Could you have designed a better Warbird?

i would make a combo of the p-51 p-47 the 190 the 109 and the spitfire

Burmese Bandit said:

Regarding armament...I intend to keep ammo at average levels, at only 800 20 mm cannon shells, but I intend to add an extra pair of 20 mm in the wing roots to get a total of EIGHT 20 mm cannon! Two in the upper nose, two in the belly, two in each wing root! This will give a total of only nine seconds firing time if you fire all eight at once (MG 151/20 with electrical synchronization fires at 700 rpm less 10% or so), but it will give 36 seconds if you fire them two at a time. The electrical firing system of the German 20 mm shells should make this two position firing switch easy to make.

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Is it possible to syncronize 6 20mm's through the propeller all being at various different distances from the propeller? has that ever been done before? if it hasn't I can sure see why

Turning into a bomber destoyer? one quick point ,say this did all happen and you were a german avoiding all other possible problems .For a combat instance I interecepted a raid with this "Fw 47" of B-17's B-24's and with the amazing armament I was able you shoot down say 2 B-17's .I'm then in a plane with the weight of 8 20mm's and with a big bullseye that quite a few P-51/47's are not just staring at????

fly boy said:

i would make a combo of the p-51 p-47 the 190 the 109 and the spitfire

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Wanna try?

I believe I would, given hindsight, mated the Merlin to the Mustang on day 1.. and let the evolution of the H and the P-82 take it's natural course two years earlier.

Basket: my planned operational dated is 1944. All the elements I describe, the MG 151/20, the BMW, the Argus, were available is 1940. Thus I score on the historical plausibility index...

As I explained above, designs in this thread are limited to what was available at the time. I would have loved to have designed a bomber destroyer for the Axis with a R-4360 and counter rotating props. Or some other even better engine designs that came out in 1946.

As for using the twin engine on each wing solution which led to the 38, the 110, the Mosquito, etc etc etc, problems of wing weight leading to poor roll limit heavy twins in actual combat - something the USAAF and the Luftwaffe and the RAF found out when they tried to use above examples as fighters.

Watanabe: I have based my damage estimates and hit probability on actual USAAF and Luftwaffe research of the time. See Bronson in this forum, and Antony Williams' EXCELLENT site, for gun and cannon info.

109 Roaming: ditto.

Watanabe, 109 roaming: regarding LW escape maneuvers see actual reports by allied pilots on dogfighting at the time plus advisorys and manuals by RAF and USAAF on fighting LW. Warnings of the transition tactic used by FW 190 flyers are especially prominent.

Drgondog: Yep, me too! But that point you raised belongs more in the "How would you develop...." thread!

Additional info: Luftwaffe estimate of 20 mm shells needed to knock down a b-17-

16-20

LW estimate of hits scored by an average pilot - 2.5% to 4% of total shots fired

Experten of course would double or treble that number

This is why even experten flying the 109 against the B-17 could not knock them down...one 20 mm motor cannon in the nose just aint gonna cut it. And why even experten flying the FW 190 with the wing cannon found it difficult, for even 4 20 mm cannon would only damage, but not kill, the Boeing beast!

Of course the B-24 with its highly inflammable hydraulic fluid was a much easier target.

Well, there are lots of things you could do to aircraft from the get-go to improve performance, considering the level of technological advancement and refinement that went into aircraft over the 1939-1945 period.

I'm a RAF fan and my personal favourite aircraft of the war is the Typhoon. If you take a whole lot of minor improvements that happened to the Typhoon airframe (new aerials, gun shrouds, tail wheel doors, internal mass balance, new propeller, new exhaust, internal rear view mirror) and add them all together, then you end up with an startling improvement in performance.

The Typhoon improved its level speed from about 390 mph at best altitude (~18,000 - 20,000 ft) to about 415 mph at the same alt on the same power over the course of three years of refinements. 25 mph for what are essentially minor modifications to the airframe is not bad. What if they had all been there from the start? What if the Camm had designed the Tempest II from the start, instead of progressing from the Typhoon

Suppose that a couple of things happened in the Typhoon design process:

1. Sir Sydney Camm ignores both the incorrect advice of the RAE about the effect of thick, Hurricane style wings on performance and RAF's concerns about the vulnerability of wing radiators and goes with thinner, better performing wings and no chin radiator (also putting a larger fuel tank in the fuselage). Result: Better speed and dive performance at the cost of a little range, although climb performance may of suffered (although it mostly depends on wing profile and size);

