Boston Logan received its first scanner this week and will get two more next week. All will be installed in the same terminal.
Los Angeles, Charlotte and Chicago O'Hare are also getting the scanners. Eleven airports in the U.S. will begin using the scanners during the next two years. The TSA bought 150 scanners last year and will take delivery of 300 more this year and 500 next year.
The scanners are 9 feet long and 6½ feet wide, much larger than metal detectors. They are much larger and slower than the metal detectors now in use and some airport officials are concerned. They have to be monitored very closely because they can slow down lines very quickly.
About half of nearly 40 airports that answered a survey last month by the Airports Council International said their security checkpoints are too small to handle the machines. Metal detectors will still be available and passengers who want to avoid scanners can opt to go through a metal detector and be hand-searched by a screener.