Individually Owned: 150,657
Corporate Owned: 137,281
Nampa Airport
Aircraft Accident/Incident Report
Nampa, Idaho 83686
Monday, August 16, 2010 11:50 MDT
NTSB Narrative Summary Released at Completion of Accident
The pilot was performing a series of high-speed taxi test runs and planned to complete his first flight in the recently completed amateur-built experimental aircraft later in the day. During the first test run, the fully-castoring nose wheel began to shimmy, and the pilot appeared to slightly raise and lower the airplane's nose, in what was assumed by witnesses to be an attempt to eliminate the shimmy. Upon reaching the end of the runway, the pilot reversed course and made another test run in the opposite direction. During the second test run, the nose wheel began a significant shimmy, followed soon thereafter by the nose of the airplane beginning to rise. Almost immediately after the nose began to rise, the airplane, in what was most likely an unintended consequence, lifted off the runway. Soon after it became airborne, the airplane's nose lowered, in what appeared to be the pilot's attempt to get it back onto the runway surface. The nose wheel then contacted the runway, and the airplane entered into a porpoising sequence that ultimately resulted in the nose gear strut collapsing. The airplane then slid off the side of the runway, and, after encountering soft terrain, it nosed over onto its back. The reason for the occurrence of the nose wheel shimmy could not be determined. The pilot had a reported history of sinus and migraine headaches, which had previously occurred during flight, requiring the pilot to turn over the aircraft controls to a different pilot. Results of post mortem toxicology testing were consistent with the relatively recent use of two different impairing antihistamines, which are often used to treat sinus symptoms. It is possible that the pilot was impaired by his recent use of the antihistamines or by the condition for which the medication was taken, though the possible role of any such impairment in the accident sequence could not be established.
NTSB Probable Cause Narrative
The pilot's failure to maintain aircraft control, which resulted in a collision with terrain during a rejected inadvertent takeoff.
Event Information
| Type of Event | Accident |
| Event Date | 8/16/2010 |
| Event Day of the Week | Monday |
| Time of Event | 1150 |
| Event Time Zone | Mountain Daylight Time |
| Event City | Nampa |
| Event State | IDAHO |
| Event Country | -- |
| Zipcode of the event site | 83686 |
| Event Date Year | 2010 |
| Event Date Month | 8 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 433453N |
| Event Location Longitude | 1163123W |
| Event Location Airport | Nampa |
| Event Location Nearest Airport ID | S67 |
| 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 | 2537 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1155 Mountain Daylight Time |
| Direction of event from weather observation facility (degrees) | 90 |
| Weather Observation Facility ID | KMAN |
| Elevation of weather observation facility | 2537 |
| Distance of event from weather observation facility (units?) | 5 |
| Time Zone of the weather observation | MDT |
| 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) | 27 |
| Dew Point at event time (in degress fahrenheit) | 7 |
| Wind Direction (degrees magnetic) | 340 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 5 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 30.02 |
| 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) | 28488 |
| NTSB Notification Source | FAA Operations Center |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Jul 13 2011 11:29AM |
| User who most recently changed record | andj |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N621AL |
| NTSB Number | WPR10LA407 |
| Missing Aircraft Indicator | -- |
| 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 | Clark |
| Aircraft Model | RV-6A |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 24062 |
| Certified Max Gross Weight | 1650 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | Yes |
| Flight Crew Seats | 1 |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 2 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Conditional |
| Date of Last Inspection | Aug 11 2010 12:00AM |
| Airframe hours since last inspection | 0 |
| Airframe Hours | 0 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | Unknown |
| Aircraft Owner Name | Alan R Clark |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | Nampa |
| Aircraft Owner State | ID |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 83686 |
| Operator is an individual? | No |
| Operator Name | Alan R Clark |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | Nampa |
| Operator State | ID |
| Operator Country | USA |
| Operator Zip code | 83686 |
| Operator Code | -- |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | No |
| 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 | Yes |
| Departure Airport Code | S67 |
| Departure City | Nampa |
| Departure State | ID |
| Departure Country | USA |
| Departure Time | 1150 |
| Departure Time Zone | MDT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | S67 |
| Destination City | Nampa |
| Destination State | ID |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | May 19 2011 8:32PM |
| User who most recently changed record | stam |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | 11 |
| Runway Length | 5000 |
| Runway Width | 75 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |