Schleicher AS-K13 accident near Gregory, Michigan, December 14, 2006
On December 14, 2006 at about 6:15 pm local time, a Schleicher AS-K13 (glider), registered N545TT, was substantially damaged in an accident near Gregory, Michigan. 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 unexpected encounter with wind shear and his inability to remain clear of the trees while on final approach to land.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- December 14, 2006 · about 6:15 pm local time
- Place
- Gregory, Michigan · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Schleicher AS-K13 · all AS-K13s on the register
- Registration
- N545TT · registry record · serial 13083
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The glider contacted trees while on final approach to land. The pilot reported the accident occurred during his second flight of the day. He reported that he checked the winds prior to takeoff and that the flight was bumpy up to 2,000 feet above ground level (agl) at which point it smoothed out to 3,000 feet agl where he was released from the tow plane. He stated that after a 15 minute flight he returned to the airport where he entered a left hand traffic pattern at 1,000 feet agl for runway 18. The pilot reported that when he entered the traffic pattern he noticed the wind sock was shifting and the glider was losing altitude at a rate that was faster than the previous flight. He stated that because of this, he turned onto base leg sooner than normal. He reported, "Upon turning there was an immediate sense of an inability to penetrate thru the airmass as the glider continued to lose altitude." He stated he lowered the nose of the glider in an attempt to gain airspeed and flew an abbreviated base leg, heading straight for the runway. The pilot reported he then noted a shift in the wind and the glider descended into the 75 foot tall trees northeast of the approach end of the runway. The pilot of the tow plane reported he flew 4 flights on the day of the accident and that during the first 3 flights the winds were from the southwest at less than 15 knots. He reported that for the accident flight the windsock indicated the winds were from the southeast and that the automated weather observing system (AWOS) indicated the winds were from 170 degrees at 8 or 9 knots. He stated that after he landed the windsock indicated the winds had shifted again to the southwest. He stated he checked the AWOS from the Mason-Jewett Airport (TEW), Mason, Michigan, and it was indicating the winds were variable from 160 to 240 degrees at 9 knots gusting to 16 or 20 knots. He reported that this was at the same time that the glider was in the traffic pattern to land. The winds rpeorted at TEW, located 20 miles west-northwest of the accident site at 1317 were from 200 degrees at 5 knots gusting to 14 knots. Twenty minutes prior, the TEW winds were reported as being from 200 degrees at 5 knots. The winds reported at the Howell-Livingston County Airport (OZW), Howell, Michigan, located 15 miles north-northeast of the accident site at 1317 were from 170 degrees at 9 knots. Twenty minutes later the OZW winds had shifted to 200 degrees at 10 knots gusting to 15 knots.
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
Pilot
- Certificate: commercial pilot
- Ratings: rotorcraft: glider
- Flight time: 181 hours in all; 101 in this make and model; 14 in the last 90 days; 1 in the last 30 days; 140 as pilot in command
- Medical certificate: None
The aircraft
- Landing gear: fixed
- Engine:; 0 hours total
The flight
- Departed from: 69G Gregory MI at 6:00 pm
- Destination: 69G Gregory MI
- Flight plan: none
Weather at the time
- Light: daylight
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| 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.
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 CHI07CA040.