Converting Civil Aircraft to Military use

[elmayerle]

Actually, a better approach for an AEW MU-2 would be to use conformal arrays similar to IAI's PHALCON system.  Starting with a long-body MU-2 (perhaps a Marguise re-engined with a still-later TPE331 variant), extend the sponsons forward to house the side-looking arryas and do a longer, reduced-taper nose to house the forward array (either that or use a cylindrical extension of the nose such as was proposed for mounting the FLIR in the MU-2 entry for the Customs inspection aircraft (as I remember, that was won by a Citation derivative).  Rearward-looking array would likely require a bulge in the aft fuselage, somewhere.  You could probably do some interesting mods to the tiptanks, too.  Most of this is working from 30-year-old memories from when I worked for Mitsubishi Aircraft International in San Angelo, TX as one of the few engineers at that facility.

Another reason I'd suggest the conformal arrays is that the MU-2 doesn't sit that high off the deck and there's not much room underneath to carry a stowed radar antenna.

[kengeorge]

Morning,
    Thanks guys for the comments. Yes The Sherpa Snoopy is ugly, and that is the point. I tried to make it in a phalcon style as I thought it would be impractical to have a rotodome or any other type of radar fit.
    The back stories to the Sherpa's goes a bit like this;-
    The US Air Force bought some 18 C-23A's to use as intra-theatre transports between 1984-5, by the USAFE as a cost-effective trash hauler for its EDSA (European Distribution System Aircraft Program), and created the 10th MAS to operate them.
    This lasted all of five years, as the USAFE disbanded both the EDSA and the 10th MAS in 1990 (no idea why). 15 C-23A's were transferred to the US Army. In my whiff the USAF had been studying a concept of using small to medium sized STOL type aircraft as a low cost special forces transport and possibly as a light weight gunship to compliment the AC-130's in both Iraq and Afghanistan....
    As for the Falklands Sherpa's, I think there is a thread somewhere on alt.history about the second Falklands war, or something like that, as I thought about what type of aircraft would be suitable for use by a small air force on those islands. Short runways, etc.
    That's enough waffle for now, got some more profiles to get finished, like a 70's vintage Israeli B707 tanker and Aeronavale Dassault Mercurie MPA's
    TTFN
    Ken

[dy031101]

Actually, a better approach for an AEW MU-2 would be to use conformal arrays similar to IAI's PHALCON system.

Another big nose......? 

Is there one that fits Lawman's requirement for a fixed-wing STOL aircraft capable of taking off from a 24000-28000 tons carrier without catapult or arresting gear (he mentioned reverse pitch propellers to reduce landing distance) and out-performing Sea King AEW at altitudes but does not need to have a big nose?

[elmayerle]

Actually, a better approach for an AEW MU-2 would be to use conformal arrays similar to IAI's PHALCON system.

Another big nose......? 

Is there one that fits Lawman's requirement for a fixed-wing STOL aircraft capable of taking off from a 24000-28000 tons carrier without catapult or arresting gear (he mentioned reverse pitch propellers to reduce landing distance) and out-performing Sea King AEW at altitudes but does not need to have a big nose?

Well, the trick for the MU-2 would be going for a reduced taper on the nose, to allow a decent view for the pilots while making room for an adequate antenna (it doesn't need to be a "snoopy" nose, just a longer one).  The fairing forward of the gear doors on the long MU-2 are just fiberglass and could easily be extended to cover the [/i]PHALCON[/i]-style arrays on either side and the tip tanks could be mod'ed much as those on the U-36 Learjets for the Japanese to carry more antennae without causing much more drag), the big problem would be the aft-looking array which would need some bulges.  The long MU-2 would be a good choice since it's got excellent short field performance and a very sturdy landing gear (a variant of the short MU-2 was used as an "army cooperation" aircraft by teh JGSDF and carried an internally mounted .50 cal machine gun).  You would likely also need a very good high-speed datalink to the carrier because even the long MU-2 is not a roomy aircraft.  The MU-2, though, is a very rugged aircraft and has the advantage of no hydraulics to give you fits, everthing is mechanical or electro-mechanical.

[dy031101]

I came across a description of the An-71 last night......

Would its scheme of a radome on the new forward swept tailfin work on STOL turboprop planes like MU-2 as well?

[elmayerle]

I came across a description of the An-71 last night......

Would its scheme of a radome on the new forward swept tailfin work on STOL turboprop planes like MU-2 as well?

Probably, though you couldn't put as large an antenna on top with the difference in airframe size.  Still, I'd think it eminently feasible.  It'd take a bit of engine system installation redesign, but you could likely mount a second alternatore on each engine (where the hydraulic pump would normally go) to supply the extra power your radar would require.  From a weight and interior room standpoint, you'd almost have to do this with the Marquise or one of its predecessor long-body MU-2s.

