Aug 132010
 

In 1974, the US Navy was looking forward to smaller “Sea Control Ship” aircraft carriers packing VTOL fighters like the ill-fated Rockwell XFV-12. Smaller carriers would be cheaper than giant supercarriers, so there could be more of them, spread to the numerous hotspots of the world… or at there very least there would be some of them, as the military budget was way down. The VTOL capability of the fighters would mean the smaller decks would not be a major hinderance to flight operations.

Planners were sufficiently optimistic about the chances for VTOL fighters that companies began sketching out ideas for minimum-size carriers. Normally nobody would ever think of landing a jet fighter on something the size of a Coast Guard cutter, yet helicopters do so with some regularity; so in principle is should be possible to operate VTOL fighters from ships this size. So companies and military organizations produced artwork (it’s unclear how detailed and rigorous the actual designs were) of small ships capable of carrying one or two fighters.

One Boeing notion called for the use of a fast hydrofoil boat to carry a single fighter. In this case the fighter was a VATOL (Vertical Attitude Takeoff and Landing) design… not exactly a tailsitter, but instead operating in the same fashion as the Ryan X-13. A landing platform would be raised to the vertical (like a billboard), and the fighter, standing on its tailjets, would mosey on up to it and latch on. Aware of the difficulties encounted by similar VATOL craft in the past, specifically the trouble the pilot has in seeing where he’s going when his cockpit is pointing straight at the sky, Boeing fitted their fighter design with a cockpit that could tilt “down” 90 degrees, allowing the pilot to remain comfortably upright while the plane bent underneath him.

boeing.GIF

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A US Navy concept sketch used the XFV-12, with two of these planes operating from an Advanced Marine Vehicle. This would be used to support a larger conventional carrier group, by providing a ring of interceptors and similar missions.

amv.GIF

Of course, the whole idea fell flat. The XFV-12 proved wholly incapable of lurching itself into the sky, and the one VTOL fighter to enter US service, the AV-8 Harrier, proved to be somewhat troublesome (it’s jet exhaust would happily bore holes through the decks of most ships, for instance). By the 1980’s, the budget for the military began to go back upwards, and Cheap Small Aircraft Carriers fell out of favor.

 Posted by at 10:51 pm

  4 Responses to “VTOL on a boat”

  1. The XFV-12 aircraft was one of the single most embarrassing moments in the history of the whole US Navy.
    “What do you mean: ‘It can’t even take off?’ “.
    You know, after the Lockheed Hummingbird flop, they should have realized that this whole propulsion concept didn’t work:
    http://www.liveleak.com/view?i=577_1243691437
    ..yet it shows up again in the Boeing JSF prototype.
    Apparently, every major aircraft firm must have a take at this concept only to watch it blow up in their faces.
    Let’s wait to see what the future Northrop one will look like. 😀

  2. Regarding that top drawing BTW…you know, a hydrofoil needs to be going forward fairly fast to remain foil-borne.
    Raising a giant airbrake at the stern is not going to help it maintain high speed.
    In fact, when you raise it at foil-borne speed there’s a real good chance that the front foil is going to come clean out of the water and the whole works flip onto its back. 😀

  3. One of my aerodynamics professors told a story that he’d supposedly heard from a friend at Rockwell. A team of engineers were trying to calculate devise a solvable formula for one of aspects of the lift engine design (computer simulations weren’t viable for this yet). They had several white boards filed with equations when an old, gray-haired senior engineer stopped by.

    He asked what they were working on, and when they told him he responded with something along the lines of “Just use .85 – that what we’ve measured for that sort of thing on every test I’ve been involved with.” The other engineers thanked him for his advice, then turned back to their equations. When the prototype was finally built, and failed to fly, my professor claimed that the old guy’s number was almost exactly what they measured.

  4. They keep trying that vertically-entrained ambient atmosphere concept that’s going to increase vertical lift thrust markedly via something like the venturi effect…sometimes up to large scale models in a wind tunnel… and it _never_ ends up giving the estimated lift thrust in the actual aircraft once it’s built.
    Boeing got an award for their work on it for their JSF prototype…not that anyone was actually going to build the flying iron bathtub with a delta wing atop it concept, but Boeing had to be saluted for doing a better job on a really crappy lift engine concept than anyone had ever done before. 😀

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