CEN21LA310 · Aeronca 11AC
Aeronca 11AC · Accident: ground handling event while standing
From an unrecorded airport to James Clements Municipal Airport (3CM)
Event
- NTSB case
- CEN21LA310
- 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
Aeronca 11AC
- Aircraft type
- Aeronca 11
- 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
- N9149E
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From not recordedTo James Clements Municipal Airport (3CM), Bay City, MI
- Aircraft age
- About 75 years (built 1946)
- 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
- Standing · engine(s) start-up
- 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
- Ground handling event
- 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 handling/service
- Aircraft › Aircraft systems
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The airplane was not equipped with an electrical system and the engine was started by hand propping. The pilot reported that he did not have a passenger to hold the brakes in the cockpit during engine start, nor did he use wheel chocks and/or tether the tail to a fixed object because he thought using the airplane’s parking brake would keep the airplane stationary after the engine had started. Before the engine was hand propped, the pilot set the throttle about ¼” to ½” forward of the idle position, but the engine’s speed was much higher than he had expected after the engine started. The unoccupied airplane initially moved forward before it entered a left turn on the ramp in front of a row of hangars. Although the pilot was able to reach into the cockpit to move the throttle to idle, the airplane continued in the left turn and struck a closed hangar door, resulting in substantial damage to the right wing. The pilot did not report any mechanical malfunctions with the airplane that would have precluded normal operation.
Probable cause
The pilot’s inadequate engine hand propping procedure resulting in the unoccupied airplane’s unintended movement and subsequent impact with a hangar.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN21LA310
- Event ID
- 20210708103443
- Case number
- CEN21LA310
- 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, 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: 4b0a7b0f50ddae482ba0d21db2e6106e1e7133551a0bf7c60e4a22b7454bfefe; retrieved 2026-09-16T14:16:17.382Z.