2. Napier goes to Bristol in 1940 instead of 1942 to sort out some of the kinks in the Sabre, meaning a reliable engine by 1941;

3. Napier has the necessary funding to develop a two speed, two stage supercharger for the Sabre, meaning a 2,000 hp + engine that delivers rated second stage power to about 22-23,000 feet, instead of about 15-16,000 feet;

4. Camm redesigns the rear fuselage to eliminate the problem of rudder flutter and sympathetic vibrations buckling the rear fuselage at the tail joint;

5. A larger, Tempest V/II style tail is fitted to deal with torque on takeoff;

6. The cockpit seals are redesigned, meaning that carbon dioxide and other nasty gasses don't flood into the cockpit;

7. Bubble canopy from the get-go (already somewhat present on the Whirlwind), improving visibility;

8. Spring tab ailerons fitted from the start, notably improving roll performance, always a Typhoon weak spot;

9. Four bladed prop fitted from the start, improving acceleration;

10. Gun-bays redesigned, allowing more ammunition to be carried (think it was about 20 more rounds per gun at the end of the war);

11. All the little improvements previously mentioned are already there

So, with all of the redesigns what do you get?

First of all you get better reliability and serviceability. Operational readiness, the Typhoons major bugbear in the first 12 months of operations, is radically improved. No to-ing and fro-ing with the RAF about whether its going to get cancelled or not. No welding fishplates to the rear fuselage. No erks standing by with a fire extinguisher on start-up for 18 months. Pilots don't have to continually wear oxygen masks in the aircraft.

Second, overall speed is significantly improved. The big difference comes from eliminating the thick draggy wings (a la Tempest) and the honking great chin radiator. I'm not going to put an estimate down on paper, but with the thick wind and chin rad, the Tyffie could still do 417 mph at 20,000 feet

Thirdly, high level performance is DRAMATICALLY improved. Thin wings and a two stage, two speed supercharger mean that the speed and climb of the Typhoon at higher altitudes (say, above 18,000 ft) is transformed. Maybe not in the same league as the later Spitfires, but at least as good as the Merlin 61 powered Mk IX up to 25-26,000 feet.

Fourthly, the Typhoon becomes a fighter. With more speed, more power at altitude and, very importantly, a better rate of roll (spring tab ailerons) the Typhoon gets turned back into an offensive, manuverable fighter, instead of a 400 mph brick that rolls like an elephant stuck in tar.

This means offensive Rhubarbs and Rodeos at 25,000 feet across Europe and right through the Northwestern German border. No stooging about at 12,000 feet over France, looking for ground targets while being subject to flak and being bounced by all and sundry. The Typhoon's range was about 175 miles better on internal fuel than that of a Spitfire IX and range with 2 x 45 gal drop tanks was bang on 1,000 miles. Guesstimate a combat range of 350 miles, maybe more with larger D/Ts. How about the image of Typhoons escorting Lancasters and Halifaxes to Essen and Dusselfdorf, or perhaps further?

Fifthly, and finally, the aircraft becomes available earlier than historically. With a reliable Sabre, no faffing around with the Tornado/Tempest/Fury line until later in the war, no changing RAF/RAE design requirements and no redesign of minor items, the Typhoon becomes available at least 4-6 months earlier than in the actual historical timeline. That means that the Spit V has some help on hand when the FW 190s start to really make their presence felt in late 1941.

Purely hypothetically, the RAF could of had an aircraft with similar (if not the same, or perhaps a little better at altitude) performance to the Tempest in mid-1941. Around 365-375 mph on the deck, 425-435 mph at 25,000 feet, 3,600 ft/min + rate of climb, good rate of roll (never great though) and 1,000 mile range.

You can repeat this whole process for the Spitfire as well. Maybe put in a 30 gal rear fueslage tank from the start, 20 mms properly installed, better fuselage skinning and panel design for reduced drag, new profile radiators, wheel well covers, rear wheel cover, wide track, forward raked landing gear, small forward wing tanks, metal skin ailerons, internal bullet proof windscreen, better tail/rudder design, revised elevator design, multi ejector stacks, more aerodynamic windscreen, fully sealing fuel tanks, larger capacity nose tanks, revised wing spar design, revised rudder balance, stronger control linkages, frise type ailerons, blown canopy ect, ect, ect

Spring tabs aren't necessarily the best way of improving the aileron performance. (short of hydraulic boosting) If the Typhoon used a cable control system like the Spitfire and hurricane, control could be signficantly improved by switching to push tubes. (used on all operational WWII US fighters iirc, as well as the Fw 190)

Also boost tabs could be used. (as used on the Corsair's ailerons)
Boost-tabs

I theorised adoption of spring tabs because the British had been researching them since the 1920s and they were well known in the country at the time, unlike push rods, which very few British aircraft used to to best of my knowledge.

