Amateur-built EXEC 90 accident near Hermiston, Oregon, August 12, 1996
On August 12, 1996 at about 3:35 pm local time, a amateur-built EXEC 90 (helicopter), registered N6183P, was substantially damaged in an accident near Hermiston, Oregon (Hermiston airport). It was a personal flight under general aviation rules (Part 91). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
slippage of the drive belts, while hover taxiing in ground effect, which resulted in loss of power to the rotor system; and inadequate remedial action by the pilot, which led to a roll over during touch down (forced landing). A factor relating to the accident was: inadequate maintenance and/or inspection of the drive belts.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 12, 1996 · about 3:35 pm local time
- Place
- Hermiston, Oregon · Hermiston · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built EXEC 90
- Registration
- N6183P · no longer on the register · serial 1942S
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot stated that he was practicing hovering and turns at an altitude of 10 feet, and was moving forward at about 5 mph, when power to the main rotor was lost due to slippage of the drive belts. He stated that he heard a sound like a rock hitting the fuselage, then the engine rpm increased from its rated rpm of 4,250 to 4,700. During recovery, the pilot pulled collective and used right cyclic to level out and maintain altitude. The helicopter slowed its descent and almost leveled out, but landed on the skids with a slight left drift. The helicopter rolled over after ground contact. The pilot held limited solo privileges for helicopters. He had first soloed a helicopter about three months before the accident and had a total of 17.2 hours of rotorcraft time. He stated that before the accident, he had just flown the helicopter for about one hour, then landed and checked the aircraft for 'tensions etc [sic]' before taking off again. According to operation and maintenance instructions furnished by RotorWay International, the main rotor drive belt tension should be checked and adjusted at new belt installation and at 30 minutes, 1 hour, 2 hours, and 10 hours of service (to prevent slippage). The aircraft and engine logbook copies submitted by the pilot contained no documentation of any checks or adjustments to the drive belt tensions after new belt installation on 7/10/96.
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: private
- Ratings: single-engine land
- Flight time: 157 hours in all; 29 in this make and model; 26 in the last 90 days; 13 in the last 30 days; 76 as pilot in command
- Medical certificate: Class 3 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 14 hours
- Last inspection: annual inspection, July 2, 1996; 14 hours since
- Maximum gross weight: 1,425 lb
- Seats: 2
- Landing gear: fixed
- Engine: Rotorway 152 (piston); 0 hours total
The flight
- Departed from: S22 at 2:35 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 15 statute miles
- Sky: clear
- Temperature: 82°F (28°C), dew point 0°F (-18°C)
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.
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.