CEN14LA507 · Manweiller ACRO SPORT II
Biplane Crazy Manweiller ACRO SPORT II · Accident: loss of control in flight while maneuvering
From Butler Co Regional Airport - Hogan Field (HAO) to Butler Co Regional Airport - Hogan Field (HAO)
Event
- NTSB case
- CEN14LA507
- 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
- 2 · 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
Manweiller ACRO SPORT II
- Aircraft type
- Manweiller ACRO SPORT
- 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
- N94SM
- Operator
- Biplane Crazy
- 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 20 years (built 1994)
- 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
- Maneuvering · aerobatics
- 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 control in flight
- 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 oper/perf/capability
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot and pilot-rated passenger were flying a local flight and performing aerobatic maneuvers in the experimental amateur-built airplane. A witness reported that she heard the airplane approaching and then saw it and noted that it was at a lower altitude than she normally saw aircraft in the area. The airplane then started to pitch nose up into a loop. As the airplane reached the top of the looping maneuver, the sound of the engine stopped, and the airplane then immediately started descending. The airplane then entered a spiral/spin, and the witness lost sight of the airplane behind some trees. She then heard the sound of an engine, consistent with the pilot adding engine power, followed immediately by the sound of impact. The airplane was engulfed in flames upon her arrival. The witness demonstrated what she had seen with a model airplane, and the demonstration was consistent with an attempted loop with a spin out of the top of the maneuver.
Witness marks at the accident site revealed that the airplane was producing power at the time of impact. An examination of the engine and flight controls did not reveal any preimpact anomalies that would have precluded operation. A weight and balance calculation showed that the airplane was within its published limits. The airplane likely experienced an aerodynamic stall at the top of the looping maneuver and then entered a spin from which the flying pilot was not able to recover. The investigation could not determine which occupant was manipulating the controls during the flight.
Probable cause
The failure of the flying pilot to maintain airplane control after an aerodynamic stall/spin occurred during the aerobatic maneuver following a reported intermittent loss of engine power for reasons that could not be determined during postaccident examinations.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN14LA507
- Event ID
- 20140920X14503
- Case number
- CEN14LA507
- 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: da28ef991f44c15bf8616aa16ca3c93df9fc516ae1a7b43ecceee21e5891094e; retrieved 2026-09-14T17:26:21.093Z.