What if Western Allies tried to develop a ground-attack airplane equivalent to the the IL-2 Sturmovik?

[riggerrob]

What if the Western Allies had tried to build an armoured, ground attack airplane equivalent to the Soviert IL-2 Sturmovik?
Which engine?
Can you bury a radial engine deep enough in a cowling that you can armour it against ground-fire?
What armament?
Please keep in mind that the rockets fired from RAF Typhoons were "less than accurate."

 

[_Del_]

I think they did alright with the Jugs and Typhoons along with everything else.

The solid-nose A-26's and equivalents also did fairly well for themselves. The Invader served a long, long time.

 

[Christopher Wang]

You are pretty much talking about the Republic P-47 Thunderbolt which performed excellently as a ground-attack aircraft for the USAAF and RAF. An interesting question would be if the P-47's large wings could be adapted to carry the 20mm M2 / M3 or 37mm M4 autocannons.

 

[CV12Hornet]

There's also the Marine AU-1 Corsair, which is an F4U modified with more armor and bomb racks for close air support missions. It had a max bombload capacity of 8200 lbs.

Doing that to the P-47 and/or Typhoon strikes me as the most likely option if the WAllies decide they really need a specialist CAS aircraft.

 

[Scott Kenny]

IIRC, the belly skin of the Shturmovik was 12mm thick steel, and backed by a layer of concrete.

The genius of the Il-2 was that the armored tub was mostly the stressed skin of the plane, instead of armored plates inside the skin like the A-10 uses.

So I could see either a P-47 or a Corsair as the equivalent plane. The P-47 could ditch the huge turbocharger which would free up a lot of space in the fuselage. Either one would need a lot of their skin replaced with steel armor.

 

[Archibald]

Beech A-38 Grizzly ?

 

[Dilandu]

The Allies did not experience a shortage of powerful engines - which plagued Soviet aircraft industry early in the war - so they could just build fighter-bombers, capable of performing more functions. The Il-2 was formidable, but not without major deficiences; its combat load was pretty limited and it have targeting problems.

 

[Archibald]

It was also very vulnerable to attacks from the rear. Surely enough it had a rear gunner but (from memory) it only had SHKAS light machine guns. It was the same issue as Lancaster 7.7 mm or the B-17 12.7 guns: very high rate of fire but the munition was too light and not explosive : unlike a 20 mm shell. The LW soon armored its 109s and FW-190s, also their pilots learned very quickly about wallies planes vulnerabilitiess (think of the B-17s shot in frontal attacks, and later with R4M rockets firing farther than the 12.7 guns could reach).

Out of 36 000 Il-2s manufactured, almost one-third were shot down (think 10 000 or even 11 000). A trully horrific lost rate. The Soviets however churned more Il-2s, faster than LW Expertens could shoot down...

Beechcraft XA-38 Grizzly - Wikipedia

en.wikipedia.org

There were also Mosquitos with a 57 mm and B-25 with a 75 mm gun. And probably others I forgot. Hurricanes with 40 mm anti-tank gun pods under wings.

-My understanding is that the above mentionned "contraptions" suffered from gun recoil, somewhat like the F-16s in GW1 that were supposed to replace A-10 with a centerline gun pod. Bad luck, recoil was so atrocious it shook the F-16 and blurred targetting.

-In stark contrast the Beech A-38 used the same trick as the A-10. To manage recoil better, they build the whole plane around the gun from the beginning. So that the plane itself - a few tons of metal - tamed the recoil.

-More generally, in WWII there was no easy solution to the basic issue of "demolishing a tank with an airplane." The belligerants tried all kind of different weapons - bombs, rockets, guns - on many different airframe: as diverse as a HS-129, a Breguet 693, a Stuka, a Fairey Battle, a P-47, a Beech A-38, an Il-2, a Typhoon with rockets, B-25 and A-26. None solution was entirely satisfying.
- Bombs and rockets tended to miss the tanks
- a large caliber gun could eventually demolish a tank if the shell hit. But that was the theory.
-Smaller guns (let's say, 20 mm to 30 mm) could fire quickly and de facto get more chance to land a shell right on the tank
BUT
that light shell might not be able to demolish the tank or at least knock it out.
-As for the larger guns ( from a P-39's 37 mm to a B-25's 75 mm) they just fired too slowly, compared to the plane high velocity. A good pilot could get its sight on the tank and fire, but the gun would only fire one shell in the meantime.

