Fun question! Imagine you’re an ace WWII pilot in your leather flight suit and cap, sitting in a folding wooden chair in a yellow army briefing room, shoulder to shoulder with 14 fellow pilots. The officer before you points his long metal rod at a series of paper sketches on a tack board—an unusually state-of-the-art briefing. His face is grave.

“These sketches, gentlemen, show a new enemy aircraft. The good news is there’s only one of them. Your mission is to find and kill it. We’re sending your entire wing. If you approach high and in loose formation, we expect 100% chance of success and that some of you will definitely come home.”
“That makes no sense, Sir. We’ve shot down a hell of a lot of enemy fighters. Besides, that thing looks like just a bomber with no turrets. We’ll kill it and be home for lunch.”
“It looks like a bomber son, but it moves like our fighters. It has nearly your speed, nearly your maneuverability, practically never runs out of fuel, and is mostly armored beyond your guns’ capacity to damage. Its gun is more powerful than yours, and has longer range. You’ll minimize that advantage by attacking from above—the enemy likes to fly low—and staying engaged until it’s dead. For the love of God don’t turn your back and run. Do that and you’re dead.”
“One gun sir?”
“I’ll spare the details except to say it’s dangerous. Yours converge at 750 feet, with a low percentage kill chance on the enemy. The enemy has a 100% kill chance on you at 4000 feet. Maybe 6000.”
“Jesus Christ.”
“Loose formation, son.
“I’ll say, sir.”
“One more thing. It carries two seeker-rockets that outrange your guns, so two members of your wing will be down before they get a shot off. It’ll be up to the surviving fighters to down the enemy.”
“…but you said we can’t penetrate its armor?”
“It’s not all armored, pilot. Keep shooting and one of you will eventually damage something critical. It can’t outrun you, so you’re guaranteed a win if you stay engaged.”
“Unless we run out of fuel or ammo, right?”
“Best not screw around then, eh?”

FROM THE COMMENTS SECTION…“Did they get it?”
ANSWER BELOW INCLUDES UPDATED TECHNICAL DETAILS based on feedback from A-10 pilots and fans in the comment sections. Thanks everyone!

A stalemate. They can damage the A-10—mostly it's not "armored" so much as "able to fly while damaged"—but they'll only get one pass at best.

On their first encounter they catch the A-10 unawares from above but, fearing its gun, they attack from straight on high. Even with their superior dive speed, aren't able to catch it—they're not enough faster to cover both the vertical and horizontal distances—and the A-10 escapes without knowing it was pursued.

The next time they spot the A-10, they attack high and front. The A-10 sees them coming and looses its IR-guided defensive Sidewinders, but it’s a warm day and they fail to track the piston driven fighters precisely…two are damaged but still airborne. The A-10 pilot knows that his GAU-8A cannon burns through its 1-ton of ammo in about 9 short bursts, so there's no way for him to defeat 15 attackers even with an epic feat of precision gunnery. It also occurs to him that, though he's tagged air targets with his cannon in practice, few A-10 pilots have ever done so in war; the WWII airmen, on the other hand, could be seasoned dogfighters. The pilot’s fingers twitch at his radio: in his own time he'd call for air superiority and F-15s or 16s would be inbound in minutes. Alas.

With a sigh and a grumble he heels the flight stick around. He throttles up and the whine of the General Electric turbofans enfolds him like a defensive blanket. A few shots ping against his airframe but the fighters are firing wild, still well outside their effective range, merely blanketing the airspace with lead in an attempt to prevent his escape.

It's no use. The flyboys can only watch gape-mouthed as the A-10 climbs away faster than any aircraft they've ever seen, vaulted by its great square wings as if borne away into the sky by angels.

*How can the A-10 have similar top speed to WWII planes yet completely outperform them? POWER! Or more accurately, thrust—which the A-10’s turbofans generate far more efficiently than the old planes’ props. The A-10 is pushed along by 18000 lbs of thrust—a pittance compared to modern air superiority fighters, but eye-popping compared to, say, a P-51 Mustang, at about 1000 lbs of thrust. It’s remarkable that the WWII planes are so streamlined that they can about match the Warthog’s speed, and so elegantly airworthy that they can about reach its operational ceiling, but Physics says takes them much longer to reach those heights and speeds, and much longer to recover any energy lost to maneuvers.

The A-10 would be a terrifying foe to WWII pilots. It’s roughly the size of a B-25 but turns like a fighter and accelerates like it was driven by 18 props!

I don’t think people seem to realize just how large the General Electric GAU-8 Avenger is. That’s the primary armament of the A-10 Warthog, and it fires rounds that chew through concrete with ease.

The picture below is of a 30mm autocannon round next to a .30–06 Springfield round, considered to be a relatively large round for a rifle.

Now here’s the gun itself. Did I forget to mention that it can fire 3900 of these 30mm rounds per minute?

The reason it has so many barrels (which rotate) is because the barrel would literally melt off the gun if a single barrel were used.

Now the A-10 Warthog flies at about 439 miles per hour, about the same speed as one of the fastest fighters of the war, the Supermarine Spitfire.

I don’t think there’s any question that the Warthog would destroy everything you could throw at it from World War II.

Hell Yeah. It should be able too (as other posters have noted).

The cannon's original design could be switched by the pilot to 2,100 or 4,200 rounds per minute; this was later changed to a fixed rate of 3,900 rounds per minute. The cannon takes about half a second to come up to speed, so 50 rounds are fired during the first second, 65 or 70 rounds per second thereafter. The gun is accurate enough to place 80 percent of its shots within a 40-foot (12.4 m) diameter circle from 4,000 feet (1,220 m) while in flight. The GAU-8 is optimized for a slant range of 4,000 feet (1,220 m) with the A-10 in a 30-degree dive.

However the main gun of the A-10 is a 30mm Gatling gun was designed to be an anti-tank ground attack weapon not an air-to-air weapon. It is even angled slightly downwards for this task of ground strafing.

Update:

The A-10 uses the General Electric GAU-8/A Avenger gun. It is a 30mm hydraulically driven seven-barrel Gatling-type cannon. Its rate of fire is 3,900 rpm.

A Spitfire MKI and II had eight Browning .303 machine guns, with a rate of fire of 1,150 rounds per minute.

American WW2 fighter planes which used the 50 cal (12.7mm) machine gun had firing rates of about 550 rounds per minute to 750 rpm.

The British used a Hispano 20mm cannon gun which had a rate of fire of 500 - 600rpm.

Meanwhile, the Germans used several 30mm cannon guns which had between 50 - 600rpm.

So, the A-10 30mm cannon gun would have done the job admirably in WW2, except that its angled slightly downwards.

The max speed of the A-10 is 439MPH (761 kmh). That would be enough to enable it to take on WW2 aircraft.

The A-10 pilot would be wise to avoid dog-fighting with enemy fighters and rely on its superior speed to “boom and zoom”, shoot at the enemy planes before darting away. If it does engage the enemy in a dog-fighting environment, other factors like turning radius, stall speeds, climb rates would have be factored in.

The German ME262 had max speeds of 559mph (900kmh). So on paper, a good pilot in an ME262 would be able to chase and shoot down an A-10.

But the question is whether the A-10 can shoot down WW2 fighter planes, and taking into account the A-10’s gun, speed and modern design, it will be able too.

The ME262 had the speed and weapons to take down an A-10.

Source:

The WWII Fighter Gun Debate: Gun Tables

Pilot Chalks Up First 'Warthog' Air Kill : Aerial combat: Iraqi copter is downed by a plane not known for its dogfighting capabilities.

Messerschmitt Me 262 - Wikipedia

There’s two parts to the question.

Weapons: The Warthog had some awesome gattling guns, larger than 1.2″ diameter that were intended to take out Armored ground vehicles, so WWI aircraft which were usually using .30 and .50 (inch) calibers to shoot each other would have been macerated by the 30 mm rounds (1.2″) of the A-10… the other answers all have comparison pictures. There is no doubt that being hit by these would be much more deadly to WWII fighters than just about anything they faced. Here’s a Toyota SUV hit by a few rounds from an A-10

Can they Engage: Well, the Warthog top speed is not much greater than any WWII fighter. Its speed ranged from stall at 120 knots to 381 knots max. Some WWII planes could literally pull away from a Warthog, Me262 at 490 knots, A P-51 could stall at 87 kn and fly up to 383 kn. Certainly the operational ceiling was much higher than WWII aircraft for a fighting advantage. I suspect a slow flying, maneuverable early WWII vintage plane might have been hard for a A-10 to track… but, it would take only one bullet hit.

Yes - if the pilot flying that WW2 plane is not an ace and the A-10 pilot knows his trade.

Air-to-air combat is never machine versus machine, but always human versus human. The aircraft is merely a tool here. And a good pilot in a mediocre aircraft will always win a mediocre pilot in a good aircraft.

The performance of A-10 is slightly superior to WWII fighters, and it is surprisingly agile. On paper, A-10 has all the advantages over most WWII fighters - except perhaps on aerobatics and agility. It has higher stall speed than most WWII aircraft, meaning it is more prone to high speed turning stalls than WWII fighters.

If the A-10 pilot knows his trade, he will attempt to avoid dogfighting and manoeuvre combat, but instead employ the pendulum tactics. The best bet is always to use weather (direction of Sun, clouds etc) as your asset If, however, the WWII pilot knows his trade, he will attempt to negate all the assets of A-10 and force him to dogfight. A-10 has superior climbing ability, but it also bleeds energy pretty quickly, so certain WWII aircraft with a lot of power and low wing loading could be dangerous here.

The best bet would be a quick dive from Sun’s direction and use Sidewinders. The WWII era piston engine ought to make large enough heat signature to get to missile lock. Failing that, the next best bet would be head-on approach - the Avenger gun ought to be enough to shred any WWII aircraft into chaff.

[But a good WWII plane pilot would have done, of course, his homework.]

Definitely yes, even though it isn’t designed or dogfights. Technically, the A-10’s max speed is comparable those of the best WW II fighters, but generally has a higher ceiling and significantly better climb rate. As such, the A-10 would likely conduct slashing attacks from high altitude, the climb back up quickly for another attack.

It probably has the most powerful gun of any fighter in WW II. I suspect the big issue will be ammo load. It also helps that the A-10 can carry AIM-9 Sidewinders.

While the A-10 does not have radar, it can be mounted with a FLIR in the form of a Sniper XR or a LITENING target pod, giving it an advantage at night or even cloudy conditions.

The HUD will also help should they do get into a dogfight.

The A-10 would have been a fantastic tool for WW2. Probably the best ‘modern’ plane to take back there (assuming it comes with the right support staff that knows how to keep it going, otherwise any modern plane is mostly useless in WW2).

We have many fancier planes than the A-10 but what the A-10 has over most of them that would suit it well in WW2 is ruggedness. It could conceivably operate from improvised cow/farm field air strips that were common in WW2.

None of the fancy jets like F22s and whatever could do that which would drastically limit how deployable they would be in WW2. The A-10 is also much less fiddly when it comes to maintenance out in the field, enjoying a far better flying hours to maintenance hours ratio.

The A10 is also built for ground attack which is great because that is mostly the kind of war that WW2 was. It can take quite a licking from AA fire before it goes down and it can deal out tremendous damage to ground targets.

A squadron of A10s supported by good intel could likely wreak so much havoc on an opposing forces infrastructure that they would be a deciding factor in the war for whichever faction had them.

EDIT: Some additions based on interesting discussions in the comments.

• I think it would be possible for WW2 era science to create fuel for an A-10. Perhaps not to the standard of todays JP-8 jet fuel but good enough to get it flying at least. The main component of jet fuel, kerosene, is not a particularly recent invention.
• I think it would be possible for WW2 era manufacturing to create ammunition for the brrt cannon. Not as effective as the DU ammunition it uses today but effective enough to make it a relevant weapons platform.
• I think it would be possible for WW2 era engineers to retrofit the A10’s hardpoints to be used with ordonance of the time. Obviously this would be less effective than modern ordonance but at the same time the A10 would still be the best bomber around by a mile, just because of the superior airframe compared to the planes of the time.

All in all I think an A10 in WW2 would be less effective than an A10 today with all the support it gets in modern times but would still be far more effective than anything in use in WW2. The main issue would be maintenance as damage to electronics and the like would be basically irreperable. Despite being quite a rugged plane this probably would mean that it would need to be used effectively and decisively before its relative limited airtime is expended. Having said that, I think and A10 would run far longer without a modern day maintenance crew than any other fighter flying today.

Made it home, not a problem (irreperable in WW2 though)

Flew home and landed all without hydraulics (possibly reperable in WW2, not sure)

Depends when in the war. Up to about 1942, the A-10 is not doing too badly in terms of speed (380 knots flat out, clean, no pylons or external weapons), and it’s reasonably agile and doesn’t climb too badly compared to the aircraft it would be fighting (Me109 up to -F model, Spitfires up to -V). Its gun is a winner on anything it hits, though I don’t think the sight is optimised for air-to-air work (certainly doesn’t have any ranging) and it’s resistant (though not immune) to HMGs and cannon fire.

By the time you’re into 1944, aircraft like the Spitfire XIVe or the F4U Corsair match or beat it for kinematic performance, and the A-10 does suffer from the problem of being huge by comparison - there’s the important point of “first sight wins the fight” and, lacking any sensor advantage, the A-10 is likely to be seen first. It’s not losing, but it’s got no clear edge and it’s starting to have drawbacks.

The other issue is where the fight happens: the A-10 is happiest down low, so if it’s going against Soviet Yakovlevs and Lavochkins on the deck, it’s still ahead at war’s end. If it’s fighting P-51Ds and P-47Ds or -Ms above 20,000 feet, it’s less happy and confident in any kinematic advantage.

So, short answer, yes: but early in the war it would be a holy terror, late in the war it would be having to tread much more carefully since it’s likely to be badly outnumbered by smaller opponents it’s got no major advantage over.

The A-10 Thunderbolt:

See those two missiles outboard on the port wing? AIM-9 Sidewinders.

So yes, it absolutely could, and wouldn’t even need to get particularly close to them.

People always get very excited about the gun on the A-10 but it’s a long, long way from the only tool in the Hog’s toolbox and a lot of the time what’s hanging under the wings will do a better job.

“Could” it be used in aerial combat?

Sure.

Hawg drivers have the tools and training to tangle with other aircraft.

In practical terms of “does it stand a reasonable chance of winning against a dedicated air superiority jet?”

Not. At. All.

It’s like asking “Could Michael Jordan play baseball?”

Sure.

In baseball, Michael Jordan was a respectable player

In basketball, Michael Jordan is a legend.

Air-to-air is not the Hawg’s job. It was designed from the ground up to be a close air support aircraft. In that arena, it’s still the best there is at what it does.

From Lynn Taylor's post in Defense Quorum - The A-10 is NOT a Dogfighter:

There I was…

The one time I was privileged to join in a dissimilar air-to-air combat training, it went down something like this…

Elmendorf AFB was having a combat readiness exercise, and their F-15 Eagles and F-15E Strike Eagles (a.k.a. Mud Hens) needed some opposition in order to strut their stuff. Eielson AFB was volunteered to be that opposition with our F-16s and A-10s. It was decided to split the defenders into “high cover” and “low cover.” The F-16s were in the high block. I was Hog 4 in a four-ship of A-10s assigned to play the role of Defensive Red Air in the low block. (Go ahead and laugh. We did.)

The Eagles and Mud Hens were supposed to escort some C-130s that were to ingress at low altitude and deliver some paratroopers to a drop zone behind our lines. Our job was to stop them.

Dramatis personae, left to right: Mud Hen, Viper, Hawg, Eagle (photo: Air Combat Command)

The Eagles came in first. We could see the wall of contrails high above as they came bearing down on the hapless Vipers. We lost track of them as they (I presume) descended into a turning fight to clean up whatever survived their first volley.

We listened to several minutes of radio chatter as our Viper brethren called out shots, kills, and losses. All we could do was fly our lazy circles in the sky, listen, and wait. As the radio started to calm down, Two Bears (the ground-based radar tracker/controller who acted as referee) jumped in on all frequencies with a muffled call that no one really caught.

“Say again, Two Bears?” asked the F-16 lead.

“I say again: All the F-16s are dead. All the Hogs are alive,” came the reply.

Well, then. The Mud Hens would be here shortly.

It didn’t take long.

At first, it was just a little tickle in the headset. A little burble in the radar warning detector informed us that someone was glancing at us, but only just. They had found us, and we were looking hard for them.

My flight lead and I saw the first of them about the same time, while we were in a gentle right turn. Looking over my shoulder at my right four o’clock was the unmistakable sight of two big rectangle intakes framing a round nose, and it was getting bigger fast.

“Break right! Bandit…” my flight lead called out over the radio as our four ship split apart to engage our attackers.

I had scarcely completed my break maneuver before Two Bears called out again, “Killed: Hog 1 and 4.”

Well, that was fast.

Fortunately, as Red Air, the rules allowed us to trundle back to the respawn point and come back in for some more fun as “reinforcements.” I linked up with Hog 1 and we headed that way.

Looking around, we spotted the C-130s sliding through a valley, trying to slip by unnoticed.

C-130 over Alaska (photo: U.S. Air Force photo/Tech. Sgt. Keith Brown)

They were noticed.

Hog 3 was the squadron’s Weapons School graduate, and he swooped in with a good strafe against the lumbering transports before arcing back up again to rejoin the fight with the Mud Hens, who had blown through what was left of our formation and were in the process of turning around for another go. (Why close to visual range with us in the first place? Because dissimilar air combat training, especially against Hawgs, is a very rare thing. Might as well make the most of it!)

Meanwhile, Hog 1 and I had hit the respawn and were on our way back in. He was soon engaged in a turning fight with a Mud Hen, while I took an opportunity shot at another one that was trying to go over the top of us to get around behind. I hauled back on the stick and “fired” my two AIM-9s in succession as he reached the engagement limits of the weapon. He didn’t fire flares in response, so I called the two Fox-2s over the radio to Two Bears as a kill.

Rolling onto my back to point my nose at the ground and recover the airspeed I had just lost, I saw Hog 3 zip by with a Mud Hen close on his tail. I moved to assist, and was working out the geometry of where I needed to go to get a bead on the dark gray jet when Hog 3 went vertical.

Now, you generally don’t go vertical in the Hawg. That’s something you just don’t do, especially in a dogfight. But he did, and it probably saved him.

His jet traded airspeed for altitude quickly, and suddenly the Mud Hen had a faceful of Warthog about to land in his lap. He pulled hard to avoid ending up in Hog 3’s front arc, which allowed me to slip in behind him and line up for a shot up his tailpipes.

“All flights, terminate,” radioed Two Bears.

Well, dang. The fight was over.

But it was a heck of a lot of fun while it lasted!

All things considered, we did pretty well. The “all things” to consider, though, include the following:

• Our attackers decided to close with us instead of just smoking us from a distance with radar missiles, which would have been more realistic, but largely a waste of a rare mutual training opportunity.
• Half of our flight was still destroyed in the first pass.
• Our attackers decided to stick around and play with us in a big furball (a chaotic, turning, multiple aircraft dogfight).
• We were able to complicate matters by respawning and re-entering the fight in short order.

So… yes, if you stack the odds in favor of the mighty Warthog, it can do reasonably well in a dogfight. But dedicated air-to-air fighters intent on splashing you won’t play that game. They will engage in a very unfair fight against the Hawg and use their superior radar detection and missile range to kill them before anyone even sees each other. If they happen to find themselves in a close-in fight, they’ll know enough to get clear, line up again under their terms, and pick us off from range again.

The A-10 is a close air support platform. If you pit any other tactical combat aircraft against the ground weapons delivery capability of the Hawg, the best they’ll be able to do is match it. And, quite often, they won’t even do that, as demonstrated by the 354th Fighter Wing Turkey Shoot of April 2000.

But that is a story for another day…

(Photo: U.S. Air Force)

BRRRRRRRRTTTTTTTT!!!!

There are some really great answers already here as to how well the A-10 would hold up as a fighter in WWII. I also answered a very similar question a while back here:

Juan Rabat's answer to How would the A-10 Warthog perform in air combat against WWII or Korean War-era fighters?

You can check out that one if you want for some other info.

In that answer, I do give an interesting scenario. Imagine now the A-10 not as a fighter, but as a GERMAN HEAVY fighter. This means that the other fighter escort the A-10 so that the A-10 can engage the B-17’s. Now that would be interesting… The A-10 would be able to take anything the bombers could throw at it while totally schredding the bomber formations. In fact, considering the accuracy and range of the Avenger cannon, it can easily down B-17’s while maintaining out of their defensive weapon’s range. Can you imagine the panic of bomber formations?

And even if a couple of P-51’s manage to get to the A-10, it should still be able to hold its own OK. You could even save your sidewinders for such ocassions…

OK, this is fun. :)

As the other (good) answers have noted, the A-10 is not designed as a fighter. So not really ideal for the task. Visit the basic numbers…

• P-51D - North American P-51 Mustang - Wikipedia
• 440 mph maximum speed (at altitude), 368 mph at sea level
• 3200 ft/min rate of climb
• 41900 ft service ceiling
• A-10 - Fairchild Republic A-10 Thunderbolt II - Wikipedia
• 439 mph maximum speed (at sea level)
• 6000 ft/min rate of climb
• 45000 ft service ceiling

The P-51D is arguably the best fighter of WWII. One-on-one a P-51D pilot has almost no chance.

The A-10 is faster, has a (much!!) better rate of climb, and higher service ceiling. We have not got to the cannon on the A-10. Or the armor.

Keep in mind, the air is thicker at low altitude. The A-10 at sea level is roughly as-fast as WWII fighters at altitude. Not remotely fair.

Given the thrust and weights, an A-10 is (very roughly) the equivalent of 5-9 WWII fighters in one airframe. Could a single A-10 defeat 9 of the best WWII fighters, at once? Probably not. The A-10 pilot would run out of ammunition. But the A-10 pilot then could out-climb and out-run the surviving opponents.

Barring bad luck (or choices), the A-10 would survive, and many of the opponents would not.

Perhaps a more fun question would be can an A10 down a Sopwith Camel.

The problem here is that the top of speed of the Camel is way below the stall speed of the A10.

So with the Camel maneuvering (wobbling) all over the place, the A10 has to get a decent hit on the Camel before it flies right past and has to turn around. Leaving the Camel a chance to get its torpedo away. I say a decent hit because the armour piercing munitions of the A10 might well pass straight through the Camel without doing too much damage.

I believe the Fairey Swordfish deployed this tactic effectively during WW2, particularly in the Mediterranean.

If the question is which one better in BFM, WW2 fighter planes are enjoying a better maneuverability. If the question is who won in a real fight, WW2 planes’ guns are probably underpowered against the A-10 thick armor, while the BRRRT cannon in the A-10 is obviously over powered to WW2 planes' structure which were designed to be light and agile. Not to mention the A-10 sometimes carries sidewinder on it's mission for self defense.

Now your question is simply whether it can shoot a WW2 plane down, you don't say what maneuver the WW2 plane does, and there's no armament limitation assumption, so the answer is clearly yes it could…

Thanks to Juan Rabat for doing the heavy lifting by creating a table that compares important performance numbers between the mighty Hawg and some notable aircraft from WWII and the Korean conflict. That’s really what you need to look at when comparing any two aircraft in a head-to-head dogfight. (Turn rate and radius would also be helpful, but I don’t know how easy those numbers are to obtain for the various aircraft.)

Left to Right: A-10, F-86, P-38, P-51

I’ll simply elaborate a little on what Juan’s numbers mean.

World War II

It looks like the A-10 would be all over the WWII fighters. It would be a screaming demon that would pounce on and perforate the little prop-jobs, striking terror into the hearts of otherwise unflappable warriors.

While the Hawg may be a titch less maneuverable than the old spinners (though I haven’t seen any numbers on relative turn rates), it could overpower them by taking advantage of its superior speed and climb rate. (Yes, as I write this I’m laughing that the A-10 has a “superior speed and climb rate” compared to anything else with teeth. But, there you have it.)

How do I know that speed and climb rate make more of a difference in a dogfight than cornering ability? Because those very factors are what make the Hawg a juicy target to dedicated air-to-air platforms. See The A-10 Is NOT a Dogfighter on The Defense Quorum.

Korean Era

Airpower turned a corner in capability going into the Korean conflict. Again, referencing the numbers shared by Juan Rabat, it looks like the advantage goes to the early jets. Sure, the Hawg might be able to effectively duel against the nimble little buzzards, but it would be fighting from a disadvantage in speed and power.

The two possible compensating factors would be:

1. The GAU-8 Avenger loaded up with high-explosive incendiary (HEI) rounds. The Gun is a powerful beat stick with lots of rounds and a really long reach. It would only need to nick an early jet to put a serious hurting on it. (If we get to include the two Sidewinders, that would help, too. F-86 and MiG-15 exhaust is probably hot enough to grab the attention of the little heaters.)
2. The Hawg can take quite a beating and keep on ticking. Odds are that it could take a few hits and keep on fighting effectively. See How does the A-10 stack against MANPADS? and How much damage can the A-10 Thunderbolt endure before being shot down?

At best, I imagine it would be a draw, or might come down to comparative pilot ability in a dogfight.

It would be severely outclassed by any late-war prop fighter performance-wise.

The A-10 can top at around 700 km/h, which is an average-to-slightly good top speed for a late war prop. Bf 109 G-10s, K-4s, P-51 Ds, late Fw 190 Ds, Ta 152 Hs, P-47 Ds, Spitfire XIVs, etc, etc.

A-10’s climb speed is good for late war props, with around 23 m/s in clean configuration, still being out-climbed by Bf 109 G-10s, K-4s, Spitfire XIVs, and the list continues.

While I couldn’t find reliable data about its diving ability, it would most likely be very good, having powerful jet engines and a sturdy structure.

Energy retention would be however under the average. The A-10 is massive (huge drag coefficient) and not built for maneuvering effectively.

Firepower is theoretically impressive: theoretically one shot or two can blast a WW2 prop fighter into oblivion. We’re talking about a 30 mm Gatling cannon with a ~65 rounds/second fire rate, good muzzle velocity and a lot of ammo, so it should be devastating. Downside of being a rotary gun, however, is that the cannon has a 0.5-ish seconds delay before activating (as the gun needs to rotate before firing). And in a dogfight, when firing solutions are very often extremely limited in time, having this disadvantage is a massive hinderance.

In terms of maneuverability and turn performance, the A-10 is very agile and turns tightly, for an attack aircraft. I mean, it still is a dog when you compare it to a P-51, a Bf 109 or a Spitfire. It had a wing loading of ~480 kg/m^2, which is roughly 2.5 times that of a Bf 109 K-4 (~190 kg/m^2). There’s no chance it wins a conventional dogfight. And although it’s roll rate is nice, that wouldn’t be enough.

Sturdiness is per se not a performance advantage for the A-10. No 1v1s are won with pure sturdiness. Anyways, it wouldn’t matter too much anyways since -while exceptionally survivable-, the A-10 was optimized to survive 14.5 mm or DShK hits, and that that vast majority of WW2 had already 20 mm cannons which would eventually take down the A-10. Oh, and not talking about 30 mm cannons, like the late Bf 109’s MK 108 cannon:

(MK 108s fired horribly effective 30 mm HE shells with a good fire rate. For information, 1 MK 108 HE shell has 100 g of explosives)

Which would transform the A-10 in a puzzle within seconds.

By the way, the concentrated fire of 12.7 mm machine guns such as the American M2 HMG would still bring the A-10 down in not so much time.

To sum up, I would say it would perform poorly against WW2 prop fighters, but it wouldn’t be totally un-winnable either. A close match for it would be the P-47 D, but for the likes of the Bf 109 K, Spitfire XIV, P-51 D-30, etc, I wouldn’t bet my money on it.

How would this:

Stack up against these:

Well, let’s start with some figures:

Some important notes: (1) the WWII aircraft max speed is at altitude, while the jets are at sea level. (2) A-10 combat radius is derived from half the ferry range (we are not lugging around missiles and bombs, right), and the P-51 includes drop tanks. Also (3) the 37mm cannon of the Mig 15 got cropped from the image, but they did have that!

Looking at the climb rates and speeds, it is obvious that the A-10 would be less than useful in the Korean War. It is hard to say if the Mig 15 would have been able to bring it down efficiently (it does have a 37mm cannon that could prove problematic to the A-10, especially since the A-10 probably would not be able to out run it, out turn it - because of wing loading - or out climb it), but the A-10 would have had a hard time catching up the enemies to shoot them down anyway.

In WWII, the scenario would be a little different, since here the A-10, although it would probably not be able to turn and burn with the lower wing loading propeller aircraft, would be able to climb out of trouble. Not to mention, any fighter caught by the Avenger cannon would go from airplane to minced meat rather quickly…

Now, if you want a scary thought, think how much of a difference would A-10’s in the hands of the Luftwaffe would have done… It would take some serious efforts by the P-51’s to bring down A-10’s that can not only out-climb it, but also take a punch from their .50 cal guns and keep on trucking!

And imagine the Avanger cannon shredding B-17 formations! Even with the B-17’s ability to take damage, I doubt many would keep on flying after a short burst of an Avanger cannon loaded with PGU-13/B High Explosive Incendiary (HEI) rounds. Keep in mind that the Avenger’s “5 mil, 80 percent" means that the A-10 would be able to pepper bombers at 4,000 feet of distance with devastating force (at 4,000 feet, the cone of the Avenger is 40 feet; the wingspan of a B-17 is 104 feet!).

EDIT 1: Corrected the chart. I divided instead of multiplying when converting from metric to imperial units…

EDIT 2: Yes, I know the A-10’s armor is optimized for frontal ground fire and that fighters would still be shooting from behind. But it is still a tough plane to shoot down. It can still take a licking and keep on ticking!

Ooh, ooh, I know this one!

Very simply: the A-10 is pretty easy to fly. In some ways it’s easier to fly that other fighters, but in some ways it is more difficult. However, it’s performing the close air support mission that’s really challenging.

That said, every aircraft I’ve piloted had its own quirks that you had to respect or “something bad” could happen. For comparison, I’ve had a least a little stick time in the following military jet aircraft:

• F-16 Fighting Falcon (Commonly called the “Viper” in fighter circles. I was a back seat passenger, but was able to fly it enough to get a feel for the jet.)
• BAE Systems Hawk (As part of an instructor exchange with our sister school in England. We did several low-level training runs for the JTACs, then popped over to the Lake District to play for a bit.)
• Canadair CT-114 Tutor (Scored a spare seat in the press familarization flight with the Canadian Snowbirds. That gave me a whole new perspective on “close” formation flying.)
• Boeing B-52 Stratofortress (A training flight to watch the initial B-52 Weapons School cadre execute a close air support training mission. I got to drive the bus for about 10 minutes.)
• T-38 Talon (Pilot training, phase 2.)
• Cessna T-37 Tweet (Pilot training, phase 1.)

T-38 Talon

Out of all of those jets, the trickiest one to fly was the T-38. The venerable Talon was designed as a Century Series trainer. It is nimble and responsive, with the fastest roll rate of any jet I know at 720 degrees per second. Yes… if you throw the stick all the way to one side, you will go from right-side-up to upside-down to right-side-up to upside-down to right-side-up again… in one second. I once just rolled it and rolled it and rolled it until the nose dropped low enough that I had to recover. I lost count of how many spins that was, and had to drive straight and level for a while until the gyros in my noggin settled down again. Once was enough of that for me.

The T-38 has some… unique… stall characteristics, and you have to be careful when going into and out of afterburner. You do that one engine at a time, just in case an engine decides to flame out in the transition. There’s a fantastic write-up of what it’s like to fly a T-38 here: Warbird Alley: Northrop T-38 Talon Pilot Report. Compared to the T-38, the A-10 is a very stable and forgiving platform, as long as you respect its quirks.

Hawk & Viper

The Hawk probably has more in common with the T-38 than the F-16, but it was also much more forgiving than the Talon, so I’ll include it with the Viper for comparison with the A-10.

Power is the word that comes to mind when noting the biggest difference between these two jets and the Hawg. Need more airspeed? Shove the throttle forward and you have it, pretty much on demand. That makes high-energy maneuvers a dream. You still need to keep an eye on your airspeed, and fuel is a limited resource, but you don’t have to wonder if the engine will give you what you need when you need it.

One consideration that was a factor in these faster “fast movers” is turning radius. In the A-10, we can nestle down in some pretty small valleys, and can bump up close against the edge of our airspace borders before having to haul back on the stick to turn around.

Neither one of them were particularly difficult to fly. They are very responsive to control inputs, with lots of power to do what you ask. (Of course, even these jets have limits, but I wasn’t there to test them.)

The Hawg

The A-10 is very maneuverable. Even with those big Hershey bar wings, it has a very good roll rate (which you can actually increase a bit more by opening the speed brakes just a little). It can turn on a dime and give you change, it just can’t keep that turn rate up for long without bleeding off all of its energy. You can usually expect to get a good 180 degrees of hard turn without losing too much, which is usually about as far as you need to turn in a hurry, anyway. More than that and you need to lighten up on the stick a little to conserve energy.

All the jets are a little bent out of shape after so many years of high-g maneuvering, so you need to keep an eye on your trim to keep the jet from wandering, but it generally stays pointed where you want it to. (See the Autopilot section of Given carte blanche, how would you improve upon the A-10 Thunderbolt II "Warthog?".) A-10 drivers get fairly good at flying straight and level, or in gentle turns, using their knees to move the stick while their hands are busy holding maps, writing on the canopy, etc.

As a weapons platform, the A-10 is very stable. It also has a cool feature when firing the GAU-8 Avenger cannon. After lining up on a target, you pull the trigger back halfway and a flight control dampener engages, so you can make larger stick movements with less flight control responsiveness. That makes it easier to fine-tune the shot and line it up just right. Then, when you squeeze the trigger the rest of the way and the nose wants to dip from the force of the cannon firing 66 rounds per second, the system adjusts to keep the nose where it was pointed when you pulled the trigger. (Side note: that system can be disengaged when you don’t want that feature, such as when dogfighting, or strafing an area instead of shooting a point target.)

The toughest part of flying the A-10 is energy management. With amazing maneuverability, but only half an engine on each side, it’s easy to demand more from the jet than it can sustain, and you can quickly find yourself with little airspeed and few options. With experience, though, that problem is easy to manage. You learn how much you can demand from your jet, and what it will take to recover whatever you spend in maneuvers. You learn where the edges of the flight envelope are, and can bring your jet right up to the edge of max performance without pushing it over.

Like every other jet, once you learn its secrets, you can do amazing things with it.

The Mission

As I mentioned at the beginning, the REAL challenge comes when it’s time to learn how to use the jet as a weapon. Close air support is one of the most demanding mission types (I would place it behind combat search and rescue and airborne forward air control, which the A-10 also does). There are a lot of moving parts, a host of changing factors to consider, and the stakes for screwing it up are extremely high.

Fortunately, the flight characteristics of the Hawg make the job easier instead of harder. It’s stable, maneuverable, pretty forgiving (as long as you don’t let your energy state get away from you), and feels like a reliable partner in accomplishing the mission.

Oh God yes.
Not just the GAU-8, which is really more of a ground attack weapon (but did take out a chopper in Desert Storm), but a host of missiles, Sidewinders for A-A, Mavericks… Thirteen hard-points. Speed is decent, not too fast and hence maneuverable.

(I recall the F4 pilots in the late 1970s saying the A10 was the only jet to get bird hits -from the rear and that the airspeed indicator should be replaced with a calendar. Funny bastards those Phantom Jockeys)…

So yes, perfectly capable and can take a beating. I would not call it a match but a skilled prop pilot might be able to take one out.

There’s a lot of variability here.

Early Zeros and Bf109s (e.g., “Bf-109E) would have a hard time with the A-10.

The A-10 is much faster (Top Speed: 450mph) versus the Bf-109E (355mph), and this combined with an A-10’s initial climb rate of 6,000ft/min (far better than the ww2 fighter climb rate) means that the A-10 can boom-and-zoom the early ww2 fighters…all day.

Obviously, a single 30mm shell hit on a fighter just about decides the fight. Depending on circumstances, I think the early fighters might get a couple rounds into the A-10 just because they can turn tighter. However, if the A-10 pilot “fights in the vertical” properly, he/she should have the advantage.

However…

When we come to late-war American super-props like the F4U-4b and the P-47N, things get more interesting. The F4U-4 has a top speed of 446mph and the P-47N a top speed of 460mph. The A-10 speed advantage evaporates. However, its climb rate is still superior. The F4U-4 has a climb rate of 4,700ft/min, which is better than early war fighters, but still not as good as the A-10.

The F4U-4b carries 4x20mm cannons and if it can get a good sight picture, it can beat up an A-10 pretty bad. The “titanium tub” of the A-10 protects the pilot from ground fire, but not 20mm rounds crashing through the canopy. The rest of the A-10 is not protected as well as the pilot, so the Corsair can be a dangerous foe. The 8x.50 cal guns of the P-47N may not be sufficient, though.

F4U Corsair.

So, late war American fighters (and British fighters like the Spitfire Mk XXII and Tempest Mk II) would get some licks in in any battle with the A-10.

Certainly.

Which country would you assign it to support? And in what year would you have it intervene?

If China had a squadron of A-10s in 1942, for instance, along with supplies, it would probably force Japan to withdraw from mainland China within a year. The Republic of China would gain so much prestige from possessing such a weapon that the Chinese communists would be crushed soon after.

Meanwhile, the Soviets would reconcile with the Chinese government and Germany would attempt to end its war with the Soviets on the 1941 boundary while its scientists would attempt to duplicate the new technology. This was fail, as neither they or anyone else has the capacity to manufacture the alloys involved in any quantity or machine them to tolerance.

The Anglo-Americans would continue their war cautiously, while pressing forward with nuclear weapons research to ensure that they will have a counter to Chiang Kai Chek’s new superweapon.

While all of this was going on, every major power would be doing their utmost to find the source of this weapon and to capture samples for reverse engineering.

Sounds like the making of a great anime series.

Its the name sake of the greatest ground attack aircraft of all time, the Republic P-47 Thunderbolt. The technology has changed but the philosophy is the same, and the A-10 pilots I knew all gave the highest credit to their namesake, the P-47 Thunderbolt, and her pilots:

High firepower in guns/gun:

(Above: The whole SIXTEEN yards!” The P-47 was the heaviest armed American fighter with eight Browning M2 .50 caliber machine guns and 3400 rds of ammo. It could thrown out 12.75 lbs of lead per second and had 31 seconds of firing. (A P-51 had six .50’s and only 1880 rds of ammo, 9.35 lbs of lead per second and about 21 seconds of firing.)

(Above: 30 mm GAU-8/A cannon, 1500 armor-piercing depleted uranium and high explosive incendiary rounds, apox. 17 seconds of firing.)

Lots of externally hung ordnance:

(Above: 3000 lbs of bombs, AN-M64 500 lb and AN-M65 1000 lb were very common, AND ten 5″ HVAR rockets, the rockets alone giving a P-47 the broadside of a destroyer!)

(Above: A-10’s have eight under-wing and three under-fuselage pylon stations, including 500 pound Mk-82 and 2,000 pounds Mk-84 series low/high drag bombs, incendiary cluster bombs, combined effects munitions, mine dispensing munitions, AGM-65 Maverick; AIM-9 Sidewinder.)

Lots of fuel for linger time over there battle or until called on:

(Above: The P-47D could carry as much as 750 gallons of fuel and a range of over 1000 miles, but since the ground attack targets were usually within 100 miles, it gave them literally hours of linger time to circle above and behind the lines till given a target.)

(Above: With a range of 2,580 miles the A-10 has lots of linger time, too. It can loiter near battle areas for extended periods of time and operate in low ceiling and visibility conditions. The wide combat radius and short takeoff and landing capability permit operations in and out of locations near the front lines like it's P-47 big brother. Using night vision goggles, A-10 pilots can even conduct their missions in darkness.)

Physically tough enough to survive the beating as ground support is THE toughest mission an aircraft can fly:

(Above: The P-47 had THE best loss per mission ratio of WWII tying the Mosquito, astonishing as it was THE “workhorse” of American aviation in WWII and flew 746,000+ missions, more than the P-38, P-40 AND P-51 combined, and 400,000+ of them f=ground attack the toughest mission an aircraft can fly, getting pounded down on the deck. The P-47 could get her pilots biome with entire cylinders ripped away from her P&W air-cooled R-2800 engine, multiple cannon hits, (Robert S. Johnson, our #2 ace in the ETO, 27 victories, exclusively in P-47s, took on seventeen Fw 190s and was hit with twenty one 20mm cannon shells and they stopped counting mg bullets at 200…and it still got him home! The large size made duplication of many of the crucial systems possible, that also let her get home shot to hell.)

(Above: A-10 pilots are protected by titanium armor that also protects crucial parts of the flight-control system. The redundant primary structural sections allow the aircraft to enjoy good survivability during close air support. The A-10 can survive direct hits from even armor-piercing and high explosive projectiles up to 23mm. It’s self-sealing fuel cells are protected by internal and external foam. Similar to its P-47 n=big brother, it has its manual systems backed up including redundant hydraulic flight-control systems. This allows pilots to fly and land even if hydraulic power is lost.)

I knew dozens of old P-47 pilots from WWII who talked with dark faces about ground attack sorties: the grind of often multiple missions a day flown off airfields only a few miles behind the front lines, and the cold efficiency of the German anti-aircraft defenses, firing everything from Kar 98 rifles, to quad Mg 42s, to 20mms, to 37mms, to 88mms, to 128mm antiaircraft guns at them, with the accuracy that comes from a lot of experience, trains filled with flak guns in ambush, attacking German Aerodromes bristling with AAA guns, the stress of getting bombs and rockets delivered to assist desperately pinned down American GIs. The deaths, the mental breakdowns, the booze, the despair.

(Above: Shooting up German airfields.)

(Shooting up railroads.)

JUST in Europe, from D-Day through the end of the war, P-47 units of the 9th Air Force are given credit for destroying 86,000 German railway cars, 9,000 locomotives, (their railroad system was, also arguably, the Germans greatest weapon of WWII), 6,000 armoured fighting vehicles, and 68,000 trucks. It did untold damage to German infantry, likely killing over 100,000, and sadly untold numbers of the horses and wagons that truly propelled the Wehrmacht, not to mention uncountable German artillery pieces, anti-tank guns, /machine-gun-emplacements/pillboxes that the P-47’s, guided by other P-47 pilots grounded, working with the American infantry, sometimes even in the turrets of forward Shermans, that could bring in close support sometimes within a recorded 50 yards! Danger Close!

