Lockheed A-12 "Oxcart" . Lockheed A-12 "Oxcart" high speed high altitude reconnaissance aircraft and ground support ladder. Model features opening cockpit, detailed Q-bay with camera rig, fully functional landing gear, opening inflight refueling recepticle, and positionable flight control surfaces including flaps, ailerons, and ruddervators. .
Closeup of the model with the boarding ladder in place. The A-12 did not have an integrated boarding ladder or foothold system, so pilots were reliant on ground crew support to board or deplane from the aircraft. This was multiplied from the need for the pilot to wear a full spacesuit (same as later used for the Space Shuttle) while in the aircraft due to the extreme temperatures inside and high altitude conditions it operated in. Temperatures were so great that pilots could cook their tube food by holding it against the canopy glass in flight to heat it, and that after landing ground crews were instructed to wait 30 minutes before attempting to touch the aircraft to allow adequate time for cooling.
The Lockheed A-12 was a black project developed at the behest of the CIA for a replacement reconnaissance aircraft for the Lockheed U-2, itself having recently proven to be too vulnerable to the new generation of Soviet anti aircraft missiles. The aircraft represented a quantum leap in aeronautical design and engineering, necessitating the development of many new materials and manufacturing techniques still in use today. Kelly Johnson, the head designer for Lockheed and father of their "Skunk Works" special projects division, was quoted as saying "I believe I can truly say that everything on the aircraft, from rivets and fluids, up through materials and power plants had to be invented from scratch". The A-12 would only serve a few years with the CIA before being retired in favor of the more capable 2 seat SR-71 operated by the US Air Force.
Closeup of the A-12 cockpit and Q-bay. Unlike the successor SR-71, the A-12 was a single seat aircraft. The area behind the cockpit was known as the Q-bay, a pressurizable hold containing the reconnaissance equipment. In this case, it holds the typical stabilized gimbal pod with fore and aft facing cameras.
The corrugated appearance on the wing surfaces were necessary to counter the effects of extreme heat on the aircraft's skin during flight. A flat panel would expand due to aerodynamic heating. The corrugation allows the skin to stretch without putting undue stresses on the aircraft skin or structure. The A-12 and SR-71 both were known to excessively leak fuel when on the ground due to this phenomena, as the aircraft was only truly "sealed" at altitude and speed with the aircraft at it's hottest and the skin expanded. Due to this, the aircraft would take off with a minimal fuel load and rendezvous with a tanker aircraft immediately, then climb to altitude and accelerate.
Lower right view of the model with the landing gear retracted. The nose gear retracts forwards with clamshell doors that close over top of the main strut and a rear door that closes forward over the retraction strut. The main gear retract inwards with dual door over each, one over the strut closing inwards and another mounted on the centerline that closes outwards. Just ahead of the nose gear is the window for the cameras.
Top view of the model. Unlike the all-black (actually indigo) paint applied to the SR-71s, most A-12s spent their operational lifetime in natural metal finishes with black paint applied only to those areas reaching the highest temperatures during flight.
Rear right view showing the movable flight control surfaces. The inner controls are large flaps, while the outer controls are combined aileron/elevators. The ruddervators are canted 15 degrees inward and also serve a dual function of combined rudder and elevator.
Business end of the J-58 engine. Two of these massive engines could push the A-12 over three times the speed of sound. At speed they functioned more like ramjets than turbojets, with the aircraft being pulled thru the air more than the engines providing thrust. The aircraft was found to use less fuel the faster it flew, and later NASA tests with the SR-71 would find that over 50% of the aircraft's drag was generated as a result of the high bypass nature of the engines nacelle design. To date it remains the fastest air breathing aircraft ever developed (the heavier SR-71 was slightly slower due to the added weight of the second cockpit).
Data from A-12 Utility Flight Manual
Length: 101.6 ft (30.97 m)
Wingspan: 55.62 ft (16.95 m)
Height: 18.45 ft (5.62 m)
Wing area: 1,795 ft² (170 m²)
Empty weight: 54,600 lb (24,800 kg)
Loaded weight: 124,600 lb (56,500 kg)
Powerplant: 2 × Pratt & Whitney J58-1 afterburning turbojets, 32,500 lbf (144 kN) each
Payload: 2,500 lb (1,100 kg) of reconnaissance sensors
Maximum speed: Mach 3.35 (2,210 mph, 3,560 km/h) at 75,000 ft (23,000 m)
Range: 2,200 nm (2,500 mi, 4,000 km)
Service ceiling: 95,000 ft (29,000 m)
Rate of climb: 11,800 ft/min (60 m/s)
Wing loading: 65 lb/ft² (320 kg/m²)