Amateur-built XF4 accident near Brooksville, Florida, February 29, 2000
On February 29, 2000 at about 8:45 pm local time, a amateur-built XF4, registered N9VY, was substantially damaged in an accident near Brooksville, Florida (Hernando County 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 owner/builder's failure to build the airplane within the design stress limits of the drive shaft assembly, that resulted in the failure of the Flex Coupling Retention Bolts.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 29, 2000 · about 8:45 pm local time
- Place
- Brooksville, Florida · Hernando County · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built XF4
- Registration
- N9VY · registry record · serial 1973-92
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
Approximately 35 minutes in to the flight, the pilot experienced a loss of propeller thrust. The pilot stated that he heard a loud 'bang' from the engine compartment and experienced loss of thrust. The pilot said that the engine tachometer went to redline, and the propeller rpm decreased. The pilot said , changing the engine rpm did not change the propeller rpm. The pilot declared an emergency and started an emergency descent for a landing on runway 27. As the pilot maneuvered the airplane on the final approach, he cleared a stand of trees on the final approach to runway 27. While on short final to land, the airplane initially collided with the ground short of the runway surface and subsequently came to rest on a taxiway. The examination of the wreckage revealed that the Rex Flex Coupling Assembly had failed and that three out of the six Rex Bolts had also failed. The pilot stated that the Flexidyne Drive Shaft was designed for a 100 horse-power engine. The pilot/builder stated that he installed a 150 horse power engine on the airplane.
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: airline transport pilot, flight instructor, flight engineer
- Ratings: multi-engine land; single-engine land; instructor: airplane single-engine; instrument: airplane; rotorcraft: glider
- Flight time: 8,866 hours in all; 9 in this make and model; 5 in the last 90 days; 3 in the last 30 days; 4,138 as pilot in command; 350 on instruments
- Medical certificate: Class 3 (valid medical--w/ waivers/lim.)
- Seat: frt
The aircraft
- Airframe total time: 9 hours
- Last inspection: annual inspection, September 15, 1999; 2 hours since
- Maximum gross weight: 1,750 lb
- Seats: 2
- Landing gear: retractable
- Engine: Lycoming O-320 (piston); 0 hours total
The flight
- Departed from: BKV at 8:00 pm
- Flight plan: none
- Runway 27, 7,001 ft by 150 ft
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 77°F (25°C), dew point 55°F (13°C)
- Altimeter: 30.00 inHg
- Observation at 8:53 pm from PIE, 41 miles away
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.