[Shasper]

Dam thats sum good stuff!

Just thinking aloud here, but would the Sherpa be able to take the force of the Bofor? I admit I know nothing of the type's capability but it looks like the 40mm would really tax the airframe due to the recoil of the said gun. Having said that, what about a "Jackhammer Lite" (Ball Ping Hammer?), armed with a pair of M134 Miniguns & a M197 20mm cannon (same gun as on the AH-1W) plus the externals you listed?

Shas

[dy031101]

Probably, though you couldn't put as large an antenna on top with the difference in airframe size.  Still, I'd think it eminently feasible.  It'd take a bit of engine system installation redesign, but you could likely mount a second alternatore on each engine (where the hydraulic pump would normally go) to supply the extra power your radar would require.  From a weight and interior room standpoint, you'd almost have to do this with the Marquise or one of its predecessor long-body MU-2s.

I'm kinda still thinking about one with systems taken directly or derived from Sea King AEW (or am I underestimating the capacity of the Sea King?) with a different radome similar in style with An-71 but not necessarily similar in size.

How would the alternator on each engine have looked like externally?

[kengeorge]

Morning,
 
    Shasper, good thinking, I have an RAF Sherpa needing some fine tuning and may alter it, or have two gunships for the boys in blue, or better still, operated by the Army, to provide their own air support to supplement the AAC's AH-64's? Though I don't know what to call them. "Jackhammer" might be an inappropriate name for an RAF type, so I'm open to suggestions.
     Got one for you now, my take on what if Boeing won the US Navy's 1957 type spec 146 Maritime Patrol and Anti Submarine Warfare proposal instead of Lockheed and their P-3.
     More soon,
     Ken
 
   

[Shasper]

Ken,

For an RAF AC Sherpa, why not use the gun load-out I suggested except swap the 20mm for a 27mm Mauser? And whatabout "Wraith" for a name?

Shas

[elmayerle]

Probably, though you couldn't put as large an antenna on top with the difference in airframe size.  Still, I'd think it eminently feasible.  It'd take a bit of engine system installation redesign, but you could likely mount a second alternatore on each engine (where the hydraulic pump would normally go) to supply the extra power your radar would require.  From a weight and interior room standpoint, you'd almost have to do this with the Marquise or one of its predecessor long-body MU-2s.

I'm kinda still thinking about one with systems taken directly or derived from Sea King AEW (or am I underestimating the capacity of the Sea King?) with a different radome similar in style with An-71 but not necessarily similar in size.

How would the alternator on each engine have looked like externally?

The extra alternator likely would've shown only as a small NACA-scoop cooling intake on the top of the cowling, if at all.  The "spare" drive pad was centered on the engine from side to side and was above the pad and interfaces from the prop governor and other prop controls.  I think you'd want a rotodome at least as large in diameter as the radome on the AEW Sea King, bigger if possible just to get as much radar performance as possible.  You're likely to need some extra antennae for a high-speed secure datalink back to the ship for more in depth processing of the raw data.  I would expect internal seating in the long-body MU-2 to be similar to that of the E-2 and I suspect the windows would be closed out, too.

[Weaver]

Ken,

For an RAF AC Sherpa, why not use the gun load-out I suggested except swap the 20mm for a 27mm Mauser? And whatabout "Wraith" for a name?

Shas

Or a 30mm Aden for that matter.....

Also, if you buy an Airfix Scorpion tank, you also get a barrel and mantlet for the Scimitar's 30mm RARDEN. Now the clip-fed RARDEN isn't suitable for a gunship as is, but you could always use it as the basis of a whiffed belt-feed model.

[dy031101]

I think you'd want a rotodome at least as large in diameter as the radome on the AEW Sea King, bigger if possible just to get as much radar performance as possible.

Would changing the Searchwater radome from a dome to a dish sound like a good idea?

If it would, how much would the long-body MU-2's takeoff and landing characteristics be affected?

[elmayerle]

Well, I suspect that under that dome there's a rather smaller antenna.  I don't think going from a dome to a rotodisk would cause all that many problems.  Too, I don't know that it'd affect the long-body MU-2's takeoff and landing characteristics much, it wouldn't interfere with the full-span flaps and the engines, especially in the Marquise, as significantly flat rated that I doubt there'd be much effect.

[kengeorge]

Morning,
   Nearly Christmas,just thought I'd cheer every one up.
   Shasper,good idea on the Sherpa, took your advice, look at the profile,
under the cockpit window.
   I have done  a Royal Norwegian Air Force P-4 as well.
   Been considering, apart from the usual suspects, what other countries, would/could use
Maritime Patrol / Anti Sub aircraft, that at present don't. Any suggestions? As I'm stuck.
   Ken.