Based upon Gulfstream 550 N544GD, this unique conversion was first taken on charge by the USN's VX-30 "Bloodhounds" range and test unit based at NAS Pt Mugu, CA, in 2018. The NC-37's mission includes keeping missile ranges clear of hazards during tests, gathering telemetry data from launches and serving as a communications relay platform. It replaced one of the ageing NP-3D 'Billboard' range support aircraft but still awaits some further work as seen here at Tucson, where it is unfortunately not possible to photograph the aircraft sunny side other than by being airside.