What was found
PILOT REPORTED VIBRATION COMING FROM NR 1 ENG WHICH VARIED WITH THROTTLE ALONG WITH A VOLTAGE SPIKE ON AC VOLTMETER. AFTER EXTENSIVE TROUBLESHOOTING, FOUND ALTERNATOR BEARINGS HAD FAILED, SHORTING OUT ALTERNATOR CONTROL UNIT, AC VOLT METER AND HORIZ STAB ANTI-ICE CONTROL UNIT. ALTERNATOR ON NR 2 ENGINE FAILED 5 HRS LATER SHORTING OUT ALTERNATOR CONTROL UNIT ALSO. ALTERNATOR BEARINGS HAVE A SERVCIE LIFE OF 2,000 HRS. FIRST ONE FAILED AT 1,618 HRS AND SECOND AT 1623 HRS SINCE OVERHAUL. (X)