Ever been on a flight and looked on with wonder as someone remained riveted to his or her portable electronic device -- obliviously or defiantly -- even after the flight attendant had asked passengers to turn them off? More likely, have you ever not?Airline deal website Airfarewatchdog.com recently polled 1,200 people about whether they use electronics such as cellphones and laptops after the cabin door has been closed and a flight attendant has requested they be turned off. Not surprisingly, 24 percent said they don't always comply. Many chalked it up to missing the announcement or needing to finish a phone call, but 9 percent said they stayed on even if they heard the plea.

The finding "suggests that there are quite a few privileged people flying these days," said George Hobica of Airfarewatchdog.

Privileged, or disbelieving. Some people don't buy the argument that the devices can interfere with a plane's navigation gear or radios. Research suggests they can.

The compass system of a Canadair regional jet malfunctioned after takeoff, but began working after a passenger turned off an iPhone, USA Today reported in December after a review of government and airline documents. That was just one of 32 incidents of interference from electronics reported by pilots and air traffic controllers between January 2001 and December 2011.

Interference doesn't happen often. It seems to depend upon airplane type, where the offender is seated and which device is on. But why risk it? Powering down for the brief but critical times when a plane takes off and lands is a small price to pay for safety.

Send your questions or tips to travel editor Kerri Westenberg at travel@startribune.com, and follow her on twitter @kerriwestenberg.