Enstrom TH-180 accident near Menominee, Michigan, February 12, 2016
On February 12, 2016 at about 5:23 pm local time, a 2015 Enstrom TH-180 (helicopter), registered N180TH, was substantially damaged in an accident during approach (VFR pattern base) near Menominee, Michigan (Menominee-Marinette Twin Count airport). It was a flight test under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The failure of the torque meter mounting bolts, which resulted in a loss of engine power to the main drive belt and rotors.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 12, 2016 · about 5:23 pm local time
- Place
- Menominee, Michigan · Menominee-Marinette Twin Count · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Enstrom TH-180, built 2015
- Registration
- N180TH · registry record · serial 10001
- Damage
- Substantial damage
- Flight
- Flight test · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The commercial pilot of the helicopter departed to conduct a flight test of an onboard data acquisition system. About 18 minutes later, the pilot decided to return to the airport because of weather moving into the area. On final approach, the pilot felt a "jolt in the airframe," and the helicopter yawed left and began to descend. The pilot added engine power, but the main rotor rpm continued to decay until the low rotor rpm horn sounded. The pilot entered an autorotation to a city street in a residential neighborhood. During the landing, the main rotor struck an electric utility pole and the helicopter slid 300 ft before coming to a stop. A postaccident examination of the helicopter revealed that the eight mounting bolts for the engine torque meter had sheared, separating the engine from the main belt drive system. The torque meter was test equipment installed between the engine prop flange and a modified lower drive pulley for the purpose of gathering engine data during the flight tests. No other preaccident anomalies were found.
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 approach (VFR pattern base) defining event
- Autorotation Off-field or emergency landing
- Collision with terrain or object (not controlled flight into terrain) during landing
- Landing gear collapse during post (impact)
The NTSB's findings
- cause Aircraft › Aircraft propeller/rotor › Main rotor drive › Engine/transmission coupling › Failure
Pilot
- Certificate: commercial pilot
- Ratings: instructor: instrument helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 438 hours in all; 33 in this make and model; 45 in the last 90 days; 23 in the last 30 days; 240 as pilot in command
- Last flight review: October 23, 2014
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Maximum gross weight: 2,250 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming HIO-390-X (piston); 0 hours total
The flight
- Departed from: MNM Menominee MI at 3:57 pm
- Destination: MNM Menominee MI
- Flight plan: none
- Runway 32, 5,100 ft by 100 ft
Weather at the time
- Light: daylight
- Wind: from 330° at 13 knots, gusting 24
- Visibility: 10 statute miles
- Sky: broken clouds at 4,300 ft
- Temperature: 14°F (-10°C), dew point -2°F (-19°C)
- Altimeter: 30.05 inHg
- Observation at 4:15 pm from KMNM
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
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.