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

[Navalwarrior]

Found this interesting analysis of CAS in North Africa. I had noticed that after Kasserine, DAF and American air assets were directed much more heavily against Axis airfields, and because this coincided with the arrival of the Americans, I had assumed it was instigated by them. But apparently not, it was a British officer who changed the Strategy and reorganized the basis of CAS at this time. He also apparently specifically changed the CAS focus from attacking tanks to attacking troops and lightly armed vehicles. This took place around Spring of 1943. Bold emphasis is mine:

https://history.army.mil/html/books/093/93-7/CMH_Pub_93-7.pdf

"Of all the critics, none was more influential than British Air Vice Marshal Sir Arthur Coningham, who replaced Kuter as commander of the centralized Allied Air Support Command during the Kasserine operation. While Eisenhower was opposed to the British "committee system"* of command, he also advocated a commander having the flexibility to organize forces to suit national proclivities, and he gave Coningham the freedom to operate by his own style. Coningham now helped convince Eisenhower and other high-level Allied leaders that close air support forces must be organized on a basis of scarcity and that, in particular, ground commanders could not expect as much close air support as they heretofore thought necessary. In the context of military reversals, such as Kasserine, the senior leaders of the Tunisian campaign found the economy-of-force principle more acceptable. Coningham ultimately discontinued several other Tunisian cooperative practices, some first seen when he took over the Western Desert Air Force. He criticized the defensive air cover flying mode, then used by the XII Air Support Command and No. 242 Group. With the scarcity concept accepted, he promoted the centralization of all tactical air resources under his control as air specialist on the staff of the highest field commander. Division and corps commanders would have to request close air support through the highest army commander. Although they were primarily associated with their national force, the XII Air Support Command and No. 242 Group would be commanded by Coningham rather than by the II Corps or British First Army commanders. Coningham condemned the former employment practice of having fighters on call and assigning them piecemeal to a variety of targets that were not critical to the battle. He proclaimed that, henceforth, air support missions would be offensive, with fighters seeking out the enemy's air force at or near Axis bases.

For ground attack missions, enemy concentrations and soft-skinned vehicles, rather than tanks, would be appropriate targets. Centralized control was a fundamental premise of Coningham's air support concept. In view of limited air resources, all aircraft units should be used in the highest priority missions. None could be held in reserve for the future use of a currently inactive ground unit. Coningham, or another air commander fully conversant with air capabilities, would determine allocation and employment upon the ground commander's determination of objectives. "

Resp:
Very interesting!

 

[Schweik]

Based on Christopher Shores Mediterranean Air War series, the new strategy was successful. Attacking bases was the best way to achieve air superiority. German fighters had previously had the option to attack any Allied planes they wanted to, and could pick the easiest targets. Attacking their bases forced them to fight on the Allies terms - for example at the altitude that worked best for the Allied fighters (well below 20k ft) because the Germans needed to target the bombers. This greatly improved the win / loss ratio which you can see in the German and Allied records.

But they rarely shot down more than a handful of German planes on a given day. Again, per Shores, you can see that the bomber attacks with fighter-bombers, specialized dive bombers like the A-36, with medium bombers (Baltimores, A-20s, B-25s, B-26s) and even heavy bombers like B-17s and B-24s, they sometimes destroyed dozens of Axis aircraft along with ammunition, fuel, repair facilities, and all kinds of other stuff. On a single raid.

This wore down and gradually crippled the Axis air forces, giving the Allies at least local air superiority (albeit often contested) by mid 43.

The Allied doctrine was supposed to isolate the battlefield (operational level strikes on communication infrastructure like trucks and trains) with medium bombers and fighter bombers, and only then to go after the front line. One way that they isolated the battlefield was by shooting down vast numbers of Axis transports (Ju-52s, giant Me 323's, Italian SM 82s, even huge BV-222 flying boats) that were trying to bring supplies and reinforcements to North Africa, and sinking ships on the same mission. Both of these were definitely done effectively dozens of Axis transports were shot down, and Axis naval activity in the southern Med was basically brought to an end.

What I don't know and am still trying to determine is if they were successful in destroying their operational targets (trucks, trains etc.) and especially per the thread, how good they were at taking out tactical targets such as AT guns, AFV's and tanks. Anecdotally they did and this was critical to the victory in particularly fierce battles like El Alamein (in Oct 42), at Kasserine (Feb 43), the Mareth Line (March 43), El Guettar (March-April 43) and Wadi Akarit (April 43). But I've yet to find any confirmation with actual counts of hardware losses. How many tanks did they get, how many trucks, AT guns, artillery pieces and so on.

