How effective were ground attack aircraft against armor and other hardened land targets

[Schweik]

Regardless of gun calibre the main problem still stands: scooting around the deck strafing tanks is a good way to lose a lot of aircraft ... if we're going to believe those that actually carried it out.

Well that depended a lot on when and where exactly - certainly Anglo-American and German columns got better AAA support with vehicles like the M15 and M16 MGMC, the 'Duster', and the Wirbelwind and so on for the Germans. But ground based AAA wasn't invincible, did have certain limitations, and could itself be targeted which is what generally speaking was done from my understanding particularly on the Russian Front. They would send in dive bombers quite often to take out AAA vehicles and positions and then follow up with the anti-tank and anti-personnel raids.

 

[pbehn]

If a 20mm or 30mm gun was effective against tanks then the soldiers on the ground would have used them. A big enough gun to guarantee disabling a tank is generally so big with such a low rate of fire that hitting the tank is a real problem. Removing all infantry and soft skinned vehicles from around a tank squadron was almost as good as removing the tanks themselves though.

 

[GrauGeist]

An aircraft carrying a 30mm cannon has a far better chance at disabling an AFV than a comparable 30mm at ground level - because the AFV's armor was designed to counter ground-fire, not airborne cannon...

 

[Milosh]

That's a great trick, especially if the tank is on a road, on cobblestone streets in a town, village or city etc.

Except that the belly armour because of the angle the deformed round hit would be many times more the actual armour thickness.

 

[Shortround6]

One thing I am dubious about is that the rear armor on a lot of early to mid-war WW2 tanks was quite thin, as little as 10-15mm thick. Penetration of a 20mm Hispano with AP ammo should be about 20- 25mm at 200-400 meters. With Mk III AP Ammo (available from May 1943) they could penetrate 39mm at 600 meters.

Once you get passed the MK I and MK II tanks the German tanks being producedin 1940-41 (not prewar left overs) had 30 mm of armor all around, then they started beefing up the front.

Again, look at the angles. to get a 30 degree angle of impact on the top of a tank you need a 60 degree dive and how high do you have to be to pull out?

See the fall off in penetration as the angle of impact gets shallower, at low impact angles the shot ricochets off.

As for the MKIII ammo, just because it was approved or tested does not mean it was available in large quantities. and if it was APDS (or more likely APCR) the penetrator was about 11-13mm in diameter. Please also note that the penetration figures for the standard AP do not include any boost from the speed of the aircraft. APCR shot loses velocity and penetration quicker than normal shot, enough so the cross over point is often below 1000yds sometimes well below for small caliber (50mm ?) and under.

 

[pbehn]

A single hit with a 30mm shell of any type didn't guarantee taking down an aircraft let alone a tank.

 

[IdahoRenegade]

That's a great trick, especially if the tank is on a road, on cobblestone streets in a town, village or city etc.

Interesting to see how much dispersion there is from the wing mounted guns, and the convergence point relatively shortly in front of the plane. Not hard to believe that the effectiveness against "hardened" ground targets is limited-by the time you hit the convergence point of both sets of guns and put rounds on target it's time to pull up to avoid running into the ground.

 

[tyrodtom]

Just how thick was the armor on top of the engine compartment ?
Around Radiators ? Most of the Axis, and Soviet tanks had liquid cooled engines.
You don't have to blow the turret off, or even put a hole in the crew compartment, to disable a tank.

 

[Shortround6]

getting back to the original proposition.

They may hit only 5 or 10% of the time but if you send say 24 planes out three times a day you are fairly likely to get a hit or two...

You may get a hit or two but in 72 sorties you may lose a plane or two just due to operational losses, (bad landing, engine failure, etc.) let alone any ground fire or, heaven forbid, enemy fighters.

German close air support in 1939-40-41 depended on a number of things.
1, they usually had air superiority. Their enemies were not able to intercept the ground support planes a significant amount of the time.
2, Their enemies had crap for local AA guns, in quantity, caliber and doctrine.
3. The targets, in the majority, were soft targets. Ir much softer than many later tanks/targets.

I would note in the photos of the blown up tanks they appear to be internal explosions, which means either a direct hit from the bomb and it exploding inside (two elements of luck) or the stowed ammunition cooked off and exploded. The latter could have been caused by a near miss or setting the tank on fire.

At Falise, one post action assessment put the number of tanks knocked out by rockets as low as 7 tanks. There is no doubt and darn little argument that the air attacks stopped the German armoured movement. The argument comes from how.
Bombing a formation of tanks can often disrupt the the formations movement/s. Not by killing or even damaging a number of the tanks but by causing confusion, limiting vision and causing the formation to temporarily disperse. Artillery bombardments can disrupt armored attacks and the chances of artillery shells (HE) actually killing tanks is not great, damage them yes but actually destroy them no.

 

[Shortround6]

Just how thick was the armor on top of the engine compartment ?
Around Radiators ? Most of the Axis, and Soviet tanks had liquid cooled engines.
You don't have to blow the turret off, or even put a hole in the crew compartment, to disable a tank.

