Fedex MD10 near Toronto on Dec 29th 2013, engine vibrations

A Fedex Federal Express McDonnell Douglas MD-10, registration N321FE performing freight flight FX-132 from Memphis,TN (USA) to Toronto,ON (Canada) with 2 crew, was enroute at FL370 when the crew felt vibrations from the left hand engine (CF6), the left hand EGT increased with the N1 decreasing. The crew reduced thrust to idle resulting in the vibrations disappearing, descended the aircraft to FL330 and worked the relevant checklists. When thrust was increased again on the left hand engine, the vibrations reoccurred. The crew therefore worked the severe engine damage checklist, about 60nm out of Toronto descending towards Toronto the crew shut the engine down and discharged the fire bottles into the engine. The crew continued for an approach to Toronto's runway 23, however on short final about 3nm before touchdown a frontal system passed over the aerodrome causing a rapid wind change to 15 knots from 010 degrees prompting the crew to go-around. The aircraft positioned for another approach to runway 33R for a safe landing about one hour after the onset of vibrations and about 13 minutes after going around.

Metars:

CYYZ 300100Z 35015KT 15SM BKN007 OVC011 M03/M04 A2969 RMK SC6SC2 SLP062

CYYZ 300025Z 35016G24KT 15SM OVC007 M02/M04 A2967 RMK SC8 PRESRR SLP055

CYYZ 300009Z 35017KT 15SM BKN005 OVC018 M01/M02 A2966 RMK SC7SC1 PRESRR SLP049

CYYZ 300000Z CCA 36016KT 15SM SCT005 OVC018 M01/M02 A2965 RMK SF3SC5 WSHFT 2352 PRESRR SLP046

CYYZ 292300Z 26007KT 15SM BKN034 BKN190 02/M01 A2962 RMK SC5AC2 SLP036

CYYZ 292253Z 26007KT 15SM BKN034 BKN190 02/M01 A2962 RMK SC5AC2 SLP036

CYYZ 292200Z 28009KT 15SM BKN180 BKN210 03/M01 A2961 RMK AC5CC2 SLP032

CYYZ 292100Z 25005KT 15SM SCT170 BKN190 03/M01 A2961 RMK AS4AC3 SLP033

CYYZ 292000Z 23005KT 15SM OVC170 04/M02 A2962 RMK AS8 SLP035