Robinson Helicopter R22 BETA accident near Mendon, Utah, May 7, 2010
On May 7, 2010 at about 11:32 pm local time, a Robinson Helicopter R22 BETA, registered N393LE, was substantially damaged in an accident during maneuvering near Mendon, Utah. 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
A loss of engine power due to a failure of the magnetos as a result of inadequate maintenance.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 7, 2010 · about 11:32 pm local time
- Place
- Mendon, Utah · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Robinson Helicopter R22 BETA · all R22 BETAs on the register
- Registration
- N393LE · no longer on the register · serial 4393
- 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 (CFI) and student pilot departed on a local area training flight and found a suitable area to perform practice autorotations. During the first autorotation, the engine experienced a loss of power. The CFI assumed control of the helicopter and the student attempted to restart the engine. During the touchdown, the right skid caught on the terrain, and the helicopter rolled to the right. The CFI indicated that it appeared the grass-covered terrain was flat and would make a good emergency landing spot; however, upon touchdown he realized that the terrain was rough. A post accident examination and test run of the engine by a Federal Aviation Administration (FAA) inspector did not reveal any operational anomalies with the helicopter. Disassembly of the magnetos revealed evidence of internal arcing. The magneto manufacturer and engine manufacturer had issued service bulletins related to the inspection of the magnetos every 100 hours and 500 hours. The 500-hour inspection required that the magnetos be removed from the engine, disassembled, inspected, and serviced. According to the FAA inspector, review of the maintenance records for the helicopter showed that neither service bulletin had been complied with.
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
- Loss of engine power (total) during maneuvering defining event
- Off-field or emergency landing during emergency descent
- Roll over during landing (flare/touchdown)
The NTSB's findings
- cause Personnel issues › Task performance › Maintenance › Scheduled/routine maintenance › Maintenance personnel
- factor Environmental issues › Physical environment › Terrain › Rough terrain › Contributed to outcome
- cause Aircraft › Aircraft power plant › Ignition system › Magneto/distributor › Not serviced/maintained
Dual student
- Certificate: student
- Flight time: 22 hours in all; 22 in this make and model; 22 in the last 90 days; 11 in the last 30 days
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: rgt
- Injury: no injuries
Flight instructor
- Certificate: flight instructor, commercial pilot
- Ratings: instructor: helicopter; instructor: instrument helicopter; rotorcraft: helicopter
- Flight time: 1,208 hours in all; 906 in this make and model; 140 in the last 90 days; 33 in the last 30 days; 1,149 as pilot in command; 699 on instruments
- Last flight review: July 11, 2008
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 1,000 hours
- Last inspection: annual inspection, April 22, 2010; 45 hours since
- Maximum gross weight: 1,370 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming O-360-J2A (piston); 0 hours total
- Operator: Mountain Ridge Helicopters LLC
The flight
- Departed from: LGU Logan UT at 11:00 pm
- Destination: LGU Logan UT
- Flight plan: none
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 52°F (11°C), dew point 9°F (-13°C)
- Altimeter: 30.18 inHg
- Observation at 11:50 pm from LGU, 5 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 N393LE 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.