Malfunctioning Navigation System Caused Global Hawk to Break Up Mid-Flight

The USAF RQ-AB Global Hawk that was destroyed in last year's incident was totally destroyed at a loss of $79 million. Air Force photo by A1C Tristan D. Viglianco.

An Air Force RQ-4B Global Hawk broke up mid-air because its navigation systems malfunctioned, causing it to enter unusual altitudes and airspeeds beyond its limitations and eventually crash near Lone Pine, Calif., in June 2017, the Air Force announced Wednesday.

The RQ-4B, from the 9th Reconnaissance Wing at Beale AFB, Calif., was flying from Edwards AFB, Calif., to Beale and was operated by a contractor aircrew from Northrop Grumman, according to an Accident Investigation Board report released Wednesday.

Shortly after takeoff, the remotely piloted aircraft navigated to planned waypoints “uneventfully” until one of the aircraft’s navigators began to produce erroneous data. The Global Hawk did not detect the erroneous data, which prompted it to roll until it was almost inverted. The aircraft then dove, causing excessive airspeed, and eventually broke up during flight, eventually crashing in a rugged, unpopulated area that included part of the Inyo National Forest near Mount Whitney, according to the report.

The AIB report stated that a preliminary environmental analysis indicated no significant impact to nature, and the Air Force is still working with the US Forest Service to clean up part of the wreckage.

The RQ-4 was completely destroyed at a loss of $79 million.