The British experimented with spring tabs all through the war. There is a very interesting Hellcat test here

http://www.wwiiaircraftperformance.org/f6f/jv224.pdf

showing the difference in rolling speed between a Hellcat with and without spring tabs fitted. The spring tabs helped the Hellcat to roll up to 19 deg/sec faster, although at some speeds its was only boosted by 1-2 deg/sec. 360 deg roll time was cut by up to 2 seconds, which is a big improvement.


Boost tabs and spring tabs appear to be virtually the same thing, unless I am mistaken. Maybe it is a difference in nonclamenture?

AHEM.

(with apologies to Lewis Carrol, forgive me my sins, Rev Dodgson...)

"T'was brillig, and the silv'ry Tiffs,
did gyre and gimball-roll in the Wind
All mimsy were the Boeing planes,
And the main planes outraided!"

Ok...silly time over...back on Topic.

Jabberwocky, thanks for an excellent post. One quick point, however. The reason why the 20 mm was so late into entry into the RAF was the terrible reliability problems of the early cannons. See Antony Williams' excellent site.

I shall now try to describe the companion I have designed for the " Burmese FW 47" which is my uber 109.

Just one point before I do, though - I do agree that having two engines in my FW 47 presents a maintenance and supply headache for the ground staff. Against that, however, I would like to point out that the Argus gained an excellent reputation for reliability and the ability to resist battle damage in actual use by the Luftwaffe on the Eastern Front.

Now I want to describe the design I've thought up for an uber 109, the flying mate of the "Burmese FW-47" I've posited above. As I've posted before, the aim is to have a dogfighter with the maneuverability of the 109 Frederich combined with the speed of the Gustav and a firepower stronger than both. As a bonus it would have potentially greater range and better pilot vision. The design constraints are that it has to be ready to be in service by early 1944 at the latest and it has to use components that were at least in production, and preferably in mass production, at the time.

As you will see this second design is actually less technologically ambitious than the previous one, but for all that it has a number of design elements which I consider to be quite innovative...as in my previous design.

My uber 109 will be designed from the get-go to have the choice of two engines: either the DB 605 at 1475 hp or the Jumo 211 at 1400 hp. In this way it will already have a production advantage in that shortages of one or the other engine could be compensated for. It will be a single liquid cooled engine design, with a tractor propeller in front and a narrow frontal area.

So far, a conventional design. However, I now intend to do something radical...I intend to split the supercharger, having one supercharger behind the engine, and a second supercharger behind the pilot's seat. The second supercharger will be run by a powershaft that comes out of the engine, goes between the pilot's legs, and goes behind the pilot's seat The output of the first charger will feed into the second, as in the Merlin 60 series ....a two stage supercharger. .

Why should I do this complex arrangement, when Rolls Royce, for example, were perfectly happy to have a conventional arrangement of two superchargers one behind the other?

Well, the answer is - efficient intercoolers and aftercoolers. With my split supercharger design, I can compress the air with the first supercharger behind the engine, and then send the supercharged air (which has been unavoidably heated by the supercharger, and thus has less density than it should have) through an intercooled pipe towards the supercharger at the back. The intake for the intercooler will be in the wing root. The intercooler will increase the density of the air as it enters the second supercharger, where it will be further compressed - and, unavoidably, re-heated - as it exits the second supercharger. From there it will be piped to the engine...but not before it is aftercooled, through an aftercooler having its intake in the other wing root.

Thus we should be able to get at least an extra 100 hp out of each engine, and most likely something like 150 hp. I shall be conservative and claim only an output of 1600 hp for the DB and 1500 hp for the Jumo. Also, the best speed height should increase, from about 20,000 feet to about 23-25,000 feet.

Now about the Radiator. This, too, is something of an innovation. I intend to put my Engine and oil Radiators in the rear fuselage of my design, but unlike the mustang's square radiator, mine will be oblong, fairly tall in height and slim It will take its cooling air from a chin intake, with a venturi tube wide at the chin intake, narrowing as it moves under the belly of the aircraft, and widening again as it moves up behind the pilot's seat. The heated air from the radiator will exhaust directly under the vertical tail, and that exhaust will have two flaps on each side to regulate the airflow to achieve the optimum Meredith effect. Thus the exhaust air will not only contribute thrust but that thrust will be exactly on the centerline of the airplane's direction of flight. Think of it as akin to the jet thrust of a single engine jet fighter.

