Amateur-built GP 4 and amateur-built RV-8 mid-air collision near Reno, Nevada, September 17, 2017
On September 17, 2017 at about 3:20 pm local time, 2 aircraft, amateur-built GP 4 (CGTPX) and amateur-built RV-8 (N248DF), were involved in a mid-air collision near Reno, Nevada (Reno/Stead airport). 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
The pilot's failure to maintain clearance from another airplane during the line-abreast formation.
The other pilot's failure to maintain clearance from the airplane during the line-abreast formation.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 17, 2017 · about 3:20 pm local time
- Place
- Reno, Nevada · Reno/Stead · map
- Type
- Accident · mid-air collision
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft 1
- Amateur-built GP 4, built 2016
- Registration
- CGTPX · no longer on the register · serial PT 572
- Damage
- Minor damage
- Flight
- Air show or air race flight · general aviation rules (Part 91)
- Aircraft 2
- Amateur-built RV-8, built 2013
- Registration
- N248DF · registry record · serial 81751
- Damage
- Substantial damage
- Flight
- Air show or air race flight · general aviation rules (Part 91)
The NTSB's narrative for the amateur-built GP 4 final · quoted from the NTSB record
During the initial start of an air race, nine airplanes were positioned in a line-abreast formation. The RV-8 was positioned in the No. 7 slot, and the GP 4 was right of the RV-8 in the No. 8 slot. The RV-8 pilot reported that, during the race start, he felt an air current push down his airplane. He then moved forward of the No. 6 slot airplane and initiated corrections to reestablish his position within the formation. The GP 4 pilot reported that he saw the RV-8 descend below his airplane's left wing and that he reduced power while initiating a slight right bank in an attempt to "back out" of the formation. The pilot who was in the No. 9 slot reported that he observed the GP-4 move forward back into the formation very quickly. At that time, he noticed the pilot of the GP-4 trying to slow or correct his position to the right using ailerons. Shortly after, the propeller of the GP-4 struck the right aileron of the RV-8. Following the collision, the RV-8 entered an uncommanded left roll; however, the pilot was able to level the airplane and land uneventfully. The GP-4 pilot pitched his airplane upward and rolled right to avoid the surrounding airplanes and was also able to land the airplane uneventfully. It is likely that, if the pilot of the GP-4 had maintained adequate lateral distance from the RV-8 while advancing forward to maintain a line-abreast formation, he would have been able to maintain clearance from the RV-8 as it descended and would not have needed to bank right, which further reduced the GP-4 pilot's visual contact with the RV-8 and led to the midair collision.
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 NTSB's narrative for the amateur-built RV-8 final · quoted from the NTSB record
During the initial start of an air race, nine airplanes were positioned in a line-abreast formation. The RV-8 was positioned in the No. 7 slot, and the GP-4 was right of the RV-8 in the No. 8 slot. The RV-8 pilot reported that, during the race start, he felt an air current push down his airplane. He then moved forward of the No. 6 slot airplane and initiated corrections to reestablish his position within the formation. The GP-4 pilot reported that he saw the RV-8 descend below his airplane's left wing and that he reduced power while initiating a slight right bank in an attempt to "back out" of the formation. The pilot who was in the No. 9 slot reported that he observed the GP-4 move forward back into the formation very quickly. At that time, he noticed the pilot of the GP-4 trying to slow or correct his position to the right using ailerons. Shortly after, the propeller of the GP-4 struck the right aileron of the RV-8. Following the collision, the RV-8 entered an uncommanded left roll; however, the pilot was able to level the airplane and land uneventfully. The GP-4 pilot pitched his airplane upward and rolled right to avoid the surrounding airplanes and was also able to land the airplane uneventfully. It is likely that, if the pilot of the GP-4 had maintained adequate lateral distance from the RV-8 while advancing forward to maintain a line-abreast formation, he would have been able to maintain clearance from the RV-8 as it descended and would not have needed to bank right, which further reduced the GP-4 pilot's visual contact with the RV-8 and led to the midair collision.
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 for the amateur-built GP 4 from the NTSB's investigation tables, in plain English
What happened, in order
- Miscellaneous/other during maneuvering
- Midair collision during maneuvering defining event
The NTSB's findings
- cause Personnel issues › Psychological › Attention/monitoring › Monitoring environment › Pilot
- cause Environmental issues › Physical environment › Object/animal/substance › Aircraft › Effect on operation
Pilot
- Certificate: airline transport pilot
- Ratings: multi-engine land; multi-engine sea; single-engine land; single-engine sea; instrument: airplane
- Flight time: 9,300 hours in all; 110 in this make and model; 85 in the last 90 days; 30 in the last 30 days; 7,800 as pilot in command
- Last flight review: April 29, 2017
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Last inspection: annual inspection
- Seats: 2
- Landing gear: retractable
- Engine: Lycoming IO-360-A1A (piston); 0 hours total
The flight
- Departed from: RTS Reno NV at 3:15 pm
- Destination: RTS Reno NV
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 350° at 4 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 50°F (10°C), dew point 34°F (1°C)
- Altimeter: 30.10 inHg
- Observation at 3:15 pm from KRTS, 1 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
The factual record for the amateur-built RV-8 from the NTSB's investigation tables, in plain English
What happened, in order
- Miscellaneous/other during maneuvering
- Midair collision during maneuvering defining event
The NTSB's findings
- cause Personnel issues › Psychological › Attention/monitoring › Monitoring environment › Pilot of other aircraft
- cause Environmental issues › Physical environment › Object/animal/substance › Aircraft › Effect on operation
Pilot
- Certificate: airline transport pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 16,500 hours in all; 227 in this make and model; 165 in the last 90 days; 40 in the last 30 days; 16,300 as pilot in command; 2,500 on instruments
- Last flight review: October 1, 2016
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: frt
- Injury: no injuries
The aircraft
- Last inspection: condition inspection, September 1, 2017; 10 hours since
- Seats: 2
- Landing gear: fixed
- Engine: Mattituck IO-360 (piston); 0 hours total
The flight
- Departed from: RTS Reno NV at 3:15 pm
- Destination: RTS Reno NV
- Flight plan: none
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The NTSB has not released the docket for this case yet. The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), is usually released when the investigation is nearly complete, and the list here is refreshed when it appears. Check 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.