Amateur-built THORP T-18 accident near East Quogue, New York, June 20, 1994
On June 20, 1994 at about 7:04 pm local time, a amateur-built THORP T-18, registered N64628, was substantially damaged in an accident near East Quogue, New York. 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
Inadequate maintenance which resulted in oil-fouled spark plugs and the loss of engine power.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 20, 1994 · about 7:04 pm local time
- Place
- East Quogue, New York · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built THORP T-18
- Registration
- N64628 · no longer on the register · serial 825
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The airplane was being flown for the first time in about 4 years when the engine lost power during a local flight at an altitude of 4500 feet msl. The pilot did a forced landing on a the side of a highway and the airplane nosed over during the landing. Examination of the airplane revealed the number four cylinder spark plugs were oil fouled. The engine had been overhauled about a month before 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
Pilot
- Certificate: private
- Ratings: single-engine land; instrument: airplane
- Flight time: 1,800 hours in all; 250 in this make and model
- Medical certificate: Class 3 (valid medical--w/ waivers/lim.)
- Seat: ctr
The aircraft
- Airframe total time: 279 hours
- Last inspection: annual inspection, June 16, 1994; 2 hours since
- Maximum gross weight: 1,500 lb
- Seats: 1
- Landing gear: fixed
- Engine: Lycoming O-320 (piston); 0 hours total
The flight
- Destination: FOK Westhampton Bch NY
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 150° at 8 knots
- Visibility: 15 statute miles
- Sky: scat at 1,500 ft
- Temperature: 75°F (24°C), dew point 57°F (14°C)
- Altimeter: 30.00 inHg
- Observation at 6:45 pm from FOK, 3 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.