Amateur-built RV7 accident near Thonotosassa, Florida, February 9, 2021
On February 9, 2021 at about 7:53 pm local time, a 2021 amateur-built RV7, registered N611E, was substantially damaged in an accident during enroute (cruise) near Thonotosassa, Florida. It was a flight test 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 failure to apply adequate torque on the fuel pressure line aluminum adaptor fitting, which resulted in the loosening of the adapter, a loss of fuel flow, and a total loss of engine power. Contributing to the accident was the pilot’s choice of a soft aluminum automotive fitting, and the design, which required hand-tightening with a shortened, modified wrench that prevented a measured torque application.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 9, 2021 · about 7:53 pm local time
- Place
- Thonotosassa, Florida · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built RV7, built 2021
- Registration
- N611E · no longer on the register · serial 70816
- Damage
- Substantial damage
- Flight
- Flight test · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
During the previous flight, the experimental, amateur-built airplane lost total engine power, and the pilot, who was the builder of the airplane, completed a successful forced landing with no damage to the airplane. He found that the fuel pressure adapter “t”-fitting, used to attach the fuel pressure line, had disconnected from the fuel pump elbow fitting. The automotive adapter fitting was adopted during the airplane’s construction for fitment in a confined space and did not allow for measured torque application. The pilot reattached the fitting with a modified and shortened 5/8” spanner wrench for the 11/16” b-nut. The pilot departed the forced landing site and landed successfully at his destination. The accident flight was the airplane’s next flight. Minutes after takeoff, the airplane once again experienced a loss of fuel pressure and a total loss of engine power. During the subsequent forced landing, the pilot sustained minor injuries and the airplane was substantially damaged. Post-accident examination of the airplane revealed that the same fuel pump elbow fitting was disconnected from the adapter fitting. Examination of the adapter revealed that its material was soft relative to materials used in Air Force-Navy (AN) standard fittings. As a result, the shoulder on the adapter body could have been deformed under the pressure of the retaining ring even when applying minimum torque values suggested for AN standard fittings made of aluminum alloys specified in military specification. This deformation may have inhibited the proper frictional resistance in the threads to prevent the nut from backing off in service. Additionally, the body of the adapter fitting tended to rotate when applying torque to the nut. If the body was not properly secured while torque was applied to the nut during field repairs, the twisting of the adapter fitting body could have produced stresses in the attached hoses in the assembly that may have worked to rotate the adapter fitting and nut in the loosening direction during operation.
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
- Fuel related during enroute (cruise) defining event
The NTSB's findings
- Aircraft › Fluids/misc hardware › Fluids › Fuel › Related maintenance info
- Personnel issues › Task performance › Maintenance › Installation › Owner/builder
Pilot
- Certificate: private
- Ratings: single-engine land; instrument: airplane
- Flight time: 882 hours in all; 20 in this make and model; 59 in the last 90 days; 10 in the last 30 days; 830 as pilot in command
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: left
- Injury: minor injuries
The aircraft
- Airframe total time: 4.4 hours
- Last inspection: condition inspection, January 21, 2021; 4.4 hours since
- Maximum gross weight: 1,800 lb
- Seats: 2
- Landing gear: fixed
- Engine: Titan IOX-370-J4B3T (piston); 4 hours total
The flight
- Departed from: KVDF Tampa FL at 7:30 pm
- Destination: KZPH Zephyr Hills FL
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 230° at 9 knots, gusting 14
- Visibility: 10 statute miles
- Sky: broken clouds at 3,400 ft
- Temperature: 82°F (28°C), dew point 68°F (20°C)
- Altimeter: 30.13 inHg
- Observation at 2:55 pm from KVDF
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
11 documents, released by the NTSB on December 29, 2022. 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 | Materials Laboratory Factual Report 21-073 | PDF, 6 pages | View Download |
| 2 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 11 pages | View Download |
| 3 | Pilot's Statement Flight 1 | PDF, 4 pages | View Download |
| 4 | Pilot's Statement Flight 2 | PDF, 1 page | View Download |
| 5 | Pilot's Statement Part Sourcing | PDF, 3 pages | View Download |
| 6 | Pilot's Statement Lessons Learned | PDF, 2 pages | View Download |
| 7 | FAA Inspector's Statement Field Torque Testing | PDF, 1 page | View Download |
| 8 | Video File | video | View Download |
| 9 | Automotive Fuel Pressure Adapter Fitting Advertisement Excerpt | PDF, 1 page | View Download |
| 10 | FAA AC20-27G Excerpt | PDF, 1 page | View Download |
| 11 | Photo Array | PDF, 5 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.