- Date
- August 22, 1992, 17:00 local (Aug 23, 1992, 00:00 UTC)
- Place
- Big Bear, CA
- Injuries
- 4 minor
- Damage
- Destroyed
- Phase of flight
- Enroute
- Aircraft
- N20BNSocata TB-10
- Weather
- Visual (VMC) · Day
- Status
- Completed · report September 14, 1993
- Report
- Approved by Office Director
- FAA report
- 19920822032529A
- Case key
- 27740
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
The pilots decision to attempt crossing a ridge line at an altitude insufficient to allow for contingency actions in the event of an encounter with down drafts or turbulence. Factors in the accident were the high density altitude and the flight's encounter with a down draft.
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
In his written statement the pilot said that after departure on runway 25 he turned in a southwest direction to cross a ridge line at an altitude of about 7,900 feet MSL. He said that near the ridge line they encountered a sudden down draft and he could not arrest the descent prior to colliding with trees. An eye witness to the crash said the aircraft never achieved more than about 300 feet AGL at any time after takeoff. The witness observed the aircraft in a nose high attitude begin a right turn, then it descended below the tops of some trees and out of view. Two other witnesses reported hearing the sounds of a loud and strong engine until the sounds of tree impacts were heard. The airport is in a mountain valley at an elevation of 6,750 feet. Mountain ridges and peaks rise an average of 2,000 feet above the valley floor on all sides of the airport. The airport is at the east end of the valley and a large lake. A dam is at the west end of the valley at a 'v' notch in the surrounding mountains. West of the dam the terrain drops off rapidly to the greater los angeles basin. The density altitude was calculated to be about 9,400 feet. Other pilots who departed from the airport reported that turbulence existed over the valley near the surrounding ridges.
Aircraft
- Registration
- N20BN
- Reported as
- Socata TB-10
- Category
- Airplane
- Serial number
- 494
- Airframe hours
- 1,336
- Engine
- Lycoming O-360-A1AD, 180 horsepower, reciprocating
- Damage
- Destroyed
- Flight
- Personal · Part 91
- Operator
- General Aviation Company
- Registered owner
- Curtis H. Thomas
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · May 8, 1992 · 39 hours before
- Departed
- L35
- Destination
- FUL · Fullerton, CA
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
- 32
- Certificate
- Private
- Airplane ratings
- Single-engine land
- Medical
- Class 2, Valid Medical--w/ waivers/lim
- Seat
- Left
- Flight hours
- 213 total · 50 in this make and model · 151 as pilot in command · 15 in the last 90 days · 12 in the last 30 days · 2 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 250° at 10 knots
- Visibility
- 20 statute miles
- Lowest ceiling
- None
- Temperature
- 81 °F
- Altimeter
- 30.00 inHg
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.