A "Top Gun" Navy Aggressor Squadron A-4 'Skyhawk' on display at the ND Centennial Air Show. The A-4's fixed refueling probe on the starboard side of the aircraft nose. Notice the Soviet Red Star on the helmet in the cockpit. Saturday 8/19/1989, at the old Hector Airport terminal.
The A-4 pioneered the concept of "buddy" air-to-air refueling. This allows the aircraft to supply others of the same type. A designated supply A-4 would mount a center-mounted "buddy store", a large external fuel tank with a hose reel in the aft section and an extensible drogue refueling bucket. This aircraft was fueled up without armament and launched first. Once airborne, they would then proceed to top off their fuel tanks from the tanker using the A-4's fixed refueling probe on the starboard side of the aircraft nose. -wiki