Amateur-built T-18 accident near Ada, Oklahoma, February 24, 1985
On February 24, 1985 at about 7:40 pm local time, a amateur-built T-18, registered N40HB, was destroyed in an accident near Ada, Oklahoma (Ada Municipal airport). It was a personal flight under general aviation rules (Part 91). 1 person was seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The NTSB has not yet published a probable cause for this accident. Investigations usually take one to two years; this page updates when the final report is released.
Source: NTSB aviation accident database, copy made November 2, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 24, 1985 · about 7:40 pm local time · cases in 1985
- Place
- Ada, Oklahoma · Ada Municipal · cases near this airport · map
- Type
- Accident
- Injuries
- 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built T-18
- Registration
- N40HB · registry record · serial 165
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE AIRCRAFT HAD BEEN STORED FOR 8 MONTHS WITH AUTOMOTIVE FUEL IN THE TANK. DURING TAKEOFF, THE ENG LOST POWER. SUBSEQUENTLY, THE PLT LOST CONTROL & THE ACFT IMPACTED THE GROUND AT A 45 DEG ANGLE. AN INVESTIGATION REVEALED THAT SOFTENED TANK SEALANT MATERIAL WAS OBSTRUCTING THE TANK STRAINER SCREEN.
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: commercial pilot
- Ratings: single-engine land
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: unk
The aircraft
- Airframe total time: 537 hours
- Last inspection: inspection type not recorded
- Maximum gross weight: 1,200 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming O-320 (piston); 0 hours total
The flight
- Flight plan: none
- Runway 35, 5,000 ft by 150 ft
Weather at the time
- Light: daylight
- Wind: from 360° at 6 knots
- Visibility: 15 statute miles
- Sky: overcast at 2,000 ft; not recorded at 2,000 ft
- Temperature: 46°F (8°C), dew point 37°F (3°C)
- Altimeter: 30.00 inHg
- Observation at 6:51 pm from MLC, 44 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.
Connections how this case links to the rest of the register
- N40HB on the register today · the tail number may have moved to another aircraft since
- Engine: Lycoming O-320 27,303 aircraft carry this series today · as the NTSB recorded it
- Ada Regional · nearest airport
- Accidents and incidents in Oklahoma 1,300 since 1982 · 181 in the last ten years
- Oklahoma 5,655 aircraft registered
The whole map of how records connect · these connections as data: /graph/accident/FTW85LA127.json.
The bigger picture in Aviation Analytics: accidents over time since 1982, by model, by phase of flight and conditions, by place and on the map.
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 does not name anyone involved, its policy at this time. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.