(Above: A-10 practice strafing run on Humvees.)

(Above: A-10 ground attack.)

And I knew a very few A-10 pilots when I was commissioned by the Air Force to design the new West Coast A-10 Demonstration Team’s new should patches right after the Gulf War in the early ‘90’s. The toasted the P-47 pilots facing that cruel German “gauntlet”: as men whose balls wouldn't fit in Yankee Stadium.

Thank you for the A2A!

TL;DR: Yes.

(Revised and expanded as of 7/13/2015.)

Long Version:
That is a great question, and one which necessitates the most beloved of A-10 (and perhaps fighter pilot in general) responses: "It depends."

What is a "Take Down"?
There are almost as many ways to take down a tank as there are to skin a cat. These multitudinous ways are generally grouped into three categories that describe the effect on the tank/target:

M-kill - A mobility kill. In today's highly mobile battlefield environment, an immobilized tank can quickly become irrelevant as the battle lines sweep past them. They also become a lot easier to hit by just about everything, including artillery.

F-kill - A firepower kill. Neutralize the weapons on a tank (especially that big metal pipe that swings around on top), and it becomes the most powerful contender in a demolition derby. Beyond running into things, it can't do nearly as much as it used to.

K-kill - The dream shot... a catastrophic kill. (Why is it a k-kill instead of a c-kill? No idea, except maybe the military loves alliteration. Or perhaps it's a "kill" kill instead of a "sort of" kill.) A k-kill is usually accompanied by Hollywood effects like fire, smoke, and maybe even an explosion.

So, considering the full spectrum of "take down," yes, the GAU-8 Avenger cannon is able to effectively combat neutralize a T-90. Tank armor is great for protecting the softer insides (crew, ammunition, fuel, engine, etc.) but there are plenty of exposed and vulnerable spots that, if damaged, would knock the tank out of the fight.

Now, let's talk about how difficult it is to crack the shell...

The A-10 and the GAU-8 Avenger
In the blue corner, we have the most powerful gun ever mounted on a fighter-scale aircraft.

The GAU-8 was designed to penetrate hard targets like tanks. Since the gun was built, tank armor has continued to evolve, but A-10 ammunition hasn't. (Remember, though, that you don't have to actually poke holes in the armor to "kill" a tank.) Let's look at some unclassified (a.k.a. "best guess") numbers.

Sources vary on their data, but let's pick some numbers for discussion's sake. My fuzzy memory says that the 30 mm API (armor piercing incendiary) rounds can penetrate somewhere over 100 mm (4 inches) of rolled homogeneous armour (RHA). Online sources say up to 200 mm (8 inches, which I think is a very generous rounding up). Let's give the GAU-8 a head start and say 200 mm worth of penetrating power.

[NOTE: The A-10's 30 mm API rounds are depleted uranium (DU). In case you were wondering.]

The T-90 Main Battle Tank
And in the red corner, we have one of the most advanced targets... erm... tanks... ever built.

The T-90 is mobile, fast, powerful, and armored to shrug off just about anything you can throw at it.

I must admit here that I'm about to use some terms that I'm not an expert in. Still, the numbers should be instructive.
Armor type: Steel-composite-reactive blend
vs. APFSDS: 550-650mm, with Kontakt-5 = 800–830mm;
vs HEAT: 1,000mm with Kontakt-5 = 1,150–1,350mm

Here is where things start getting fuzzy, and for some reason manufacturers don't like to advertise anything other than the thickest armor on their tank. It should be immediately obvious that an A-10 shooting straight up the schnoz of a T-90 will do little more than activate some reactive armor and create a cool looking shower of sparks. (Unless, of course, the tank commander is up getting some fresh air. Then things get messy.)

So... tanks carry their thickest armor on the front, expecting that is where they're going to take most of their hits. (This is likely true on an average day, and we CAS flyers are happy to let them continue to think that way.)

The problem with armor, though, is that it is heavy. Eventually you reach a point where your engine can't push the hulk around the battlefield, or that bridge you have to cross just cries "uncle" and collapses. Also bad for your tank.

So, where do you trim the weight? Well, in the areas you expect to not get hit as much, of course.

So, the sun roof and back doors tend to be less well protected. Which is good for those of us who can maneuver to get a good look at those tender areas. Here's the kicker, though... I haven't been able to find exactly how thick the skin is in those areas.

Plus, it looks like someone figured out that aircraft sometimes take an interest in tanks and thought about slapping some additional protection on top. One source says: "Explosive reactive armor [ERA] bricks on the turret roof provide protection from top-attack weapons." (T-90 at Federation Of American Scientists -FWIW.)

So, the question remains... is it enough?

What's Your Angle? (Attack Angle, That Is.)
Since we don't know exact numbers, let's just estimate the front armor average to be about 1,000 mm. If the top armor is only 10% of that, we're looking at 100 mm, which is what the A-10 can fairly consistently punch through... at a 90 degree impact angle. While it is possible to do that from the top, that sort of attack is as hairy as it is exciting. (See How effective are air brakes in aircraft?) In most cases, your shots will be at some angle less than 90 degrees.

Tanks like to move, and diving at one from directly above usually means that by the time you get your nose pointed straight down at it, it has moved on, forcing a non-straight-down shot anyway. As a result, even from medium/high altitude, any gun attacks will usually be from a direction that results in hitting one of the sides (rear preferred) from an elevated angle.

Truth be told, I don't recall armor thickness being a prevalent topic of conversation when discussing tanks as targets. It was all "shoot any tank in the rear if you can, and in the side if you can't. Don't bother with the front."

[NOTE: A huge h/t to Paul Dezso deHolczer for sharing this classic, and for helping me answer the question of what to give as a gift this Christmas:
Cold War Coloring Book Taught A-10 Pilots to Kill Soviet Tanks]

JJ Hantsch provided this enlightening information (thanks JJ!):

I have seen stats that when first brought out in 1983 the T-90 had just under 20mm of roof armor. This was augmented to 90mm of roof armor and then finally an added 101 mm of applique. Of this just 21 mm is the hardest shell stuff and the rest is there to prevent fragmentation.

If that is the case (and it does jibe with the note about ERA bricks), then we're looking at just under 200mm of armor, some of it questionable quality.

If anyone can share some definitive numbers on the top side of T-90 tank armor, that would go a long way towards answering that question for sure. Unless it is down in the "10% of front armor" range, though, after factoring in the optional ERA bricks, your odds of perforating the skin are still mighty slim, Slim.

The M1 Abrams Main Battle Tank
Let's detour a little bit to get some more perspective. While this section isn't about the A-10 or the T-90, there is some interesting information on the T-90's contemporary vs. 25 mm and 30 mm rounds.

From M1 Abrams at War by Michael Green (p.99-100)

Armor-piercing rounds from an enemy 30mm gun (possibly from an Iraqi army BMP-2) disabled one Abrams tank after hitting it in the rear of the hull, near the engine exhaust grilles - a mobility kill. Two Abrams tanks were lost in friendly-fire incidents during the opening stages of Operation Iraqi Freedom. In one incident, an army Bradley infantry fighting vehicle (IFV) fired a number of 25mm armor-piercing DU projectiles at the rear engine grilles of an Abrams tank and destroyed its gas turbine engine.

