Amateur-built MINI 500 accident near Agua Dulce, California, August 1, 1997
On August 1, 1997 at about 2:45 am local time, a amateur-built MINI 500 (helicopter), registered N501GM, was substantially damaged in an accident near Agua Dulce, California (Pvt Helipad 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
failure of the owner/builder to obtain and comply with service literature from the kit manufacturer, which resulted in improper setting of the carburetor fuel mixture and led to loss of engine power. An additional cause was the pilot's failure to successfully autorotate the helicopter to an emergency landing. The pilot's lack of total experience in the type helicopter and lack of recent experience in performing autorotations were related factors.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 1, 1997 · about 2:45 am local time
- Place
- Agua Dulce, California · Pvt Helipad · map
- Type
- Accident
- Injuries
- 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built MINI 500
- Registration
- N501GM · registry record · serial 00221
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot of the recently completed, kit-built helicopter, stated that the engine stopped abruptly about 150 feet above helipad elevation as he was on base leg for landing. A hard landing resulted from an unsuccessful autorotation. Examination of the helicopter revealed that the size of the metering jet installed in both carburetors by the owner/pilot was too small, and that the fuel metering pin in both carburetors was improperly set so as to create an excessively lean fuel/air mixture, which resulted in loss of engine power. The pilot reported having 50 hours total helicopter flight time and that he last practiced autorotations 22 years prior to the accident. A revised aircraft assembly manual, which added a discussion of fuel jets and metering pins, was offered to holders of the earlier manual at a reduced price; however, the owner/builder did not purchase it. An article in the manufacture's newsletter, again discussing the importance of this subject, was sent to the owner/builder's address of record.
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
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; single-engine land; single-engine sea; instrument: airplane; rotorcraft: helicopter
- Flight time: 3,432 hours in all; 16 in this make and model; 20 in the last 90 days; 8 in the last 30 days; 3,200 as pilot in command
- Medical certificate: Class 3 (valid medical--no waivers/lim.)
- Seat: frt
The aircraft
- Airframe total time: 15 hours
- Last inspection: inspection type not recorded
- Maximum gross weight: 840 lb
- Seats: 1
- Landing gear: fixed
- Engine: Rotax 582 (piston); 0 hours total
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: dusk
- Visibility: 40 statute miles
- Sky: clear
- Temperature: 88°F (31°C), dew point 30°F (-1°C)
- Altimeter: 30.00 inHg
- Observation at 2:50 am from WJF, 16 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| 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.