The U.S. National Transportation Safety Board (NTSB) report into the crash of Boeing's Passenger Air Vehicle prototype on June 2, 2019, highlighted an apparent design or system weakness in the aircraft. According to detailed analysis of aircraft data, excessive levels of vibration caused the aircraft to enter "ground mode," which resulted in the motors being shut down incorrectly. This caused the aircraft to fall quickly to the ground, causing significant damage.
Boeing's Aurora subsidiary has not publicly responded to the NTSB findings. However, in mid-November it indicated that it intends to resume test flights in early 2020.
The aircraft was being operated remotely by a test pilot on the ground. After flight engineers became aware of abnormal motor speeds, the pilot initiated an autoland procedure and the unintended motor shutdown occurred soon after this command.
The NTSB report findings will likely have prompted the Aurora engineering team to consider what additional system redundancy may have to be built into the aircraft to prevent a repeat of this or similar errors. It begs questions about the ability of the remote pilot to override an incorrect system command.