Old designs with modern engines

[Diamondback]

It's all SO much easier in plastic......................... 

I'm remembering that line in The Hunt for Red October about "it might seem just that simple in a cubicle at Langley, but out here on the North Atlantic with half a million tons of Soviet warships bearing down on us things get a bit more complex."

Sorry, just struck me as relevant in a humorous way.

[PR19_Kit]

I'm remembering that line in The Hunt for Red October about "it might seem just that simple in a cubicle at Langley, but out here on the North Atlantic with half a million tons of Soviet warships bearing down on us things get a bit more complex."

Sorry, just struck me as relevant in a humorous way.

Oh yes, one of my fave films ever, I just wish they'd cast Harrison Ford in the Jack Ryan role, I can't think of Alec Baldwin as him these days.

[Diamondback]

Ford refused because he went Bitchy Little Girl about playing second-fiddle to Sean Connery again after Indiana Jones and the Last Crusade, where he felt Connery overshadowed him in what was supposed to be HIS movie.

Bonus for the Movie WHIF: Cast Ford = no Career Launching Event for Baldwin  = Baldwin stays a nobody = Rust never gets made = Halyna Hutchins alive today.

[McColm]

There's an interesting drawing in the book Nimrod's Genesis a proposal to re-engine the Avro Shackleton MR.3 with the Napier Eland turboprop.
I've got the Airfix Avro Shackleton MR.2 in the stash along with the engines from the Airfix and Revell Fairey Rotodyne. There's a broken propeller on the Airfix kit so these will be changed.

[Spino]

Jon:

Agree with you about how to do it model-wise.

Real-world wise, it doesn't matter if you go inboard or outboard when making the A-5's intakes bigger, because they go through a hole in a fuselage frame (two actually, if you count the one at the front of the engine). Whether you make that hole bigger inboard, outboard, upwards or downwards, you're still removing metal from a major structural component, which will require it's redesign and restressing, and all the knock-on consequences for the rest of the airframe. It's not that it can't be done, it's that it involves so much work that it probably wouldn't be economically viable. That doesn't mean it would never be done either: politics and/or military neccessity can sometimes make economically dubious decisions neccessary. If the UK had bought A-5s instead of F-4s, we might well have Spey-ised them too for political reasons, and hang the cost.

It's also worth pointing out that although the changes to the Spey-Phantom might have be slight dimensionally, they were still enough to signifantly screw up the aerodynamics to the detriment of performance. That means that if you expand the A-5's intakes upwards, downwards or outboard, you'll probably also have to put it back in the wind tunnel and make further aerodynamic modifications, at more cost, time etc...

So putting TF41s in an A-5 might have been a job due to the engine installation, but its USAF counterpart would have had no such issues 
In my mind, that makes for a really interesting what-if scenario where the F-111 never happens (otherwise there would be no need to update the things it was supposed to replace), and instead TAC's old Century Series fighter bomber stays around (F-105 or F-107) and SAC keeps the B-58.  Because its engines were podded, an engine swap on the B-58 would theoretically be about as easy as you could ask of a supersonic strike aircraft/bomber.  All you'd need would redesigned engine nacelles to some extent, worst case they have to be completely re-worked.  Still that seems a lot more feasible than re-working the internal arrangement of something like an A-5.

[Weaver]

Jon:

Agree with you about how to do it model-wise.

Real-world wise, it doesn't matter if you go inboard or outboard when making the A-5's intakes bigger, because they go through a hole in a fuselage frame (two actually, if you count the one at the front of the engine). Whether you make that hole bigger inboard, outboard, upwards or downwards, you're still removing metal from a major structural component, which will require it's redesign and restressing, and all the knock-on consequences for the rest of the airframe. It's not that it can't be done, it's that it involves so much work that it probably wouldn't be economically viable. That doesn't mean it would never be done either: politics and/or military neccessity can sometimes make economically dubious decisions neccessary. If the UK had bought A-5s instead of F-4s, we might well have Spey-ised them too for political reasons, and hang the cost.

It's also worth pointing out that although the changes to the Spey-Phantom might have be slight dimensionally, they were still enough to signifantly screw up the aerodynamics to the detriment of performance. That means that if you expand the A-5's intakes upwards, downwards or outboard, you'll probably also have to put it back in the wind tunnel and make further aerodynamic modifications, at more cost, time etc...

So putting TF41s in an A-5 might have been a job due to the engine installation, but its USAF counterpart would have had no such issues 
In my mind, that makes for a really interesting what-if scenario where the F-111 never happens (otherwise there would be no need to update the things it was supposed to replace), and instead TAC's old Century Series fighter bomber stays around (F-105 or F-107) and SAC keeps the B-58.  Because its engines were podded, an engine swap on the B-58 would theoretically be about as easy as you could ask of a supersonic strike aircraft/bomber.  All you'd need would redesigned engine nacelles to some extent, worst case they have to be completely re-worked.  Still that seems a lot more feasible than re-working the internal arrangement of something like an A-5.

Oh hell yes: afterburning TF-41s would be very easy to do on a B-58 and they'd be a huge advantage since range was the aircraft's primary failing and the turbofans' better fuel consumption in the cruise would increase it significantly.

Imagine if Polaris had run into more development troubles and wasn't ready by 1962. Kennedy might have offered Macmillan Spey-engined B-58s instead of Polaris at Nassau, with the British then runiing a national programme to develop a stand-off missile to replace the free-fall bomb in the split pod. An anti-flash-white B-58 with fat engine pods, a missile on the pod and low-vis RAF markings sounds pretty sexy...

