The BAe Nimrod Tanker/Cargo version

[McColm]

Hi,
I thought of building a tanker/cargo version of the BAe Nimrod MK2. I read somewhere that a proposal of fitting a longrange fuel tank in the weapons bay had been submitted, along with a fifth engine in the tail section.
I would use the Victor hose and drogue kit, that way I can display the finished model in flying mode on a stand.
having been directed to the Heritage Models and David J Parkins sites my options have increased and the price of the Airfix kit has come down.
Traditionalists are going to hate me, but we are in whiff-land so the unthinkable can be built.
What if there was an aircraft carrier large enough to handle a Fleet Air Arm version? I know that you couldn't stow it away in the maintenance hold,but folding wings. Now there's a thought.

[Weaver]

Folding wings would not be beyond the bounds of possibility: the wings of the MRA.4 (and I presume of the MR.2) are made in separate inner and outer sections. The joint is just outboard of the undercarriage.

[James]

What if there was an aircraft carrier large enough to handle a Fleet Air Arm version? I know that you couldn't stow it away in the maintenance hold,but folding wings. Now there's a thought.

Mental idea. 




Do it! 

[McColm]

Thanks,
Maybe a plug to extend the fuslage forward of the wing section, the searchlight replaced by a weather radar.

[McColm]

Some pics for inspiration:

[Nigel Bunker]

Two things about putting a Nimrod onto a carrier.

Firstly, you would need a massive arrestor wire, along with a beefing up of all the assiciated apparatus. I have a mental image of an unstoppable Nimrod rolling on down the deck, draggind the arrestor wire behind it with the retading apparatus bouncing after it, writing off parked planes as it goes.

Secondly, how much would a fuelled Nimrod tanker weigh? I an just see it as the catapult is released, and the Nimrod sits there, the catapult having insufficient energy to move the Nimrod - or perhaps the Nimrod slowly moving along the deck then falling off of the front of the flight deck.

I think it will have to stay land based.

[PR19_Kit]

I an just see it as the catapult is released, and the Nimrod sits there, the catapult having insufficient energy to move the Nimrod - or perhaps the Nimrod slowly moving along the deck then falling off of the front of the flight deck.

Nope, as the cat officer gives the 'Fire!' order the Nimrod stays were it is and the CARRIER goes smartly astern at some impressive rate of knots!   

What a diorama THAT would make! 

[Mossie]

There was a COD variant of the DC-9 proposed IIRC so putting a Nimrod on board a carrier is only a little bit nuts!  Maybe HMS Habbakuk 1980?

[kitnut617]

A C-130 was landed on an aircraft carrier during some tests.  Its about the same size as a Nimrod

[Weaver]

A C-130 was landed on an aircraft carrier during some tests.  Its about the same size as a Nimrod

In addition to Flatley, the crew consisted of Lt.Cmdr. W.W. Stovall, copilot; ADR-1 E.F. Brennan, flight engineer; and Lockheed engineering flight test pilot Ted H. Limmer, Jr. The initial sea-born landings on 30 October 1963 were made into a 40-knot wind. Altogether, the crew successfully negotiated 29 touch-and-go landings, 21 unarrested full-stop landings, and 21 unassisted takeoffs at gross weights of 85,000 pounds up to 121,000 pounds. At 85,000 pounds, the KC-130F came to a complete stop within 267 feet, about twice the aircraft's wing span! The Navy was delighted to discover that even with a maximum payload, the plane used only 745 feet for takeoff and 460 feet for landing roll. The short landing roll resulted from close coordination between Flatley and Jerry Daugherty, the carrier's landing signal officer. Daugherty, later to become a captain and assigned to the Naval Air Systems Command, gave Flatley an engine "chop" while still three or four feet off the deck.

...

