Amateur-built RV4 accident near Butler, Pennsylvania, June 7, 2018
On June 7, 2018 at about 3:00 pm local time, a 2015 amateur-built RV4, registered N7765X, was substantially damaged in an accident during enroute (climb to cruise) near Butler, Pennsylvania (Pittsburgh/Butler Rgnl 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
The pilot's improper decision to fly the airplane with a known engine problem and his improper modification of the engine control unit fuel delivery software, which led to the engine running too lean and resulted in a total loss of engine power during climb.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 7, 2018 · about 3:00 pm local time
- Place
- Butler, Pennsylvania · Pittsburgh/Butler Rgnl · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built RV4 UNDESIGNAT, built 2015
- Registration
- N7765X · no longer on the register · serial 3890
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
Shortly after takeoff on an extended crosswind leg about 800 ft mean sea level, the engine lost total power. The private pilot continued ahead and landed the airplane in a field. During the landing, the airplane impacted a wire fence and brush, which resulted in substantial damage to the fuselage and wings. During postaccident interviews, the pilot reported that this was the first flight after he had made maintenance repairs to the automobile-converted engine due to an engine failure 1 month before the accident. He stated that he installed an aftermarket engine control unit and modified the fuel delivery software, which resulted in the engine running too lean for flight and likely caused detonation and piston damage to occur. During the run-up before the accident flight, the pilot was aware that the engine was not producing power as it should. However, he decided to depart with a known engine problem, and his decision to do so led to the accident.
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 enroute (climb to cruise) defining event
- Off-field or emergency landing during enroute (climb to cruise)
- Collision with terrain or object (not controlled flight into terrain) during enroute (climb to cruise)
The NTSB's findings
- cause Personnel issues › Action/decision › Info processing/decision › Decision making/judgment › Pilot
- cause Personnel issues › Task performance › Maintenance › Modification/alteration › Pilot
- cause Aircraft › Aircraft power plant › Power plant › (general) › Incorrect service/maintenance
- cause Aircraft › Aircraft handling/service › Maintenance/inspections › (general) › Incorrect service/maintenance
- Aircraft › Aircraft power plant › Power plant › (general) › Failure
- Environmental issues › Physical environment › Object/animal/substance › Fence/fence post › Contributed to outcome
- Environmental issues › Physical environment › Object/animal/substance › Wire › Contributed to outcome
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 420 hours in all; 90 in this make and model; 1 in the last 90 days; 420 as pilot in command
- Last flight review: July 15, 2017
- Medical certificate: BasicMed
- Seat: frt
- Injury: minor injuries
The aircraft
- Airframe total time: 90 hours
- Last inspection: annual inspection, October 25, 2017
- Maximum gross weight: 1,500 lb
- Seats: 2
- Landing gear: fixed
- Engine: General Motors ECOTEC L61 (piston); 90 hours total
The flight
- Departed from: BTP Butler PA at 2:56 pm
- Destination: BTP Butler PA
- Flight plan: none
- Runway 26, 4,801 ft by 100 ft
Weather at the time
- Light: daylight
- Wind: at 3 knots
- Sky: clear
- Temperature: 63°F (17°C), dew point 0°F (-18°C)
- Altimeter: 30.12 inHg
- Observation at 2:56 pm from BTP, 2 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
4 documents, released by the NTSB on October 16, 2018. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 2 | Record of Conversation (FAA Inspector) | PDF, 1 page | View Download |
| 3 | Record of Conversation (Pilot in Command) | PDF, 1 page | View Download |
| 4 | Photo Array | PDF, 2 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
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.