LOS ANGELES  By now, everyone knows the airport drill, its inconveniences offset by its clarity: take off your shoes, pop your laptop in a tray, have your driver’s license at the ready. But in the three days since the attempted terrorist attack on a Detroit-bound airliner, the beleaguered traveler has once again been beset by a confusing and inconsistent set of rules.

Could you keep your blanket, as on Continental, or would it be snatched at the end of the flight, as it was on Lufthansa? Would security measures be visibly unchanged, as they were at the Houston airport, or would passengers be surprised by a careful swabbing of their hands and purses, like those in South Carolina? Would this week resemble Sunday, when JetBlue’s entertainment system was shut down on international flights, or Monday, when the movies began flowing on that airline once more?

“I just wish they’d have something, a list of rules, and stick to it,” said Sherri Hemmer, who made a point of using the bathroom early on her Monday flight from Phoenix to Pittsburgh and was then annoyed to learn that a prohibition against moving around the cabin in the last hour of flight did not seem to apply to her flight.