I normally do not post, I want to let the aircraft owners know that in the last two weeks we have found two cracks in two different aircraft propeller hubs under AD 2009-22-03. Both had been inspected 100 hrs earlier and had shown no discrempencies. Not sure what to think, is it a vibration, time, age that these are just now showing up cracked. We had not had a hub cracked in 15 years so we are treating this very seriously.