CEN18LA173 · Grumman American AVN. CORP. AA 1B
Grumman American AVN. CORP. AA 1B · Accident: loss of engine power (total) during takeoff
From Butler Co Regional Airport - Hogan Field (HAO) to Butler Co Regional Airport - Hogan Field (HAO)
Event
- NTSB case
- CEN18LA173
- 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
- API-reported fatalities
- 0 · all aircraft and ground
- 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
Grumman American AVN. CORP. AA 1B
- Aircraft type
- Grumman American AA-1
- 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
- N6550L
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Butler Co Regional Airport - Hogan Field (HAO), Hamilton, OHTo Butler Co Regional Airport - Hogan Field (HAO), Hamilton, OH
- Aircraft age
- About 44 years (built 1974)
- 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
- Takeoff
- 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
- Loss of engine power (total)
- 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
- Not determined › Not determined
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
About 1 month before the accident, the prior owner of the accident airplane performed a maintenance test flight after an engine replacement. The airplane failed a run-up because of engine roughness. The mechanic/accident pilot who performed the engine replacement felt that the roughness was caused by oil getting by the new piston rings and fouling the spark plugs. The mechanic/pilot cleaned and reinstalled the plugs.
The maintenance test flight was then reattempted, and the prior owner flew in the right seat with the mechanic/pilot as the pilot flying. The prior owner indicated that the mechanic/pilot took the active runway without completing an engine run-up. The takeoff power appeared normal until about 100 ft above ground level, when the engine failed abruptly and without warning. The airplane's nose dropped, and the pilot landed the airplane, stopping it about 30 ft from the end of the runway.
The mechanic/pilot subsequently sent the carburetor out for overhaul. After reinstalling the carburetor, the mechanic/pilot attempted another maintenance test flight, which was the accident flight. Witnesses stated that the airplane took off; they heard the engine stop, and the pilot attempted to circle back to the airport but did not make it. The airplane impacted terrain during the landing, which resulted in substantial damage to the wing and fuselage.
The mechanic/pilot completed an accident report that did not contain a narrative of the accident flight and advised that he did not recall the accident. Further, the pilot did not indicate the date of his last flight review.
A postaccident engine examination revealed no evidence of preimpact mechanical malfunctions or failures that would have precluded normal operation. The engine monitor sustained damage; no engine data was recorded for the accident flight.
At the time of the accident, the weather conditions were conducive to moderate carburetor icing at cruise power and serious carburetor icing at descent power. However, the engine was operating at takeoff power; the investigation was unable to determine if the pilot conducted any ground operations during which carburetor ice could have formed.
Thus, a reason for the loss of engine power could not be determined.
Probable cause
The loss of engine power during takeoff for reasons that could not be determined because postaccident examination revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN18LA173
- Event ID
- 20180515X23947
- Case number
- CEN18LA173
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- 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. 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: 54305fcffc90957367d6eb761ece03c9fb193aa97775d4ab380a86fbb4da4655; retrieved 2026-09-16T07:10:17.902Z.