Amateur-built WOODSTOCK accident near Mankato, Minnesota, September 5, 1988
On September 5, 1988 at about 11:30 pm local time, a amateur-built WOODSTOCK (glider), registered N369DK, was destroyed in an accident near Mankato, Minnesota. It was a personal flight under general aviation rules (Part 91). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
AIRCRAFT STRUCTURAL FAILURE DUE TO OVERLOAD INDUCED BY PILOT IN THE PERFORMANCE OF UNAUTHORIZED MANEUVERS.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 5, 1988 · about 11:30 pm local time
- Place
- Mankato, Minnesota · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built WOODSTOCK
- Registration
- N369DK · no longer on the register · serial 369
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE HOMEBUILT EXPERIMENTAL GLIDER EXPERIENCED AN INFLIGHT STRUCTURAL FAILURE OF BOTH WINGS WHICH SUBSEQUENTLY RESULTED IN A LOSS OF CONTROL AND IMPACT WITH THE TERRAIN. EXAMINATION REVEALED THE WINGS FAILED DUE TO OVERLOAD AT WING MIDSPAN NEAR THE SPOILERS. RECOVERY FROM LOOPS UTILIZING THE SPOILERS AS AIR BRAKES WILL CAUSE AN INCREASED BENDING MOMENT OUTBOARD OF THE SPOILERS AND REDUCE WING STRENGTH IN THE SPOILER BOX AREA. THE PLT HAD 35 HRS OF FLT TIME IN THE ACFT, AND HAD LOGGED PERFORMANCE OF LOOPS IN HIS PLT LOGBOOK. AEROBATICS ARE PROHIBITED IN THIS ACFT.
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: private
- Ratings: single-engine land; rotorcraft: glider
- Flight time: 182 hours in all; 35 in this make and model
- Medical certificate: Class 3 (valid medical--w/ waivers/lim.)
- Seat: ctr
The aircraft
- Airframe total time: 35 hours
- Last inspection: annual inspection, March 24, 1988; 35 hours since
- Maximum gross weight: 450 lb
- Seats: 1
- Landing gear: fixed
- Engine: (type not recorded); 0 hours total
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 320° at 5 knots
- Visibility: 15 statute miles
- Sky: broken clouds at 6,000 ft
- Temperature: 66°F (19°C), dew point 0°F (-18°C)
- Altimeter: 29.00 inHg
- Observation at 9:55 pm from MKT, 15 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 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.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.