avatar_rallymodeller

Applying the Singaporean Skyhawk idea to other aircraft

Started by rallymodeller, July 19, 2011, 02:01:58 AM

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rallymodeller

The A-4S was pretty spectacular, I think we can all agree. With the F404 engine, new avionics and so forth it was basically a brand-new and much more potent Scooter. It got me to thinking...

Follow me, here. I was flying around the Sim Universe in my lovely Virtavia Supermarine Scimitar F.1, an update of the old Alphasim one (also lovely).

Suddenly, an idea.

RR Avon 301R (as fitted to Lightning F.6): 
Length: 126" (3200mm)
Diameter: 35.7" (907mm)
Dry Weight: 2,980lb (1310kg)
Max thrust: 12,690lbf dry, 16,360lbf reheat

F404-GE-402:
Length: 154" (3912mm)
Diameter: 35" (889mm)
Dry Weight: 2,282 lb (1036kg)
Max thrust: 11,000lbf dry, 17,700lbf reheat

Now, there have been specific F404 variants developed that dispense with reheat (as intended for the A-6G) that make more dry thrust, although I have no figures handy at the moment.

So here's my thought. Just about anything with an Avon could be re-engined relatively easily with an F404: Canberra, Lightning, Scimitar, Swift, Hunter, Draken...

The F404 is better on fuel, lighter, better service intervals, and is basically self-contained (so no issues with accessory drives and such). In an application such as the Lightning, much of the extra length comes from the convergent/divergent nozzle, and that would poke out the back.

In something like a Hunter, the benefits would be pretty spectacular; same goes for a GE-engined Scimitar. A Lightning with an extra 2000lb thrust in reheat would be awesome.

Any other ideas along the same lines?  The SNECMA M88 (Rafale) is about the same size as an Avon as well...

So put it all together. A Lightning with F404s, Blue Vixen radar, advanced HUD, Sky Flash and Sidewinders (F.53 pylon fit)... a 60s fighter that could turn and burn with the best of them. Or if you want to go really bat-guano insane, power it with EJ200s (20,000lbf in reheat -- an extra four tons of thrust!)

Alternately (and this was the idea I had for an AU Jamaica I'm toying with, more below), a Scimitar with "semi-reheat" F404s (single-stage reheat for T/O and speed boost only). Delete the wingfold and associated carrier gear and add a couple of extra lightweight pylons (500lb each) for ECM or Sidewinders, and a belly pylon for recon gear. Return the original rounded nose to house the bombing/nav system out of a Jaguar GR.4B or Harrier GR.7.

Quick version about Jamaica: in the wake of the Cuban War (a quick, indecisive combat stemming from the Missile Crisis, Kruschev didn't blink) Great Britain arms Jamaica and retains a substantial presence there. All the existing Scimitars (about 35) are transferred from the RN to the Jamaican Defense Forces along with some Hunters and such. Later Lightnings are provided, all F.2s brought up to full F.6 standard. And so it goes...

If anyone wants to flesh that out, have at it. I just really thought that the Scimitars got a bad break and would have made a brilliant land-based strike aircraft but the carriers kinda got the better of them.
--Jeremy

Poor planning on your part does not constitute an emergency on my part...


More into Flight Sim reskinning these days, but still what-iffing... Leading Edge 3D

rallymodeller

--Jeremy

Poor planning on your part does not constitute an emergency on my part...


More into Flight Sim reskinning these days, but still what-iffing... Leading Edge 3D

GTX

All hail the God of Frustration!!!

PR19_Kit

Oh YESSSSSSSSSSSSSSSSSSS!

Now that I like, a lot!  :wub: :thumbsup: :bow:
Kit's Rule 1 ) Any aircraft can be improved by fitting longer wings, and/or a longer fuselage
Kit's Rule 2) The backstory can always be changed to suit the model

...and I'm not a closeted 'Take That' fan, I'm a REAL fan! :)

Regards
Kit

ChernayaAkula

Cheers,
Moritz


Must, then, my projects bend to the iron yoke of a mechanical system? Is my soaring spirit to be chained down to the snail's pace of matter?

Rheged

Quote from: PR19_Kit on July 20, 2011, 03:00:48 AM
Oh YESSSSSSSSSSSSSSSSSSS!

