Kaman HH43 B/F accident near Coleville, California, August 31, 1991
On August 31, 1991 at about 3:24 pm local time, a Kaman HH43 B/F (helicopter), registered N53RH, was destroyed in an accident near Coleville, California. It was an other work-use flight under external-load helicopter rules (Part 133). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
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.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 31, 1991 · about 3:24 pm local time
- Place
- Coleville, California · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Kaman HH43 B/F
- Registration
- N53RH · registry record · serial 59-1569
- Damage
- Destroyed
- Flight
- Other work-use flight · external-load helicopter rules (Part 133)
The NTSB's narrative final · quoted from the NTSB record
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.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: commercial pilot, private
- Ratings: multi-engine land; single-engine land; rotorcraft: helicopter
- Flight time: 10,000 hours in all; 2,500 in this make and model; 200 in the last 90 days; 100 in the last 30 days; 10,000 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 4,182 hours
- Last inspection: annual inspection, March 7, 1991; 47 hours since
- Maximum gross weight: 9,150 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming T53L11D (turboshaft); 0 hours total
- Operator: Rogers Leasing
The flight
- Departed from: NONE Clovis CA at 12:30 pm
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 15 statute miles
- Sky: clear
- Temperature: 50°F (10°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.