Amateur-built Rotorway Exec 90 accident near Westport, Oklahoma, March 8, 2008
On March 8, 2008 at about 8:00 pm local time, a amateur-built Rotorway Exec 90 (helicopter), registered N5251B, was substantially damaged in an accident during maneuvering near Westport, Oklahoma. It was an instructional 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
An unsuccessful precautionary landing due to an electrical system malfunction.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- March 8, 2008 · about 8:00 pm local time
- Place
- Westport, Oklahoma · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built Rotorway Exec 90
- Registration
- N5251B · registry record · serial 5251
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The certified flight instructor and the student pilot were on an instructional flight to practice autorotations and simulated engine failures. About 45 minutes into the flight the instructor noticed the engine tachometer read lower than the rotor tachometer. The student pilot checked the battery voltage and said that it was "low". The instructor reported that the engine's fuel pump and ignition systems were not independent and he did not want to risk a downwind autorotation landing. When the instructor saw the rotor tachometer drop to 90 percent, he initiated an autorotation, assuming the helicopter had or was about to lose engine power. During the landing the left skid sank into the soft terrain and the helicopter subsequently rolled on to its side. The helicopter sustained substantial damage during the precautionary landing.
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
What happened, in order
- Electrical system malf/failure during maneuvering defining event
- Autorotation Collision with terrain or object (not controlled flight into terrain)
The NTSB's findings
- cause Aircraft › Aircraft systems › Electrical power system › (general) › Malfunction
- factor Environmental issues › Physical environment › Runway/land/takeoff/taxi surfa › Soft › Not specified
Flight instructor
- Certificate: commercial pilot
- Ratings: single-engine land; instructor: helicopter; instructor: instrument helicopter; instrument: helicopter; rotorcraft: glider; rotorcraft: helicopter
- Flight time: 498 hours in all; 22 in this make and model; 113 in the last 90 days; 19 in the last 30 days
- Last flight review: November 1, 2007
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: frt
- Injury: no injuries
Dual student
- Certificate: sport pilot
- Ratings: single-engine land
- Medical certificate: Sport Pilot
- Injury: no injuries
The aircraft
- Airframe total time: 983 hours
- Last inspection: condition inspection, March 1, 2008
- Landing gear: fixed
- Engine: Rotorway RW-100 (piston); 0 hours total
The flight
- Departed from: 95F Cleveland OK
- Destination: 4F1 Westport OK
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 010° at 12 knots, gusting 16
- Visibility: 10 statute miles
- Sky: overcast at 6,000 ft; not recorded
- Temperature: 36°F (2°C), dew point 23°F (-5°C)
- Altimeter: 30.13 inHg
- Observation at 7:53 pm from KRVS, 20 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight 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.
Other NTSB records under N5251B 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.