The radiators were inside, what you see on the decks are armoured louvers or fans.

 

[AlfaKiloSierra]

A single hit with a 30mm shell of any type didn't guarantee taking down an aircraft let alone a tank.

It guaranteed the destruction of a fighter aircraft. There was a clip of a gun testing of an MK 108 on a Spitfire. The round hitting the rear fuselage has so much exploding power that it blew up the other side of the fuselage. Such explosive power would've broken the wing of a P-47 or P-40.

 

[tyrodtom]

The radiators were inside, what you see on the decks are armoured louvers or fans.

But how thick was that armor, in comparison with the crew compartment ?

 

[Shortround6]

The point is it was enough to stop small arms (or even heavy machine gun fire).

The German tank hunters used teller mines (around 5 kg) under T-34 turret overhangs, satchel charges, 6 potato masher grenade heads wrapped around a 7th to be placed on an engine deck (42oz of TNT total) and other engineering explosives to disable russian tanks rather than climbing up on the engine deck (which some of these weapons required) and firing a clip from a submachine gun down through a grate/louver into the radiator. Smart tank designers also put in a baffle or two to prevent the gasoline from molotov cocktails from dripping down through the grills/louvers onto the engine and accessories.

Some tanks were better than others.

Engine (or transmission ?) cover up on a Matilda. Long mushroom type covers over raised slots. Bullets would have to change direction twice to get inside.

Light tanks of course are thinner

Box on the slope next to driver is for the radiator air. You either shoot through the box or the bullet needs to change direction several times.

 

[Shortround6]

You don't have to blow the turret off, or even put a hole in the crew compartment, to disable a tank.

True but if you just cause a water leak that same tank may be back shooting at you tomorrow.

A burnt tank could not be repaired (the heat of the fire affected the strength of the armor) while even a heavily damaged tank that did not burn could be repaired.
In a number of cases a heavy hit by some sorts of weapons knocked a crew unconscious which lead to some tanks coming back to life and shooting up the attackers from the rear.
It became a common practice to shoot a tank until it either burned or the crew was seen to bail out,

 

[tyrodtom]

True but if you just cause a water leak that same tank may be back shooting at you tomorrow.

A burnt tank could not be repaired (the heat of the fire affected the strength of the armor) while even a heavily damaged tank that did not burn could be repaired.
In a number of cases a heavy hit by some sorts of weapons knocked a crew unconscious which lead to some tanks coming back to life and shooting up the attackers from the rear.
It became a common practice to shoot a tank until it either burned or the crew was seen to bail out,

I've always though if I was in a tank crew, and saw a tank in sight, that just didn't immediately look beyond a doubt disabled, I'd make sure it was before I moved on.

That's why I have a little doubt on these after action reports on what each tank was put out of action by.
It's likely every tank in sight was fired at many times after it was already out of action, just by crews playing it safe.

 

[PAT303]

I think you have to take into account the physiological value, knowing that if you are spotted aircraft will soon appear overhead loaded with 500lb bombs or cannons with pilots only too keen to attack you would wear you down both physically and mentally.

 

[mikemike]

When the Luftwaffe replaced most Ju87 by Fw190F for ground-attack purposes, the aircraft often used cluster bombs, called Abwurfbehaelter (literally: drop containers) weighing 250 or 500 kg. The submunitions used for anti-tank purposes were HL4 or HL10 hollow-charge warheads (4 resp. 10 kg heavy). The HL4 would pierce 130 mm (just over 5 inches) of armour. I don't know how many submunitions fit into the containers, but I would guess 80-100 in the 500 kg container. Now cluster bombs are not really precision weapons, but the scatter effect would probably be effective against groups of tanks, and a direct hit from a HL4 would likely disable any tank. I've never seen any statistics how effective these cluster bombs were in actual combat, however.

 

[Greyman]

The British tried the same thing with SBCs containing 24 x 9-lb anti-tank bombs (so 48 per Hurricane). These used the squash principle to defeat armour, and the scattering was to increase the chances of a hit on the intended target (read: individual tank).

The whole affair was reasonably effective but the attack profile required to use the weapon was too dangerous (again, AA fire), and the weapon was shelved.

 

[swampyankee]

Since most tank commanders usually had their heads outside due to the need for situational awareness, how much would the air attack — or even its threat —reduce a tank's effectiveness because it's buttoned up and outside vision is seriously reduced?

 

[Shortround6]

Maybe a lot, let's not forget the drivers vision either. Depending on terrain things could get difficult, charging about the dessert with reduced vision was bad enough, driving into a ditch, clipping a stone building (or large tree) or simply trying to drive down a slope with bad vision while under attack could be rather dangerous, many early war tanks (and some late ones) used clutch and brake steering which suffered from reverse steering if the engine was not driving the tank. That is to say that one imputon the steering controls caused the tank to turn one way if the tank was on the level or going up hill but caused the the tank to turn the other way when going downhill on a trailing throttle (you are not accelerating).