Bell UH-1B accident near Bieber, California, August 14, 1990
On August 14, 1990, a Bell UH-1B (helicopter), registered N64789, was substantially damaged in an accident near Bieber, California. It was a public-use flight under external-load helicopter rules (Part 133). 1 person was seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE PILOT'S FAILURE TO MAINTAIN AIRCRAFT CONTROL WHEN INTENTIONALLY SLOWING HIS AIRCRAFT TO OFF LOAD WATER ON FIRE. CONTRIBUTING TO THE ACCIDENT WAS THE PILOT'S FAILURE TO ARM AND RELEASE THE EXTERNAL LOAD.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 14, 1990
- Place
- Bieber, California · map
- Type
- Accident
- Injuries
- 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell UH-1B · all UH-1Bs on the register
- Registration
- N64789 · no longer on the register · serial 62-4598
- Damage
- Substantial damage
- Flight
- Public-use flight · external-load helicopter rules (Part 133)
The NTSB's narrative final · quoted from the NTSB record
THE PILOT WAS FLYING A FIRE FIGHTING MISSION AND WAS APPROACHING SOUTHERLY ASCENDING TERRAIN FROM THE EAST. THE AIRCRAFT APPROACHED THE TERRAIN AND SLOWED TO MAKE A WATER DROP. AS IT SLOWED THE TAIL TURNED TO THE LEFT AND THE HELICOPTER LOST ALTITUDE AND SETTLED INTO THE TREES. THE PILOT HEARD THE LOW RPM AUDIO AND SAW THE LOW RPM WARNING LIGHT. HE ATTEMPTED TO RELEASE THE WATER LOAD. EXAMINATION OF THE ENGINE AND ENGINE COMPONENTS REVEALED NO EVIDENCE OF A MALFUNCTION OR FAILURE. THE TEMPERATURE REPORTEDLY WAS BETWEEN 82 TO 86 DEGREES F WITH THE WIND FROM THE NORTH AT 5 TO 8 KNOTS.
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
- Ratings: rotorcraft: helicopter
- Flight time: 20,000 hours in all
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 5,220 hours
- Last inspection: annual inspection, December 15, 1989; 46 hours since
- Maximum gross weight: 8,500 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming T53-L11 (turboshaft); 0 hours total
- Operator: Intermountain Air Services
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 270° at 8 knots
- Visibility: 6 statute miles
- Sky: clear
- Temperature: 86°F (30°C), dew point 43°F (6°C)
- Altimeter: 29.00 inHg
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.
Other NTSB records under N64789 the same tail number, which may have belonged to a different aircraft at the time
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.