Enstrom F-28F accident near Twin Falls, Idaho, October 10, 2000
On October 10, 2000 at about 2:30 pm local time, a Enstrom F-28F (helicopter), registered N223RS, was substantially damaged in an accident near Twin Falls, Idaho. It was a flight of an unrecorded kind 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 pilot's failure to maintain adequate rotor rpm. Unsuitable terrain was selected for the maintenance test flight operation.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 10, 2000 · about 2:30 pm local time
- Place
- Twin Falls, Idaho · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Enstrom F-28F · all F-28Fs on the register
- Registration
- N223RS · registry record · serial 748
- Damage
- Substantial damage
- Flight
- Flight of an unrecorded kind · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that during a maintenance test flight to check controls, collective pitch position, throttle positioning, and rpm correlation control entering an autorotation, he entered the autorotation with low rpm. When the pilot corrected with collective pitch, the correlator over responded, resulting in an rpm overspeed. The pilot closed the throttle and increased the collective, however, the rpm dropped and the pilot had to complete the autorotation to touch down on rough terrain. So as not to have any forward speed at touch down, and fearing that the helicopter might roll over, the pilot anticipated a hard flare to stop the forward speed. Just prior to touch down, the tailrotor contacted the ground, and the tailrotor gearbox separated from the tail boom. The helicopter yawed to the right about 150 degrees before the pilot was able to level the helicopter, arrest the yaw and land without further incident.
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: flight instructor, commercial pilot
- Ratings: single-engine land; instructor: helicopter; instrument: airplane; rotorcraft: helicopter
- Flight time: 1,599 hours in all; 196 in this make and model; 132 in the last 90 days; 70 in the last 30 days; 1,398 as pilot in command; 96 on instruments
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 2,949 hours
- Last inspection: annual inspection, October 5, 2000; 2 hours since
- Maximum gross weight: 2,300 lb
- Seats: 3
- Landing gear: fixed
- Engine: Lycoming HIO-360 (piston); 0 hours total
The flight
- Departed from: TWF Twin Falls ID at 2:00 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 360° at 6 knots
- Visibility: 10 statute miles
- Sky: broken clouds at 10,000 ft; not recorded
- Temperature: 46°F (8°C), dew point 46°F (8°C)
- Altimeter: 29.00 inHg
- Observation at 1:53 pm from TWF, 5 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 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.