- Date
- April 29, 1990, 07:10 local (14:10 UTC)
- Place
- Mammoth Lakes, CA
- Injuries
- 2 minor
- Damage
- Substantial damage
- Phase of flight
- Enroute
- Aircraft
- N8560MRobinson R22
- Weather
- Visual (VMC) · Day
- Status
- Completed · report October 2, 1992
- Report
- Approved by Office Director
- FAA report
- 19900429013099A
- Case key
- 26787
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
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.
Sequence of events
NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.
Analysis
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.
Aircraft
- Registration
- N8560M
- Reported as
- Robinson R22
- Category
- Helicopter
- Serial number
- 0476
- Engine
- Lycoming O-320-B2C, 160 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Registered owner
- Louis W. Thacker
- Departed
- B1H · Bishop, CA
- Destination
- MEV · Minden, NV
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 57
- Certificate
- Private
- Medical
- Class 3, Valid Medical--w/ waivers/lim
- Flight hours
- 131 total · 131 in this make and model · 65 as pilot in command · 32 in the last 90 days · 20 in the last 30 days · 2 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 0° at 6 knots
- Visibility
- 50 statute miles
- Lowest ceiling
- None
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.
Other investigations on N8560M · 1
Matched to the same aircraft by N-number and date.