From Kirtland Field, Manhattan Project scientists were flown back and forth to Wendover Army Air Base for testing in a disguised "Green Hornet" aircraft. Members of the USAAF made similar trips from Wendover through Albuquerque to Los Alamos. A special Manhattan Engineer District, Military Police unit was located at Kirtland Field to guard facilities used to load Los Alamos–assembled ordnance and test shapes on Silverplate aircraft. The loading pit constructed at Kirtland Field, although primitive and manually operated, operated until December 1945, when a hydraulic lift was installed.