What was found
DURING TROUBLESHOOTING ON THE LEFT HAND DOOR HOLD OPEN STOP, NOTICED WHEN THE DOOR WAS OPENED AGAINST THE STOP, THE BOTTOM FUSELAGE DOOR HINGE ATTACHMENT MOVED. FURTHER INSPECTION REVEALED A CRACK IN THE AFT FORWARD DOORPOST APPROXIMATELY 2.75 INCHES LONG NECESSITATING REPLACEMENT OF THE DOOR POST. AN INSPECTION OF THE FLEET OF 172'S FOUND THE SAME CONDITION ON 6 OUT OF 9 AIRCRAFT. M.D. REPORTS WILL BE FILED ON EACH.