Northrop Flying Wing N-9M Down 22/04/2019
 

That's very sad, I was able to have a really good look at this airplane late in it's restoration while I visited Chino in 1994. We of course keep a thought for the pilot, though many people put their heart into the restoration.

It tried a barrel roll at low altitude right before the crash according to the NTSB prelim report.

https://app.ntsb.gov/pdfgenerator/Re...relim&IType=FA

Witness descriptions of the final moments of flight indicate a loss of control due to some sort of failure, not an intentional aerobatic manuever IMO.

Yaw Control Factors
 

A friend of mine is familiar with the background on this aircraft and who knew the pilot has suggested that the yaw stability of the aircraft was not wonderful and speculated that an event like loss of an engine or other yaw inducing event could potentially cause a loss of control.
This aircraft incorporated pioneering design features and there may have been handling characteristics that would not have been acceptable in a regular production aircraft.

A comment from the preliminary NTSB report seems to suggest that the pilot was preparing to bail out: " several witnesses reported that after the maneuver, the airplane "wobbled [from] side to side" before the airplane's canopy separated."