# NTSB LAX94LA027: Schweizer SGS 2-33A, N7779S, Mokuleia, HI, October 28, 1993

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: October 27, 1993, 14:30 local (Oct 28, 1993, 00:30 UTC)
- Place: Mokuleia, HI
- Coordinates: 21.569351, -158.119201 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=21.5694&lon=-158.1192&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report August 1, 1994
- Report: Approved by Office Director
- NTSB case key (mKey): 28581
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX94LA027
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/28581/pdf
- Page: https://openairdocs.org/ntsb/LAX94LA027

## Probable cause

the student pilot's misjudgement of descent rate and terrain clearance while manuevering along a ridgeline.  Factors in the accident were the downdrafts and the mountainous/hilly nature of the terrain.

## Sequence of events

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

- In flight collision with object, maneuvering
  - terrain condition - mountainous/hilly (contributing factor)
  - weather condition - downdraft (contributing factor)
  - descent - misjudged, pilot in command (cause)
  - clearance - misjudged, pilot in command (cause)

## Analysis

According to FAA Inspectors, the student pilot was operating in weak ridge conditions and encountered a sinking air mass while manuevering along a ridgeline.  In so doing, the right wing of the glider struck a tree.  The pilot was able to continue the flight and landed at Dillingham Airfield without further incident.  An off-duty FSDO supervisor saw the aircraft in the hangar and noticed damage to the aircraft.

## Factual narrative

On October 27, 1993, at 1430 Hawaiian standard time, a Schweitzer SGS 2-33A, N7779S, struck a tree with the right wing while soaring along a ridge line.  The student pilot was conducting a local visual flight rules solo instructional flight.  The glider, operated by Honolulu Soaring Club, Inc., sustained substantial damage.  The student pilot, the sole occupant, was not injured.  Visual meteorological conditions prevailed.  The flight originated at Dillingham Airfield, Waialua, Hawaii, at 1330 Hawaiian standard time.

According to FAA Inspectors, the student pilot was operating in weak ridge conditions and encountered a sinking air mass.  In so doing, the right wing of the glider struck a tree.  The pilot was able to continue the flight and landed at Dillingham Airfield without further incident.  An off-duty FSDO supervisor saw the aircraft in the hangar and noticed damage which consisted of a five inch dent in the leading edge between the third and fourth wing ribs, counting inboard from the tip.  The skin was severely wrinkled, extending from the impact point on the leading edge, aft to the trailing edge.

## Aircraft

- Registration: [N7779S](https://openairdocs.org/deregistered/N7779S-2012-09-06), registration cancelled 2012-09-06, S/N 149, built 1969 (OpenAirDocs)
- Reported make and model: Schweizer SGS 2-33A
- Registry model: [Schweizer SGS 2-33A](https://openairdocs.org/model/schweizer-sgs-2-33a) (registry code 8051606) (OpenAirDocs)
- Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs)
- Category: Glider
- Serial number: 149
- Airframe hours: 5281
- Engines: unknown
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Registered owner: Honolulu Soaring Club, Inc.
- Airworthiness certificate: Standard, Utility
- Last inspection: 100 hour, October 5, 1993, 15 hours before
- Departed: HDH, WAIALUA, HI

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 21; student; medical: unknown, unknown; seat: front; flight hours: 54 total, 54 in this make and model, 9 in the last 90 days, 2 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 10° at 10 knots
- Visibility: 7 statute miles
- Lowest ceiling: 10,000 ft broken
- Temperature: 73 °F, dew point 55 °F
- Altimeter: 29.00 inHg

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19931027041019A](https://openairdocs.org/incident/19931027041019A), Oct 27, 1993: Scwzer SGS233A, Mokuleia, HI, Substantial damage. Right wing struck tree while soaring near a ridge. Encountered downdraft. Remained airborne. Returned to hdh.

## Other investigations on N7779S (1)

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.

- [NTSB LAX70D0155](https://openairdocs.org/ntsb/LAX70D0155), Oct 4, 1969: Schweizer 2-33 (N7779S), Pearblossom, CA, substantial damage

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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