What was found
TURNED BACK TO BASE DUE TO GEN FAILURE. AN EMER WAS DECLARED & THE ACFT LANDED WITH NO FURTHER INCIDENT. FOUND THE RT GEN SHAFT SHEARED. THE SHAFT COUPLING WAS REPLACED & AN OVERHAULED GEN INSTALLED. LEAK & OPERATIONS CHECKS WERE GOOD & THE ACFT RETURNED TO SERVICE. THIS WAS A DUAL GEN FAIL. ACFT OPERATED ON ESSENTIAL POWER UNTIL APU GEN WAS BROUGHT ONLINE. LT GEN WAS R & R. LEAK & OPERATIONS CHECKED GOOD.