Bell 206-L4 accident near Thermal, California, April 26, 1995
On April 26, 1995 at about 2:50 am local time, a Bell 206-L4 (helicopter), registered N6197N, was substantially damaged in an accident near Thermal, California (Thermal airport). It was a public-use flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The CFI's failure to follow the flight manual procedures by using full up collective during an autorotation landing.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 26, 1995 · about 2:50 am local time
- Place
- Thermal, California · Thermal · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 206-L4 · all 206-L4s on the register
- Registration
- N6197N · no longer on the register · serial 52014
- Damage
- Substantial damage
- Flight
- Public-use flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE CFI WAS DEMONSTRATING A HOVERING AUTOROTATION TO TOUCHDOWN. THE HELICOPTER WAS EQUIPPED WITH FULL SKID SHOES, AND A QUARTERING HEADWIND OF 15 KNOTS, GUSTING TO 30 KNOTS, EXISTED. THE CFI APPLIED FULL UP COLLECTIVE TO CUSHION THE LANDING. THE TOUCHDOWN WAS SMOOTH, BUT THE HELICOPTER CAME TO AN ABRUPT STOP. WHEN THE CFI RETURNED TO THE PAD, HE NOTICED THAT THE TAILBOOM SKIN WAS WRINKLED. THE MANUFACTURER HAD ADDRESSED THE TAILBOOM WRINKLING IN AN OPERATIONAL SAFETY NOTICE (OSN) WHICH WAS INCORPORATED IN THE HELICOPTER FLIGHT MANUAL. THE OSN STATES THAT THE MAIN ROTOR BLADES RPM SHOULD NOT BE LESS THAN 70 PERCENT, AND THAT THE COLLECTIVE SHOULD BE IMMEDIATELY LOWERED ON TOUCHDOWN.
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: instructor: helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 104 in the last 90 days; 41 in the last 30 days; 3,030 as pilot in command; 311 on instruments
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 948 hours
- Last inspection: approved inspection programme, April 21, 1995; 7 hours since
- Maximum gross weight: 4,450 lb
- Seats: 7
- Landing gear: fixed
- Engine: Allison 250-C30P (turboshaft); 0 hours total
The flight
- Departed from: TRM
- Flight plan: none
- Runway 30, 4,993 ft by 100 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 280° at 15 knots, gusting 30
- Visibility: 20 statute miles
- Sky: clear
- Temperature: 90°F (32°C), dew point 0°F (-18°C)
- Altimeter: 29.00 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 |
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.