Air turbulence caused by a helicopter rotor.U.S. military officials say rotor wash from the helicopter may have blown down the banner....
Once the offload was complete and we began to take off, several of the children rushed under the helos in order to have the rotor wash send them tumbling along the ground.
Keeping the helicopter and the raft within hoisting range was a challenge because our rotor wash constantly blew the raft away from us.