# NTSB LAX87DJA06: Schweizer SGS2-33, N11468, Mokuleia, HI, April 23, 1987

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Final report
- Date: April 22, 1987, 16:00 local (Apr 23, 1987, 02:00 UTC)
- Place: Mokuleia, HI
- Coordinates: 21.570068, -158.120773 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=21.5701&lon=-158.1208&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious, 2 minor
- Status: Completed, report October 7, 1988
- Report: Approved by Office Director
- NTSB case key (mKey): 25292
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX87DJA06
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/25292/pdf
- Page: https://openairdocs.org/ntsb/LAX87DJA06

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- In flight encounter with weather, maneuvering
  - weather condition - windshear (cause)
  - altitude - inadequate (contributing factor)
- Loss of control - in flight, cruise - normal
- In flight collision with object, descent - emergency
  - object - tree(s) (contributing factor)

## Analysis

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.

## Aircraft

- Registration: N11468 (not matched to a registry record)
- Reported make and model: SCHWEIZER SGS2-33
- Category: Glider
- Serial number: 76
- Airframe hours: 7817
- Engines: unknown
- Damage: Destroyed
- Flight: Personal, Part 91
- Operator: Honolulu Soaring Club, Inc., doing business as Honolulu Soaring Club, Inc.
- Registered owner: Honolulu Soaring Club Inc
- Airworthiness certificate: Standard, Utility
- Last inspection: 100 hour, March 9, 1987, 93 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 66; commercial; airplane ratings: single-engine land, multi-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: front; flight hours: 5,400 total, 497 in this make and model, 5,100 as pilot in command, 120 in the last 90 days, 40 in the last 30 days, 5 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 50° at 15 knots
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: 77 °F, dew point 63 °F
- Altimeter: 29.00 inHg

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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