Jsnww81 From United States of America, joined Jan 2002, 1938 posts, RR: 16 Reply 5, posted (9 years 10 months 4 days 6 hours ago) and read 2189 times:
The FAA in the United States uses prototypes for high-activity control towers, which explains why there's so much duplicity.
The first prototype was introduced in the late 1960s - a slender concrete tower designed by I.M. Pei. You can find them at JAX, IAH (old), STL (old), TPA, ORD (old), ELP, IND, MEM and several other airports.
The second prototype - the four pillar design - was introduced at Dallas/Fort Worth in 1974. You can find them at COS, PHL, PIT, MIA (old), FLL, PHX, ABQ, SAT, MSY, BHM, ATL, RDU, CLT, ALB, ROC, SYR, BDL, HNL, LAS, MKE, ABE, and a few others. It's been largely phased out, although some middle-level airports, such as MSY, BHM and BDL, have built them in the last decade.
The newest prototype premiered in 1992 at DTW. They've since been built at DFW (twice), SDF, IAH, AUS, DEN, SLC, PDX, CVG, ORD, MCI, STL and SEA. Some airports have taken this design and added some architectural flourishes to it - LAX, JFK, MCO, SJU, CLE and CMH, for instance.
There's also a lower-tier prototype for less-busy jet airports, which you can find at SAN, OGG, MDW, HOU, DAL, ONT and SNA.