Should pilots filter their Instagramming habits?

There's a growing trend on Instagram: Pilots taking and posting photos, captured from their unusual vantage point inside the cockpit. And hundreds, sometimes thousands of people have been flocking to their accounts, waiting for the next round of stunning images.

Though the images may be beautiful, taking the photos while piloting a commercial aircraft is against U.S. and European aviation rules.

David Yanofsky, a reporter for Quartz, a digital business news publication, conducted a six-month investigation into the trend.

"There's no rules specifically against taking a photograph," he said. "What there are rules on are the type of device that you can use. And using a device that has wireless capabilities is, in fact, always forbidden in a cockpit by FAA rules unless there's an emergency and the captain says that that is necessary."

According to Yanofsky, pilots are taking these photos at critical periods of flight, like takeoffs and landings.

"During those times there's an even heightened sense of awareness that needs to be taking place in the cockpit," he said. "And during those times, pilots can't even drink a cup of coffee, let alone talk to the flight attendant. And there have been some photographs that I've seen that appear to be taken during those times."

Some of the photos have captions and a time stamp, so it's easy to tell when and where they're taken. And while there are critical periods of flight, there are also cruising altitudes when pilots can use the bathroom, eat or even say, complete a crossword puzzle.

"If they're taking a break, they're not at their duty station," Yanofsky said. "And the FAA rules specifically mentions the duty station when taking the picture. You don't want someone to get sucked into a device and be focused on that more than flying the airplane, where that might not be the same case with printed material."

Yanofsky said he has spoken with the FAA, which said it's never taken action against a pilot for using a personal electronic device while in the cockpit. Neither have the airlines he contacted.

"The aviation community has reacted somewhat negatively to this story because it is a part of their community that they treasure," he said. "As such, they've started blocking me on various social media, so it's hard for me to determine how this has all changed."

EDITOR'S NOTE -- The Air Line Pilots Association (ALPA) responded to the above report on Dec. 15, 2014, with the following statement:

"A cornerstone of ALPA's commitment to safety is promoting the highest standards of professionalism among airline pilots and flight crews. This includes strict adherence to Federal Aviation Regulations (FARs) and airline policies and procedures. Under the FARs, a critical phase of flight is considered to be any non-cruise portion of the flight below 10,000 feet, including ground taxi. The use of personal cameras during non-critical phases of flight is not prohibited by the FARs. While some photos may appear to be taken in critical phases of flight, they may well have been taken in non-commercial operations such as repositioning or maintenance flights or corporate flights where such photos are not prohibited by the regulations. Every day and on every flight, the professional airline pilots of ALPA are committed to maintaining the highest standards of safety and exhibit complete professionalism."