Defensive armament consisted of a single 20 mm (0.79 in) T-171E-3 rotary cannon with 1,200 rounds of ammunition in a radar-aimed tail barbette. It was remotely controlled through the Emerson MD-7 automated radar fire-control system only requiring the DSO to lock-on a selected target blip on his scope and then fire the gun. The system computed aiming, velocity or heading differential, and range compensation. Offensive armament typically consisted of a single nuclear weapon, along with fuel tanks, in a streamlined MB-1C pod under the fuselage. Incurable difficulties with fuel leakage resulted in the replacement of the MB-1C with the TCP (Two Component Pod), which placed the nuclear weapon in an upper section while the lower fuel component could be independently jettisoned. This had the added benefit of allowing the pilot to "clean up" the aircraft for fuel efficiency or in case of emergency, while still retaining the (somewhat) slimmer weapon.