Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Yellowstone Nat, Wyoming 82190
Monday, August 4, 2003 18:35 MDT
NTSB Narrative Summary Released at Completion of Accident
Several witnesses at Yellowstone National Park's Midway Geyser basin area reported seeing the airplane approaching them at a "low altitude" from the southeast. The airplane was quiet, and was observed gliding with its wings tipping back and forth. Next, it was observed to corkscrew, or spiral to the ground. The airplane's propeller was a highly modified constant speed Hamilton Standard 12D40 hub. Neither of the two 7 pound counterweights were found at the accident site. Examination of the #2 counterweight bracket revealed a fatigue crack at the proximal end of the counterweight slot. The propeller's shim plates exhibited impact signatures of the two blades indicating an angular difference of 10 degrees. The propeller's cylinder was crushed on one side, locking the piston inside the cylinder; the location of the piston inside the cylinder correlated to a blade angle of 34.9 degrees. If a propeller counterweight had separated in flight, aerodynamic forces would have driven the blade towards fine pitch or low blade angle. The blade's rotation would be limited to the low blade angle, of 24 degrees, by the remaining portion of its counterweight bracket arm which would contact and be stopped by the propeller’s barrel. If one blade was at the low blade angle of 24 degrees, the measured angular difference of 10 degrees, would indicate that the other blade was at an angle of 34 degrees. The agreement between this derived blade angle of 34 degrees and the piston position of 34.9 degrees suggests that one blade was still slaved to its counterweight at the time of impact and one blade was not.
NTSB Probable Cause Narrative
The in-flight loss of a propeller counterweight, followed by the pilot's loss of aircraft control during a forced landing attempt and subsequent inadvertent stall/spin to the ground.
Event Information
| Type of Event | Accident |
| Event Date | 8/4/2003 |
| Event Day of the Week | Monday |
| Time of Event | 1835 |
| Event Time Zone | Mountain Daylight Time |
| Event City | Yellowstone Nat |
| Event State | WYOMING |
| Event Country | -- |
| Zipcode of the event site | 82190 |
| Event Date Year | 2003 |
| Event Date Month | 8 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 443131N |
| Event Location Longitude | 1105003W |
| 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 | Full |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1746 Mountain Daylight Time |
| Direction of event from weather observation facility (degrees) | 320 |
| Weather Observation Facility ID | WYS |
| Elevation of weather observation facility | 6644 |
| Distance of event from weather observation facility (units?) | 18 |
| Time Zone of the weather observation | MDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 4000 |
| Lowest Non-Ceiling Height | 4000 |
| Sky/Lowest/Cloud Conditions | Thin Broken |
| Sky Condition for Lowest Ceiling | Broken |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 20 |
| Air Temperature at event time (in degrees celsius) | 22 |
| Dew Point at event time (in degress fahrenheit) | 9 |
| Wind Direction (degrees magnetic) | 160 |
| 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) | 30.26 |
| Density Altitude (feet) | 9477 |
| 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) | 17414 |
| NTSB Notification Source | FAA COMM CTR |
| NTSB Notification Date | Aug 4 2003 12:00AM |
| NTSB Notification Time | 2007 |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Mar 30 2005 6:20AM |
| User who most recently changed record | NTSB\JOHB |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | Casper, WY |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N258Y |
| NTSB Number | DEN03FA138 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | No |
| Damage | Destroyed |
| Aircraft Fire | Ground |
| Aircraft Explosion | Ground |
| Aircraft Manufacturer's Full Name | Wright |
| Aircraft Model | Hughes 1-B |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 2 |
| Certified Max Gross Weight | 4806 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | U.S. Registered/U.S. Soil |
| Aircraft is a homebuilt? | Yes |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 1 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Conditional |
| Date of Last Inspection | Jun 12 2003 12:00AM |
| Airframe hours since last inspection | 61 |
| Airframe Hours | 74 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | James L. Wright |
| Aircraft Owner Street Address | 33300 Molitor Ranch Rd. |
| Aircraft Owner City | Cottage Grove |
| Aircraft Owner State | OR |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 97424 |
| Operator is an individual? | No |
| 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? | -- |
| 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 | GCC |
| Departure City | Gillette |
| Departure State | WY |
| Departure Country | USA |
| Departure Time | 1730 |
| Departure Time Zone | MDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | EUG |
| Destination City | Eugene |
| Destination State | OR |
| Destination Country | USA |
| Specific Phase of Flight | Maneuvering |
| Report sent to ICAO? | No |
| Evacuation occurred | -- |
| Date of most recent change to record | -- |
| User who most recently changed record | -- |
| 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 | -- |