Thinking about it further, the problem of killing a tank from the air was ultimately solved by a) A-10 Whartog and b) AH-1 Cobra and all the other attack helicopters.
- A-10 was still very fast but got a big gun (30 mm) that could fire quick enough: the solution was called GATLING. 6000 rounds per minute, now that's talking seriously. 100 shells per second, that's plenty enough for a few of them to find the tank and demolish it.
-Helicopters could hover at zero velocity and from there, dump on the tank a) unguided rockets and later b) TOW guided missiles.

 

[Dilandu]

More generally, in WWII there was no easy solution to the basic issue of "demolishing a tank with an airplane." The belligerants tried all kind of different weapons - bombs, rockets, guns - on many different airframe: as diverse as a Breguet 693, a Stuka, a Fairey Battle, a P-47, a Beech A-38, an Il-2, a Typhoon with rockets, B-25 and A-26. None solution was entirely satisfying.

USSR found the most satisfying - still not perfect! - solution. A very small shaped charge bombs (PtAB-1.5), that were disperced from low altitude, basically a direct ancestors of submunitions. The PtAB weren't a perfect tank killers also, but were extremely popular, because they also have a good fragmentation and could be used as general-purpose weapon against both armored and unarmored targets (including troops in trenches)

 

[Archibald]

The Hs.129 was the closest thing from an A-10 in WWII. https://en.wikipedia.org/wiki/Henschel_Hs_129
And it used a 30 mm gun, perhaps the best caliber when trying to balance rate-of-fire vs shell explosive weight.
Unfortunately ground-based anti-tank guns had already shown that 30 mm wasn't enough to smash a 1940-41 tank. Things got worse as the T-34 improved. So they tried flying bigger guns (37 to 75 mm), but - back to square one: they fired too slowly for fast planes, plus they were very heavy.
Mounting ground-based anti-tank guns on plane was probably foolish. On the ground they had zero velocity, on planes they flew at 400 kph or more.

The A-10 returned to a 30 mm caliber "only" : which at first glance stood no chance against any post WWII tank. The "secret sauce" is depleted uranium.

 

[Foo Fighter]

https://www.secretprojects.co.uk/threads/martin-baker-tankbuster.29526/

The problem with this idea is partly addressed by the link ^ and confounded by post war studies suggestin g aircraft of the type attacking tanks etc were NOT what they were thought to be and in fact, much LESS successful than was suggested.

Even on this August site.

 

[TomS]

IIRC, the belly skin of the Shturmovik was 12mm thick steel, and backed by a layer of concrete.

I think this might be a misunderstanding somewhere. The Il-2 armor plate was "cemented," which is a form of face hardening using acetylene gas to increase the carbon content of the surface of the steel. It does not involve concrete.

 

[Colonial-Marine]

It was also very vulnerable to attacks from the rear. Surely enough it had a rear gunner but (from memory) it only had SHKAS light machine guns. It was the same issue as Lancaster 7.7 mm or the B-17 12.7 guns: very high rate of fire but the munition was too light and not explosive : unlike a 20 mm shell. The LW soon armored its 109s and FW-190s, also their pilots learned very quickly about wallies planes vulnerabilitiess (think of the B-17s shot in frontal attacks, and later with R4M rockets firing farther than the 12.7 guns could reach).

Most of the two-seater IL-2s had a UBT 12.7mm machine gun which had an impressive rate of fire for the caliber. But I believe the bigger problem was that, unlike the pilot, the rear gunner had very little armor protection. I recall reading that the casualties those gunners took were so heavy that it was something of a "punishment" assignment. If the gunner gets killed by a burst of MG fire quickly it means the attacking fighter can easily maneuver for a shot with his heavier cannons. I think the very late-war IL-10 gave the gunner some suitable armor coverage but by then the Luftwaffe didn't have much of anything airborne to attack them.

I know the IL-10 saw some use by the North Koreans during the invasion of South Korea, initially quite successfully, but it seems like USAF F-51s and F-80s didn't have too much difficulty in defeating them and the Yaks (3s or 9s, not sure which) they had as escorts. I'm not sure how much trouble the defensive fire gave the attacking aircraft.

https://www.secretprojects.co.uk/threads/martin-baker-tankbuster.29526/

The problem with this idea is partly addressed by the link ^ and confounded by post war studies suggestin g aircraft of the type attacking tanks etc were NOT what they were thought to be and in fact, much LESS successful than was suggested.

Even on this August site.

They may have been less successful than believed against actual tanks, but with their supply trucks and light armor often devastated by such air attack it was a poor omen for the future of those tanks.

