Tilt Rotor Aircraft Since 1955

Scratch said:

Maybe just nitpicking, but that XC-142A would have complemented, or filled a similar role to, the CH-46 Sea Knight, wich the V-22s are replacing. Not the CH-47 Chinook, wich is larger in pretty much every conceivable aspect and in use with the army.
While looking fairly similar at first glance, these two are really different choppers, as I understand it.

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You are exactly right, Scratch...and thanks for clarifying.

They look similar, but are in fact, as you say, completely different aircraft, with the Chinook being far larger, and the Sea Knights being the ones operating off of the LHDs.

I will clarify that in my earlier posts with thanks to you.

The following pictures illustrate why you need lots of math, lots of tests, and lots of practical experience applied.

My Dad was one of the brightest aerodynamics and dynamics engineers during his generation. He worked for Vought and then Ling-Tempco-Vough for about 50 years.

He was a lead aerodynamic or dynamic engineer on multiple projects including the F-7 Cutlass, the F-8 Crusader, the A-7 Corsair and the XC-142A aircraft. He later went into their missiles division and produced a number of very cutting edge and capable designs.

The following pictures show the XC-142A being readied for wind tunnel testing. Early on, despite the very best calculations from vry broight minds like my Dad's...they had some failutres and some real life issues tro address that alluded their calculations (and at the point that the XC-142A wwas being designed, they were not novices)>

But the XC-142A wing and its ability to rotate from Horizontal to vertical, presented unique challenges at the time.

So you would get this:


Despite this, they continued on, and ultimately produced five prototypes for actual flight tests.

Even then, one of those crashed and tree good friends of my Dad's were lost.

But they soldiered on and ultimately produced an aircraft that fulfuilled all of the test requirements.


The US Air Force placed a production order for the C-142A Aircraft...only to have the Defense Department Secretary cancel it. (McNamara).

Just the same, NASA got a couple of those aircraft and flew them for some time.


Lots and lots goes into the production of these aircraft.

Of course, back then they only had relatively simply calculators and slide rules which helped their minds and vision.

With today's 3D modeling software they can do a lot more in terms of computer modeling and tests before they actually build something to test. But in the end...they will still build the test models, the prototypes, the test production aircraft, and then the actual production aircraft.

They just may be able to do so with a lot less chance of loss, and fewer of them...if they do their jobs right.

A lot of people never realized (because it was never built) that the C-142 was going to be a little larger aircraft than the XC-142.

This had already been worked out with the Air Force and was what they ordered.

Here is a comparison on how they would have differed. (The XC-142A is in the dark shade, within the outline of the planned C-142):

Love that craftsmanship on that model during the early days of wind tunnel testing.

Tilt rotors do have some major problems.

Can't have door guns, asymmetric lift causing the "death roll" when one engine is lost, can't fly high enough to avoid AA, can't fly low enough to hide from it, escort helicopters are too slow to keep up with the tilt rotor transports.

Honestly, I hope Russia avoids tilt rotors like the plague.

That said, Kamov has made some interesting fast moving gunships and transports which are not tilt rotors.

Ka-34

That is a lot of blades! I mean don't have to worry about any bird strike since this thing will just grind it all up into ground beef before the poor dead bird hits the ground.

Equation said:

That is a lot of blades! I mean don't have to worry about any bird strike since this thing will just grind it all up into ground beef before the poor dead bird hits the ground.

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There used to be a comedy show with an American actor named Tim Allen that was a host of a home improvement program within his show. I see this design and all I can think is “more power!”

Miragedriver said:

Tilt rotors do have some major problems.

Can't have door guns, asymmetric lift causing the "death roll" when one engine is lost, can't fly high enough to avoid AA, can't fly low enough to hide from it, escort helicopters are too slow to keep up with the tilt rotor transports.

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Oh Mirage I expected better from you my friend.
The issue of door guns is mostly limited to Tiltrotors of the Osprey and AW609 generation.

The problem is the Nacelles and how they interfere with the defencive arc in low speed flight. If you wanted to properly mount guns on V22 It would be in the side doors or windows the problem with V22 is in low speed when you need those guns the Nacelles are in the line of fire.

The next generation of Tiltrotor looks to change that using a fixed engine Nacelle with the Rotor tilting this allows the full defencive arc allows use of side ramps for troops and even other side mounted weapons.

As for Asymmetric lift, both engines are in fact interconnected, if one engine stops working the other can power both. the only real issue would be if you lose the rotor. in that case the pilot would push the other rotor into forward flight and glide into a landing.
As for altitude It actually can fly higher than anti aircraft fire the main issue that demands escort is when it comes into a landing and that is a problem for any aircraft trying to land in a hot zone. the escort issue is mostly a issue of the escorts just not being able to keep up. Early on in Iraq the Marines tried to fly Osprey like the Sea Knights they replaced, but they realized that's not the best use of Osprey using it's speed makes is more effective.

Honestly, I hope Russia avoids tilt rotors like the plague.

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I think Russia will pursue Compound helicopters if they can allocate the funds.
Kamov KA92 concept

That said, Kamov has made some interesting fast moving gunships and transports which are not tilt rotors.

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Gunship/ attack Transverse rotor helicopter with pusher
Kamov V100 never built

Ka-34

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Transverse rotor transport helicopter with tractors never built
the Homer... Mil Helicopter V12 Transverse rotor heavy lift helicopter actually flew in 1968.

TerraN_EmpirE said:

Oh Mirage I expected better from you my friend.

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I now stand ashamed, but better educated. Thank you TerraN.

PS: never seen a real tilt-roter I was basing on assumptions