Cessna 150 accident near Heavener, Oklahoma, August 15, 2021
On August 15, 2021 at about 10:00 pm local time, a 1968 Cessna 150, registered N50055, was substantially damaged in an accident during enroute near Heavener, Oklahoma. 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
A total loss of engine power due to the failure of the No. 2 cylinder exhaust valve for reasons that could not be determined.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 15, 2021 · about 10:00 pm local time
- Place
- Heavener, Oklahoma · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 150 H, built 1968 · all 150s on the register
- Registration
- N50055 · no longer on the register · serial 15069042
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
While in cruise flight, the airplane’s engine began to run rough. As the pilot was attempting to restore engine power, the engine experienced a total loss of engine power. The pilot performed a forced landing to a field and the airplane collided with terrain. A postaccident examination of the engine revealed that the No. 2 cylinder exhaust valve had failed, damaging the piston head and resulting in a loss of engine power. Machining of the fracture surfaces precluded determining the mode of failure. The engine was last overhauled about 32 years before the accident with just over 1,030 hours logged on the components. The engine manufacturer recommends an overhaul every 1,800 hours or 12 years.
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
- Loss of engine power (total) during enroute defining event
The NTSB's findings
- Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng cyl section › Failure
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 201 hours in all; 160 in this make and model; 86 as pilot in command
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: left
- Injury: minor injuries
The aircraft
- Airframe total time: 3,469.2 hours
- Last inspection: 100-hour inspection, April 1, 2021
- Maximum gross weight: 1,600 lb
- Seats: 2
- Landing gear: fixed
- Engine: Continental O-200A (piston); 3,469 hours total
The flight
- Departed from: KTKI Mckinney TX at 8:00 pm
- Destination: KBDQ Morriltton AR
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 070° at 4 knots
- Visibility: 10 statute miles
- Sky: overcast at 8,000 ft; scat at 6,000 ft
- Temperature: 75°F (24°C), dew point 73°F (23°C)
- Altimeter: 30.03 inHg
- Observation at 5:15 pm from KMEZ, 21 miles away
Weather report (METAR): METAR KMEZ 152215Z AUTO 07004KT 10SM SCT060 OVC080 24/23 A3003 RMK AO2 LTG DSNT S THRU NW=
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
3 documents, released by the NTSB on December 29, 2022. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 2 | Photos | PDF, 6 pages | View Download |
| 3 | Engine Examination | PDF, 3 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
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.