Aircraft Mfg & Dev. Co. (Amd) CH601XLi accident near Farmersville, Texas, August 14, 2008
On August 14, 2008 at about 4:00 pm local time, a Aircraft Mfg & Dev. Co. (Amd) CH601XLi, registered N451BB, was substantially damaged in an accident during enroute (cruise) near Farmersville, Texas. It was an instructional flight under general aviation rules (Part 91). 1 person was seriously injured and 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The inadvertent tail stall and subsequent loss of airplane control as a result of the open canopy. Contributing to the accident was the inadequate emergency procedures provided by the airplane manufacturer and the inadequate design of the canopy latching mechanism.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 14, 2008 · about 4:00 pm local time
- Place
- Farmersville, Texas · map
- Type
- Accident
- Injuries
- 1 person was seriously injured and 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Aircraft Mfg & Dev. Co. (Amd) CH601XLi
- Registration
- N451BB · no longer on the register · serial 601-051S
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
According to the private pilot receiving instruction, during the flight he became aware of increased airflow on his side of the airplane and noted that the canopy on the flight instructor's side had become unlatched. He mentioned this to the flight instructor and the flight instructor attempted to relatch the canopy. The canopy came completely unlatched and opened to a position of 50 degrees. The nose of the airplane pitched down violently to 60 degrees. The open canopy disrupted the airflow over the empennage resulting in a stalled condition. Neither the private pilot nor flight instructor was able to close the canopy or recover the airplane from the nose low attitude. An examination of the airframe, power plant, and flight control surfaces revealed no anomalies. The latching bolts and latches related to the canopy exhibited scratching consistent with the flexing and movement of the canopy assembly. There is no mechanism to relatch just one side of the canopy without opening the other side of the canopy. According to the pilot operating handbook emergency procedures, in the event that the canopy becomes completely unlatched, the pilot is to ignore the open canopy and wind noise and land the airplane normally. The emergency procedures imply that the airplane is controllable when the canopy is open. The emergency procedures do not address a partially open canopy. Further review of the pilot operating handbook revealed conflicting airspeed information between several chapters in the book and with the markings on the airspeed indicator in the airplane.
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 enroute (cruise) defining event
- Loss of control in flight during enroute (cruise)
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
The NTSB's findings
- cause Aircraft › Aircraft structures › Doors › Passenger/crew doors › Malfunction
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Pitch control › Attain/maintain not possible
- factor Organizational issues › Development › Manufacture/production › Document/info production › Manufacturer
- factor Organizational issues › Development › Manufacture/production › Equipment manufacture › Manufacturer
Dual student
- Certificate: private
- Ratings: single-engine land
- Flight time: 359 hours in all; 1 in this make and model; 2 in the last 90 days; 2 in the last 30 days; 294 as pilot in command
- Last flight review: July 17, 2008
- Medical certificate: Sport Pilot
- Seat: left
- Injury: minor injuries
Flight instructor
- Certificate: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 3,643 hours in all; 84 in this make and model; 3,377 as pilot in command; 2,857 on instruments
- Last flight review: June 17, 2008
- Medical certificate: Sport Pilot
- Seat: rgt
- Injury: serious injuries
The aircraft
- Airframe total time: 131.5 hours
- Last inspection: 100-hour inspection, July 8, 2008; 36 hours since
- Maximum gross weight: 1,320 lb
- Seats: 2
- Landing gear: fixed
- Engine: Continental O-200 (piston); 0 hours total
The flight
- Departed from: TKI Mckinney TX at 3:30 pm
- Destination: TKI Mckinney TX
- Flight plan: none
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 210° at 4 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 88°F (31°C), dew point 64°F (18°C)
- Altimeter: 29.94 inHg
- Observation at 4:05 pm from KGVT, 15 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | 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.