Forner USAF 56-3899 To Flight Systems as N404FS in 1979. Returned to the USAF as 56-3899 in 1990 and stored at Davis Monthan AFB with park code FE630. Transferred to the US Army with park code VA002 then to Tracor Flight Systems at Mojave in 1992. Used for an Army contract. Preserved at the Glenn Martin Aviation Museum at Glenn Martiin Airport, Baltimore, MD from 1995.