Now that I like, a lot!  :wub: :thumbsup: :bow:

I would like to be associated with this gentleman's assessment of the work!
"If you can keep your head when all about you
Are losing theirs and blaming it on you....."
It  means that you read  the instruction sheet

Geoff

Quote from: Rheged on July 20, 2011, 09:27:37 AM
Quote from: PR19_Kit on July 20, 2011, 03:00:48 AM
Oh YESSSSSSSSSSSSSSSSSSS!

Now that I like, a lot!  :wub: :thumbsup: :bow:

I would like to be associated with this gentleman's assessment of the work!

Wot they said!!!!!!

Mossie

Go for it!  How about introducing the solid nose & full belly pack of the VG naval variant.  Would mean you wouldn't have to worry about fleshing out the fuselage for the extra width needed by the Speys & would give you better range & weapons carriage (a weapons bay could be incorporated into the pack).

I don't think it's nice, you laughin'. You see, my mule don't like people laughin'. He gets the crazy idea you're laughin' at him. Now if you apologize, like I know you're going to, I might convince him that you really didn't mean it.

rallymodeller

I was thinking about the VG Lightning when I was working this out, but the criteria I used were that there had to be as few airframe mods as possible. Everything that I chose had to theoretically fit in or on an existing Lightning airframe such as would be in storage at a fictional British version of AMARC. Things like composite vertical tails, horizontal stabs and non-structural belly tanks are relatively cheap and easy. Since the original belly pack is non-structural and detachable, the idea of making it out of composite and enlarging it slightly, then fixing it to the airframe wasn't a stretch. I nixed the solid nose for the same reason; might as well build new aircraft instead of updating old ones. A fuselage stretch forward of the wing would be possible, but only within the limitations of aerodynamics and keeping the area rule in effect.

Cost is also why I chose the RB199 or F404 as engine choices as opposed to the EJ200; the RB199 and F404 are proven engines that can be had relatively easily and are still in use (and can be swapped with the Avon almost without modification), while the EJ200 is a newer design that is still pretty pricey; same goes for the SNECMA engine from the Rafale (the Rafale prototypes used F404s).

While the performance improvement of this Lightning wouldn't be spectacular -- the original was pretty racy in the first place -- the benefits would come in serviceability, cost of use and combat effectiveness.

Once again, the inspiration for this came from the A-4S(Mod), and to some extent the Israeli Super Kurnass Phantom program.

Working on a couple more, including a Hunter and a Buccaneer.
--Jeremy

Poor planning on your part does not constitute an emergency on my part...


More into Flight Sim reskinning these days, but still what-iffing... Leading Edge 3D

jcf

The data I have for the RB.146 Avon 300 series gives a diameter of 44" and length of 138" (Jane's ATWA 1968-69),
this length is of course w/out afterburner.  Avon diameters vary between 39 and 42 inches.

Anyhow, as the Lightning's engines are not located in the tail of the aircraft, and the exhaust/reheat system is completely
separate from the engines, you could pretty much use anything that will fit in the engine bays.  :thumbsup:


rallymodeller

Thanks for that cutaway, John! It answers some questions I had (and requires me to rethink the layout a little). I think my choice of engine is still valid; swapping a modern low-bypass turbofan for the Avon turbojets would still be of benefit, methinks. Just now you wouldn't be able to tell by looking at the side; the convergent-divergent nozzles would be hidden. The F404 and RB199 are still the only choices I can come up with that fit the diameter requirement and are still short enough to fit in the engine access hatches (most low-bypass military engines are more than 150" long, although some might be shorter without the integral afterburner sections attached -- the RM8B lists as 28' long!).

Gonna have to do more research. 



--Jeremy

Poor planning on your part does not constitute an emergency on my part...


More into Flight Sim reskinning these days, but still what-iffing... Leading Edge 3D

jcf

#11
The non-afterburning F404-GE-100D used on the A-4S is 89 inches long:
http://www.geae.com/engines/military/f404/f404-100d.html

The F404-F1D2 from the F-117 is 83 inches long:
http://www.geae.com/engines/military/f404/f404-f1d2.html

So it looks like, lose the integral afterburner - lose half the length.  ;D

An RB199 w/out the integral afterburner/thrust reverser would probably be equally compact,
but would require redesign.
http://www.mtu.de/de/products_services/military_business/programs/rb199/brochure_rb199.pdf

Silver Fox

Of course, any surviving Lightning F.7s could be fitted with the GE F414. Same dimensions as the F404, but a modest thrust upgrade to 22,000 lbs in burner. :)