Sultan:
"Impact of weapon exhaust on the tail has always been a concern and looked at very closely. That’s why the weapons are placed on all helicopters I know of where the tail rotor is not directly behind it. On the Raider the pusher is very big and face on to the back blast. If damaged the pusher wouldn’t just stop working, but be significantly out of balance. If the unbalance is large enough you loose the whole tail."
I wonder if you've hit on another, unannounced, reason why Bell changed the location/type of tail rotor on Invictus. In the initial configuration, the shrouded tail rotor was directly in line with the fuselage. This was no big deal on previous uses of this technology. However, in the case of the Bell 360, this also puts tha air flowing through it would be in line with the exhaust from missile launch. Their studies might have indicated this turbulence could potentially be a problem. Moving it to a conventional design higher up takes it out of this area. Could that be another reason for the move?
