Boerne Stage Field Airport
Aircraft Accident/Incident Report

San Antonio, Texas 78006
Saturday, August 28, 1999 13:00 CDT

NTSB Narrative Summary Released at Completion of Accident

The wing of the glider struck a tree when the solo student pilot was correcting the flight path to align the glider with the runway centerline during the final approach. The density altitude was calculated at 4,215 feet. The student pilot had 15.2 hours of total flight time in gliders. He was endorsed for solo flight and had 2.4 hours of solo flight time in the glider. The operator reported that the accident could have been prevented by 'maintain[ing] adequate clearance over obstacles.'

NTSB Probable Cause Narrative

The pilot's failure to attain proper runway alignment of the glider resulting in failure to maintain obstacle clearance. A factor was the high density altitude.

Event Information

Type of Event Accident
Event Date 8/28/1999
Event Day of the Week Saturday
Time of Event 1300
Event Time Zone Central Daylight Time
Event City SAN ANTONIO
Event State TEXAS
Event Country --
Zipcode of the event site 78006
Event Date Year 1999
Event Date Month 8
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport BOERNE STAGE FIELD
Event Location Nearest Airport ID 5C1
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 1380
Weather Briefing Completeness Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 1255 Central Daylight Time
Direction of event from weather observation facility (degrees) 103
Weather Observation Facility ID SAT
Elevation of weather observation facility 809
Distance of event from weather observation facility (units?) 13
Time Zone of the weather observation CDT
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 7000
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 36
Dew Point at event time (in degress fahrenheit) 17
Wind Direction (degrees magnetic) 160
Variable Wind Indicator Unknown
Wind Speed (knots) 10
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 29
Density Altitude (feet) 4215
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Serious
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None --
Injury Total Serious 1
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 613
NTSB Notification Source --
NTSB Notification Date Aug 28 1999 12:00AM
NTSB Notification Time 1000
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Jan 10 2001 10:00AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N103MS
NTSB Number FTW99LA238
Missing Aircraft Indicator N
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 None
Aircraft Manufacturer's Full Name Burkhart Grob
Aircraft Model 103C
Aircraft Series Identifier 103C
Aircraft Serial Number 34-756
Certified Max Gross Weight 1323
Aircraft Category Glider
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 2
Number of Engines --
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Jun 4 1999 12:00AM
Airframe hours since last inspection 85
Airframe Hours 1049
ELT Installed Unknown
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name BOB BRUCE
Aircraft Owner Street Address 100 BERNIE STAGE AIRFIELD
Aircraft Owner City SAN ANTONIO
Aircraft Owner State TX
Aircraft Owner Country
Aircraft Owner Zipcode 78006
Operator is an individual? --
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? No
Certified for Part 133 or 137 Operation Unknown
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 No
Departure Point Same as Event Yes
Departure Airport Code 5C1
Departure City
Departure State
Departure Country
Departure Time 1200
Departure Time Zone CDT
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 Jan 10 2001 12:27PM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 17
Runway Length 3400
Runway Width 40
Sight Seeing flight No
Air Medical Flight No
Medical Flight --