The nation's largest flight attendants union is arguing that the Federal Aviation Administration flouted federal law when it ruled last year to allow the use of electronic devices during all phases of the flight, including takeoff and landing. 

The U.S. Court of Appeals for the D.C. circuit will listen to arguments from the flight attendants union and the FAA on Friday. 

Before the FAA's announcement last October, passengers were required to power off small electronic devices, such as cell phones, tablets and music players, during flight takeoffs and landings. Now, passengers are able to use them as long cell phones are in "airplane mode" and electronic items are either held or placed in the seatback pocket. 

But the flight attendants union believes that the FAA changed the rules last year without following the proper steps required by law. According to the union, the use of electronics during takeoff can distract passengers from getting important safety information. The flight attendants union also argues that electronic devices could become projectiles that may injure others during takeoff and landing.