Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Wurtsboro, New York 12790
Saturday, April 6, 1991 12:20 EST
NTSB Narrative Summary Released at Completion of Accident
THE GLIDER WAS OBSERVED IN A STEEP NOSE DOWN PITCH ATTITUDE. JUST ABOVE THE TERRAIN, THE NOSE PITCHED UP AND THE LEFT WING FAILED AT THE WING ROOT. THE GLIDER STRUCK TREES, DESCENDING TO THE GROUND. POST CRASH EXAMINATION SHOWED THE WING HAD FAILED IN OVERLOAD. ACCORDING TO THE MANUFACTURER, THE WING HAD AN ULTIMATE FAILURE LOAD OF 9.72G. EXAMINATION OF THE GLIDER SHOWED TAPE ON THE TRIM DISCONNECT SYSTEM AND CONTROL STICK. THIS IS A TECHNIQUE USED BY COMPETITION PILOTS TO REDUCE THE CONTROL FORCES. THERE IS A FLIGHT MANUAL LIMITATION AGAINST OPERATING WITH SPEEDS IN EXCESS OF 108 MPH WITH THE TRIM DISCONNECTED. FLIGHT TESTING BY THE MANUFACTURER SHOWED THE GLIDER HAD 'NEAR TO NEUTRAL STABILITY' WITH THE TRIM DISCONNECTED.
NTSB Probable Cause Narrative
AN INFLIGHT FAILURE OF THE LEFT WING SPAR DUE TO OVERLOAD FROM PILOT INDUCED CONTROL INPUTS, WHILE RECOVERING FROM A DIVE. FACTORS RELATED TO THE ACCIDENT WERE, THE PILOT'S DECISION TO FLY WITH THE TRIM SYSTEM DISCONNECTED AND LACK OF RECENT EXPERIENCE IN MAKE AND MODEL OF GLIDER.
Event Information
| Type of Event | Accident |
| Event Date | 4/6/1991 |
| Event Day of the Week | Saturday |
| Time of Event | 1220 |
| Event Time Zone | Eastern Standard Time |
| Event City | WURTSBORO |
| Event State | NEW YORK |
| Event Country | -- |
| Zipcode of the event site | 12790 |
| Event Date Year | 1991 |
| Event Date Month | 4 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | |
| Event Location Nearest Airport ID | |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | 0 |
| Degrees magnetic from airport | 0 |
| Airport Elevation | -- |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Witness |
| Time of the weather observation | 0 |
| Direction of event from weather observation facility (degrees) | 0 |
| Weather Observation Facility ID | |
| Elevation of weather observation facility | 0 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | |
| 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) | 25 |
| Air Temperature at event time (in degrees celsius) | -- |
| Dew Point at event time (in degress fahrenheit) | -- |
| Wind Direction (degrees magnetic) | 270 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 10 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Unknown |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | -- |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | Unknown |
| METAR weather report | -- |
| Event Highest Injury | Fatal |
| On Ground, Fatal Injuries | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | 1 |
| Injury Total Minor | -- |
| Injury Total None | -- |
| Injury Total Serious | -- |
| Injury Total All | 1 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 1530 |
| NTSB Notification Source | -- |
| NTSB Notification Date | -- |
| NTSB Notification Time | 0 |
| Fiche Number and/or location -used to find docket information | 45377 |
| Date of most recent change to record | Dec 12 2000 9:46AM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N3620D |
| NTSB Number | NYC91LA102 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | -- |
| Damage | Destroyed |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | SCHWEIZER |
| Aircraft Model | SGS-1-30 |
| Aircraft Series Identifier | SGS-1-30 |
| Aircraft Serial Number | 20 |
| Certified Max Gross Weight | 710 |
| 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 | 1 |
| Number of Engines | 0 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | 100 Hour |
| Date of Last Inspection | Feb 20 1991 12:00AM |
| Airframe hours since last inspection | 26 |
| Airframe Hours | 1240 |
| ELT Installed | No |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | WURTSBORO FLIGHT SERVICE, INC. |
| Aircraft Owner Street Address | RD#1 BOX 382 |
| Aircraft Owner City | WURTSBORO |
| Aircraft Owner State | NY |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 12790 |
| Operator is an individual? | -- |
| Operator Name | WURTSBORO FLIGHT SERVICE, INC. |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | RD#1 BOX 382 |
| Operator City | WURTSBORO |
| Operator State | NY |
| Operator Country | |
| Operator Zip code | 12790 |
| 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) | Personal |
| Second Pilot on Board | No |
| Departure Point Same as Event | Yes |
| Departure Airport Code | |
| Departure City | |
| Departure State | |
| Departure Country | |
| Departure Time | 1200 |
| Departure Time Zone | EST |
| 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 | Descent |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 2 2001 10:35AM |
| User who most recently changed record | dbo |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 0 |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |