L118 sling load unstable in flight

[Marsvinet]

Now that the L118 can finally be picked up without slamming into the helicopter, the next problem shows itself. When carrying at speeds below 40kts, it merely bounces around and starts swinging without any manouvering. Above 40kts, it gains enough energy to risk slamming into the carrying helicopter. Above 60kts, even a gentle manouver is almost guaranteed to cause the gun to swing into the fuselage. 

The gun is tested to be stable at 120kts when in a single point sling, according to US TM 4-48.10 "Multiservice Helicopter Sling Load: Single-Point Load Rigging Procedures". 

Attached is a track showing how it behaves in steady (except the gun swinging wildly enough to make it not steady) forward flight at increasing speeds.

ArtilleryKarate.trk