 

[Schweik]

Incidentally, the quite ubiquitous Yak-9T (about 3,000 built) was armed with the Nudelman-Suranov NS-37 cannon. According to this site, that cannon shot a 735 gram projectile at a velocity of 900 m/s, and was capable of penetrating 50mm of armor at 200m or 30mm at 500m and 45 degrees.

That is more than enough to penetrate the side or rear armor of most German AFV's up to the Pz III Ausf G, most marks of Pz IV, StuG III etc., and also Panthers.

 

[Schweik]

Found an interesting interview with a 3 RAAF fighter pilot, (flying Kittyhawk II and III) on fighter bomber missions:

Brian Eaton Interview Transcript

">Well moving on a little bit. The period that you joined No. 3 Squadron was really leading up to the end of the North African campaign. During that period what had been the main uses that the squadron had been put to?

Mainly ground strafing, stopping MT and troops and tanks, and ack-ack guns. We used to take off at night and try and spot the ack-ack guns that were shooting at our airfield.​

>Did you do any reconnaissance flying?

Oh yes, all the time. We found them, and then our guns were sectored on to them, and that stopped them for a while, but I don't think it wiped them out.​

>But the main role was –?

Mainly ground interdiction.​

> And the aerial combat was just as a –?

Just as it happened, as it arose, yeah.​

> But you weren't actually seeking –?

No, we weren't seeking aircraft.

> Right. How effective was the Kitty in that role of ground attack aircraft?

I think it was very good. It could take an awful lot of punishment and still get you home. It was a very, very –. You had six .5s, could carry two 250-pounds – later two 500-pound bombs – and still later carried a thousand pound bomb and two 500- pound bombs. So almost like a light bomber. Oh, it was a very good aircraft.​

> Would it be possible to tell us the kind of typical sequence of a typical ground strafing attack, how it was set up, how you went in, how close you pushed the attack?

Well first of all you'd bomb from about 10,000 feet down to about 3,000 feet, then you'd pull up and see what was left, and then you'd get round, come in, come in low at speed and strafing. But the closer you got the more accurate you became, so the closer you got the more kills you got. And then try, always try and get a flame again.​

> What do you mean by a flame?

We'd get it on flames – you'd hit his petrol tank – and then you were sure you had him.

> You're talking about aircraft here?

No, trucks. Trucks and tanks.​

> Hm, How low were you flying when you came in on those strafing attacks?

Oh about a hundred feet.​

> So, I mean, very very low.

Very, very low, yes, oh yes.

> Now much time did you have? I mean, from when you would see a target and begin firing, to when you were literally over it and beyond it?

About two minutes; oh two to three minutes I suppose.

> And how long would you have, what period of time would you have in which you could actually fire, you were close enough to actually fire?

About twenty seconds, and you only tried to do one strike and then get out of it. If you did too many strikes, you always got shot down. If you kept doing circuits and bumps on them, you're bound to get shot down.​

> Right, so by and large, after the bombing you'd have …

You'd have one run-through and then get out.​

>Right, and you wouldn't come back again?

You wouldn't come back, no."

 

[Schweik]

Detailed account of a battle with close air support. I think this is a good example of an incident in which both the supply chain had to be interrupted, but the attacking columns of tanks also had to be stopped. 3 RAAF was able to do both.

3SQN Termoli Battle - Italy 1943

Excerpts:

"On 4 October the 8th Argylls and 6th Royal West Kents advanced north some five miles from Termoli along the coast road, Highway 16, aiming to capture the village of San Giacomo, when they ran into forward units of 16th Panzer. Only four infantry battalions, two commandos and some Special Forces were across the Biferno river. To try to stop the Panzers they had only one field regiment of artillery and a few anti-tank guns. The infantry were on their own, cut off on the north side of the river. A torrid unequal battle, tanks versus exposed infantry, had commenced for Termoli. Devoid of armoured support, lacking anti-tank artillery and any reinforcements, the 78th Division infantrymen were being systematically killed and pushed back all around the Termoli perimeter. A bulldozed ford over the Biferno did enable six Sherman tanks to cross, before it became a morass from the rain and flooding river. (It achieved little, as four of the Shermans were quickly destroyed by the Germans' Mark IV Panzers.)

