Aircraft Accident/Incident Report

Gregory, Michigan 48137
Thursday, December 14, 2006 13:15 EST

NTSB Narrative Summary Released at Completion of Accident

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.

NTSB Probable Cause Narrative

The pilot's unexpected encounter with wind shear and his inability to remain clear of the trees while on final approach to land.

Event Information

Type of Event Accident
Event Date 12/14/2006
Event Day of the Week Thursday
Time of Event 1315
Event Time Zone Eastern Standard Time
Event City Gregory
Event State MICHIGAN
Event Country --
Zipcode of the event site 48137
Event Date Year 2006
Event Date Month 12
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 422630N
Event Location Longitude 0840400W
Event Location Airport --
Event Location Nearest Airport ID --
Indicates whether the acc/inc occurred off or on an airport --
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness --
Investigator's weather source Unknown
Time of the weather observation
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID --
Elevation of weather observation facility --
Distance of event from weather observation facility (units?) --
Time Zone of the weather observation --
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions --
Sky Condition for Lowest Ceiling --
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) --
Air Temperature at event time (in degrees celsius) --
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) --
Variable Wind Indicator --
Wind Speed (knots) --
Wind Velocity Indicator --
Wind Gust Indicator Unknown
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) --
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 Docket Number (internal use) 21207
NTSB Notification Source FAA
NTSB Notification Date Dec 15 2006 12:00AM
NTSB Notification Time --
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Mar 26 2007 9:33AM
User who most recently changed record NTSB\lema
Basic weather conditions Visual Meteorological Cond
FAA District Office Detroit, MI FSDO

Aircraft Involved

Aircraft #1

Aircraft Registration Number N545TT
NTSB Number CHI07CA040
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 Schleicher
Aircraft Model AS-K13
Aircraft Series Identifier --
Aircraft Serial Number 13083
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 Sandhill Soaring Club
Aircraft Owner Street Address P.O. Box 2021
Aircraft Owner City Ann Arbor
Aircraft Owner State MI
Aircraft Owner Country USA
Aircraft Owner Zipcode 48106
Operator is an individual? No
Operator Name John P. Walker
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address --
Operator City Mason
Operator State MI
Operator Country USA
Operator Zip code 48854
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) Personal
Second Pilot on Board --
Departure Point Same as Event Yes
Departure Airport Code 69G
Departure City Gregory
Departure State MI
Departure Country USA
Departure Time 1300
Departure Time Zone EST
Destination Same as Local Flt crash at destination city
Destination Airport Code 69G
Destination City Gregory
Destination State MI
Destination Country USA
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 9 2007 2:34PM
User who most recently changed record DINC
Since inspection or accident --
Event Location Runway Number and Location --
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --