The airport was constructed by the Port of Seattle in 1944 to serve civilians of the region, after the U.S. military took control of Boeing Field for use in World War II. The Port received $1 million from the Civil Aeronautics Administration to build the airport, and $100,000 from the City of Tacoma. The first scheduled airline flights were Northwest and Trans-Canada in 1947; Western and United moved from Boeing Field in the next couple of years, and Pan Am in 1952–53, but West Coast stayed at Boeing Field until after the Hughes merger. Two years later, the word “international” was added to the airport’s name as Northwest Airlines began direct service to Tokyo, Japan. In 1951, there were four runways at 45-degree angles, from 5,000 to 6,100 ft long; the NE-SW and NW-SE runways intersected just west of the N-S runway that eventually became today’s runway 34R. The runway was lengthened twice, first in 1959 to allow use by jets, and again in 1961 to handle increased traffic for the upcoming Century 21 World’s Fair.
The April 1957 OAG shows 216 departures a week on United, 80 Northwest, 35 Western, 21 Trans-Canada, 20 Pan Am, 20 Pacific Northern, and 10 Alaska. In 1966 Scandinavian Airlines inaugurated the airport’s first non-stop route to mainland Europe. The first concourse opened in July 1959. The two-story North Concourse (later dubbed Concourse D) added four new gate positions and a new wing 600-feet long and 30-feet wide. The one-story South Concourse (aka Concourse A) opened in 1961 adding another 688 feet to the length of the airport. The 800-foot-long Concourse B opened in December 1964. It added eight gate positions, bringing the total to 19, a 12,000 square-foot area housed international arrivals, and the offices of U.S. Customs, Immigration, Public Health and the Department of Agriculture. Concourse C opened in July 1966. Just four years later, it was extended to include another 10 gates, bringing Sea-Tac’s total to 35. The Port embarked on a major expansion plan, designed by The Richardson Associates and lasting from 1967 to 1973, adding a second runway, a parking garage, two satellite terminals, and other improvements. A $28-million new terminal literally swallowed up the old 1949 structure; it was built over and around it. Opened in the 1973, the new terminal quadrupled the area for public use. On July 1, 1973, the Airport dedicated two new satellite terminals along with an underground train system to connect them to the Main Terminal. In the mid-1980s, the Main Terminal was renovated and another 150 feet was added to the north end. Concourse D was expanded in 1987 with a rotunda that added four new gates. In 1993, Concourses B. C, and D were renovated. The project, designed by NBBJ, included the addition of 150,000 square feet and the renovation of 170,000 square feet of space in Concourses B. C, and D. On June 15, 2004, the 2,102-foot renovated Concourse A was unveiled with 14 new airline gates, a dozen new restaurants, new artwork and the airport’s first moving sidewalk.
Residents of the surrounding area filed lawsuits against the Port in the early 1970s, complaining of noise, vibration, smoke, and other problems. The Port and the government of King County adopted the Sea-Tac Communities Plan in 1976 to address problems and guide future development. The Port spent more than $100 million over the next decade to buy homes and school buildings in the vicinity, and soundproof others nearby. In the mid 1980s the airport participated in the airport noise-compatibility program initiated by Congress in 1979. Airport-noise contours were developed, real estate was purchased and some homes were retrofitted to achieve noise mitigation.
In 1978 the U.S. ended airline regulation. Subsequently, U.S. airlines were allowed to determine routes and fares without government approval. Deregulation resulted in new service to Seattle, including TWA, which was the fourth-largest U.S. airline.
After the death of U.S. Senator Henry Martin “Scoop” Jackson in 1983, the Seattle Port Commission voted to change the name of the airport to Henry M. Jackson International Airport. Denizens of Tacoma interpreted the change as an insult to their community —the second time in the airport’s history that the port authorities had attempted to remove “Tacoma” from the official name. But the $100,000 that Tacoma had provided for the airport’s construction during World War II had come with an explicit promise that the city would be included in the airport’s name. The controversy regarding the name change was resolved after several polls of both Seattle and Tacoma area residents indicated their preference for the original name by margins as much as 5:1. Helen Jackson – the widow of the late Senator Henry M. Jackson expressed her desire that their family remain neutral in the debate. With a 3–2 vote of the Port of Seattle Commission the long-standing moniker, and the name reverted to Sea-Tac early in 1984.
Starting in the late 1980s, the Port of Seattle and a council representing local county governments considered the future of air traffic in the region and predicted that airport could reach capacity by 2000. The planning committee concluded in 1992 that the best solution was to add a third runway to the airport and construct a supplemental two-runway airport in one of the neighboring counties. Members of the community strongly opposed a third runway, as did the Highline School District and the cities of Des Moines, Burien, Federal Way, Tukwila, and Normandy Park, but a 1994 study concluded there were no feasible sites for an additional airport. The Port of Seattle approved a plan for the new runway in 1996, prompting a lawsuit from opponents. The Port secured the necessary permits by agreeing to noise reduction programs and environmental protections. Runway opponents appealed these permits, but dropped their challenges in 2004. The runway opened on November 20, 2008, with a total construction cost of $1.1 billion.
The three parallel runways run nearly north-south, west of the passenger terminal, and are 8,500 ft (2,600 m) to 11,900 ft (3,600 m) long. During 2008 the airport averaged 946 aircraft operations per day, 89% being commercial flights, 10% air taxi operations, and 1% transient general aviation.
The interior of Sea-Tac’s control tower, commissioned in 2004, is 850ft2 (79m2). Visible at center is a radar display; at top right is the tower’s light gun.
A new control tower was constructed for the airport beginning in 2001, and brought into service November 2004, at a cost of $26 million. The floor of the new tower’s control cab is 233 ft (71 m) above ground level; the tower’s overall height including antennas is 269 ft (82 m). The cab has 850 sq ft (79 m2) of space and was originally designed to support operation by ten controllers, with possible future expansion up to 15. The site and construction method of the tower were designed to maximize visibility and efficacy of radar systems. The airport’s original control tower, built in the 1950s, is now located in the airport’s passenger terminal and used as a ground control tower, after being repaired from damages caused by the Nisqually Earthquake in 2001.
A recurring operational problem at the airport is misidentification of the westernmost taxiway, Taxiway Tango, as a landing surface. A large “X” has been placed at the north end of the taxiway to prevent confusion, but a number of incidents of aircraft landing on the taxiway have still occurred. The FAA issued an alert notice dated from August 27, 2009, to September 24, 2009, urging airplanes about taking precautions such as REILs and other visual cues while landing from the north.
In 2007, the airport, together with the University of Illinois Center of Excellence for Airport Technology (CEAT), became the first airport to implement an avian radar system providing 24-hour monitoring of wildlife activity across the airfield. This pilot program was designed to decrease potentially fatal incidents involving avian collisions and provide a test bed for widespread implementation of the technology in the US which was expected to begin in 2009. The technology is part of a multi-pronged strategy to reduce the dangerous presence of wildlife on the airfield.