A row of seats coming unbolted off the floor of an aircraft mid-flight should be a freak occurrence. It isn't for American Airlines, and now that it's happened twice, the Federal Aviation Administration is getting involved. "Got an unusual one for you. Passenger seats rows 12D, E and F, uh, came loose out of the floor. Passengers are unable to, uh, sit in that seat." said the pilot of American Airlines flight 685 in a call to air traffic control picked up by CBS New York. Flight 685 was the first instance of this seat malfunction, which for now seems to only be plaguing American Airlines, which has some unhappy labor unions at the moment. As CBS reports, Flight 443 was supposed to fly from JFK airport to Miami, and had to turn back because of the same seat malfunction—a row of seats came loose and passengers were moved to other seats and for the turnaround, and were put on a different plane. And those two separate occurrences now have the attention of the Federal Aviation Administration which is starting an investigation along with an internal investigation from American Airlines itself. 

So far, there are two hints about why these seats are coming loose. "The Federal Aviation Administration said both planes had recently undergone maintenance work that required seats to be removed and reinstalled," reports the AP which adds that "American spokeswoman Andrea Huguely said an initial review found that there could be a problem with the way the seats fit into tracks on the floor." And because this is American, everyone's most hated and the country's most delayed airline at the moment, there's also a conspiracy floating around: that these seat malfunction coincidences might be the work of union workers unhappy with American's dealings, one retired pilot told CBS. Either way, American has grounded eight 757s and has promised to proactively inspect them for loose seats.