Amateur-built THORP T-18 accident near Chatham, Massachusetts, June 13, 1993
On June 13, 1993 at about 6:30 pm local time, a amateur-built THORP T-18, registered N221DP, was destroyed in an accident near Chatham, Massachusetts. It was a personal flight under general aviation rules (Part 91). 1 person was killed and 1 person was seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
the pilot's performance of an aerobatic maneuver, with insufficient altitude for recovery, resulting in a collision with the water
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 13, 1993 · about 6:30 pm local time
- Place
- Chatham, Massachusetts
- Type
- Accident
- Injuries
- 1 person was killed and 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built THORP T-18
- Registration
- N221DP · registry record · serial 294
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE PILOT DEPARTED IN HIS AEROBATIC AIRPLANE, WITH A PASSENGER, TO OVER FLY JET SKIERS ON THE WATER. SEVERAL PASSES AT VARYING ALTITUDES AND AIRSPEEDS WERE ACCOMPLISHED IN THE VICINITY OF THE JET SKIERS. AT APPROXIMATELY 25 FEET, ABOVE THE WATER, A 360 DEGREE AILERION ROLL WAS COMPLETED. AT THE COMPLETION OF THE ROLL THE RIGHT WING CONTACTED THE WATER FOLLOWED BY THE MAIN FUSELAGE. THE AIRPLANE BROKE UP AND SANK IN 18 FEET OF WATER.
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, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane single-engine; instrument: airplane
- Flight time: 21,100 hours in all; 270 in this make and model; 20 in the last 90 days; 1,600 on instruments
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 548 hours
- Last inspection: annual inspection, June 26, 1992; 144 hours since
- Maximum gross weight: 1,650 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming O&VO-360 (piston); 0 hours total
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 20 statute miles
- Sky: clear
- Temperature: 79°F (26°C), dew point 0°F (-18°C)
- Observation at 6:30 pm
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 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.