Seattle-Tacoma International Airport experienced dramatic growth between 1950 and 1970 as a result of new aircraft technologies, the increasing popularity and affordability of air travel, and the Puget Sound region’s expanding economy and population. The advent of passenger jets in the late 1950s placed a strain on Sea-Tac’s runways and facilities and led to a continuing series of improvements in response to ever-faster and bigger aircraft.
The Port of Seattle agreed to develop Seattle-Tacoma International Airport in 1942 to help relieve pressure on existing airports, notably Seattle’s Boeing Field and Tacoma’s McChord Field, during World War II. The original runways were completed in 1944 and significant civilian operations began in 1946. The first permanent Administration Building and terminal opened in 1949 under the direction of Earl Bigler.
Northwest Airlines and United Air Lines were the first airlines to set up shop at the new airport, and Western Airlines, Alaska Airlines, and Pan American Airways operated frequent flights through Sea-Tac, although through 1949 most scheduled service remained based at Boeing Field. In 1950, Sea-Tac’s first full year of operation, more than half a million passengers -- 86 percent of all Seattle-area commercial air traffic -- and 6,234 tons of air freight passed through its gates.
This volume of traffic, and the introduction of faster and larger aircraft such as the four-engine DC-6, quickly strained the capacity of the main north-south runway. The strip was extended to 7,500 feet in 1950 and resurfaced two years later at a total cost of $900,000. Meanwhile, traffic soared with the arrival of Trans-Canada Airlines on August 1, 1951, followed by Alaska Airlines, when it won federal approval for scheduled operations later that same month.
Flying Tiger Line, many of whose pilots had “flown the hump” ferrying troops and war material over the Himalayas, began regular airfreight service to and from Sea-Tac in 1952. Pan Am and Western airlines permanently shifted over from Boeing Field the following year, followed by Pacific Northern Airlines. Sea-Tac was finally “taking off.”
Overtaken by Jets
In the early 1950s, Douglas Aircraft supplied the mainstays for these and most other U.S. airlines, including the durable DC-3, the four-engine DC-4, the newer DC-6 with a pressurized cabin, and later, the luxurious, high-speed DC-7. Lockheed’s Constellation and Boeing’s 377 Stratocruiser remained popular with passengers on long flights, but these planes were really updates of decade-old designs. The next leap forward in aircraft size and speed would require a new kind of power plant.
The first jet engines were developed in the 1930s, and German engineers developed advanced jet-aircraft designs during World War II. Much of this data became available to U.S. airplane makers after the war and aided Boeing engineers in creating jet bombers such as the B-47 and B-52. Meanwhile, across the Atlantic, Britain’s de Haviland company rolled out the world’s first passenger jetliner, the Comet, in 1949.
Although the Comet was plagued by accidents, it raised the ante in passenger aircraft design. As Boeing delivered the last of its propeller-driven Stratocruisers in 1950, it began exploring designs for a jet-powered aerial tanker (ultimately the KC-135) and recognized that the same principles could be applied to a passenger jetliner. Boeing invested $16 million of its own funds in the prototype Model 367-80, or “Dash-80,” which flew for the first time on July 15, 1954, from Boeing Field. From this design would follow Boeing’s popular 707 and 720 jetliners, but Sea-Tac’s runways were as yet too short to accommodate them.
In the year of the Dash-80’s first flight, the number of passengers annually using Sea-Tac nudged past the one million mark. Port planners knew that air travel was poised for explosive growth with the coming of jets. The 707 was soon joined by the DC-8 and the Convair 880, and these new planes were not only faster than their piston antecedents, they were much larger. This meant longer landing and takeoff rolls, more frequent flights on major routes, and more passengers and luggage to handle per departure and arrival. Sea-Tac would have to scramble to be ready for the revolution launched in its backyard.
The Port bought an additional 80 acres north of the airport so that the main runway could be extended by 1,000 feet to handle jets. A parking lot was added for 500 more cars and a new Air Cargo Terminal was built. The longer strip permitted the Dash-80 to pay its first call at Sea-Tac on September 27, 1956, but planners decided that further expansion was needed. Another 170 acres were acquired on the north and the Post Office built a new airmail center in 1957. A new northern wing was added to the terminal and parking was expanded for another 500 cars.
The main runway was extended and state-of-the-art “strobeacon” lights and ground-control radar were installed to improve safety. The Port also established the airport’s first professional fire department, taking over responsibility from airlines and local volunteers. Construction was done in time for the airport’s first regular jet service, inaugurated on October 3, 1959, when a Pan Am 707 took off for Honolulu. That same year, Japan Airlines became the first Asian-flag airline to operate at Sea-Tac when its DC-7 Supercourier arrived from Tokyo on June 28.
