CEN17LA238 · Aeronca 7BCM
Aeronca 7BCM · Accident: loss of engine power (partial) during takeoff
From Mahnomen County Airport (3N8) to Mahnomen County Airport (3N8)
Event
- NTSB case
- CEN17LA238
- 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 7BCM
- Aircraft type
- Aeronca 7
- 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
- N2558E
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Mahnomen County Airport (3N8), Mahnomen, MNTo Mahnomen County Airport (3N8), Mahnomen, MN
- Aircraft age
- About 71 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
- 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 (partial)
- 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
- Not determined › Not determined
- Personnel issues › Action/decision
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The sport pilot reported that the initial takeoff roll was normal but that he then noted that the airplane was not gaining airspeed and that the engine was not developing full power; however, he decided to continue the takeoff. He stated that, once he was committed to the takeoff, there seemed to be an even "greater loss of power." The airplane only reached 150 ft, and he decided to turn right to avoid a highway and power lines. He initiated a 20° bank, and subsequently the airplane stalled and then impacted a bean field adjacent to the airport.
Postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. Although weather conditions at the time of the accident were conducive to moderate icing at cruise power or serious carburetor icing at descent power, given the airplane was at takeoff power, it is unlikely that carburetor ice accumulated and caused the power loss. The pilot's decision to not abort the takeoff at the first sign of a loss of engine power resulted in a slow airspeed during the initial climb during a turn, which resulted in the aerodynamic stall.
Probable cause
The pilot’s failure to abort the takeoff after recognizing a partial loss of engine power during the takeoff roll and his subsequent inability to maintain adequate airspeed during a turn to avoid power lines, which resulted in an aerodynamic stall. The reasons for the loss of engine power could not be determined because postaccident examination of the engine 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 CEN17LA238
- Event ID
- 20170620X21734
- Case number
- CEN17LA238
- 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: local date, investigation status. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2017-06-21.
- API snapshot SHA-256: 34a3f522e7d53cded37a86fbf4eb2104184af3f08c99dac6c8b62a763cf9bc24; retrieved 2026-09-16T05:25:59.774Z.