(CNN) -- American Airlines has found cracks in large pylons that hold engines onto the wings of two of its 767-300 aircraft, according to the airline and the planes' manufacturer.
Concerned the problem may exist on other airline fleets, Boeing says it plans to advise airlines to inspect the parts more frequently than the current recommendation of every 1,500 takeoff and landing cycles.
"This is considered a safety issue. You're talking about the strut that connects an engine to the wing," said Boeing spokesperson Peter Conte.
American Airlines spokesman Tim Wagner said the problem was first discovered on one of its 767-300s about two weeks ago during a maintenance check targeting other parts of the aircraft.
The airline then found cracking on one more 767-300 after inspecting a total of 56 aircrafts -- 767-300 and 767-200s -- a process American Airlines completed Monday night.
