CEN21LA390 · Mantooth THORP T-18
Mantooth THORP T-18 · Accident during initial climb
From an unrecorded airport to Gillespie County Airport (T82)
Event
- NTSB case
- CEN21LA390
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- Event fatalities
- Unknown
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Mantooth THORP T-18
- Aircraft type
- Mantooth THORP T-18
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N78DW
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From not recordedTo Gillespie County Airport (T82), Fredericksburg, TX
- Aircraft age
- About 41 years (built 1980)
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Initial climb
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Unknown or undetermined
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Aircraft › Aircraft power plant
- Environmental issues › Conditions/weather/phenomena
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot was planning a short cross-country flight with his passenger. Prior to takeoff, he fueled the airplane with 10-15 gallons of fuel and added one quart of oil to the engine. He performed an engine run-up that included checking the carburetor heat. The takeoff and initial climb were normal, but as he turned the airplane onto the downwind leg to depart the traffic pattern, the engine began running rough and lost total power. The pilot attempted to regain engine power by adjusting the engine mixture, but no change in engine performance was noted. Unable to maintain altitude, he performed a forced landing into trees. The airplane came to rest on its nose and sustained substantial damage. Postaccident examination of the engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. Weather conditions reported at the time of the accident were conducive for serious carburetor icing at glide power. However, the pilot applied the carburetor heat during the engine run-up before takeoff, which should have either melted any ice that may have accumulated on the ground or resulted in a rough running engine, which the pilot did not report. The application of carburetor heat during the run-up combined with the high-power setting during takeoff and initial climb reduced the likelihood of carburetor ice.
Probable cause
The loss of engine power after takeoff for undetermined reasons.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN21LA390
- Event ID
- 20210830103775
- Case number
- CEN21LA390
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (5)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, cause areas. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 803dfb1b217cd08ad1d0ed062fbe952a9eb3487b9f806ab0ef43d6268a4f5180; retrieved 2026-09-16T14:28:08.769Z.
- Corrected after a review of the NTSB narrative, which states these values explicitly: destination. T82 is Gillespie County Airport at Fredericksburg, Texas; the city name is missing an 'e' in the record.