Q&A on the News

Q: I have a metal joint replacement and always have to have a pat down when going through airport security since I set off the metal detector. If I submit to a full body scan (which I am quite ready to do), will I still have to undergo a separate pat down for the joint replacement?

—Jack Johnson, Atlanta

A: If there are no anomalies during advanced imaging technology screening, then a separate pat down is not required, Jon Allen, spokesman for the Transportation Security Administration in Atlanta, told Q&A on the News in an e-mail. He said passengers with joint replacements or other medical devices who regularly alarm a metal detector often prefer this technology because it is quicker and less invasive than a pat down.

Q: When days are clear and skies are blue, we often see numerous high-flying aircraft overhead, criss-crossing the sky. Are those military aircraft at high altitude? Do commercial aircraft leave all those contrails?

—Dan Sea, Lilburn

A: Military aircraft do not practice or train over populated areas, Jim Weslowski, spokesman for Dobbins Air Force Base, told Q&A on the News. "What they are seeing are the ice crystals coming off the wings and the tails (also known as condensation trails or contrails)," he said. "They may sit up there for half hour to five hours later. They just made ice crystals when they went through the clouds. And that's a common occurrence." As temperatures drop, the contrails created by large airplanes are larger, and they appear closer to the ground, he said.

Lori Johnston wrote this column. Do you have a question about the news? We’ll try to get the answer. Call 404-222-2002 or e-mail q&a@ajc.com (include name, phone and city).