The Hall of Arms is the center of dwarven military power, and houses trainers for warriors and hunters as well as battlemasters and several quest givers. It is located in the The Military Ward in the dwarf city of Ironforge. Here, assembled Flying Machines are launched from the exit in the roof to the Dun Morogh airfield, and Steam Tanks are assembled for use by Alliance forces.
If you go to the circle of NPC's, they have a map laid out before them. If you notice, it is a map of just outside the gates of Ironforge and it has four figures on it, two tank-like figures, and two plane-like figures. It appears as if they are planning a battle just outside the gates of Ironforge. Also, it looks as if one of the planes crashed.