Aircraft Accident/Incident Report

Warner Springs, California 92086
Friday, October 10, 1997 17:00 PDT

NTSB Narrative Summary Released at Completion of Accident

The sailplane pilot departed on a 40-minute scenic flight. The sailplane was released from the airplane tow at 8,000 feet. According to passenger statements, they reached a height of 14,000 feet msl. They also stated that near the end of the flight time, the pilot descended through clouds. The sailplane collided with mountainous terrain about 6,000 feet msl. An ocean/atmosphere scientist glider pilot was flying the same area near the accident time. He stated that the day was dominated by powerful, yet rapidly changing lee wave systems, producing 10/20 knot updrafts and downdrafts in the coastal mountain ranges of the lower Southern California Bight. He stated that the lee wave structure is normally very steady and reliable. Based on about 1,800 hours of flying the wave, he believed that this unusual day was a 1 in 1,000 occurrence changing minute by minute. He stated that on three separate occasions, he encountered abrupt disintegration of a well ordered non-hydrostatic wave, which resulted in the immediate loss of 7,000 to 10,000 feet of altitude.

NTSB Probable Cause Narrative

the pilot's inadvertent flight into instrument meteorological conditions after inadvertently encountering mountain wave and associated downdraft conditions. The obscuration and high/mountainous terrain were related factors.

Event Information

Type of Event Accident
Event Date 10/10/1997
Event Day of the Week Friday
Time of Event 1700
Event Time Zone Pacific Daylight Time
Event City WARNER SPRINGS
Event State CALIFORNIA
Event Country --
Zipcode of the event site 92086
Event Date Year 1997
Event Date Month 10
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport
Event Location Nearest Airport ID
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 1646 Pacific Daylight Time
Direction of event from weather observation facility (degrees) 240
Weather Observation Facility ID CRQ
Elevation of weather observation facility 328
Distance of event from weather observation facility (units?) 43
Time Zone of the weather observation PDT
Lighting Conditions Day
Lowest Ceiling Height 3000
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Unknown
Sky Condition for Lowest Ceiling Broken
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 30
Air Temperature at event time (in degrees celsius) --
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 240
Variable Wind Indicator Unknown
Wind Speed (knots) 10
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 29
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Fatal
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal 1
Injury Total Minor 1
Injury Total None --
Injury Total Serious 1
Injury Total All 3
Investigating Agency NTSB
NTSB Docket Number (internal use) 1261
NTSB Notification Source --
NTSB Notification Date Oct 11 1997 12:00AM
NTSB Notification Time 1300
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 8 2000 12:37PM
User who most recently changed record dbo
Basic weather conditions Instrument Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N242DB
NTSB Number LAX98FA007
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Schweizer
Aircraft Model 2-32
Aircraft Series Identifier 2-32
Aircraft Serial Number 42
Certified Max Gross Weight 1430
Aircraft Category Glider
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 3
Number of Engines --
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Sep 12 1997 12:00AM
Airframe hours since last inspection 42
Airframe Hours 6204
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name BRETT WILLAT
Aircraft Owner Street Address 31930 HIGHWAY 79
Aircraft Owner City WARNER SPRINGS
Aircraft Owner State CA
Aircraft Owner Country
Aircraft Owner Zipcode 92086
Operator is an individual? --
Operator Name
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address
Operator City
Operator State
Operator Country
Operator Zip code
Operator Code
Owner has at least one certificate None
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Unknown
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Instructional
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code CL35
Departure City
Departure State CA
Departure Country
Departure Time 1625
Departure Time Zone PDT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code
Destination City
Destination State
Destination Country
Specific Phase of Flight Maneuvering
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:34AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 0
Runway Length --
Runway Width --
Sight Seeing flight Yes
Air Medical Flight No
Medical Flight --