Amateur-built STOL CH701 accident near Maple Lake, Minnesota, June 22, 2018
On June 22, 2018 at about 11:30 pm local time, a 2016 amateur-built STOL CH701, registered N736MM, was substantially damaged in an accident during approach (VFR pattern downwind) near Maple Lake, Minnesota (Maple Lake Muni-Bill Mavencamp airport). It was a personal flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The total loss of engine power for reasons that could not be determined based on the available evidence.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 22, 2018 · about 11:30 pm local time
- Place
- Maple Lake, Minnesota · Maple Lake Muni-Bill Mavencamp · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built STOL CH701, built 2016
- Registration
- N736MM · registry record · serial 7-8943
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The private pilot and the flight instructor were flying in the airport traffic pattern. The pilot indicated that he smelled a "burnt electrical" smell after takeoff, so they decided to remain in the traffic pattern. After about 10 minutes of flight, the engine began to backfire and then lost total power. The pilot switched fuel tanks, turned the fuel boost pump on, and attempted a restart of the engine with no success. The pilot reported that he initially decided to attempt a forced landing on the runway. However, he assessed that he would be unable to clear power lines and instead decided to execute a forced landing onto a road. The airplane landed short of the road, impacted a ditch, and came to rest in a grass-covered field. During the forced landing sequence, the nosewheel collapsed, which resulted in substantial damage to the fuselage and engine mount, and the right wing impacted a sign and sustained substantial damage. Postaccident examination of the airframe and engine revealed no preimpact mechanical malfunctions or failures with the airframe and engine that would have precluded normal operation. However, the engine would not start after multiple attempts. The origin of the "burnt electrical" smell could not be determined. Fuel was found on board; thus, fuel exhaustion did not occur. The reason for the loss of engine power could not be determined based on the available evidence.
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 (total) during approach (VFR pattern downwind) defining event
- Attempted remediation/recovery during approach (VFR pattern downwind)
- Off-field or emergency landing during approach (VFR pattern downwind)
- Collision with terrain or object (not controlled flight into terrain) during landing
The NTSB's findings
- cause Not determined › Not determined › (general) › (general) › Unknown/Not determined
- Environmental issues › Physical environment › Object/animal/substance › Sign/marker › Contributed to outcome
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 3,180 hours in all; 1.5 in this make and model; 54 in the last 90 days; 19 in the last 30 days
- Last flight review: June 22, 2018
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Maximum gross weight: 1,100 lb
- Seats: 2
- Landing gear: fixed
- Engine: Suzuki / Raven Redrive 1300SVS (piston); 0 hours total
The flight
- Departed from: MGG Maple Lake MN at 11:20 pm
- Destination: MGG Maple Lake MN
- Flight plan: none
- Runway 10, 2,796 ft by 60 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 81°F (27°C), dew point 63°F (17°C)
- Altimeter: 29.81 inHg
- Observation at 11:35 pm from KMGG
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 2 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
5 documents, released by the NTSB on January 31, 2020. 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 - Pilot | PDF, 9 pages | View Download |
| 2 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 - Owner | PDF, 9 pages | View Download |
| 3 | Accident Photographs | PDF, 3 pages | View Download |
| 4 | Pilot - Record of Conversation | PDF, 1 page | View Download |
| 5 | FAA Aviation Safety Inspector - Record of Conversation | PDF, 1 page | 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.