A B737-700 ON TKOF ROLL HAD MAIN GEAR WHEEL CHOCKS FALL OUT DURING TKOF.

Narrative

I WAS PUSHING OUT ACFT X FROM HANGAR WHEN WE SAW THAT HANGAR RON HAD PARKED AN ACFT AT THE END OF THE RAMP BEHIND HANGAR. WE CHKED ACFT X AND WENT TO MOVE ACFT Y OUT OF THE WAY. BY THE TIME I GOT TO ACFT Y; HANGAR SUPVR WAS WAITING AT THE NOSE OF THE ACFT READY TO HOOK UP THE TOW BAR. SUPVR REMOVED THE TOW BAR FROM THE TUG AND HOOKED UT UP TO ACFT Y. WE THEN HOOKED IT BACK TO THE TUG. THEN SUPVR REMOVED THE CHOCKS FROM THE ACFT NOSE GEAR. THE WING WALKERS WERE IN PLACE AND BRAKE RIDER WAS IN PLACE. WE MOVED THE ACFT Y BEHIND 'A' BAY SO ACFT X COULD TAXI BY. AFTER ACFT X WAS CLR; HANGAR RON GOT IN THE ACFT -- 2 GUYS AND 1 IN A TRUCK. THEY ASKED IF WE WOULD PUSH THEM BACK. WE SAID WE WOULD. WHEN WE WERE ABOUT TO PUSH THE ACFT BACK AND POINTED OUT THAT THE #2 COWL LOWER ACCESS DOOR WAS OPEN; THEY SAID THEY HAD A LEAK CHK TO DO. SO WE PUSHED THEM BACK IN FRONT OF HANGAR AND LET THEM GO. THE NEXT DAY I WAS INFORMED THAT SOME CHOCKS FROM ACFT Y FELL OUT DURING TKOF. I DON'T REMEMBER ANY CHOCKS REMOVED FROM MAIN LNDG GEAR AND DON'T KNOW IF THEY WERE REMOVED BEFORE I GOT TO THE ACFT OR IF THEY WERE IN MAIN LNDG GEAR WHEEL WELL OR ON THE WING DOOR. I DO NOT THINK I AM AT FAULT. I BELIEVE THAT IF THEY WERE THERE; THAT HANGAR RON WOULD HAVE FOUND THEM ON THEIR WALKAROUND OR WHEN THEY WERE DOING THEIR LEAK CHK BECAUSE THEY SHOULD HAVE HAD IT CHOCKED THEN. IF HANGAR RON DID NOT SEE THEM; THE FLT CREW SHOULD HAVE SEEN THEM ON THEIR WALKAROUND AND IF THEY WERE ON THE MAIN LNDG GEAR WING DOORS; THEY COULD NOT HAVE BEEN MISSED WHEN THE GEAR PINS WERE REMOVED. AND LAST; THE CREW WHO PUSHED BACK THE ACFT FROM THE GATE WOULD HAVE PULLED THE CHOCKS LAST.