...

During 5 October the Germans forced the defensive lines back to within a half mile of the town. On the edge of Termoli itself, the infantry made a brave but futile stand at the brickworks site to try and stem the German offensive, before they were forced to withdraw. To save the troops in the bridgehead across the Biferno, and have any chance of turning back 16th Panzer, the river had to be bridged so that tanks could cross to support the infantry. As the battle for Termoli reached a critical tipping point, and 78th Division hung on grimly against German armour, DAF made some telling strikes to help force the Germans to pull back...

In two operations No.3 Squadron RAAF struck at both supply traffic and German forces. In the first operation against a convoy of petrol tankers, 12 RAAF Kittyhawk fighter-bombers claimed 25 flamers, three smokers, and 25 damaged, as well as destroying two other motor vehicles and three petrol dumps. The tally broke the Squadron's own record for one operation. In the second operation, Commanding Officer of 3SQN, Brian Eaton, led the Squadron to bomb German troops who were advancing to attack less than a mile from 78th Division troops.
Two weeks earlier Eaton had broken his left hand, and now flew with his hand and forearm encased in plaster, with a modified cockpit for his constrained hand movements.
It seemed that Eaton was little handicapped though, as he claimed a tank set ablaze, an armoured car and two other motor vehicles destroyed. This second operation also hit a road convoy bringing reinforcement and supplies to the German front-line forces. The Germans' attack was stopped and Eighth Army sent a message to Eaton thanking the squadron for its effort, which largely prevented the enemy advance. The two operations were typical demonstrations of how fighter-bomber interventions in close support of the army could affect the momentum of a battle."​

 

[swampyankee]

Even without the information posted by GrayMan, just above, I would think that strafing attacks against top armor would not be as effective as they would seem at first glance: flying into the ground is a career limiting maneuver, and the shallow angle needed for strafing would mean that projectiles are going to be impacting top armor at angles far off normal impact. It doesn't take much armor plate to stop a 0.5 in (or 30 mm DU) projectile when it's impacting 80 or 85 degrees from the normal.

Rather obviously, not all land vehicles are tanks. The vertical armor on many vehicles would be vulnerable to those same 0.5 in projectiles, especially since the speed of the aircraft adds another 300 or so fps in effective muzzle velocity. Even those vehicles that are tanks would be impeded: sighting equipment may be damaged, and commanders would face the choice of buttoning up or being shot up.

 

[fubar57]

Just need a few shells to enter the top of the engine deck of a Tiger

 

[Admiral Beez]

This thread is specific, "ground attack aircraft against armor and other hardened land targets". I don't think Typhoon, Tempest or Thunderbolt cracked a lot of tanks, being more focused on trains and road convoys and other soft targets. Mosquito and Beaufighter likely rarely faced a tank.

Hurricane with four 20mm cannons would have been a welcome tank buster in Malaya.

 

[GrauGeist]

I've read plenty accounts where U.S. fighters caught German tanks in columns and while the chances were slim that they'd disable a Tiger, Panther or similar, they'd most certainly destroy the accompanying transports carrying fuel, ammo, support and supplies. Not to mention the personnel (including troops) and horse teams used in many cases.

So while the heavy armor hasn't been knocked out, it's ability to get into position and deploy has been greatly interrupted.

 

[Shortround6]

Just need a few shells to enter the top of the engine deck of a Tiger

True, but the question how.

The engine itself is under the armored hatch in the middle of the deck, It is the radiators and oil coolers on the sides under the vents. The vents have a fair amount of depth and the only path for a bullet or shell is from a steep angle. An impact/strike at a shallow angle is going to skip off the deck/hatch and a hit on a vent is going to see most/all of the force absorbed by the thick partitions of the vent.
Next

A 1/6 scale model but the radiator cores were under the deck, immediately adjacent to the fans. There were air boxes under the vents the leading to the radiators with baffles in place to protect the radiators.
Tank designers were well aware of small explosive charges, gasoline bombs being thrown onto engine decks in an effort to stop the tanks and some effort (not 100% successful) was made to defeat these types of attack (Germans for instance used a bundle charge of 7 stick grenade heads wired together against T-34s, 42 oz (1190 grams) of explosive. Not the 5-20 grams of a 20mm shell. An AP shot has to get through the vent and then the baffles (or land in exactly the right spot at exactly the right angle) to have a chance at the radiators.

I am not saying it was never done but the chances are pretty low.