As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ACFT WAS IN CRUISE WHEN A RUMBLING/VIBRATION WAS FELT AND HEARD. THEY ELECTED TO RETURN TO BASE AND AS THEY WERE RETURNING THE NR 1 GENERATOR FAILED. INVESTIGATION SHOWED THAT THE GENERATOR FAN HAD RUBBED AGAINST ITS HOUSING AND WAS IN THE PROCESS OF DESTROYING THE FAN BLADES AS WELL. ENGINE AND ATTACHING STRUCTURE WERE INSPECTED, STARTER GENERATOR REPLACED AND THE ACFT RETURNED TO SERVICE.