Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Oso, Washington 98223
Thursday, April 1, 2004 17:00 PST
NTSB Narrative Summary Released at Completion of Accident
While flying in trail along a ridgeline at the same altitude, the pilot of the Glaser-Dirks (lead glider) made a left turn, while the pilot of the Glasflugel (trailing glider) remained on course over the ridgeline. The Glasflugel pilot reported that he recalled that the Glaser-Dirks was at his 10:00 position when he encountered turbulence and he looked down to check his airspeed. When he looked back up, he lost sight of the Glaser-Dirks and assumed that he had rolled out to run the ridgeline to the south. The Glasflugel pilot continued along the ridgeline to the north when the Glaser-Dirks pilot transmitted to the Glasflugel pilot to "watch out/it." The Glasflugel pilot looked around to his left and spotted the other glider about 80 feet away at his 8:00 position and converging at the same altitude. The Glasflugel pilot reacted by making a right banking turn. During this maneuver, the left wing tip of the Glasflugel glider came up under the right wing of the Glaser-Dirks glider. The left wing tip of the Glasflugel contacted the underside of the right wing of the Glaser-Dirks about 13 feet 5 inches outboard of the wing root resulting in the outboard section of the right wing separating in flight. The pilot of the Glaser-Dirks was fatally injured, while the pilot of the Glasflugel was able to bail-out and deploy his parachute.
NTSB Probable Cause Narrative
The pilot of the Glaser-Dirks (lead glider) failure to maintain clearance form the Glasflugel (trailing glider) resulting in a mid-air collision while maneuvering.
Event Information
| Type of Event | Accident |
| Event Date | 4/1/2004 |
| Event Day of the Week | Thursday |
| Time of Event | 1700 |
| Event Time Zone | Pacific Standard Time |
| Event City | Oso |
| Event State | WASHINGTON |
| Event Country | -- |
| Zipcode of the event site | 98223 |
| Event Date Year | 2004 |
| Event Date Month | 4 |
| MidAir Collision Indicator | Yes |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 481423N |
| Event Location Longitude | 1215400W |
| 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 | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | -- |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1655 Pacific Standard Time |
| Direction of event from weather observation facility (degrees) | 230 |
| Weather Observation Facility ID | AWO |
| Elevation of weather observation facility | 137 |
| Distance of event from weather observation facility (units?) | 11 |
| Time Zone of the weather observation | PST |
| Lighting Conditions | Day |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | Clear |
| 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) | 12 |
| Dew Point at event time (in degress fahrenheit) | 2 |
| Wind Direction (degrees magnetic) | 310 |
| 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) | 30.41 |
| 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 | 1 |
| Injury Total None | -- |
| Injury Total Serious | -- |
| Injury Total All | 2 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 16427 |
| NTSB Notification Source | WA State Aeronautics S&R |
| NTSB Notification Date | Apr 2 2004 12:00AM |
| NTSB Notification Time | 936 |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Sep 29 2004 1:02PM |
| User who most recently changed record | NTSB\MONR |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | Seattle, Washington |
Aircraft Involved |
||
|---|---|---|
Aircraft #1 |
Aircraft #2 |
|
| Aircraft Registration Number | N161D | N400WJ |
| NTSB Number | SEA04LA063A | SEA04LA063B |
| Missing Aircraft Indicator | -- | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation | Part 91: General Aviation |
| Type of Flight Plan filed | None | None |
| Flight plan Was Activated? | No | No |
| Damage | Substantial | Substantial |
| Aircraft Fire | None | None |
| Aircraft Explosion | None | None |
| Aircraft Manufacturer's Full Name | Glasflugel | Glaser-Dirks |
| Aircraft Model | STD Libelle 201B | DG-400 |
| Aircraft Series Identifier | -- | -- |
| Aircraft Serial Number | 22 | 4-91 |
| Certified Max Gross Weight | 770 | 1014 |
| Aircraft Category | Glider | Glider |
| Aircraft Registration Class | U.S. Registered/U.S. Soil | U.S. Registered/U.S. Soil |
| Aircraft is a homebuilt? | No | No |
| Flight Crew Seats | -- | -- |
| Cabin Crew Seats | -- | -- |
| Passenger Seats | -- | -- |
| Total number of seats on the aircraft | 1 | 1 |
| Number of Engines | -- | 1 |
| Fixed gear or retractable gear | Retractable | Retractable |
| Aircraft, Type of Last Inspection | Annual | -- |
| Date of Last Inspection | Aug 8 2003 12:00AM | -- |
| Airframe hours since last inspection | 14 | -- |
| Airframe Hours | 3147 | -- |
| ELT Installed | No | No |
| ELT Activated | No | No |
| ELT Aided Location of Event Site | No | No |
| ELT Type | -- | -- |
| Aircraft Owner Name | Paul J. Adriance | William S. Burhen |
| Aircraft Owner Street Address | -- | -- |
| Aircraft Owner City | Marysville | Seattle |
| Aircraft Owner State | WA | WA |
| Aircraft Owner Country | USA | USA |
| Aircraft Owner Zipcode | 98270 | 98102 |
| Operator is an individual? | No | No |
| Operator Name | -- | -- |
| Operator Same as Owner? | Yes | Yes |
| Operator Is Doing Business As | -- | -- |
| Operator Address Same as Owner? | Yes | Yes |
| Operator Street Address | -- | -- |
| Operator City | -- | -- |
| Operator State | -- | -- |
| Operator Country | -- | -- |
| Operator Zip code | -- | -- |
| Operator Code | -- | -- |
| Owner has at least one certificate | None | 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 | Personal |
| Second Pilot on Board | No | No |
| Departure Point Same as Event | No | No |
| Departure Airport Code | AWO | AWO |
| Departure City | Arlington | Arlington |
| Departure State | WA | WA |
| Departure Country | USA | USA |
| Departure Time | 1120 | 1600 |
| Departure Time Zone | PST | PST |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere | dest & departure same, accident can occur anywhere |
| Destination Airport Code | -- | -- |
| Destination City | -- | -- |
| Destination State | -- | -- |
| Destination Country | -- | -- |
| Specific Phase of Flight | Maneuvering | Maneuvering |
| Report sent to ICAO? | No | No |
| Evacuation occurred | No | No |
| Date of most recent change to record | Aug 6 2004 1:53PM | Aug 6 2004 1:53PM |
| User who most recently changed record | STAM | STAM |
| Since inspection or accident | Time of Accident | -- |
| Event Location Runway Number and Location | NA | NA |
| Runway Length | -- | -- |
| Runway Width | -- | -- |
| Sight Seeing flight | No | No |
| Air Medical Flight | No | No |
| Medical Flight | -- | -- |