Nov. 1 (Bloomberg) -- From the headlines, you might think you will be able to chat, tweet and shop on your mobile phone throughout your next flight. The Federal Aviation Administration said yesterday that it's lifting a five-decade-old ban on using electronic devices whenever planes taxi, take off and land.

But the new policy is far more circumscribed than the news articles let on. Whether you can use a device will depend on what type it is, what airline you fly and even the weather. The whole thing is so confusing and arbitrary it's questionable whether to call it an improvement.

First, cellphone calls and text messages are still verboten. The Federal Communications Commission, not the FAA, oversees voice and text communication, and the FCC isn't changing its policy. Why? Because sky-high cellphone connections could disrupt cell networks on the ground.

Wi-Fi and short-range accessories like Bluetooth and wireless keyboards will be allowed, but voice calls won't. (That's probably a good thing.)

Second, the devices that are now allowed "gate-to-gate," as they say -- e-readers, digital music players, tablet computers, portable DVD players -- must be in airplane mode (which turns off the cell connection).

That means podcasts are allowed, but tuning into a radio station online isn't. You can use your smartphone to watch a movie stored on your device, but you can't use it to download a new movie, make a call or send a text.

You can read a downloaded book or listen to stored music but you can't surf the Internet unless you're on a flight that offers Wi-Fi service that works below 10,000 feet. Right now, the dominant Wi-Fi service from GoGo Inc. only works above 10,000 feet.

Going online using a plane's Wi-Fi service is allowed once a plane climbs above 10,000 feet. But if you regularly fly American, Continental, Delta, United or USAirways, which all offer inflight Wi-Fi service, this isn't new.

Third, video games are allowed, but not if the game needs an Internet connection to operate. So you can play Angry Birds, but not Words with Friends. (Sorry, Alec Baldwin.)

Fourth, larger electronic devices, including laptop computers, will have to be stowed during takeoff and landing. This is because they can become harmful projectiles in rough weather.

Fifth, these new freedoms won't be available at the same time on all carriers, or even on all planes operated by the same carrier. Airlines must conduct tests to make sure aircraft navigation systems and radios are shielded from interfering signals. Once that happens, they can apply to the FAA for permission to allow personal devices while taxiing, taking off and landing. Some carriers may have stricter policies than others, and some may have older planes that won't qualify.

And sixth, when visibility is low and pilots must land planes by following radio beams instead of by eyeballing the runway, devices may have to be turned off.

How will attendants know that devices are in airplane mode? They won't, says Michael Huerta, the FAA chief. He admits that flight attendants have no quick way of telling whether a cellphone or tablet is really in airplane mode, but that isn't a safety problem (ah-ha, we knew that all along!) so much as a technical issue: Devices with live cellular connections will keep searching for a cell while in-flight, and that means the battery could be dead when the plane lands.

(Paula Dwyer is a member of the Bloomberg View editorial board. Follow her on Twitter.)