Me too, especially rappelling out of a UH-1 on a hot day in gusty winds. UH-1, UH-60, CH-47, they all seemed unstable to me for some reason.
Army will be getting a replacement for the Blackhawk
- Thread starter KillerFord1977
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RickAnderson
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That is because they are unstable, there is no static or dynamic stability in helicopters like fixed wing aircraft. Later models had more sophisticated AFCS systems, would use computers to react to maintain better stability and with auto-pilot functions it can be a lot like a fixed wing aircraft but in turbulence, simply because the rotary mass, and the military resources/priority to maintain comfort vs the heavy usage and ops tempo, results in a rough ride...
The CH-47 and little brother the CH-46, because of the tandem rotor configuration do out do other helicopters in hover stability...
Yeah, did a lot of air mobile with the CH-47D models in California and Korea that air lifted our howitzers. Even saw one drop a gun during low visibility. That was a sight watching 16,000 pounds of metal hit the dirt.
RickAnderson
Custom
I have picked up LAV's in the CH-53E, just short of 30k lbs. With a sling load that heavy, the combined center of gravity is outside of the aircraft, as you maneuver the aircraft actual swings, rotating about a point around the slings in-between the aircraft and the load.
A buddy of mine had to drop an LAV, he and the co-pilot screwed the engine SCL's (governors) trying to prevent an overtemp on take-off, they drooped turns, descended and put the load in the tree's, which just dragged them down further. Once tree branches started hitting the wind screen, they pickled the load.
A couple months later, I'm picking up a LAV, they had sections of chains in the slings. One of the chains got kinked/knotted and stayed that way after we put tension on the sling. We were on the downwind when the weight pulled the kink/knot out of the chain, and with that much weight, it pulled out with a Ka-Boom and the entire aircraft bounced up and down violently. My crewchief knew exactly what I was thinking, because before I could say it, he said, "the Load is still on the aircraft"... ....I thought for sure the slings had broke and it was headed for the ground...
Despite the sophisticated AFCS of the CH-53E, compared to the CH-47 in a hover, its wriggling all around. That is what the Tandem rotor gives you.
The Fly by Wire on the CH-53K, will be a game changer for load hook up, it holds a perfect hover, and adjusting hover with guidance from the crew chief is a matter of bumping the stick. He says come left three feet, you bump the stick 3 times and relax, the aircraft move precisely 3 feet to the left.
The CH-53E has warning lights for two aerodynamic uniqueness, that will cause the Tail Pylon to shake and create conditions conducive to creating a #2 engine fire from disrupted airflow... ...the CH-53K fly by wire might be able to eliminate that, although I think they changed the exhaust nozzle configuration to in the "K" to remedy one of the problems.... ....fly by wire is not simply the same thing done a different way, it is totally different from the ground up..