Do devices really pose danger to planes?

BRIAN WILLIAMS, anchor: So Alec Baldwin 's in the news and on a lot of front pages and a lot of newspapers and websites for his fracas over failing to turn off his phone when ordered to. He was thrown off an LA -to- New York flight for it. And however people feel about Alec Baldwin , it's clear a whole lot of people who fly in this country have a hard time believing that anything they do with their electronics is going to affect that big giant aircraft they're flying in. It is a top-of-mind topic right now, and NBC 's Tom Costello has our report.

Offscreen Voice: Mr. Baldwin ...

TOM COSTELLO reporting: On his return to New York , Alec Baldwin was again met by cameras, all for being thrown off a plane when he refused to turn off his iPhone and the game he was playing. Among air travelers today, not a lot of sympathy.

Unidentified Woman #1: He's a star. He loves to do that.

Unidentified Man: I think that he needs to abide by the same rules everyone else does.

COSTELLO: But also a question.

Unidentified Woman #2: I just wondered on my flight here, 'Why can't I read my iPad while I'm sitting here?'

COSTELLO: The FAA 's rules are clear.

Unidentified Flight Attendant: Ladies and gentlemen , at this time please turn off all cellular telephones and all other electronic devices.

COSTELLO: Everything must be in the off position before the plane pushes back and when it's preparing to land. But do they really pose a danger? Boeing engineers in Seattle recently showed us the RF signals that come just from the video screens on portable devices.

Mr. BRUCE DONHAM (Boeing Technical Engineer): There is a potential for these signals to cause interference to the radio.

COSTELLO: Pilots have complained of interference with their flight computers and radios, but there's no hard proof of it ever causing an in-flight problem or a crash. Part of the problem, say the experts, is that mobile device technology is changing so quickly there's no way of knowing whether the next device that comes along might pose a threat.

Mr. JOHN COX (Former Airline Captain): Are they OK or are they not? And until they're tested, the FAA has no way to determine it.

COSTELLO: Despite the rules, some press and sports team charter flights regularly ignore them. Even those who fly on Air Force One don't seem worried. While the Air Force has similar restrictions, all kinds of electronics are used in flight. As for Alec Baldwin , he apologized in a statement for delaying his fellow passengers, saying, "It was never my intention to inconvenience anyone." But he's also blamed the flight attendant. Now NBC News has learned the flight attendants union will ask that Baldwin be banned from future American Airlines flights along with his NBC TV show, "30 Rock." Tom Costello, NBC News, Washington.