Aircraft Accident/Incident Report

Mokuleia, Hawaii 96791
Wednesday, April 22, 1987 16:00 HST

NTSB Narrative Summary Released at Completion of Accident

DURING A LOCAL SIGHTSEEING FLT ALONG A RIDGE LINE, WHILE MANEUVERING AROUND A CLOUD BUILD-UP, THE ACFT ENTERED A WINDSHEAR THAT SUDDENLY NOSED THE ACFT OVER IN AN APRX 75 DEG VERTICAL DIVE. JUST PRIOR TO COLLIDING WITH TREES, THE PLT WAS ABLE TO REGAIN SOME CONTROL OF THE ACFT AND COLLIDED WITH THE TERRAIN IN AN APRX 45 DEG ATTITUDE. IN THESE MOUNTAINS A CATABATIC WIND OFTEN FLOWS DOWNSLOPE AS SOLAR HEAT IS RADIATED FROM THE TERRAIN, COOLING THE TERRAIN SURFACE. THE TRADE WINDS CROSS THE RIDGES OBLIQUELY RESULTING IN EDDIES THAT PRODUCE OFF RIDGE FLOW. WHEN THE EDDIES AND CATABATIC GUSTS COINCIDE, A WIND SHEAR CAN OCCUR.

NTSB Probable Cause Narrative

Not Yet Reported

Event Information

Type of Event Accident
Event Date 4/22/1987
Event Day of the Week Wednesday
Time of Event 1600
Event Time Zone Hawaii Standard Time
Event City MOKULEIA
Event State HAWAII
Event Country --
Zipcode of the event site 96791
Event Date Year 1987
Event Date Month 4
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 0
Degrees magnetic from airport 0
Airport Elevation 0
Weather Briefing Completeness Unknown
Investigator's weather source Witness
Time of the weather observation 0
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID
Elevation of weather observation facility 0
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 50
Air Temperature at event time (in degrees celsius) 25
Dew Point at event time (in degress fahrenheit) 17
Wind Direction (degrees magnetic) 50
Variable Wind Indicator Unknown
Wind Speed (knots) 15
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
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 Serious
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor 2
Injury Total None --
Injury Total Serious 1
Injury Total All 3
Investigating Agency FAA
NTSB Docket Number (internal use) 1450
NTSB Notification Source --
NTSB Notification Date Apr 22 1987 12:00AM
NTSB Notification Time 1700
Fiche Number and/or location -used to find docket information 34819
Date of most recent change to record Dec 13 2000 2:15PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N11468
NTSB Number LAX87DJA06
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Destroyed
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name SCHWEIZER
Aircraft Model SGS2-33
Aircraft Series Identifier SGS2-33
Aircraft Serial Number 76
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 Mar 9 1987 12:00AM
Airframe hours since last inspection 93
Airframe Hours 7817
ELT Installed No
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name HONOLULU SOARING CLUB INC
Aircraft Owner Street Address BOX 626
Aircraft Owner City WAIALIIA
Aircraft Owner State HI
Aircraft Owner Country
Aircraft Owner Zipcode 96791
Operator is an individual? --
Operator Name HONOLULU SOARING CLUB, INC.
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address P. O. BOX 626
Operator City WAIALIIA
Operator State HI
Operator Country
Operator Zip code 96791
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) Personal
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code
Departure City
Departure State
Departure Country
Departure Time 1600
Departure Time Zone
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 Descent
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:35AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 0
Runway Length 0
Runway Width 0
Sight Seeing flight No
Air Medical Flight No
Medical Flight --