The other (Aero)space Race
On June 5th, 1963, President Kennedy gave a speech challenging the US aerospace industry, nearly 9 months after challenging the same industry to get set foot on the moon before the end of the decade, to create a commercially viable supersonic airliner. The United States was racing the Soviet Union to the moon, and racing the French and the British to who could dominate the future of aviation. At the time the US was on the losing side of both races; the USSR had fielded the first man-made object, the first man and woman in space. In the atmosphere, the Franco-British Concorde project was just two years away from starting construction on the European supersonic jet. While the US through its aerospace companies and NASA had done a lot of research, they were no closer to a preferred design of a supersonic transport. What JFK promised was government backing of 75% development costs for the finalist company able to present the best proposal. The proposal did not just have to meet the French and the British specifications, it had to obliterate them, a plane 1.5 times faster, more than double the passengers, all while flying further.
Three companies presented initial proposals to the government: North American Aviation, Boeing and Lockheed. Boeing and Lockheed were selected initially to move to the second phase. On December 31st, 1965, the Boeing design was chosen as the official American SST, besting the Lockheed L-2000. This is the story of the Lockheed L-2000, the other American Supersonic contender.
Boeing 733
North American NAC-60
Lockheed L-2000
Although JFK’s speech in Colorado Springs sounds like the beginning of the US’ foray into supersonic airliner development, is was more of a halftime push. Aerospace manufacturers and NASA had been investing heavily in research and development for years and the government challenge was an attempt to turbocharge the efforts to get it past the finish line. The research and development process was iterative, testing different concepts and without access to computerized simulation tools used today in aircraft design, physical models had to be built and tested in wind tunnels, each tweak requiring hours or days of modification and testing.
With the three aircraft manufacturer’s proposals in hand, the FAA and ruled out the North American proposal based off of the XB-70 supersonic bomber. Boeing and Lockheed would be awarded a contract for further study on January 1, 1965 along side Pratt & Whitney and General Electric working on propulsion.
Original Lockheed plans included using Pratt & Whitney J58 turbojets, engines Lockheed had experience using on the world’s fastest air-breathing aircraft, the legendary SR-71 Blackbird. Later different engines were being studied in design.
Heated Rivalry
With North American out of the race, the race was on between Lockheed and Boeing to form the riposte to the European Concorde and the Soviet TU-144. Both programs adopted similar fuselage profiles, coming to similar conclusions about the shape of the fuselage. Where the programs largely diverged was on the wing design. A wing optimized for supersonic flight, with a large sweep would allow Lockheed favored a delta wing, which evolved into a double-delta wing design. Boeing preferred a more complex setup, favoring a variable geometry wing, where the wing extends wide when a subsonic, take-off and landing speeds, and sweeps back for supersonic flight. It was a design that was used on three US Military aircraft, all of which came out later (F-111 Aardvark, F-14 Tomcat and B-1B Lancer). Both designs would push supersonic flight past Mach 2 with the aim of cruise at Mach 3. At such speeds, friction would cause the fuselage to heat-up, requiring more exotic metals that would be more resistant to extreme temperatures than the Concorde had to face.
The difference in wing design was indicative of the overall design philosophies and how they diverged between Lockheed and Boeing. Lockheed, opting for a simpler wing, using aerodynamics to optimize the wing for subsonic and supersonic flight, while Boeing opted for a more complex design that increased weight and maintenance for the future aircraft. Lockheed’s design was simpler, almost a larger evolution of the Concorde design, reducing overall program risk. Boeing’s design seemed to push the barrier, almost to a point of unnecessary to make a statement that the Boeing SST is not a bigger Concorde, but that the Concorde would be irrelevant.
The Lockheed L-2000
Lockheed was arguably the world’s most knowledgeable supersonic aircraft manufacturer. Having developed the A-12 (predecessor to the SR-71 Blackbird) and the F-104 Starfighter, Lockheed had unique experience in delivering supersonic flight day after day. The design philosophy they chose was one based on their supersonic experience as well as risk reduction. Instead of a complex variable wing configuration, Lockheed chose a delta wing configuration. The design of the wing was constantly evolving through iterative research ultimately resulting in a double delta wing design, and became a major selling point for Lockheed.
Time Comparison between subsonic and supersonic flight on the L-2000 (hours)
| City A | City B | L-2000 | Subsonic | Difference | Mileage SM |
| New York | Miami | 1:18 | 2:24 | -1:06 | 1,092 |
| New York | Mexico City | 1:53 | 4:12 | -2:19 | 2,093 |
| New York | Paris | 2:45 | 6:54 | -4:09 | 3,625 |
| New York | Rome | 3:08 | 8:12 | -5:04 | 4,266 |
| New York | London | 2:40 | 6:33 | -3:53 | 3,452 |
| Paris | Rome | 1:02 | 1:42 | -0:40 | 691 |
| Rome | Karachi | 2:34 | 6:18 | -3:44 | 3,297 |
| Karachi | Bangkok | 1:59 | 4:32 | -2:33 | 2,301 |
| Bangkok | Hong Kong | 1:32 | 3:18 | -1:46 | 1,605 |
| Hong Kong | Tokyo | 1:40 | 3:39 | -1:59 | 1,789 |
| Tokyo | Honolulu | 2:54 | 7:18 | -4:24 | 3,856 |
| Honolulu | San Francisco | 2:01 | 4:42 | -2:41 | 2,400 |
| Sydney | Darwin | 1:48 | 3:54 | -2:06 | 1,960 |
| Sydney | Manila | 2:56 | 7:21 | -4:25 | 3,891 |
| San Francisco | New York | 2:10 | 5:00 | -2:50 | 2,580 |
| New York | Los Angeles | 2:09 | 4:51 | -2:42 | 2,468 |
| Chicago | Los Angeles | 1:40 | 3:33 | -1:53 | 1,751 |
| Los Angeles | Miami | 2:02 | 4:36 | -2:34 | 2,329 |
Mach 2.7, Zero Wind Day, 50 minute stop over time
L-2000 Econmics, breakeven at 30% load factor
One of the major selling points was the claim that the L-2000 would hit breakeven at 30% load factor.
Swissair was one of the airlines that Lockheed courted to sell the L-2000, below was in the prospectus sent to Swissair with a potential supersonic flight network.
Mockup
In June of 1966, both Boeing and Lockheed presented 1:1 scale mockups of their respective SST aircraft.
Will it fit?
As an airport planner, all these beautiful designs have little use if the airplanes can’t use the airport infrastructure.
Final Configuration
The order book of the the US SST vs the Concorde, in the end only Concorde was built and used by British Airways (BOAC) and Air France.
Post Scriptum
In December 1966 the US made its choice and chose the Boeing 2707 over the Lockheed-2000. It was considered more audacious from a technological perspective especially with the variable wing geometry. The irony is that the Boeing 2707 dropped the swing wing configuration and adopted the delta wing configuration adopted by Lockheed. By 1971 Congress cut funding to the SST program and the 2707 was no more. Lockheed would try to build one more commercial airliner, the L1011 before focusing exclusively on the military market.
The future?
Boom Supersonic is a company founded on the renewed promise of supersonic flight for the public. Stay tuned to see if they succeed.