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ASN Wikibase Occurrence # 196253
Last updated: 5 June 2021
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Time:13:45 LT
Type:Silhouette image of generic Q4 model; specific model in this crash may look slightly different
Northrop Grumman RQ-4B Global Hawk
Owner/operator:9th RWg USAF (9th RWg United States Air Force)
Registration: 07-2029
Fatalities:Fatalities: 0 / Occupants: 0
Other fatalities:0
Aircraft damage: Written off (damaged beyond repair)
Location:near Lone Pine, in the eastern Sierra Nevada mountain range -   United States of America
Phase: En route
Departure airport:Edwards Air Force Base, CA
Destination airport:Beale Air Force Base, CA
Investigating agency: USAF AIB
The RQ-4B, from the 9th Reconnaissance Wing at Beale AFB, California, was conducting a ferry flight from Edwards AFB, California, to Beale AFB at the time of incident. An aircrew of contractors from the Northrop Grumman Corporation was operating the aircraft at the time of the mishap.
This aircraft has four navigators and operates with two “on” and two “off” while in a normal configuration.
The AIB president found the cause of the mishap was one of the two in-use navigation systems on the remotely piloted aircraft produced erroneous navigational data and the other navigators did not detect the erroneous data.
Shortly after takeoff, two of the navigators were disabled in accordance with standard procedure. The aircraft climbed and flew to planned waypoints uneventfully until one of the enabled navigators began producing erroneous navigational data. The aircraft failed to detect the erroneous data, causing the aircraft to roll into a nearly inverted position and enter a dive that resulted in excessive airspeed. The aircraft subsequently exceeded its structural limitations and was unable to recover. The aircraft broke up during flight and crashed in an unpopulated and rugged area between Lone Pine and Mount Whitney, California.
The aircraft left a debris field from Lone Pine until its point of impact at Mount Whitney. The debris field included portions of the Inyo National Forest. Preliminary environmental analysis indicates no significant impact to the forest or wildlife. Portions of the wreckage have been recovered and the Air Force is working with the U.S. Forest Service for the remainder of the wreckage cleanup.


Accident investigation:
Investigating agency: USAF AIB
Status: Investigation completed
Download report: Final report


Revision history:

22-Jun-2017 06:28 Iceman 29 Added
22-Jun-2017 21:33 Iceman 29 Updated [Source, Embed code]
16-May-2018 15:14 harro Updated [Aircraft type, Source, Narrative]
16-Oct-2018 18:34 harro Updated [Registration, Departure airport, Destination airport, Source, Narrative, Accident report, ]
08-Feb-2020 18:47 Iwosh Updated [Operator, Operator]
09-Feb-2020 21:06 Iwosh Updated [Operator, Operator]

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