ASN Wikibase Occurrence # 123046
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information.
If you feel this information is incomplete or incorrect, you can
submit corrected information.
Date: | Saturday 11 June 2011 |
Time: | 16:01 |
Type: | Bellanca 17-31ATC Super Viking 300A |
Owner/operator: | Private |
Registration: | N79BF |
MSN: | 78-31152 |
Total airframe hrs: | 2977 hours |
Engine model: | Lycoming IO-540 |
Fatalities: | Fatalities: 3 / Occupants: 3 |
Aircraft damage: | Substantial |
Category: | Accident |
Location: | 13 miles East of Ukiah, Oregon -
United States of America
|
Phase: | En route |
Nature: | Private |
Departure airport: | Dallesport, WA (DLS) |
Destination airport: | Casper, WY (CPR) |
Investigating agency: | NTSB |
Confidence Rating: | Accident investigation report completed and information captured |
Narrative:On the morning of the visual flight rules flight, the non-instrument-rated pilot obtained a verbal weather briefing and stated that he planned to depart early afternoon, with an expected flight duration of about 3 hours. The pilot was advised of the possibility of turbulence and clouds along his route, which was primarily over mountainous terrain, with cloud tops forecast to be 25,000 feet and above. There were no records of any subsequent telephonic or computer weather briefings, and the pilot did not file a flight plan.
Although the pilot did not communicate with air traffic control (ATC), ground-based ATC radar captured the majority of the flight. When the airplane was reported overdue by relatives of one of the passengers, the radar data were used to search for and locate the airplane, which had impacted terrain in a remote wilderness area about 110 miles from the departure airport. Evaluation of the radar data indicated that the total flight duration was about 1 hour and that the airplane was above 12,500 feet for about 28 minutes and above 14,000 feet for about 8 minutes. The last 2 minutes of radar data depicted a course reversal, followed by an erratic course and an irregular, rapid descent. Meteorological data indicated that broken or overcast cloud base altitudes ranged from about 7,000 to 10,000 feet, with tops near 28,000 feet and that icing conditions could be expected in the clouds above about 10,000 feet. Terrain elevations within 30 miles of the impact site ranged from about 4,000 to 7,000 feet.
Wreckage patterns and ground scars indicated a near-vertical impact trajectory. A supplemental oxygen tank was present in the wreckage, but the tank inspection expired 8 years before the accident, and no hoses or masks were present. Postaccident examination of the airplane and engine did not reveal any preimpact mechanical malfunctions or failures that would have precluded normal operation.
The radar ground track was consistent with the pilot trying to find a route clear of the clouds. The pilot's lack of an instrument rating, combined with the erratic ground track, rapid descent, and steep impact angle, indicated that the pilot lost control of the airplane after it entered clouds. Available evidence supported the likelihood of spatial disorientation, as well as the possibility of hypoxia.
Probable Cause: The non-instrument-rated pilot's decision to conduct a visual flight rules flight over mountainous terrain into a region covered by clouds, which likely resulted in spatial disorientation and subsequent loss of airplane control.
Accident investigation:
|
| |
Investigating agency: | NTSB |
Report number: | WPR11FA256 |
Status: | Investigation completed |
Duration: | 2 years 1 month |
Download report: | Final report |
|
Sources:
NTSB
Location
Revision history:
Date/time | Contributor | Updates |
13-Jun-2011 08:40 |
bizjets101 |
Added |
03-Dec-2017 16:02 |
ASN Update Bot |
Updated [Time, Other fatalities, Departure airport, Destination airport, Source, Damage, Narrative] |
The Aviation Safety Network is an exclusive service provided by:
CONNECT WITH US:
©2024 Flight Safety Foundation