The Port Authority of New York and New Jersey (PANYNJ), which operates JFK Airport, had once intended the original structure as an entrance to the replacement terminal.

That plan did not happen, and the TWA Hotel was instead constructed between 2015 and 2019; its development entailed renovating the disused head house and adding two adjacent buildings.

The head house of the TWA Flight Center, designed by Eero Saarinen and his associates, is a pioneering example of thin-shell construction, consisting of a reinforced concrete shell roof supported at the corners.

[10] The form of the TWA Flight Center's head house is designed to relate to its small wedge-shaped site, with walkways and gates placed at acute angles.

The terminal's entry hall is composed of two arms that wrap around the TWA Flight Center's head house in a crescent shape.

[30] The ticket counter and baggage claim areas were placed at ground level, on the other side of the curbside canopy, to maximize convenience for passengers.

[13] Original plans called for the passageways to be designed as bridges with glass ceilings; each passage would have two moving walkways, one in each direction, with a stationary hallway in between.

[52][53] TWA had begun flying internationally in 1946 from New York's LaGuardia Airport with flights to Paris, London, Rome, Athens, Cairo, Lisbon, and Madrid.

[60] Saarinen's firm started researching other airports to collect data, and they also visited Grand Central Terminal, the United States' busiest railroad station, to observe passenger circulation patterns.

[11] One of Saarinen's original designs was sketched on the back of a restaurant menu, when he and Aline were eating dinner with Time magazine's associate editor Cranston Jones.

[19] One early model for the terminal was based on Jørn Utzon's winning proposal for the Sydney Opera House's architectural design competition, for which Saarinen had been one of the judges.

[16][79] The passageways were to have a glazed roof and moving walkways in the original plan, but these features were absent in the final construction, and two "arms" flanking the head house had been removed.

[19] Grove Shepherd Wilson & Kruge constructed the shells to the specifications outlined in Saarinen's contour maps, which were precise to intervals of 1 foot (0.30 m).

[68][82] By April 1961, when only the concrete vaults had been completed, Saarinen remarked that "If anything happened and they had to stop work right now and just leave it in this state, I think it would make a beautiful ruin, like the Baths of Caracalla".

[96] By 1967, TWA announced that it would build Flight Wing 1 on the northwest to accommodate wide-body aircraft, hiring Roche-Dinkeloo to design the $20 million expansion.

[107] American Airlines ceased flight operations at the terminal in December 2001 and allowed its lease inherited from TWA to expire in January 2002.

[109][110] By August 2001, the PANYNJ presented its first proposal, which entailed converting the head house into a restaurant or conference center, while encircling the existing building with one or possibly two new terminals.

[32] The theme of the show featured work, lectures, and temporary installations drawing inspiration from the terminal's architecture; it was supposed to have run from October 1, 2004, to January 31, 2005.

[34] At the time of the T5 opening, JetBlue and PANYNJ had yet to complete renovation of the original Saarinen head house, and the building had stood empty while they decided what its future role should be.

Early proposals included a conference center, an aviation museum, and a restaurant,[119] or a place to check in for flights departing from the newer JetBlue T5 building.

[28] Under TWA president Damon's guidance, Saarinen had designed the terminal as "a building that starts your flight with your first glimpse of it and increases your anticipation after you arrive".

[136] Even when the TWA Flight Center was under construction, it was often discussed in the architectural media, and the Museum of Modern Art ran an exhibit on the building in 1959.

[138] Ada Louise Huxtable, architecture critic for The New York Times, saw the TWA Flight Center as a bright spot in the "mediocrity" of JFK Airport.

[14][141] One major critic of the design was historian Vincent Scully, who disliked Saarinen's use of "whammo shapes" at the TWA Flight Center and Dulles International Airport.

[79][142] Italian engineer and architect Pier Luigi Nervi was also skeptical of the design, saying that the structure was "too heavy and elaborate for the problem it seeks to solve".

[104] Two years later, New York Times critic Herbert Muschamp called the TWA Flight Center "the most dynamically modeled space of its era".

[137] After the TWA Hotel conversion was complete, Australian Design Review wrote: "The interior curves, cantilevers and spacious mezzanines have stood the test of time.

[33] When the terminal was completed, it received numerous accolades and awards, including from the Queens Center of Commerce[147] and the New York Concrete Industrial Board.

[154] The Municipal Art Society nominated the facility for inclusion on the National Trust for Historic Preservation's list of the 11 Most Endangered Places in America in 2004, after the terminal's closure.

[18][1] The American Institute of Architects' 2007 survey List of America's Favorite Architecture ranked the TWA Flight Center among the top 150 buildings in the United States.