A B757 PIC BLASTS A LADDER INTO HIS #1 ENG COWL DURING AN ILLEGAL GND RUN-UP AT THE GATE AT EWR; NJ.

Narrative

ACFT (B757) WAS PARKED AT GATE AT EWR ARPT. MAINT HAD BEEN WORKING ON A HYD LEAK ON/NEAR THE #2 R ENG. AS PART OF THE TROUBLESHOOTING; THEY REQUESTED THAT WE START THE R ENG AND 'RUN IT IN REVERSE' WHEN DIRECTED TO DO SO BY ONE OF THE MECHS OVER THE INTERCOM. THE MECH INFORMED US THAT THE AREA AROUND THE ACFT WAS CLR AND IT WAS OK FOR US TO START AN ENG AT THE GATE. (GATE IS QUITE EXTENDED FROM THE TERMINAL.) THE CAPT SLOWLY RAISED THE REVERSE LEVER OUT OF IDLE. HOWEVER THE ENG WAS VERY SLOW TO SPOOL UP. WHEN IT FINALLY DID ACCELERATE; HE IMMEDIATELY RETURNED THE LEVER TO IDLE. WE THEN LEARNED THAT A MAINT LADDER; WHICH HAD BEEN SITTING NEXT TO THE #2 ENG (THOUGH WE WERE TOLD THE AREA WAS CLR); WAS BLOWN ACROSS THE RAMP; UNDER THE ACFT; INTO THE #1 L ENG -- DAMAGING THE FIBERGLAS COWLING. IN RETROSPECT THE ENG SHOULD NEVER HAVE BEEN RUN IN REVERSE AT OR NEAR THE GATE. AS THE FO; I WAS KIND OF REMOVED FROM THE TROUBLESHOOTING AND COM PROCESS BTWN THE CAPT AND THE LEAD MECH. I WAS SURPRISED WHEN THE CAPT ACTUALLY 'PULLED' THE REVERSE LEVER OUT OF ITS DETENT INTO REVERSE. I HAD ASSUMED THAT THE CAPT WOULD ONLY 'OPEN THE BUCKETS;' ACTIVATE THE HYD REVERSE ACCUMULATOR; WITHOUT GOING INTO FULL REVERSE THRUST. I BELIEVE THAT THIS WAS ALSO THE INTENTION OF THE MECH; BUT HE FAILED TO CLRLY COMMUNICATE THIS TO THE CAPT; WHO UNDERSTOOD 'RUN IT IN REVERSE' AS UTILIZING REVERSE THRUST. WITH BETTER COM AND CRM THIS INCIDENT COULD HAVE BEEN PREVENTED. IN THE FUTURE I WILL LEAVE ALL MECH TROUBLESHOOTING UP TO OUR MAINT DEPT. BY 'JUST WANTING TO HELP AND GET THE PAX OUT ON TIME' WE CONTRIBUTED TO THIS UNFORTUNATE INCIDENT AND ACFT DAMAGE. SUPPLEMENTAL INFO FROM ACN 437401: I LATER FOUND OUT THAT MAINT IS NOT PERMITTED TO RUN AN ENG IN REVERSE AT THE GATE. I SUSPECT THEY ASKED ME TO EXPEDITE THE PROCESS -- IE; NO TAXI TO RUN-UP AREA. POOR JUDGEMENT ON MY PART TO GET INVOLVED.