The tail itself will be a T-tail....like the F-104 starfighter, so as to have the horizontal tail above the wing turbulence, and to avoid the airflow blanketing effect of the horizontal tail on the vertical tail when maneuvering at high angles of attack.

The rear supercharger and the rear radiator will tend to make this design tail heavy, which I will compensate by...HAVING THE ARMAMENT IN FRONT OF THE ENGINE. Yes, that's right, in front of, not over, under, or between the vee of the engine block. The armament will be a 13 MM EIGHT BARREL GATLING firing the excellent german 13 mm HMG bullet. It will fire through the spinner, which will be hollow to accommodate the gatling, in a gun position reminscent of the P-39 ...but where the P-39 had a pilot between the engine and the gun, here the gun is directly in front of the engine. The spinner will be spun by a short shaft from the engine going under the gatling and driving a gearbox.

Why the 13 mm? Well, an eight barrel 13 mm strikes the exactly the right balance between gun weight, fire rate, short length, amount of ammo, and mission necessity. Too long a gun barrel will make the nose excessively long, although some of the length of the gun will be absorbed by the spinner. The lighter 13 mm ammo will also allow a greater amount of ammo to be carried. Since this design is mainly going to fight other fighters, it should do very well against the light Yaks, and well against fighters such as the pony and spit, though not too well against the heavy armoured Jug.

Gatling rotary barrel technology, by the way, was well known to all the sides in WW II. It was a tried and true mature technology. The Gatlings will be driven electrically, of course. I see no reason why 6000 rpm or even more couldn't be fired with eight barrels.

Ah, but now someone may ask - "That's all very well, but the space at the nose is small - just about enough to put your eight barrel gatling - where are you going to put your 1200 or 1600 rounds of ammo? And won't that ammo so near the nose cause a cg shift as it is used up?"

And the answer is....the belted ammo is going to be put in a very conventional place, in the same place near the cg where the 109 had its HMG ammo, but the belt will be transported to the gatling by two ROTATING HELIX CYLINDERS. This is, by the way, similar to the helix magazine used by the Calico 9mm Carbine with 100 rounds in today's modern times. If the two magazines are put one behind the other I see no reason why up to 1800 rounds couldn't be carried. Thus the cg shift problem is solved.

Fuel tanks will be in the wings, with inner and outer fuel tanks.

So we now have:

A fighter with a two stage supercharger with both intercooling and aftercooling, radiator providing direct thrust from the tail, centerline armament with no need for synchronization, a T-tail for better handling especially at high angles of attack, and wings free of armament.

A bubble canopy would be provided, for good all around view.

Weights would closely resemble the Gustav, perhaps only slightly heavier - let's say 8000 lbs. If the outer wing tanks carried additional fuel, say 9000 lbs.

The Me-109 landing gear and wing could be re-used to speed up production. The wing would however have wingtip extensions to expand total area from 175 sq feet of the normal 109 wing to 180 sq feet. The extensions should add about 2-3 feet to total wing span. The wings would, of course, lose their wing mounted radiators and the engine would lose its chin oil radiator, though it would have the chin air scoop I mentioned above.

At 1600 hp and 8000 lbs power loading of 5 lbs per hp and wing loading of 45 lbs per sq foot.

And so....

IMHO, this design is a fighter with a high rate of fire, a bullet adequate enough to kill fighters, very good maneuverability, high speed, and good high altitude performance - superior to the Frederichs and Gustavs and even in some respects to the Kurfursts, and available in numbers by early 1944!

Now, gentlemen, thoughts and criticisms please.

A point on maintenance, though.

The nose guns of the earliest P-51s, which were in a place similar to the helix drive on my uber 109 design, (except they were down under the nose instead of at the top of the nose) caused problems in maintaining the engine of those early ponies. I suspect the helix drive would, too, in my design.

The solution would seem to be to make the entire nose as one quick change detachable unit - The engine, gearbox, spinner, the cowling, the chin intake, the 13 mm gatling.

And what is this fighter going to made out of?

As I posted before - engines: available in 1941
Airframe: fuselage new, wings of 109. Available ditto.
Gatling: new. But technology pre WW I. Could well have been done.
Other design elements also very plausible in 1940 AFAIK.

What material? Aluminum? Wood? Steels? All the above and were located?

