Windshift causes altitude loss enroute
An Eva Airways Corp. Boeing 747-400, was operating as EVA651 in the vicinity of Whitehorse, YT at FL430 when they encountered windshear. EVA651 required a descent of 500 feet in order to regain airspeed. At approximately 80 nm west EVA651 encountered a second windshear event resulting in a loss of 1200 feet due to a wind change of about 60 knots over a distance of 5 nm.
Would an aircraft like this have autothrust to compensate for a loss like this over 5 miles or is it too much of a change in wind?