Amateur-built CASSUTT SPORT accident near Stilwell, Oklahoma, March 20, 1997
On March 20, 1997 at about 11:35 pm local time, a amateur-built CASSUTT SPORT, registered N86T, was destroyed in an accident near Stilwell, Oklahoma (Stilwell/Cherokee Nation airport). It was a personal flight under general aviation rules (Part 91). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
failure of the right wing spar and/or debonding of the right wing skin, which resulted in separation of the wing skin and a portion of the right wing, during high speed flight. Factors related to the accident were: previous wing damage and inadequate maintenance by other (unknown) personnel.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- March 20, 1997 · about 11:35 pm local time
- Place
- Stilwell, Oklahoma · Stilwell/Cherokee Nation · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built CASSUTT SPORT CASSUTT SP
- Registration
- N86T · registry record · serial T1
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot (plt) departed Cookson, OK, in a homebuilt aircraft (acft) for an approximate 30 minute flight to Stilwell, OK. Witnesses at Stilwell said he made a low pass on a northerly heading (about 50 ft off the ground) at a high rate of speed. One witness estimated the acft was traveling faster than 200 mph, when he saw the acft's right wing skin separate from the acft. The right wing then came off. The acft was observed to roll several times & travel about 1100 ft before it impacted the ground. Postimpact examination of the wreckage revealed a fracture in the wing spar about 18 inches in from the right wing tip. There was a discoloration in the fracture, which had the appearance of a varnish like substance. An FAA inspector reported that 'there were different color glue joints in the wing construction indicating that there were different kinds of glue used.' Also, the failure mode differed; the dark glue joints failed in the wooden structure, where as, the other glue joints failed in the bond. Some of the wing joints that had failed had discoloration between the rib & the wooden skin. The inspector suggested that 'either improper clamping during construction, prevarnishing of the contact surfaces, or bond separation followed by moisture weathering could have caused this.' The plt had purchased the homebuilt acft on 10/1/96. It had been originally certificated for flight on 10/27/72. On 2/11/73, it had been damaged during a takeoff mishap, & 'new wing construction' had been performed.
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; instrument: helicopter; rotorcraft: helicopter
- Flight time: 6,527 hours in all
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: ctr
The aircraft
- Last inspection: inspection type not recorded
- Maximum gross weight: 929 lb
- Seats: 1
- Landing gear: fixed
- Engine: Continental O-200-A (piston); 0 hours total
The flight
- Departed from: 44M Cookson OK at 11:05 pm
- Destination: 011 OK
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 270° at 10 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 72°F (22°C), dew point 45°F (7°C)
- Altimeter: 29.00 inHg
- Observation at 10:53 pm from FSM, 25 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.