On the issue of the Gatling gun, it may be derived from old technology, but just look how long it took GE to develop a practical modern weapon from it. (not to mention getting respectable performance)
Honestly I think a revolver cannon is more realistic for this timeline, and event that would be pushing it. (You may be able to get 4-6 synchronized MG 131's in there though, with 32-4800 rpm and total gun weight of ~68-102 kg)

However, I think 2x wing root cannons along with an engine cannon is an excellent choice for a fighter. (as Tony Williams arranges it in his "ideal fighter armament" and as used on the Ta 152)


It should also be noted that your proposed "surface intercooling" was used on the early models of the P-38 (pre-J), albeit along the leading edge of the outboard wing rather than the fuselage, but proved rather inadequate at altitude, somewhat unreliable, dangerous in certan circumstances, and particularly vulnerable to battle damage. (many of the same issues as evaprative engine cooling)


I may have chosen the He 100 as a starting point rahter than the Bf 109. (cleaner airframe, better canopy design, promising armament arrangement -2x wing root guns plus a motorkanone with no cowl guns) Using a streamlined belly radiator, similar to the semi-retractible one on the He 100D-1, or possibly a low drag fixed one. (though a belly mounted radiator usually elliminates the capability for a belly mounted drop tank) An extended wing span would probably be needed to keep wingloading reasonable (LE slats are a possibility as well). Provisions to accept the Jumo 211 as an alternate engine would also be a good idea.

A compact annular radiator as used by Junkers (also used on dome DB engines, including the DB-600 on early Ju 88 prototypes, and the DB-603 on several aircraft) It has the advantages of low weight, very compact arrangement, limited vulnerable area, and does not take up space in the fuselage or wings. (a compact radiator directly below the engine has similar advantages, and will also allow somewhat better visibility over the nose)

Burmese Bandit said:

AHEM.

One quick point, however. The reason why the 20 mm was so late into entry into the RAF was the terrible reliability problems of the early cannons. See Antony Williams' excellent site.

Click to expand...

Couple of points in reply. The Hispano 20 mm was hardly 'late' into RAF service: it was flying on operational Spitifres by the end of the Battle of Britain, having undergone testing since mid 1939.

Yes, these early cannon armed Spitfires were susceptible to jams. However, early RAF Hispano reliability problems were mostly to do with their installation, which was initially on its side in the Spitfire, a poorly designed drum feed mechanism and wing flex in the Spitfire.

Most of these problems were resolved by the time the Spitfire Mk Vb appeared in early 1941. None of these jamming problems were extant in the Typhoon. The reason it went with the 12 x .303 set up initially was simply that Spitfires and Hurricanes had priority for the armament and Hispano production hadn't caught up with demand.

Note too that the Hurricane, Whirlwind and Beaufighter had significantly less jamming problems with their cannon installations than the early installations in the Spitfire. The development of a better belt feed motor and slightly redesigned wing structure in the Spitfire 'C' wing also improved reliability.

Excellent points all of you...let me try to reply to you one by one..

Flyboy: Aluminium. Steel too heavy, Wooden construction theoretically possible but not practical as Germany did not have enough skilled woodworkers, and also inadequate aircraft glue production facilities. See the history of the ill-fated Tank attempt to build a wooden reply to the British Mosquito. Of course the armour will be steel.

Kool Kitty...THIS was why I wanted input from the other members of the forum! Hmmm....your comment about possible problem of the Gatling had maed me think. I shall, pending more research, accept your comments as complete fact...and that makes me think that I should revise my armament to 6 MG 131s in a staggered triple two-gun row. Quite doable in the space constraints, but now I shall have to have three helix feeds per side. AAARGH! Changes, changes...

Yep, I read Tony's ideal gun armament essay. However, I think that 13 mm is the way to go...I'll explain in my next post.

Regarding surface intercooling, the reason why it was so vulnerable to damage in the P-38 was, as you pointed out, the intercooling was done on the wing leading edges, a rather large target for an enemy. I propose to do it in the fuselage, and there will be armour protecting that area anyway - it's the side armour for the pilot. Thin armour, only 4 mm, but any attack from the rear will strike that armour at VERY high angles, so should be adequate up to 15 degrees on each side from the rear.

But first, Jabberwocky: in reply to your earlier post...The Tiffy in all its variants, particularly its later ones, is one of my favourites in the fighter heavyweight division, and I've always wondered whether it would not have been possible to mount two engine cannons in the troughs of the H-block Sabres.

And yep, my opinion of that chin radiator is the same as yours...