Accident MBB BK 117A-1 N122LF,
ASN logo
ASN Wikibase Occurrence # 75921
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information. If you feel this information is incomplete or incorrect, you can submit corrected information.

Date:Wednesday 30 April 1997
Time:18:10 LT
Type:Silhouette image of generic BK17 model; specific model in this crash may look slightly different    
MBB BK 117A-1
Owner/operator:Keystone Helicopters
Registration: N122LF
MSN: 7002
Year of manufacture:1983
Total airframe hrs:5570 hours
Engine model:Lycoming LTS101-650
Fatalities:Fatalities: 0 / Occupants: 4
Aircraft damage: Substantial
Location:Kane, PA -   United States of America
Phase: Landing
Departure airport:Bellefont, PA (N96)
Destination airport:(NONE)
Investigating agency: NTSB
Confidence Rating: Accident investigation report completed and information captured
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.

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

Accident investigation:
Investigating agency: NTSB
Report number: IAD97LA070
Status: Investigation completed
Duration: 2 years and 5 months
Download report: Final report




Revision history:

25-Jul-2010 03:06 Alpine Flight Added
20-Aug-2010 03:07 TB Updated [Aircraft type]
20-Aug-2010 04:51 TB Updated [Operator]
20-Nov-2012 12:09 TB Updated [Time, Operator, Destination airport, Source, Narrative]
21-Dec-2016 19:25 ASN Update Bot Updated [Time, Damage, Category, Investigating agency]
08-Apr-2024 15:44 ASN Update Bot Updated [Time, Operator, Other fatalities, Nature, Departure airport, Destination airport, Source, Narrative, Category, Accident report]

Corrections or additions? ... Edit this accident description

The Aviation Safety Network is an exclusive service provided by:
Quick Links:

CONNECT WITH US: FSF on social media FSF Facebook FSF Twitter FSF Youtube FSF LinkedIn FSF Instagram

©2024 Flight Safety Foundation

1920 Ballenger Av, 4th Fl.
Alexandria, Virginia 22314