AN MD80 WAS DAMAGED DURING PUSHBACK AT LAX WHEN A BOARDING STAIR WAS BLOWN INTO THE WINGTIP BY ANOTHER ACFT.

Narrative

PAX BOARDING WAS COMPLETED; ALL DOORS CLOSED AND THE JETWAY PULLED BACK. THE LEAD RAMP PERSONNEL 'CHKED IN' WITH ME VIA HEADSET; INFORMED ME THE 'WALKAROUND CHK WAS COMPLETE AND WE'RE READY FOR PUSHBACK.' WE RECEIVED CLRNC FROM RAMP CTL TO PUSH BACK TO SPOT X. I INFORMED THE LEAD RAMP PERSONNEL VIA HEADSET; 'THE BRAKES ARE RELEASED; YOU ARE CLRED TO PUSH; SPOT X.' JUST SHORTLY THEREAFTER; I FELT AN IMPACT TO THE ACFT. THE LEAD RAMP PERSONNEL REQUESTED ME; VIA HEADSET; 'TO SET THE BRAKES; AND A LADDER HAD JUST STRUCK THE L WINGTIP OF THE ACFT.' I SET THE BRAKES OF THE ACFT AND REQUESTED MAINT. UPON FURTHER INVESTIGATION; I FOUND A VERY LARGE STAIRS HAD BEEN BLOWN INTO THE L WING OF THE ACFT CAUSING DAMAGE TO THE NAV AND STROBE LIGHT LENS COVER. A HVY B747 HAD BEEN REPOSITIONED TO SPOT Y IN THE ALLEYWAY; STARTED ENGS AND WAS USING 'BREAK AWAY THRUST' WHEN THE STAIRS WERE BLOWN INTO THE ACFT. I FEEL MY PUSHBACK CREW ACTED APPROPRIATELY AND WERE UNABLE TO PREVENT THE STAIRS FROM STRIKING THE L WING OF THE ACFT. I ALSO FEEL THERE WERE SEVERAL FACTORS WHICH CAUSED THIS INCIDENT: 1) THE BRAKES ON THE PORTABLE STAIRS WERE NOT SET; THUS PREVENTING THEIR MOVEMENT. 2) THE STAIRS MAY HAVE BEEN POSITIONED IN AN INAPPROPRIATE PLACE. 3) THE SPOT ON THE D-10 ALLEYWAY DOES NOT PROPERLY SUPPORT THE EXTREME WT OF THE HVY ACFT; THUS MAKING IT EXTREMELY DIFFICULT TO GET AN ACFT MOVING AFTER COMING TO A COMPLETE STOP. MANY TIMES MAX 'BREAK AWAY' THRUST MUST BE USED TO GET THE ACFT MOVING. DUE TO THE EXTENSIVE USE OF THE HVY ACFT IN THE D-10 ALLEYWAY; I STRONGLY SUGGEST THE POS IN THE D-10 ALLEYWAY BE RECONSTRUCTED WITH A HIGH STRENGTH CONCRETE; THUS BETTER SUPPORTING THE EXCESSIVE WT DURING 'BREAK AWAY' THRUST APPLICATIONS.