A United States senator wants the Federal Aviation Administration to relax its long-standing rule against the use of portable electronic devices on airplanes during takeoff and landing. The agency has traditionally claimed the rule is necessary to avoid interference with an airplane's instruments, but it is currently reconsidering the policy.

A growing number of critics argue the rule has no scientific basis. Last week, the Federal Communications Commission Chairman Julius Genachowski sent a letter to FAA Chairman Michael Huerta urging him to revise the rules. On Tuesday, Sen. Claire McCaskill (D-MO) sent a letter of her own to the nation's top aviation regulator.

“The current rules are inconvenient to travelers, don’t make sense, and lack a scientific basis," McCaskill argued, according to The Hill. "Airline employees have the incredibly important job of keeping us safe in the air—their efforts are better spent worrying about rules that actually accomplish that goal."

"The public is growing increasingly skeptical of prohibitions on the use of many electronic devices during the full duration of a flight, while at the same time using such devices in increasing numbers," McCaskill wrote. "For example, a traveler can read a paper copy of a newspaper throughout a flight, but is prohibited from reading the same newspaper for major portions of the flight when reading it on an e-reader.

Under the current rules, passengers are permitted to use tablet computers such as iPads and Kindles when the airplane is at cruising altitude. But the use of electronic devices is prohibited during takeoff and landing.

The FAA and FCC have been studying the issue of portable devices and airline safety for years and they have yet to uncover evidence that a passenger using a tablet computer could interfere with an airplane's instruments. Indeed, the FAA gave its approval earlier this year for pilots to use iPads. It's hard to see how iPads could pose a safety hazard in the passenger compartment but not in the cockpit.

The use of cell phones is currently banned at any time during a flight. That rule is unlikely to change any time soon.