Skip to comments.The AH-56 Cheyenne attack helicopter
Posted on 06/26/2014 8:25:53 PM PDT by DemforBush
Neat video of a rather interesting (if ultimately unsuccessful) U.S. attack helicopter design from the early 1970s.
(Excerpt) Read more at youtube.com ...
It was an engineering challenge, to be sure.
I was a kid in about 1967 at Fort Rucker and remember seeing one of the prototypes of this aircraft there.
Even Cobras were advanced for the time, this thing was WAY out there.
Seems pretty bad-as to me. Why didn’t we have a bunch of these?
The project was cancelled.
There’s one big problem with fast-flying choppers —it’s possible for the backwards rotational velocity of the rotar at certain points to feature backwards speed that effectively makes it “stand still” with respect to the ground below.
This means that lift on one side is strong, while on the other lateral half there is very little lift —this rolls the chopper strongly to the weak side.
To mitigate this the rotar on fast choppers must be spun much faster and the winglets play an important role in maintaining lift, much as we see with the Mi-24, which at certain speeds acts as 50% chopper and 50% airplane.
I’m guessing because the A-10 did the same job and did it cheaper, and more reliably. The tech in this chopper probably scared them into thinking it would turn into a tarmac queen.
Are you talking about retreating blade stall?
Helicopters are too vulnerable to ground attack. All those weapons become nearly useless when some yahoo manages to put a 20 cent bullet through the CPU.
project do get cancelled because of reasons other than the merits of the system being vended.
it could have been no more than the fact that the vendor team PM’s PE’s and PA’s involved with the program were
It was cancelled. Too expensive or not?
How many hours on the ground for every flying hour, the more advanced the worst it probably gets.
Several of my projects over the years didn’t make it. You are absolutely right about merits of the system not being a priority at times. (politics)
Active Duty/Retiree ping.
That’s why we kept a couple of hangar queens back in the day, spare parts, lol. I can’t help but feeling we had an awesome platform sidelined over politics.
With it's stated 8000lb ordinance load, perhaps there wasn't anything left for crew armor.
A-10 has a titanium bathtub for pilot protection.
240mph and a 4 ton payload, sounds like we need some such even today. (isis)
This is very interesting that it is posted... I was reading all about these aircraft just the other night after someone posted a photo of an AH-1 Cobra that is for sale.
Any helicopter at cruising airspeed has the problem of `dissymmetry of lift’, where the retreating blade’s lift is subtracted, not added, to the relative wind produced by forward movement.
This problem was solved by Igor Sikorsky in the 1940’s with his rotating swashplate which not only provided control but induced additional pitch as the rotor passed front dead center from advancing to retreating.
I started Army flight school in late 1970 & they taught us all this theory while we were itching to get in the cockpit; the classroom phase was called “nuts & bolts”.
The AH-56A was still a flying prototype. We were shown training films & marveled at its rigid rotor system (unlike semi-rigid & fully articulated rotors) which enabled the Cheyenne to loop the loop (”Wow! Hope I get to do that!”).
Then it was off to Vietnam. Later the word got around that the AH-56 was cancelled because its ability to reach 300 knots with the aid of its pusher propeller was causing the tail rotor to shear off from the sideways strain.
Saw a Cheyenne outside the post museum in Fort Polk in 2001. Still an awesome machine.
“How many hours on the ground for every flying hour, the more advanced the worst it probably gets.”
True, down time gets worse as the aircraft ages as well. More parts get removed and reinstalled, wires break, connectors wear out, and all sorts of problems develop. I’ve seen more flight control issues get shot down to a broken wire, or improper connection than failure of a flight control computer, or actuator. The F-22’s are great jets right now, wait about 10, 20 years, especially with the increased flying hours and decreased maintenance personnel approach that the Air Force has taken. You’d think the powers that be would’ve learned this lesson with the F-15E and F-16, which have quite a few electronic components.
Will they be forces to change the name?
Afterall...Indians are now a protected class..
With a lot of the digital systems they are able to reduce the number of wires.
of course we offset that by adding more bells and whistles. fyi the F-35 is mostly fiberoptic.
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