Sea-Tac still wasn’t big enough in 1960 as Donald Shay succeeded his boss, Earl Bigler, as the Port’s director of aviation. On March 30, 1960, the Port Commission authorized funds to lengthen the main runway southward by yet another 1,700 feet, which required the grading of two million cubic yards of earth and a bridge over S 188th Street, the airport’s original boundary. The terminal also grew. With a new Concourse D and an expanded Concourse A, parking doubled to accommodate more than 2,000 cars, and the air cargo center was enlarged.
Workers rushed to finish these improvements by late 1961 so that the airport would be ready for visitors to Seattle’s “Century 21” world’s fair the following year. The fair’s lure helped to boost Sea-Tac’s total passenger traffic to two million in 1962 -- a jump of nearly 400,000 over the previous year.
By the time the world’s fair ended, the Port, its airline tenants, and the federal government had invested a total of $28 million in Sea-Tac’s development and operation to date. In 1962, the first analysis of Sea-Tac’s economic benefits revealed that the airport and its tenants generated an annual payroll of $40 million for 6,000 workers. In all, airport-related activities supported $133 million in regional business and 30,000 local residents.
The Next Wave
The popularity of the 707 and its imitators launched a dramatic expansion in air travel, but these four-engine jets were limited to large metropolitan airports. Despite the success of smaller four-engine jets, notably the Boeing 720, propellers still ruled the shorter routes. This began to change in the mid-1960s with the introduction of smaller “regional” jetliners such as the triple-engine Boeing 727.
Thanks in large part to the 727, passenger traffic through Sea-Tac more than doubled during the 1960s. The number of airliner “operations” (landings and takeoffs) also rebounded, having dropped to fewer than 50,000 in 1961 as jets replaced smaller prop liners on major routes. Jet service took another giant leap on September 1, 1966, when Scandinavian Airways System started flying DC-8s non-stop “over the pole” between Sea-Tac to Copenhagen. This pioneering route helped to dramatize Sea-Tac’s unique position as the only major U.S. airport located midway between Europe and Asia, being almost precisely the same distance by air from London as it is from Tokyo.
This position made Sea-Tac a natural base for the next generation of jets already on the drawing boards: supersonic transports. Speed and capacity were still the driving forces behind aircraft design (fuel efficiency and other operational economies would come later), so the idea of a large supersonic transport (SST) seemed the logical next step beyond the 707 and its cousins. Construction of such a plane became a matter of national pride. France and Great Britain joined forces to design the Concorde while the Soviet Union rushed development of its Tu-144. In the U.S., government and airline planners forecast that a fleet of 300 SSTs would be needed in the 1970s. Because of the scale and cost of the project, the federal government pledged to subsidize development of the two prototypes.
Boeing won the nod to design America’s supersonic jetliner in 1966. As its designers toiled in Seattle, the national SST project drew increasing scrutiny from congressional critics of federal “boondoggles” and from leaders of the new environmental movement, who worried that dozens of daily supersonic flights might damage the ozone layer and pollute the stratosphere. Closer to earth, residents of metropolitan areas fretted about the impact of dozens of daily “sonic booms” as SSTs roared overhead. The noise of conventional jets was already becoming an issue, especially for neighbors of airports such as Sea-Tac, whose own success had seeded nearby development.
Boeing’s other big project -- emphasis on “big” -- in the mid-1960s was the 747. Its development was closely related to the SST in that some airline executives, notably at Pan Am, calculated that long-haul passengers would opt for supersonics, and that intercontinental subsonic planes would be needed chiefly for cargo. This was something of an irony, since Boeing had lost the contract to build the Air Force’s huge C-5A transport, and it had always seen the 747 as a passenger jet. Pan Am and Boeing compromised on a giant convertible passenger-cargo design that the press immediately dubbed the “jumbo jet.” Its development and production required a corresponding “jumbo plant” at Everett’s Paine Field, north of Seattle, a structure that to this day reigns as the world’s largest building by volume.
At the other end of the aircraft scale, Douglas launched development of its small DC-9 jet, powered by two engines mounted on the tail. Boeing responded with the 737, which carried its two engines tucked under the wings. After a slow start, beginning with its maiden flight on April 9, 1967, the 737 went on to become the best-selling jet transport in history.
New generations of jets were now poised to take over most of the work of air travel, rendering Sea-Tac’s improvements for 707-class aircraft outdated after fewer than 10 years of service. Port planners recognized that it was time to catch up again, and fast.