I'd be interested in accounts of how effective the high-powered 37mm on later IL-2s was. The 23mm used by many other IL-2s was quite powerful for its caliber but still wouldn't be able to penetrate medium or heavy tanks. The closet Western allies equivalent to that 37mm was the 40mm Vickers 'S' gun used on some Hurricanes, but it was only ever used in small numbers. The small (15 rounds only I think) magazine must have been a problem.

I think the Germans considered the 37mm used by the Ju-87G effective but also limited by small magazine size and the fact that the Stuka was very vulnerable to enemy fighters.

If you really want to destroy tanks I like the idea the Beechcraft XA-38 embodied. Unlike the Hs-129 it had powerful engines to work with so probably wasn't a complete pig to fly unlike those Hs-129s fitted with the 75mm cannon.

 

[riggerrob]

USSR found the most satisfying - still not perfect! - solution. A very small shaped charge bombs (PtAB-1.5), that were disperced from low altitude, basically a direct ancestors of submunitions. The PtAB weren't a perfect tank killers also, but were extremely popular, because they also have a good fragmentation and could be used as general-purpose weapon against both armored and unarmored targets (including troops in trenches)

That sounds like a predecessor to the top-attack Javelin missiles currently being used in Ukraine.
The key point is that top armour is always thinner on armoured fighting vehicles.
While glacis plates (front of hull) and gun mantlets (front of turret) are usually proof against a tank's main gun, they are too heavy to armour the entire vehicle, so top and rear armour is thinner. Fore example, the frontal armour on an American M4 Sherman was about 75mm thick, enough to stop a medium-velocity 75mm shell.
When the Sherbrooke Fusiliers wanted to kill SS Panzer ace Michael Wittman, they used a high-velocity 76mm (aka. 17-pounder) gun and shot him in the rear of his Tiger 1.
While ground troops needed anti-tank guns powerful enough to punch through glacis plates, airplanes can aim at the much thinner armour on the roof or rear.

 

[riggerrob]

Also consider what killed Panzers during the Normandy campaign.
After the war, Operations Research scientists concluded that comparatively few Panzers were killed by airplanes. but all those thousands of fighter-bombers wrecked German supply lines. Many Panzers were abandoned in Normandy after they exhausted supplies of fuel, ammo and spare parts.

 

[Dilandu]

That sounds like a predecessor to the top-attack Javelin missiles currently being used in Ukraine.

More likely a predecessor to the anti-tank cluster munitions, like "Rockeye":

 

[Scott Kenny]

I think this might be a misunderstanding somewhere.

Damn my memory for not retaining sources, just the notes...

But I remember that the story was that after assembly, an Il-2 needed to sit for a day for the concrete to cure before flying.

The Il-2 armor plate was "cemented," which is a form of face hardening using acetylene gas to increase the carbon content of the surface of the steel. It does not involve concrete.

Done that before in welding class. Burning acetylene with just atmospheric oxygen leaves a very smokey flame and you can lay the smoke down on the metal to cover it with a layer of soot. Then you go back over the plates with a oxy-acetylene flame and watch the soot disappear.

 

[Justo Miranda]

In my opinion it would not have been a good idea to build a flying tank, this type of aircraft are very vulnerable to attack by fighters (tail surfaces cannot be armored) and would only be useful in situations of air superiority.

In Normandy the 84th Group Typhoon lost 66 percent of its strength and 150 pilots in ten weeks.

Losses were very high, the highest of all types of Soviet aircraft, though given the numbers in service this is only to be expected. Shturmovik losses (including the Il-10 type) in 1941–1945 were of 10,762 aircraft (533 in 1941, 1,676 in 1942, 3,515 in 1943, 3,347 in 1944 and 1,691 in 1945).

 

[Justo Miranda]

Photos of those who managed to return.

 

[Justo Miranda]

Post-2

 

[TomS]

But I remember that the story was that after assembly, an Il-2 needed to sit for a day for the concrete to cure before flying.

I wonder if someone in the writing process got confused about the need for the glue (aka cement) to cure. The back half of the Il-2 is basically plywood, after all.

 

[Justo Miranda]

I wonder if someone in the writing process got confused about the need for the glue (aka cement) to cure. The back half of the Il-2 is basically plywood, after all.

Wooden monocoque fuselage made from 'shpon', molded birch plywood.

