Dec 272016

Recently sold on EBay was a sizable (something like 4′ long) wind tunnel model of the Curtiss Wright Model 90 AAFSS submission. This was a derivative of their X-19… more or less a quad-tilt-rotor. The Model 90 would have been fairly highly armed, designed to fulfill the same role that the winning AAFSS design – the Lockheed AH-56 Cheyenne – was designed for: transporting troops and tearing up ground targets. The US has not had an operational vehicle like this; the Soviet “Hind” helicopter is the closest, though substantially slower, analog. EDIT: Senior moment. Not a troop transport, just a blowin’-up-stuff-on-the-ground-real-good vehicle.

The Model 90 wind tunnel model was formerly on display at an aviation museum in Teterboro, New Jersey. No idea where it ended up, but hopefully it found a good home. I made a half-assed effort to crowdfund this one, but I think the lack of a good way to split the spoils among the funders doomed the concept. How *do* you reward funders for a purchase like this? Best idea was to have the thing 3D scanned, and distribute the scan among the funders, but unlike a scan of a drawing or a document, that’s not going to be readily useful for most people.

What I’d hoped to do was to disassemble the model, male fiberglass molds of the components, reassemble and restore it to like-new-ish condition then send it on to an appropriate and willing museum, possibly Ft. Rucker (since they’re all about Army aviation and have themselves an AH-56). Then make a few fiberglass copies from the molds, converting the “wind tunnel models” into detailed display models. Alas.

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 Posted by at 10:37 pm
  • Paul451

    Neither the Cheyenne nor this beastie were intended to transport troops. They are both pure gunships.

    • Scottlowther

      You are of course correct. One of the difficulties in living among “projects” is they get muddled in the mind with the built stuff. Lockheed proposed troop-carrying versions of the Cheyenne, but never built ’em.

      • Paul451

        It probably doesn’t help that the X-19 was a people carrier.

        • B-Sabre

          The X-19 as built was not a people carrier – there was no real space available in the aircraft for anybody but the pilots. There were plans for utility and cargo variants of differing sizes, up to CH-47 equivalents.

      • B-Sabre

        The Sikorsky AAFSS entry, the S-67 Blackhawk (not to be confused with the S-70 Black Hawk) did have a small internal bay that could carry 4-6 troops, right under the main rotor/transmission pack. Entry and exit was through a pair of “bomb bay” doors. I imagine that if it it had ever entered service, that space would have been used for fuel or weapons….

  • B-Sabre

    more or less a quad-tilt-rotor….

    Well…no, it’s not a tilt-rotor. The props only had pitch control – no lag/lead hinges, and no cyclic controls. They were firmly propellors.

    Funny story – I have a book written by the lead designer of the X-19 concept, and it talks about the development of the X-19 and projects that came before and after it. At one point, they suggested to company leadership that they add cyclic controls (controlling the pitch of a blade as it moves through a specific location relative to the aircraft) to the props in order to make controlling the aircraft in hover easier, and they were told “Curtiss-Wright is a propellor company. We add cyclic control, and we are building rotors, not props. And we build props.”