Republic offered the RAF F-105s with Olympus or Conway engines as a cheaper TSR.2 alternative, so it was definitely feasible to fit it with a big afterburning turbofan like the Conway. Not sure how they intended to deal with the requirement for bigger intakes, but since they were part of the wing and the wings were separate left and right components that just bolted to fuselage frames, it would probably have been feasible to "just" design new wings to incorporate them. You also need a bigger hole in the fuselage to get the air inboard of course, but that's likely to be between fuselage frames so less of a problem.

[PR19_Kit]

Not sure how they intended to deal with the requirement for bigger intakes, but since they were part of the wing and the wings were separate left and right components that just bolted to fuselage frames, it would probably have been feasible to "just" design new wings to incorporate them. You also need a bigger hole in the fuselage to get the air inboard of course, but that's likely to be between fuselage frames so less of a problem.

How about splitting the area of the intakes horizontally on their centre line and raising the top half relative to the bottom half? The aerodynamics of the 'Ferri-ness' should stay the same as it would have the same plan view, and the minimum span-wise change shouldn't raise the drag too much, hopefully.

[Weaver]

Not sure how they intended to deal with the requirement for bigger intakes, but since they were part of the wing and the wings were separate left and right components that just bolted to fuselage frames, it would probably have been feasible to "just" design new wings to incorporate them. You also need a bigger hole in the fuselage to get the air inboard of course, but that's likely to be between fuselage frames so less of a problem.

How about splitting the area of the intakes horizontally on their centre line and raising the top half relative to the bottom half? The aerodynamics of the 'Ferri-ness' should stay the same as it would have the same plan view, and the minimum span-wise change shouldn't raise the drag too much, hopefully.

Yes that's the first thing I though of, but then it would make the wing behind the intake proportionally thicker, which isn't good for transonic aerodynamics.

The other thing you could do is add a section inboard at the wing root that makes the intake wider. Yes, there'd be more bending moment at the root, but then a bit more metal should fix that. The main thing is that the t/c ratio remains the same. That's also a good way to do it modelling-wise. Glue a sheet of plasticard to the wing root, trim off the excess, rinse and repeat.

[NARSES2]

with the British then runiing a national programme to develop a stand-off missile to replace the free-fall bomb in the split pod.

Would that be running or ruining ? The later sounds far more appropriate for any UK defence project   

[scooter]

A random thought, and one to move away from aircraft - torpedo boats make a return powered by marine turbo-diesels with pumpjets instead of screws.

[Diamondback]

Is this to prevent screw fouling or trying to reduce noise signature? Those diesels are gonna be heard for miles unless you run diesel-battery like an SSK... then you've robbed the TB (assuming you're thinking like s Vosper or an Elco MTB/PT, not the type of small destroyer) of its light weight, small size and high speed advantages.

The small-destroyer kind, outfitted as a littoral warship, it might make sense for say Taiwan or Korea, someplace that has extensive shallow offshore waters with enemies across a strait or channel rather than an ocean. Maybe some for Norway in case Putin decides to sortie what's left of the Northern Fleet, or Japan if he decides he's feeling frisky in Vladivostok.

[Charlie_c67]

Unless you made it into some sort of hydrofoil, which I believe has been done?

[Weaver]

with the British then runiing a national programme to develop a stand-off missile to replace the free-fall bomb in the split pod.

Would that be running or ruining ? The later sounds far more appropriate for any UK defence project   

It's mixed: the failures definitely get far more attention than the successes. We've been doing rather well with missiles lately, but there's hardly any publicity about it: Starstreak, ASRAAM, Meteor, Sea Ceptor, Brimstone, Martlet...

[NARSES2]

with the British then runiing a national programme to develop a stand-off missile to replace the free-fall bomb in the split pod.

Would that be running or ruining ? The later sounds far more appropriate for any UK defence project   

It's mixed: the failures definitely get far more attention than the successes. We've been doing rather well with missiles lately, but there's hardly any publicity about it: Starstreak, ASRAAM, Meteor, Sea Ceptor, Brimstone, Martlet...

Quite possibly, but I'd still like to have a look at cost over-runs (and yes I know all modern day cost estimates are ludicrously optimistic) and also projected in-service times to actual. I just grew up in a working enviroment (completely different I know) where I was expected to produce accurate estimates for both.

I was actually basing my comment to some extent on your spelling of "runiing", and yes I am the world's worst speller   

[Weaver]

with the British then runiing a national programme to develop a stand-off missile to replace the free-fall bomb in the split pod.

Would that be running or ruining ? The later sounds far more appropriate for any UK defence project   

It's mixed: the failures definitely get far more attention than the successes. We've been doing rather well with missiles lately, but there's hardly any publicity about it: Starstreak, ASRAAM, Meteor, Sea Ceptor, Brimstone, Martlet...

Quite possibly, but I'd still like to have a look at cost over-runs (and yes I know all modern day cost estimates are ludicrously optimistic) and also projected in-service times to actual. I just grew up in a working enviroment (completely different I know) where I was expected to produce accurate estimates for both.

I was actually basing my comment to some extent on your spelling of "runiing", and yes I am the world's worst speller   

That's all right Chris, I'm the world's worst proof-reader: no matter HOW many times I re-read what I've written, I ALWAYS spot something wrong 10 seconds after hitting "post".

As far as I know, all the projects I listed except ASRAAM came in more or less on-budget and on-cost, and the problem with ASRAAM was partly due to non-UK politics, because it was originally part of the UK/US missile agreement whereby we dropped Active Skyflash in favour of AMRAAM and the US was supposed to buy ASRAAM instead of yet another Sidewinder upgrade. Except then they didn't...