Schleicher ASK-21 accident near Tehachapi, California, May 10, 2008
On May 10, 2008 at about 10:40 pm local time, a Schleicher ASK-21 (glider), registered N361KS, was substantially damaged in an accident during initial climb near Tehachapi, California (Mountain Valley Airport). It was a personal flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's inadequate preflight procedures and failure to check the spoiler control position, which resulted in the inadvertent deployment of the spoilers during takeoff. A contributing factor was the pilot's misinterpretation of the tow pilot's instructions.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 10, 2008 · about 10:40 pm local time
- Place
- Tehachapi, California · Mountain Valley Airport · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Schleicher ASK-21 · all ASK-21s on the register
- Registration
- N361KS · registry record · serial 21224
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The glider was being towed to altitude by a tow airplane. During the takeoff initial climb, the spoiler handle was not locked and the spoilers momentarily extended twice and although the pilot felt that he had to input forward control forces, he did not visually check the position of the spoiler control handle. The tow pilot then gave a rudder wave signal to the pilot telling him to check the spoilers; however, because the spoilers appeared retracted when the pilot verified their position, the glider pilot misinterpreted the tow pilot and released the glider from the tow airplane at approximately 100 feet above ground level. The glider pilot force-landed the glider in a field. During the landing, the empennage broke from the remainder of the glider. The glider pilot did not report any mechanical malfunctions with the glider.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Miscellaneous/other during initial climb defining event
- Collision with terrain or object (not controlled flight into terrain) during landing
The NTSB's findings
- cause Personnel issues › Task performance › Inspection › Preflight inspection › Pilot
- cause Personnel issues › Action/decision › Action › Incorrect action performance › Pilot
- factor Personnel issues › Task performance › Communication (personnel) › Interpretation/understanding › Pilot
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane; rotorcraft: glider
- Flight time: 2,095 hours in all; 6 in this make and model
- Medical certificate: Class 2
The aircraft
- Landing gear: fixed
- Engine:; 0 hours total
The flight
- Departed from: L94 Tehachapi CA
- Destination: L94 Tehachapi CA
- Flight plan: none
- Runway 27R, 4,890 ft by 36 ft
Weather at the time
- Light: daylight
- Wind: from 010° at 8 knots
- Sky: clear
- Temperature: 88°F (31°C), dew point 25°F (-4°C)
- Altimeter: 29.90 inHg
- Observation at 10:56 pm from WJF, 25 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Other NTSB records under N361KS the same tail number, which may have belonged to a different aircraft at the time
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number SEA08CA129.