 

[1635yankee]

It was also very vulnerable to attacks from the rear. Surely enough it had a rear gunner but (from memory) it only had SHKAS light machine guns. It was the same issue as Lancaster 7.7 mm or the B-17 12.7 guns: very high rate of fire but the munition was too light and not explosive : unlike a 20 mm shell. The LW soon armored its 109s and FW-190s, also their pilots learned very quickly about wallies planes vulnerabilitiess (think of the B-17s shot in frontal attacks, and later with R4M rockets firing farther than the 12.7 guns could reach).

Most of the rear gunners in single-engined aircraft had rifle-caliber machine guns, with the corresponding lack of effect.

As for killing tanks from the air, that really became easy only after effective anti-tank guided missiles. During WW2, the RAF and Luftwaffe did equip aircraft with effective anti-tank guns, but the compromises needed to do so also rendered the carrying aircraft quite vulnerable to fighters. The larger guns -- 57mm and 75 mm -- where largely for maritime attacks. The USAAF did attempt to field an aircraft cannon that could pierce armor (the 37mm M9), but the aircraft it was used in was mostly sent to the USSR via military aid transfers.

While bombs, rockets, normal fighter cannon were generally not good at directly killing tanks, they could, and did, destroy supporting vehicles. Keegan, in his book about the weeks after D-Day (SIx Armies in Normandy) mentions a German tank unit bombed by B-17s where tanks were flipped over, buried by debris, and had optics and sighting systems messed up. The unit was demoralized to the point that one of the officers committed suicide. Of course, by the time the Western Allies were actively involved in ground combat in France, the Luftwaffe was largely broken (but still dangerous), and RAF and USAAF aircraft could pretty much go anywhere and shoot up German transport, infantry, and unarmored units at will.

 

[Hood]

Well the Brits did (Martin-Baker Tankbuster, some weird biplane Defiant winged beastie too), but quickly thought the better of wasting effort on it.

 

[Archibald]

Keegan, in his book about the weeks after D-Day (SIx Armies in Normandy) mentions a German tank unit bombed by B-17s where tanks were flipped over, buried by debris, and had optics and sighting systems messed up. The unit was demoralized to the point that one of the officers committed suicide.

The infamous low level bombing by B-17s, from memory is was to finish the Falaise pocket. Unfortunately the bombing also killed american soldiers.

 

[tomo pauk]

Allies could've certainly manufacture the alt-Sturmovik. Americans can make an aircraft around the R-2600 (later 2800), with the armored 1st half of the fuselage; British can make it around the Hercules.
Problem was that British had no doctrine of close support (same as with the doctrine of LR fighter escort) - no doctrine = no hardware. Americans were much more interested in their bomber and attack aircraft having good/great range and hefty bomb load - things where Sturmovik was weak.

 

[Scott Kenny]

Problem was that British had no doctrine of close support (same as with the doctrine of LR fighter escort) - no doctrine = no hardware. Americans were much more interested in their bomber and attack aircraft having good/great range and hefty bomb load - things where Sturmovik was weak.

I think that's the key.

Germany and Russia had identified planes as super-heavy artillery to support the Army, while the Allies had no such concept.

At least not in their air forces.

The Navy and Marines seem to have recognized that idea.

 

[Pioneer]

Of course, by the time the Western Allies were actively involved in ground combat in France, the Luftwaffe was largely broken (but still dangerous), and RAF and USAAF aircraft could pretty much go anywhere and shoot up German transport, infantry, and unarmored units at will.

I strongly agree.

Regards
Pioneer

Of course, by the time the Western Allies were actively involved in ground combat in France, the Luftwaffe was largely broken (but still dangerous), and RAF and USAAF aircraft could pretty much go anywhere and shoot up German transport, infantry, and unarmored units at will.

Agree!


Regards
Pioneer

 

[DWG]

Problem was that British had no doctrine of close support

The cab-rank controller would like a word.

We perhaps lacked a close-support doctrine in 1939, Army Cooperation wasn't the same thing, but by the North Africa campaign we were definitely evolving specialist close-support aircraft and doctrine (FACs and the cab rank), with Hurricane IIDs fitted with extra armour and the 40mm Vickers S gun. And the 3"/60lb rocket was enthusiastically adopted once it became available. The Typhoon with rockets largely replaced the Hurricane, though there were 500+ Hurricane IVs with the universal wing able to take the S guns, bombs or rockets, and the Hurricane V for ground attack in Burma.

Tony Buttler's British Secret Projects 4, Chapter 1 Light Bombers and Ground Attack, covers the un-numbered 1942 requirement for a single seat 'low attack' aircraft, which saw responses from Cunliffe Owen (biplane; twin; single), AW with the AW.49 twin-boom pusher with Merlin or Sabre, Boulton Paul with the P.99 (twin boom pusher with Griffon), P.100 (pusher with Griffon), and P.101 (biplane), Miles M.42 (2x Merlin, Libellula layout), M.43 (single pusher Libellula) and M.44 (twin Merlin). The Martin Baker Tankbuster was a late response to this. The Air Ministry opted to stick with the Hurricane IV followed by the Typhoon.

 

[tomo pauk]

The cab-rank controller would like a word.

You are certainly correct.
I've failed to say that RAF's doctrine for using aircraft to attack the enemy's tactical ground units close to the frontline was not existent in the 1930s (what happened during 'imperial policing' aside), and it took 2-3 years of war for that doctrine to actually materialize.

 

[Colonial-Marine]

I believe that despite also not having official doctrine for the concept of 'close support' US Army forces on the became pretty proficient communicating and working with USAAF fighter bombers to provide air support by 1944. I'm guessing the same skills were learned and applied on the islands of the Pacific too. I've read that much of this institutional knowledge was lost after the and many lessons had to be re-learned in Korea. An all-too-common occurrence.

 

[Justo Miranda]

The cab-rank controller would like a word.

We perhaps lacked a close-support doctrine in 1939, Army Cooperation wasn't the same thing, but by the North Africa campaign we were definitely evolving specialist close-support aircraft and doctrine (FACs and the cab rank), with Hurricane IIDs fitted with extra armour and the 40mm Vickers S gun. And the 3"/60lb rocket was enthusiastically adopted once it became available. The Typhoon with rockets largely replaced the Hurricane, though there were 500+ Hurricane IVs with the universal wing able to take the S guns, bombs or rockets, and the Hurricane V for ground attack in Burma.

Tony Buttler's British Secret Projects 4, Chapter 1 Light Bombers and Ground Attack, covers the un-numbered 1942 requirement for a single seat 'low attack' aircraft, which saw responses from Cunliffe Owen (biplane; twin; single), AW with the AW.49 twin-boom pusher with Merlin or Sabre, Boulton Paul with the P.99 (twin boom pusher with Griffon), P.100 (pusher with Griffon), and P.101 (biplane), Miles M.42 (2x Merlin, Libellula layout), M.43 (single pusher Libellula) and M.44 (twin Merlin). The Martin Baker Tankbuster was a late response to this. The Air Ministry opted to stick with the Hurricane IV followed by the Typhoon.

The Hurricane Mk. IID could only operate in the absence of enemy fighters due to the weight of the 40-mm guns.

The rocket-equipped Hurricane Mk. IV suffered 80% casualties during attacks on the V-1 missile launch ramps.

 

[Justo Miranda]

Post-2

 

[royabulgaf]

I think that's the key.

Germany and Russia had identified planes as super-heavy artillery to support the Army, while the Allies had no such concept.

At least not in their air forces.

The Navy and Marines seem to have recognized that idea.

They were fighting a different war. Carrier hangar space is limited and you can't afford a plane for every mission. So you have anti-ship torpedo bombers that can function as level bombers over land. The dive bombers function equally over sea or land, and if the fighter's guns can chew up airplanes they can chew up soldiers. Twin engine aircraft and carriers to handle them weren't ready yet, and you didn't have a road and rail infrastructure to deal with.

 

[Scott Kenny]

They were fighting a different war. Carrier hangar space is limited and you can't afford a plane for every mission. So you have anti-ship torpedo bombers that can function as level bombers over land. The dive bombers function equally over sea or land, and if the fighter's guns can chew up airplanes they can chew up soldiers. Twin engine aircraft and carriers to handle them weren't ready yet, and you didn't have a road and rail infrastructure to deal with.

It's more of a matter of Marines in particular using aircraft as battleship-caliber artillery but with better accuracy.

Lots of stories of WW2 vet pilots in Korea putting bombs into the window of a building, for example.

 

[DWG]

Of course, by the time the Western Allies were actively involved in ground combat in France, the Luftwaffe was largely broken (but still dangerous), and RAF and USAAF aircraft could pretty much go anywhere and shoot up German transport, infantry, and unarmored units at will.

We shouldn't forget the four years of combat in the Western Desert, North Africa, Sicily and Italy that went before that, where CAS was needed whatever the state of air superiority.

And of course there are the Burma and New Guinea campaigns with their own specialist CAS requirements.