From the accumulated test data, the Navy concluded that with the C-130 Hercules, it would be possible to lift 25,000 pounds of cargo 2,500 miles and land it on a carrier.

from here: http://www.theaviationzone.com/factsheets/c130_forrestal.asp

Wings:

Nimrod (MR.2) wingspan = 115ft, area =  2,121 sq/ft

C-130 wingspan = 133ft, area = 1,745 sq/ft

Weights:

Nimrod (MR.2) empty = 86,000lb, MTO = 192,000lb

C-130 empty = 75,743lb, MTO = 175,000lb

On the face of it, it looks doable. The Nimrod is about 10,000lb heavier than the C-130, but then that's an operational MR.2 full of ASW gear, which is not part of McColm's proposal. A figure for a stripped-out Nimrod is probably impossible to find, but a Comet had an empty weight of 75,400lb.

On the other hand, there are factors that arn't apparent from simple specs. For instance:

Landing speeds: the Nimrod wing has a lower aspect ratio than the C-130's, it isn't blown by four large props, and my guess would be that it doesn't have the same degree of high-lift devices either, so it's minimum speed may well be higher.

Stopping distance: the C-130 can use reverse pitch to stop very quickly. The Nimrod does have thrust reversers but they're pretty small and only on two engines, so I don't know if they're as effective.

[Nigel Bunker]

I know a C-130 landed on a US carrier but it did so without using the arrestor gear or the catapault. C-130 has a short field capability - I don't think the Nimrod has.

[kitnut617]

I think if they had thought about making a Nimrod carrier capable, the wing would have been significantly changed with high lift devices.  As you say, the standard wing just wouldn't have cut the mustard ---

The wing though is not a lot different in shape to the Sea Vixen's, it's just bigger.  What high lift devices were used on the Sea Vixen wing ?

[PR19_Kit]

The wing though is not a lot different in shape to the Sea Vixen's, it's just bigger.  What high lift devices were used on the Sea Vixen wing ?

Flaps...........

[Weaver]

Another issue would be undercarriage. The C-130's is designed to take the high sink rates associated with STOL, but the Nimrod's isn't. Surprisingly, the Nimrod has more wheels than the C-130, so I suspect static deck loading isn't an issue, although if the undercarriage isn't adapted, transient deck loadings on touchdown might be.

There are limited opportunities to add high lift devices to the Nimrod wing without completely redesigning it. The problem is that the entire outer wing box, outboard of the undercarriage, is integral tankage. The entire trailing edge is already flaps, so that means the leading edge fairing is the only place to putthe very large cable and pipe runs going to the tip pods. I think that pretty much rules out mechanical leading edge devices, although one thing that occurs to me is blowing. You could, in theory, redesign the leading edge fairing to make it a bit deeper (increasing the chord marginally), give it some droop, and run an air bleed pipe along it feeding an upper surface blowing slot in the manner of the Buccaneer. There's already a de-icing duct there, so basically, just make it bigger. Ideally, you'd want to run a blowing pipe to the tailplanes too (slot on the underside, of course), and the best way of doing that would be to take it through the ventral pannier. It'd need to go external from the back of the pannnier to a point behind the aft pressure bulkhead, but that's not the end of the world, although you would need to protect it from tail scrapes.

Of course, the other option is a bigger wing, possibly mating MRA.4-style outer wings to MR.2 inners. The MRA.4 wing adds 12ft to the wingspan (still within the C-130 envelope though) and an extra 417 sq/ft of area. If you could combine that with close to MR.2 weights then you'd have much improvement. The MRA.4's empty weight is much higher than the MR.2's of course, (112,765lb vs 86,000lb) but how much of that is in the wing?

[McColm]

Interesting thoughts.
If you were to add a triple fly-by-wire system, vectoring nozzles on all engines, arrester hook, canards. A redesigned wing, the use of carbon materials and RATO packs.
The Sea-Nimrod MK1 FRACK (fighter, reconnaissance, attack, cargo, tanker) with folding wings, state of the art avionics and a deeper weapons bay could in theory take off and land on one of the Nimitz carriers or cut and shut two Royal Navy carriers together. Now there's a whiff!!

I've found that the Revell 1/72 Tornado GR1 kit includes a buddy refueling pod, reconnaissance pod and two inflight refueling probes.
One of these will be added to my Nimrod supplied by Bungle and I could use the buddy refueling pod as well or go for a bulging centre line tank similar to the Buccaneer. Ground Clarence would be an issue, but if displayed with gear up on a stand, problem solved.