Warren-Sugarbush Airport
Aircraft Accident/Incident Report

Warren, Vermont 05674
Wednesday, June 27, 2007 16:30 EDT

NTSB Narrative Summary Released at Completion of Accident

The LET Super Blanik L23 flight instructor and a student pilot were towed to 2,700 feet above the airport, where the student pilot performed a series of maneuvers. Afterwards, the student pilot descended the glider toward a midfield downwind entry, about 1,500 feet above the airport. While descending, turbulence from an approaching rain shower increased, so the flight instructor took the controls. The flight instructor flew the remainder of the downwind leg, followed by a base leg, at 70 knots with full spoilers deployed since the glider would not descend. Turning onto final, while heading into the wind, the glider experienced an "extremely strong" sink rate, from which, the flight instructor could not recover. The glider subsequently landed hard about 100 feet short of the runway causing substantial damage. Shortly after the landing, light rain fell on the airport, and there was thunder in the distance. Ten minutes later, there was lightning 2 miles southeast of the airport, and the winds dropped and remained at less than 10 knots the rest of the afternoon. The flight instructor reported over 9,600 hours of flight time with 3,700 hours as a pilot in command of gliders.

NTSB Probable Cause Narrative

The glider's inadvertent encounter with windshear. A factor was the outflow from a nearby thunderstorm.

Event Information

Type of Event Accident
Event Date 6/27/2007
Event Day of the Week Wednesday
Time of Event 1630
Event Time Zone Eastern Daylight Time
Event City Warren
Event State VERMONT
Event Country --
Zipcode of the event site 05674
Event Date Year 2007
Event Date Month 6
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 440700N
Event Location Longitude 0724936W
Event Location Airport Warren-Sugarbush
Event Location Nearest Airport ID 037
Indicates whether the acc/inc occurred off or on an airport On Airport
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness --
Investigator's weather source Weather Observation Facility
Time of the weather observation 1651 Eastern Daylight Time
Direction of event from weather observation facility (degrees) 70
Weather Observation Facility ID MPV
Elevation of weather observation facility --
Distance of event from weather observation facility (units?) 12
Time Zone of the weather observation EDT
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling --
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 21
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 240
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 10
Wind Velocity Indicator --
Wind Gust Indicator Gusting
Wind Gust (knots) 24
Altimeter Setting at event time (in. Hg) 29.9
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor --
Injury Total None 2
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 22333
NTSB Notification Source NEROC
NTSB Notification Date --
NTSB Notification Time --
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Oct 31 2007 7:09AM
User who most recently changed record NTSB\johb
Basic weather conditions Visual Meteorological Cond
FAA District Office Portland, ME

Aircraft Involved

Aircraft #1

Aircraft Registration Number N8022
NTSB Number NYC07CA151
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion --
Aircraft Manufacturer's Full Name LET
Aircraft Model Super Blanik L-23
Aircraft Series Identifier --
Aircraft Serial Number 938022
Certified Max Gross Weight --
Aircraft Category Glider
Aircraft Registration Class --
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft --
Number of Engines 0
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection --
Date of Last Inspection --
Airframe hours since last inspection --
Airframe Hours --
ELT Installed --
ELT Activated --
ELT Aided Location of Event Site --
ELT Type --
Aircraft Owner Name Sugarbush Soaring Association
Aircraft Owner Street Address --
Aircraft Owner City Warren
Aircraft Owner State VT
Aircraft Owner Country USA
Aircraft Owner Zipcode 05674
Operator is an individual? No
Operator Name --
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address --
Operator City --
Operator State --
Operator Country --
Operator Zip code --
Operator Code --
Owner has at least one certificate None
Other Operator of large aircraft? --
Certified for Part 133 or 137 Operation --
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Instructional
Second Pilot on Board --
Departure Point Same as Event Yes
Departure Airport Code 0B7
Departure City Warren
Departure State VT
Departure Country USA
Departure Time --
Departure Time Zone EDT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code --
Destination City --
Destination State --
Destination Country --
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Sep 26 2007 9:41AM
User who most recently changed record MUZD
Since inspection or accident --
Event Location Runway Number and Location 22
Runway Length 2300
Runway Width 30
Sight Seeing flight No
Air Medical Flight No
Medical Flight --