Aeronca 7BCM accident near Mahnomen, Minnesota, June 21, 2017
On June 21, 2017 at about 1:00 am local time, a 1946 Aeronca 7BCM, registered N2558E, was substantially damaged in an accident during takeoff near Mahnomen, Minnesota (Mahnomen County Airport). It was a personal flight under general aviation rules (Part 91). 1 person was seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
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.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 21, 2017 · about 1:00 am local time
- Place
- Mahnomen, Minnesota · Mahnomen County Airport · map
- Type
- Accident
- Injuries
- 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Aeronca 7BCM, built 1946 · all 7BCMs on the register
- Registration
- N2558E · registry record · serial 7AC-6141
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
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.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Loss of engine power (partial) during takeoff defining event
- Aerodynamic stall/spin during initial climb
- Collision with terrain or object (not controlled flight into terrain) during initial climb
The NTSB's findings
- cause Personnel issues › Action/decision › Action › Lack of action › Pilot
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Airspeed › Attain/maintain not possible
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
- cause Not determined › Not determined › (general) › (general) › Unknown/Not determined
- Personnel issues › Action/decision › Info processing/decision › Decision making/judgment › Pilot
- Environmental issues › Conditions/weather/phenomena › Temp/humidity/pressure › Conducive to carburetor icing › Not specified
Pilot
- Certificate: sport pilot
- Ratings: single-engine land
- Flight time: 168 hours in all; 168 in this make and model; 27 in the last 90 days; 12 in the last 30 days; 143 as pilot in command
- Medical certificate: Sport Pilot
- Seat: frt
- Injury: serious injuries
The aircraft
- Last inspection: 100-hour inspection, September 18, 2016; 3,730 hours since
- Maximum gross weight: 1,320 lb
- Seats: 2
- Landing gear: fixed
- Engine: Continental C-86-12F (piston); 3,730 hours total
The flight
- Departed from: 3N8 Mahnomen MN at 1:00 am
- Destination: 3N8 Mahnomen MN
- Flight plan: none
- Runway 35, 3,400 ft by 75 ft
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 68°F (20°C), dew point 46°F (8°C)
- Altimeter: 29.94 inHg
- Observation at 1:15 am from 3N8
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
5 documents, released by the NTSB on April 16, 2018. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 2 | Witness Statements | PDF, 2 pages | View Download |
| 3 | NTSB Record of Conversation | PDF, 1 page | View Download |
| 4 | Carburetor Icing Chart | PDF, 1 page | View Download |
| 5 | Investigation Photos | PDF, 6 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.