seemed to have no effect on slowing the rate of descent, the rate of descent seemed to increase at this point.' The pilot determined that he did not have sufficient space to fly out of the area and at impact, all remaining collective pitch had been applied. No master caution or annunciator panel lights were noticed, nor was any audio tones heard. A helicopter aerodynamics manual described conditions conducive to settling with power, which included a vertical or near vertical descent of at least 300 feet per minute, engine power between 20 and 100 percent, during downwind steep approaches.

Quoted verbatim from the NTSB record.