After winning a competition for a government-funded contract to build an American supersonic airliner, Boeing began development at its facilities in Seattle, Washington.

Outside the field, the entire SST concept was the subject of considerable negative press, centered on the issue of sonic booms and effects on the ozone layer.

During development, the required weight and size of this mechanism continued to grow, forcing the team to switch to a conventional delta wing.

Only one month later the FAA's new director, Najeeb Halaby, produced the Commission on National Aviation Goals, better known as Project Horizon.

[4] The basic concept behind the SST was that its fast flight would allow them to fly more trips than a subsonic aircraft, leading to higher utilization.

[4] By mid-1962, it was becoming clear that tentative talks earlier that year between the British Aircraft Corporation and Sud Aviation (later Aérospatiale) on a merger of their SST projects were more serious than originally thought.

[5] In spite of marginal economics, nationalistic and political arguments had led to wide support for the project, especially from Charles de Gaulle.

[6] This set off something of a wave of panic in other countries, as it was widely believed that almost all future commercial aircraft would be supersonic,[7] and it looked like the Europeans would start off with a huge lead.

The baseline design in the report called for an aircraft with Mach 3 performance with 2,400 miles (3,900 km) range in order to serve the domestic market.

They felt that there was no way to build a transatlantic design with that performance in time to catch the Concorde's introduction, abandoning the trans-Atlantic market to the Europeans.

[6] In spite of vocal opponents, questions about the technical requirements, and extremely negative reports about its economic viability, the SST project gathered strong backing from industry and the FAA.

Juan Trippe leaked the information earlier that month, stating that the airline would not ignore the SST market, and would buy from Europe if need be.

[14] The blended wing root spanned almost all of cabin area, and this early version had a much more stubby look than the models that would ultimately evolve.

The wing featured extensive high-lift devices on both the leading and trailing edges, minimizing the thrust required, and thus noise created, during climb out.

The CL-823 lacked any form of high-lift devices on the wings, relying on engine power and long runways for liftoff, ensuring a huge noise footprint.

The use of high-lift devices on the leading edge of the wing lowered the landing angles to the point where the "drooping nose" was not required, and a more conventional rounded design was used.

The SST mock-up included both overhead storage for smaller items with restraining nets, as well as large drop-in bins between sections of the aircraft.

Environmentalists were the most influential group, voicing concerns about possible depletion of the ozone layer due to the high altitude flights, and about noise at airports, as well as from sonic booms.

[21] As the opposition widened, the claimed negative effects increased, including upsetting people who do delicate work (e.g., brain surgeons), and harming persons with nervous ailments.

Presidential Adviser Russell Train warned that a fleet of 500 SSTs flying at 65,000 ft (20,000 m) for a period of years could raise stratospheric water content by as much as 50% to 100%.

[24] During the 1970s the alleged potential for serious ozone damage and the sonic boom worries were picked up by the Sierra Club, the National Wildlife Federation and the Wilderness Society.

Labor unions also supported the SST project, worried that the winding down of both the Vietnam War and Apollo program would lead to mass unemployment in the aerospace sector.

Sidney Yates, leading the "no" camp, offered a then-uncommon motion to instruct conferees[27] and eventually won the vote against further funding, 215 to 204.

As a result of the mass layoffs and so many people moving away from the city in search of work, a billboard was erected near Seattle–Tacoma International Airport in 1971 that read, "Will the last person leaving Seattle – turn out the lights".

Through the second half of the 1970s, NASA provided funding for the Advanced Supersonic Transport (AST) project at several companies, including McDonnell Douglas, Boeing, and Lockheed.

[36] While the Soviet Tu-144 had a short service life,[37] Concorde was successful enough to fly as a small luxury fleet from 1976 until 2003, with British Airways lifetime costs of £1bn producing £1.75bn in revenues in the niche transatlantic market.

[citation needed] As the most advanced supersonic transports became some of the oldest airframes in the fleet, profits eventually fell, due to rising maintenance costs.

[39] In 1990, the mock-up was sold to aircraft restorer Charles Bell, who moved it, in pieces, to Merritt Island, in order to preserve it while it waited for a new home as the church now wanted the space for expansion.