# NTSB ATL92LA007: Kaman HH-43B/F, N55714, Mt. Vernon, AL, October 14, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: October 14, 1991, 09:02 local (14:02 UTC)
- Place: Mt. Vernon, AL
- Coordinates: 31.090118, -88.010116 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=31.0901&lon=-88.0101&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report April 23, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 8535
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL92LA007
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/8535/pdf
- Page: https://openairdocs.org/ntsb/ATL92LA007

## Probable cause

A LOSS OF ENGINE POWER FOR UNDETERMINED REASONS. A FACTOR IN THE ACCIDENT WAS THE LACK OF A SUITABLE LANDING SITE.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of engine power, cruise
  - turboshaft engine - undetermined (cause)
- In flight collision with terrain/water, descent - emergency
  - terrain condition - water
  - terrain condition - none suitable (contributing factor)
  - autorotation - performed, undetermined

## Analysis

THE HELICOPTER WAS BEING REPOSITIONED FROM AN OPERATING BARGE TO THE BASE HELIPAD FOR REFUELING. EN ROUTE THE ENGINE SPEED ROLLED BACK TO FLIGHT IDLE, UNCOMMANDED. AN AUTOROTATIVE LANDING WAS MADE IN A SHALLOW LAKE. THE HELICOPTER ROLLED ON ITS SIDE AND DESTROYED THE MAIN ROTOR BLADES. A SUBSEQUENT EXAMIONATION OF THE ENGINE AND ITS ACCESSORIES FAILED TO REVEAL THE REASON FOR THE ROLL BACK.

## Aircraft

- Registration: [N55714](https://openairdocs.org/deregistered/N55714-2013-06-12), registration cancelled 2013-06-12, S/N 154/62-4528 (OpenAirDocs)
- Reported make and model: KAMAN HH-43B/F
- Registry model: [Timber Choppers KAMAN HH-43B/F](https://openairdocs.org/model/timber-choppers-kaman-hh-43b-f) (registry code 8940101) (OpenAirDocs)
- Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs)
- Category: Helicopter
- Serial number: 62-4528
- Airframe hours: 5577
- Engines: LYCOMING T-53-L-13B 1151 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Positioning, Part 91
- Operator: Scott Paper Company
- Registered owner: Scott Paper Company
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: 100 hour, October 10, 1991, 8 hours before
- Airport: NONE, Scott Heliport, runway 1

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 39; commercial; airplane ratings: multi-engine land, single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 13,250 total, 1,150 in this make and model, 13,100 as pilot in command, 150 in the last 90 days, 100 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 66 °F, dew point 59 °F
- Altimeter: 30.00 inHg
- Observed at: MOB, 25 nm away

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19911014046499A](https://openairdocs.org/incident/19911014046499A), Oct 14, 1991: Kaman HH43BFCHOPER, Mt Vernon, AL, Substantial damage. Reported uncommanded power reduction to flight idle. Forced landed in lake. No cause for reported problem found.

## Other investigations on N55714 (2)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB SEA01LA173](https://openairdocs.org/ntsb/SEA01LA173), Sep 25, 2001: Kaman HH-43 (N55714), Bonners Ferry, ID, substantial damage, 1 fatal. Probable cause: The pilot's inadequate visual lookout which lead to his failure to maintain clearance from the nearby trees while in a high-hover. Factors include mountainous/hilly terrain, and tall trees in the…
- [NTSB SEA88LA123](https://openairdocs.org/ntsb/SEA88LA123), Jul 5, 1988: Kaman HH43 (N55714), Joseph, OR, destroyed

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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