Amateur-built MINI-500 accident near Ava, Missouri, July 19, 1997
On July 19, 1997 at about 7:30 pm local time, a amateur-built MINI-500 (helicopter), registered N500XM, was substantially damaged in an accident near Ava, Missouri. It was a personal flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
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The NTSB's probable cause their words, unchanged
Loss of engine power due to loss of engine cooling fluid. Related factors were maintenance service bulletin not complied with by the owner/pilot mechanic resulting in low output of the carburetor, and unsuitable terrain.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 19, 1997 · about 7:30 pm local time
- Place
- Ava, Missouri · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built MINI-500
- Registration
- N500XM · registry record · serial 180
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot was completing a series of flight tests that involved transitions from cruise flight into a hover. The pilot reported the exhaust gas temperature (EGT) was higher in cruise flight than when hovering and that the EGT cooled rapidly when the helicopter went from cruise flight into the hovering maneuver. The pilot stated that approximately two miles from his destination, at 2,500 feet mean sea level (msl), he began a 200 to 300 foot/min descent to reach the airport's traffic pattern altitude. He said that as soon as the descent was initiated he experienced unusual engine noises and an abrupt loss of engine power. He lowered the collective and applied full power, but received no indication of engine power. He then initiated an autorotation to landing on a field with a 30-degree slope. Upon landing, the aircraft rolled over and came to rest on its port side causing the rotor to impact the tail boom. Examination of the engine showed evidence that the engine had seized during flight. Inspection of the fuel metering system showed that the accident airplane had not complied with Revolution Helicopter Service Information Letter number 042696, which requires the original factory carburetor jet setting to be adjusted to insure that the EGT be between 1,000 and 1,150 degrees Fahrenheit. No engine coolant was found in the coolant tank and the coolant hose tee was found to be deformed and leaking fluid.
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 during descent
- FORCED LANDING during emergency descent/landing
- ROLL OVER during emergency landing
Pilot
- Ratings: multi-engine land, single-engine land, single-engine sea, none, APLN, helicopter
- Flight time: 2,808 hours in all; 23 in this make and model; 65 in the last 90 days; 46 in the last 30 days; 2,637 as pilot in command
- Medical certificate: class 1
The aircraft
- Airframe total time: 23 hours
- Last inspection: approved inspection programme, May 20, 1997; 20 hours since
- Maximum gross weight: 840 lb
- Seats: 1
- Landing gear: fixed
- Engine: Rotax 582 (piston); 0 hours total
- Operating certificate: in the vicinity
The flight
- Departed from: TVB Cabool MO at 6:05 pm
- Destination: AOV MO
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: at 6 knots
- Visibility: 7 statute miles
- Sky: clear
- Temperature: 91°C, dew point 70°C
- Altimeter: 30 inHg
- Observation at 6:54 pm from SGS, 37 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The docket at the NTSB holds the report as a PDF and the investigation's photographs and documents. This site never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number CHI97LA222.