Individually Owned: 150,657
Corporate Owned: 137,281
Merkel Field Sylacauga Airport
Aircraft Accident/Incident Report
Sylacauga, Alabama 35151
Saturday, March 31, 2007 15:30 CDT
NTSB Narrative Summary Released at Completion of Accident
Witnesses stated that the glider had been airborne for about 30 minutes when they observed both wings fold up, and the glider descend out of control until impacting into a rock quarry. The wings were located about 1/2-mile north of the impact crater on the upper rim of the quarry. Examination of the wreckage revealed that during assembly, the lower attach pin had failed to enter the lower attachment hole on the left wing. The misalignment allowed the pin to rest on the top surface of the left wing attach lug in a clamping action. Examination of the mechanism that actuates the movement of both pins found that there had been two tabs located above the center pivot, and these two tabs were not found. Examination of the area where the two tabs were missing disclosed that these tabs had been missing for an extended period of time, as the upward motion of the mechanism (center pivot) had machined into the surface above where the upper tabs should have been located. The misalignment of the attach pin in the lower attachment hole allowed the left wing to move upwards to about 45 degrees and separate.
NTSB Probable Cause Narrative
The pilot's improper installation of the left wing attachment pin, which allowed it to disengage during cruise flight, resulting in wing separation.
Event Information
| Type of Event | Accident |
| Event Date | 3/31/2007 |
| Event Day of the Week | Saturday |
| Time of Event | 1530 |
| Event Time Zone | Central Daylight Time |
| Event City | Sylacauga |
| Event State | ALABAMA |
| Event Country | -- |
| Zipcode of the event site | 35151 |
| Event Date Year | 2007 |
| Event Date Month | 3 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 331011N |
| Event Location Longitude | 0861812W |
| Event Location Airport | Merkel Field Sylacauga Airport |
| Event Location Nearest Airport ID | KSCD |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | 2 |
| Degrees magnetic from airport | -- |
| Airport Elevation | 569 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1553 Central Daylight Time |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | EET |
| Elevation of weather observation facility | 587 |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | CDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | 4200 |
| Sky/Lowest/Cloud Conditions | Few |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 26 |
| Dew Point at event time (in degress fahrenheit) | 16 |
| Wind Direction (degrees magnetic) | 150 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 8 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 30.03 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | Fatal |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| 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) | 23966 |
| NTSB Notification Source | FAA ATL ROC |
| NTSB Notification Date | Mar 31 2007 12:00AM |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Jul 30 2008 9:00AM |
| User who most recently changed record | NTSB\johb |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | FAA Com Center |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N6SZ |
| NTSB Number | ATL07LA066 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | No |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Szybowcowy Zaklad DO |
| Aircraft Model | SZD-36A |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | W813 |
| Certified Max Gross Weight | 849 |
| 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 | 1 |
| Number of Engines | 0 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Conditional |
| Date of Last Inspection | Jun 1 2006 12:00AM |
| Airframe hours since last inspection | 19 |
| Airframe Hours | 556 |
| ELT Installed | No |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | Donald R. Tawzer |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | Chattanooga |
| Aircraft Owner State | TN |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 37421 |
| Operator is an individual? | No |
| Operator Name | Robert Obrian Wallace |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | -- |
| Operator City | Birmingham |
| Operator State | AL |
| Operator Country | USA |
| Operator Zip code | 35205 |
| 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 | No |
| Departure Point Same as Event | No |
| Departure Airport Code | SCD |
| Departure City | Sylacauga |
| Departure State | AL |
| Departure Country | USA |
| Departure Time | 1500 |
| Departure Time Zone | CDT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | SCD |
| Destination City | Sylacauga |
| Destination State | AL |
| Destination Country | USA |
| Specific Phase of Flight | Cruise |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jul 18 2008 9:53AM |
| User who most recently changed record | grer |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | NA |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |