 Around 1954 , NATC modified the sole surviving XAJ @-@ 1 to conduct inflight refueling tests using the probe and drogue configuration . The turbojet engine was removed and the fuel hose and its drogue extended out from the jet 's former exhaust opening . Aircraft in service retained the turbojet and had their bomb bay doors modified to accommodate the hose and drogue . They were refueling aircraft during late 1954 . 
