Robinson R22 accident near Mammoth Lakes, California, April 29, 1990
On April 29, 1990 at about 2:10 pm local time, a Robinson R22 (helicopter), registered N8560M, was substantially damaged in an accident near Mammoth Lakes, California. It was a personal flight under general aviation rules (Part 91). 2 people had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
PILOT'S ENCOUNTER WITH A STRONG DOWNDRAFT WHILE CRUISING AT AN INADEQUATE ALTITUDE. A CONTRIBUTING FACTOR WAS THE HIGH ALTITUDE WHICH LIMITED AVAILABLE ENGINE POWER FOR RECOVERY.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 29, 1990 · about 2:10 pm local time
- Place
- Mammoth Lakes, California · map
- Type
- Accident
- Injuries
- 2 people had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Robinson R22 · all R22s on the register
- Registration
- N8560M · registry record · serial 0476
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE PILOT ENCOUNTERED A STRONG DOWNDRAFT WHILE CRUISING AT 250 TO 300 FEET AGL. HE LOST CONTROL OF THE HELICOPTER, WAS UNABLE TO ARREST THE DESCENT, AND COLLIDED WITH 7000 MSL TERRAIN.
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: private
- Ratings: rotorcraft: helicopter
- Flight time: 131 hours in all; 131 in this make and model; 32 in the last 90 days; 20 in the last 30 days; 65 as pilot in command
- Medical certificate: Class 3 (valid medical--w/ waivers/lim.)
- Seat: unk
The aircraft
- Last inspection: inspection type not recorded; 0 hours since
- Maximum gross weight: 1,370 lb
- Seats: 2
- Landing gear: retractable
- Engine: Lycoming O-320-B2C (piston); 0 hours total
The flight
- Departed from: B1H Bishop CA at 1:28 pm
- Destination: MEV Minden NV
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: at 6 knots
- Visibility: 50 statute miles
- Sky: clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
- Observation at 7:10 am
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 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.
Other NTSB records under N8560M the same tail number, which may have belonged to a different aircraft at the time
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.