Clark RV-6A accident near Nampa, Idaho, August 16, 2010
On August 16, 2010 at about 5:50 pm local time, a Clark RV-6A, an amateur-built aircraft,, registered N621AL, was substantially damaged in an accident during takeoff (rejected takeoff) near Nampa, Idaho (Nampa airport). It was a personal flight under general aviation rules (Part 91). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's failure to maintain aircraft control, which resulted in a collision with terrain during a rejected inadvertent takeoff.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 16, 2010 · about 5:50 pm local time
- Place
- Nampa, Idaho · Nampa · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Clark RV-6A, amateur-built
- Registration
- N621AL · registry record · serial 24062
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot was performing a series of high-speed taxi test runs and planned to complete his first flight in the recently completed amateur-built experimental aircraft later in the day. During the first test run, the fully-castoring nose wheel began to shimmy, and the pilot appeared to slightly raise and lower the airplane's nose, in what was assumed by witnesses to be an attempt to eliminate the shimmy. Upon reaching the end of the runway, the pilot reversed course and made another test run in the opposite direction. During the second test run, the nose wheel began a significant shimmy, followed soon thereafter by the nose of the airplane beginning to rise. Almost immediately after the nose began to rise, the airplane, in what was most likely an unintended consequence, lifted off the runway. Soon after it became airborne, the airplane's nose lowered, in what appeared to be the pilot's attempt to get it back onto the runway surface. The nose wheel then contacted the runway, and the airplane entered into a porpoising sequence that ultimately resulted in the nose gear strut collapsing. The airplane then slid off the side of the runway, and, after encountering soft terrain, it nosed over onto its back. The reason for the occurrence of the nose wheel shimmy could not be determined. The pilot had a reported history of sinus and migraine headaches, which had previously occurred during flight, requiring the pilot to turn over the aircraft controls to a different pilot. Results of post mortem toxicology testing were consistent with the relatively recent use of two different impairing antihistamines, which are often used to treat sinus symptoms. It is possible that the pilot was impaired by his recent use of the antihistamines or by the condition for which the medication was taken, though the possible role of any such impairment in the accident sequence could not be established.
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
- Miscellaneous/other during takeoff
- Collision with terrain or object (not controlled flight into terrain) during takeoff (rejected takeoff)
- Landing gear collapse during takeoff (rejected takeoff) defining event
- Nose over/nose down during takeoff (rejected takeoff)
The NTSB's findings
- cause Personnel issues › Action/decision › Action › Incorrect action performance › Pilot
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
- Personnel issues › Physical › Health/Fitness › Use of medication/drugs › Pilot
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 1,220 hours in all; 0 in this make and model
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: left
- Injury: fatal
The aircraft
- Airframe total time: 0 hours
- Last inspection: condition inspection, August 11, 2010; 0 hours since
- Maximum gross weight: 1,650 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming O-360-A1D (piston); 0 hours total
The flight
- Departed from: S67 Nampa ID at 5:50 pm
- Destination: S67 Nampa ID
- Flight plan: none
- Runway 11, 5,000 ft by 75 ft
Weather at the time
- Light: daylight
- Wind: from 340° at 5 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 81°F (27°C), dew point 45°F (7°C)
- Altimeter: 30.02 inHg
- Observation at 5:55 pm from KMAN, 5 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight 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.