Amateur-built THUNDERGULL JT2 accident near Clarksburg, West Virginia, April 4, 1994
On April 4, 1994 at about 2:40 pm local time, a amateur-built THUNDERGULL JT2, registered N73ST, was substantially damaged in an accident near Clarksburg, West Virginia (Clarksburg/Benedum airport). It was a personal flight under general aviation rules (Part 91). 1 person was seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The builder's inadequate maintenance adjustment which resulted in the aileron control assembly becoming disconnected.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 4, 1994 · about 2:40 pm local time
- Place
- Clarksburg, West Virginia · Clarksburg/Benedum · map
- Type
- Accident
- Injuries
- 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built THUNDERGULL JT2 THUNDERGUL
- Registration
- N73ST · registry record · serial ST3503
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE AIRPLANE HAD JUST TAKEN OFF AND WAS IN ITS INITIAL CLIMB WHEN CONTROL WAS LOST. THE AIRPLANE COLLIDED WITH TERRAIN IN AN UNCONTROLLED DESCENT. THE PILOT STATED, 'AFTER A GOOD PRE-FLIGHT THE TOWER CLEARED ME TO DEPART...IMMEDIATELY ON LIFT OFF, THE AIRCRAFT JUMPED TO THE RIGHT. THERE WAS DEFINITELY A CONTROL PROBLEM BUT I HAVE NOT PINPOINTED WHERE.' THE FAA INSPECTOR'S POST ACCIDENT EXAMINATION REVEALED THE BOLT CONNECTING THE TWO RODS IN THE AILERON PUSH/PULL ROD ASSEMBLY WAS MISSING. THE BOLT HOLES IN BOTH RODS SHOWED NO DEFORMATION. ADDITIONALLY, THIS BOLT WAS CONNECTED WITH THE JAM NUT FOUND LOOSE DURING THE CONFORMITY INSPECTION. THE AIRPLANE HAD A TOTAL OF 4 HOURS. A CONFORMITY INSPECTION WAS PERFORMED BY AN FAA DESIGNATED AIRWORTHINESS REPRESENTATIVE (DAR) ON NOVEMBER 29, 1993. THE DAR'S CONFORMITY INSPECTION REPORT STATED 'JAM NUT LOOSE ON AILERON CONTROL IN OVERHEAD.' THE REPORT REVEALED THAT THE CORRECTIVE ACTION TAKEN WAS THAT THE BOLT WAS 'TIGHTENED.' THE KIT MANUFACTURER SPECIFIES THE USE OF A SELF LOCKING NUT, HOWEVER, THE PILOT USED A JAM NUT.
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: private
- Ratings: single-engine land
- Flight time: 392 hours in all; 4 in this make and model; 3 in the last 90 days; 3 in the last 30 days
- Medical certificate: Class 3 (valid medical--w/ waivers/lim.)
- Seat: frt
The aircraft
- Airframe total time: 8 hours
- Last inspection: continuous airworthiness programme, November 29, 1993; 8 hours since
- Maximum gross weight: 1,200 lb
- Seats: 2
- Landing gear: fixed
- Engine: Rotax 912-WL (piston); 0 hours total
The flight
- Departed from: CKB
- Flight plan: none
- Runway 21, 5,918 ft by 150 ft
Weather at the time
- Light: daylight
- Wind: from 260° at 7 knots
- Visibility: 7 statute miles
- Sky: overcast at 2,100 ft; not recorded
- Temperature: 37°F (3°C), dew point 30°F (-1°C)
- Altimeter: 30.00 inHg
- Observation at 2:39 pm from CKB
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.