Thorp T 18 accident near Independence, Oregon, November 6, 2015
On November 6, 2015 at about 11:30 pm local time, a 1968 Thorp T 18, an amateur-built aircraft,, registered N1488, was substantially damaged in an accident during initial climb near Independence, Oregon (Independence State airport). It was a personal flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A separation of the canopy mechanism during flight, which resulted in the pilot’s precautionary landing and the airplane’s subsequent collision with a fence post.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- November 6, 2015 · about 11:30 pm local time
- Place
- Independence, Oregon · Independence State · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Thorp T 18 UNDESIGNAT, built 1968, amateur-built · all T 18s on the register
- Registration
- N1488 · registry record · serial 303
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot departed on a local flight; during initial climb, the canopy partially disconnected from the airplane and the airplane vibrated violently. The pilot made a precautionary landing in a field, and the right wing impacted a fence post. Postaccident examination revealed that the mechanism that allowed the canopy to move fore and aft and retained the aft portion of the canopy during flight separated at a weld, which resulted in airflow into the cockpit. The components were not made available for metallurgical examination and the failure mode could not be determined; however, it is possible that the separation was due to repeated loading on the canopy over time. According to the pilot and a representative of the airplane type club, the canopy design was unique to the accident airplane, and was likely the only one of its kind.
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
What happened, in order
- Sys/Comp malf/fail (non-power) during initial climb defining event
- Collision with terrain or object (not controlled flight into terrain) during landing (landing roll)
The NTSB's findings
- cause Aircraft › Aircraft structures › Doors › Passenger/crew doors › Failure
- Environmental issues › Physical environment › Object/animal/substance › Fence/fence post › Contributed to outcome
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 618 hours in all; 618 in this make and model; 18 in the last 90 days; 8 in the last 30 days
- Medical certificate: Class 3 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 1,358 hours
- Last inspection: condition inspection, March 1, 2015; 19 hours since
- Maximum gross weight: 1,540 lb
- Seats: 2
- Landing gear: fixed
- Engine: Textron Lycoming O-320-B2A (piston); 1,358 hours total
The flight
- Departed from: Independence OR
- Destination: Independence OR
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 340° at 6 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 135°F (57°C), dew point 115°F (46°C)
- Altimeter: 30.31 inHg
- Observation at 7:56 pm from KSLE, 9 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight 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.