# NTSB LAX91LA377: Kaman HH43 B/F, N53RH, Coleville, CA, August 31, 1991

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Limited investigation · Final report
- Date: August 31, 1991, 08:24 local (15:24 UTC)
- Place: Coleville, CA
- Coordinates: 38.469459, -119.480194 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=38.4695&lon=-119.4802&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed, report May 3, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27344
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX91LA377
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27344/pdf
- Page: https://openairdocs.org/ntsb/LAX91LA377

## Probable cause

THE FAILURE OF THE PILOT TO ADEQUATELY CALCULATE THE HELICOPTER PERFORMANCE.  CONTRIBUTING TO THE ACCIDENT WAS A DELAY IN JETTISONING THE EXTERNAL LOAD; THE PILOT'S OVERCONFIDENCE IN HIS ABILITIES; AND EXCEEDING OF THE HELICOPTER'S HOVER ABILITY DURING HIGH DENSITY ALTITUDE CONDITIONS.

## Sequence of events

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

- Loss of control - in flight, hover
  - weather condition - high density altitude (contributing factor)
  - performance data - not followed, pilot in command (cause)
  - overconfidence in aircraft's ability, pilot in command (contributing factor)
  - aircraft performance,helicopter hover performance - exceeded (contributing factor)
  - in-flight planning/decision - inadequate, pilot in command (cause)
  - overconfidence in personal ability, pilot in command (contributing factor)
  - load jettison - delayed, pilot in command (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - mountainous/hilly

## Analysis

THE CERTIFICATED COMMERCIAL HELICOPTER PILOT WAS ENGAGED IN A SALVAGE OPERATION OF THE WRECKAGE OF A WORLD WAR II F-4U CORSAIR, UTILIZING AN EXTERNAL 50 FOOT LONG LINE. ON THE FOURTH TRIP OF THE DAY, THE RADIAL AIRCRAFT ENGINE WITH PROPELLERS ATTACHED, WAS BEING LIFTED FROM RUGGED MOUNTAINOUS TERRAIN AT 11000 FEET MSL. THE ENGINE WAS POSITIONED AT THE EDGE OF A ROCKY GLACIAL CHUTE THAT DESCENDED AT ABOUT A 45 DEG ANGLE. THE DENSITY ALTITUDE OF 13000 FEET AND THE EXTERNAL LOAD WEIGHT, EXCEEDED THE PERFORMANCE CAPABILITY OF THE HELICOPTER. AS THE HELICOPTER ATTEMPTED TO LIFT THE ENGINE, GROUND PERSONNEL OBSERVED THE HELICOPTER IN A NOSE DOWN ATTITUDE. THE MAIN ROTOR BLADES STRUCK SURROUNDING TERRAIN. THE HELICOPTER AND ENGINE TUMBLED DOWN THE MOUNTAIN SIDE, DISINTEGRATING AS IT DESCENDED ABOUT 1/2 MILE DOWNSLOPE. ONE GROUND CREWMEMBER RECEIVED MINOR INJURIES FROM FLYING DEBRIS. THE PILOT RECEIVED FATAL INJURIES.

## Aircraft

- Registration: [N53RH](https://openairdocs.org/deregistered/N53RH-1998-11-16), registration cancelled 1998-11-16, S/N 591569 (OpenAirDocs)
- Reported make and model: KAMAN HH43 B/F
- Registry model: [Kaman HH-43F](https://openairdocs.org/model/kaman-hh-43f) (registry code 4800708) (OpenAirDocs)
- Category: Helicopter
- Serial number: 59-1569
- Airframe hours: 4182
- Engines: LYCOMING T53L11D 1100 horsepower turbo shaft
- Damage: Destroyed
- Flight: Other work use, Part 133
- Operator: Rogers Leasing
- Registered owner: Rogers Leasing
- Last inspection: Annual, March 7, 1991, 47 hours before
- Departed: NONE, CLOVIS, CA
- Flight plan: Company VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 33; commercial, private; airplane ratings: multi-engine land, single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: right; toxicology performed; flight hours: 10,000 total, 2,500 in this make and model, 10,000 as pilot in command, 200 in the last 90 days, 100 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 50 °F

## 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 19910831037579A](https://openairdocs.org/incident/19910831037579A), Aug 31, 1991: Kaman HH43FCHOPER, Coleville, CA, Destroyed, 1 fatal. External load put helicopter 799LBS over gross. Lost control on liftoff. Rotors hit hillside. Altitude a factor.

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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