BAGGAGE CART TIP INTO ACR MLG ENGINE COWL FOLLOWING INCORRECT POWERBACK TURN.

Narrative

I WAS THE PLT IN COMMAND OF A SCHEDULED ACFT TRIP BTWN BWI AND ATL. I WAS IN THE RIGHT SEAT (F/O'S) TO CONDUCT INITIAL OPERATING EXPERIENCE (IOE) TRNING OF A 1ST TIME CAPT. AFTER AN INITIAL BRIEFING ON THE ROLE OF A NEW CAPT AND HIS CHK CAPT DURING IOE TRNING; MY NEW CAPT AND I PROCEEDED TO THE AIR CARRIER AND PREPARED FOR HIS 1ST LINE TRIP. AFTER THE 'BEFORE STARTING ENGS' CHKLIST HAD BEEN ACCOMPLISHED; I BRIEFED THE NEW CAPT ON THE PROC TO BE FOLLOWED FOR HIS 1ST POWERBACK FROM GATE AT BWI; THE BRIEFING CONSISTED OF A REVIEW OF THE MATERIAL IN THE FLT MANUAL AND A DESCRIPTION OF HOW TO HOLD THE STEERING WHEEL WITH THE LEFT HAND SO THAT A TURN COULD BE MADE WITHOUT REMOVING THE RIGHT HAND FROM THE THROTTLES TO ASSIST IN THE STEERING WHEEL MOVEMENT. AFTER THE ENGS WERE STARTED AND CHKLISTS READ; THE NEW CAPT BEGAN THE POWERBACK MANEUVER. HE MISINTERPRETED THE GND SVCMAN'S SIGNAL FOR A TAIL TO THE RIGHT TURN AND TURNED THE ACFT IN THE OPPOSITE DIRECTION. I TOLD THE CAPT THAT HE HAD TURNED THE WRONG WAY AND IMMEDIATELY PLACED MY HAND ON HIS AND TOOK THE ENGS OUT OF REVERSE THRUST AND ADDED MINIMUM FORWARD THRUST TO STOP THE ACFT'S REARWARD MOVEMENT. AS THE ACFT STARTED FORWARD; I PLACED THE THROTTLES TO IDLE AND INSTRUCTED THE CAPT TO TURN TO THE RIGHT TO EXIT THE RAMP AREA. THE RESULT OF THE TURN IN THE WRONG DIRECTION AND MY CORRECTIVE ACTION RESULTED IN A BAGGAGE CART BEING BLOWN INTO ANOTHER CARRIER'S MLG; WITH THE RESULT OF A MINOR DENT. HE DEPARTED APPROX ON SCHEDULE. THE RECURRENCE OF THIS COULD BE PREVENTED WITH PRACTICE POWERBACKS IN FLT TRNING BEFORE A NEW CAPT COMES TO THE LINE FOR IOE TRNING ON PAX FLTS.