In today's world, the US Navy's fleet of aircraft carriers relies on nuclear propulsion to allow those ships to traverse and stay afloat on the high seas without fear of running out of fuel, as does the French aircraft carrier Charles de Gaulle (all other carriers in service around the world are conventionally powered). The first American nuclear-powered surface vessels, the aircraft carrier USS Enterprise and guided missile cruiser USS Long Beach, were commissioned in 1961, giving the US Navy's surface ships the ability to stay afloat on the high seas indefinitely. However, almost lost in talk about military nuclear-powered vehicles is the fact that even as the US Navy gradually commissioned more nuclear-powered surface vessels, Lockheed in the 1960s came out with an rather unorthodox proposal for a giant flying aircraft carrier running on nuclear power! This may sound surprising to most aviation historians and gurus, but even though the US Air Force gave up on nuclear-powered combat aircraft development in 1961, there was still a sliver of interest in giant nuclear-powered aircraft from the aerospace industry in southern California.
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| Artist's conception of the CL-1201-1-1 flying aircraft carrier, late 1960s |
In 1969, the California division of Lockheed began studies to determine the uses and capabilities of the largest aircraft feasible with existing technology. Using the earlier CL-1170-6-2 long-range maritime reconnaissance aircraft project as a baseline, Lockheed envisaged a clean-sheet design for a colossal nuclear-powered aircraft, designated CL-1201 by the company. The CL-1201 design had a wingspan of 1,120 feet (341 meters), a length of 560 feet (170 meters), a height of 153 feet (46 meters), a wing area of 125,000 square feet (11,612 square meters), a gross weight of 5,265 tons (5,350 metric tons) and a cruise speed of Mach 0.8 at an altitude of 30,000 feet (9,144 meters). Four gigantic turbofans were mounted atop the rear center section of the CL-1201, providing a total cruise thrust of 500,000 lb (2,224 kN), and these were fueled by a 30 foot (9.1 meter) wide nuclear reactor onboard the aircraft generating 1,830 megawatts. At altitudes up to 16,000 feet (4,876 meters), the turbofans would run on normal JP-5 fuel, but while operating at higher altitudes, they would powered by nuclear energy from the reactor. Substantial shielding would be needed to protect the crew and the reactor would be designed to have failsafe crash performance even in a high-speed head-on impact. The CL-1201 would have provisions for facilities to accommodate a maximum of 845 crewmembers, and the undercarriage comprised four separate landing gear struts, each with six wheels positioned towards the rear of the fuselage, as well as two further six-wheel units outboard of the wing roots, four-wheel stabilizing gear positioned about half way along each wing, and a substantial four-wheel nose gear unit.
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| Top: Lockheed CL-1201-1-1 three-view (from Lockheed project documents) Bottom: Schematic view of the Lockheed CL-1201-1-3 |
Two versions of the CL-1201 were proposed. The CL-1201-1-1 Attack Aircraft Carrier (AAC) was a flying aircraft carrier intended to carry a total of 24 tactical aircraft, 22 below the wings on pylons (these would be recovered in-flight after completing a mission), and two more in the fuselage hangar. There would be direct access to the aircraft via pylons for flight crews and maintenance staff with the aircraft being rearmed and refueled while attached. The notion of a flying aircraft carrier was not new; in World War II Daimler-Benz investigated designs for giant flying aircraft carriers able to carry smaller combat aircraft, and in the late 1940s and early 1950s Douglas initiated design studies for versions of the 1211 and 1240 bomber projects able to carry an array of small combat jets. None of these schemes reached the hardware phase, but the CL-1201-1-1 was destined to be the largest flying aircraft carrier design of all time, bearing uncanny resemblance to similar machines usually seen in science fiction movies like the Star Wars series, Sky Captain and the World of Tomorrow, and The Avengers series. The AAC was also considered for use as an airborne command and control center. (A CL-1201-1-2 variant may also have been considered, but no details are available.) The CL-1201-1-3 Logistics Support Aircraft (LSA) was intended to carry 400 combat troops and 1,150 tons of military equipment, and it could also dock five Boeing 707-sized transport aircraft (each with a capacity for 150 troops or 32 tons of military equipment) using nose receptors positioned at the CL-1201-1-3's trailing edge and tail. For vertical takeoff, the AAC would have featured 182 turbofan lift engines delivering 15 million pounds (66,723kN) of thrust, located along each wing behind the rear spar and in extendable units at the front of the fuselage, each containing 24 units. The LSA would have utilized 54 turbofan lift engines with a total yield of 82,500 lb (367 kN) thrust for VTOL, and accommodations for 462 crewmembers. In a serious combat situation, a single AAC would be dispatched and escorted by seven LSAs in order to deliver and keep supplied a US Army brigade comprising 3,896 troops and 6,207 tons (5,630 metric tons) of military equipment (e.g. artillery, mortars, light aircraft, and attack aircraft) for 30 days.
Despite being impressive on paper, the CL-1201 concept was all for naught. Due to the sheer size of the CL-1201, operational problems with this design would have been evident, and thus CL-1201 never proceeded beyond the drawing board. No large aircraft project was to approach the 1,120 foot span of this behemoth, namely the Bel Geddes No.4 flying ocean liner, Conroy Virtus space shuttle carrier aircraft, Boeing RC-1, Junkers J1000 flying wing airliner, Adlershof Riesenflugzeugen bomber projects, Rumpler twin-hull flying boat, and the Boeing, Lockheed, and McDonnell Douglas proposals for flying wing cargo aircraft. The Scaled Composites Model 351 Stratolaunch (which first flew in April 2019) has displaced the Hughes H-4 Hercules in terms of being the largest aircraft by wingspan (385 feet), but its span is nowhere near the monstrous wingspan of the CL-1201.
References:
Lowther, S., 2007. "Blended Wing Bodies". Aerospace Projects Review 1(3): 30-64. Link available at
http://www.aerospaceprojectsreview.com/ev1n3.htm.Rose, B., 2010.
Secret Projects: Flying Wings & Tailless Aircraft. Hinckley, UK: Midland Publishing.
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