There you go. Documented accounts of modern main battle tanks being "taken out" by a lowly 25mm round. If they can do it, the GAU-8 can do it.

Conclusion
So, yes, it is possible for a 30mm round to "take out" an advanced modern tank. It's all a question of where you put that round. You can expect a frontal shot to be laughably ineffective, while a shot to the rear can stop the tank dead in its tracks. Or remove the tracks altogether. Whatever works. As we say in the fighter world: "A kill's a kill."

Now, the question remains: "Can you ventilate the crew compartment?" (Isn't that really what you were thinking when you first read the question?) For that, we'd need to know how thick the armor is around said compartment. If you happen to know for sure and can solve that mystery, please chime in with a comment!

But Wait! There's More...
Something to keep in mind through all of this, though... Most of the A-10's targets today aren't as hard as a T-90. The rounds are still highly effective against older machines, softer targets like armored personnel carriers, artillery, wheeled vehicles, and the ever-present LPC (leather personnel carrier... a.k.a. boots on feet).

It remains a versatile, precise, and effective weapon that is (relatively) safe for use in close proximity to friendly forces. Compared with any high-explosive weapon, you can get closer to friendlies with the GAU-8 than with just about any other weapon hanging from a fighter. That is a vitally important consideration in an infantry war. So, while we often think of the A-10 as a "tank killer," its application has grown far beyond that, and it has proven to be highly effective on today's battlefields.

But, back to the T-90... There are still many ways to skin that cat with the GAU-8, too. You can either deliver an F-kill or an M-kill on a T-90, effectively removing that piece from the battlefield,
OR...
you can go out loaded for that particular kind of bear.

I give you... the AGM-65 Maverick missile.

Here’s an old video that gives you an idea of what the Maverick can do:

Parting Shot
There was once some discussion about fitting the A-10 with the AGM-114 Hellfire. Those things are so small and light, you could almost store extra rounds in your flight suit pockets and chuck 'em out the window at targets. The A-10 could carry a bazillion of them (well, 16 at least), and still have room for everything else and the kitchen sink.

Much Tanks!... er... Thanks!
Thank you to the following Quorans whose comments and information helped to make this response better than where it started:

• Paul Dezso deHolczer - The first to remind me about exactly how thin tank armor can get on soft spots, with some hard numbers as examples.
• JJ Hantsch - Who shared the first of any kind of real numbers on the T-90's armor thickness on the top side.
• User-13584768854815474418 - For asking the question to begin with!

The A-10C Thunderbolt II would be virtually unstoppable in a WW2 environment.

It's been pointed out that the A-10 would out perform and out survive any ww2 era fighter but, as Mr. Adams observed it would be vulnerable to axis fighters and ground fire. Gratuitous energy advantage aside a fully loaded A-10 starting a low level attack run is going to end up plowing a field if it gets jumped by a pair of diving FW-190s.

But in my opinion it doesn't matter because the A-10C has these

This pilot is wearing panoramic night-vision goggles or PNVGs which allow the A-10 to operate at night. Even with modern gun ranging radar and proximity fuses it's hard to bring down an aircraft at night. Trying to shoot down a fast moving low flying fighter would be almost impossible.

You would see some attrition but most of that would be wear and tear and the occasional bad luck.

The B-17 bomber was called a Flying Fortress for a reason, it had crew members all around the aircraft manning machine guns. But the real purpose of the B-17 was to deliver bombs.

The cruising speed of a B-17 was 125 MPH. Not very fast. Over bombing areas the plane would rev up to 175 MPH.

I remember listening to some elderly gentlemen talk about how they got selected for gunners. They would tell how they would be familiarized with the guns, than taken up and told to shot at some targets on the range, a couple of old trucks. After a couple of passes with the plane weaving, most were able to get the gist of it.

Bombers were slower easier targets to engage than their fighter escorts. The problem with fighters was their fuel capacity was limited, greatly restricting their protection coverage. Even fitted with drop tanks, fighters couldn’t last the distance of the bombers.

When it came to bombers shooting at fast fighters, the gunners had to be fairly accurate. Most of the time the gunners were aiming at a target coming straight on or leaving the same way. The losses in bombers really added up. It was far easier to build a fighter than a bomber. The bomber gunners did score hits, but the gunners were a last ditch effort at protection.

The number of American airmen, mainly bombing crews, held in German POW camps added up to the tens of thousands. One of the guys I listened to, bailed out and was captured. He was just under six foot and lean at the time, 165 pounds, at the beginning of January 1945. At the end of the war, he was being marched, when the Germans just disappeared, and he was freed by Americans, weighing only 85 pounds.

He defended the German guards he had, as saying they were starving also, though they received slightly more rations. All of Germany had a lack of food at the end of WW2.

The A-10 can fly with one engine, one tail, and half a wing missing. Now imagine a WWII fighter trying to shoot one down.

That durability wasn't an accident—the A-10 was designed to absorb punishment from modern anti-aircraft weapons: 23mm Soviet autocannons, shoulder-fired missiles, radar-guided AAA. That single design philosophy turns this hypothetical matchup into something far less balanced than most people expect.

The Firepower Mismatch

The GAU-8/A Avenger fires roughly 65 rounds per second. Each 30mm round weighs about 14 ounces and leaves the barrel at 3,500 feet per second. These projectiles were engineered to pierce the top armor of Soviet tanks. A WWII fighter is, by comparison, a thin aluminum skin stretched over a metal frame. A single round from the GAU-8 connecting with a Zero, Bf 109, or P-51 wouldn't just damage it—it would structurally disintegrate whatever section it hit. A half-second burst puts roughly 30 rounds downrange in a fairly tight cone. Even a glancing burst is a kill.

The Survivability Gap

This is where the matchup becomes truly lopsided. The A-10's cockpit sits inside a 1,200-pound titanium "bathtub" rated to withstand 23mm cannon fire. Its fuel tanks are self-sealing and filled with reticulated polyurethane foam. The aircraft has:

• Redundant hydraulic flight control systems
• A manual reversion backup if both hydraulic systems fail
• Two widely-spaced engines, either of which can sustain flight alone
• A design that allows it to fly with one engine, one tail, and half a wing missing

A WWII fighter's armament—whether the Zero's 20mm cannons, the Bf 109's MG 151/20, or the P-51's six .50-caliber Brownings—would land hits, certainly. But bringing down an A-10 with those weapons would require sustained, concentrated fire on critical systems. That's extremely difficult in a dynamic engagement.

Where the WWII Fighter Has an Edge

Maneuverability. The A-10 is nimble for an attack aircraft, especially at low speed, but a Zero or a late-model Spitfire can out-turn it. A skilled WWII pilot could potentially get on the A-10's six and stay there. The question is whether they could do enough damage from that position before the A-10 pilot executed a break, reversed, and brought the Avenger to bear.

Speed is roughly comparable—the A-10's max speed of around 420 knots is in the same neighborhood as late-war piston fighters. So neither side can simply run away. This keeps the engagement contested.

The Likely Outcome

The A-10 wins the vast majority of these engagements, not because it's a superior dogfighter in the traditional sense, but because the exchange rate is wildly asymmetric. The A-10 can absorb hits that would destroy three WWII fighters, and it needs only a momentary firing solution to deliver an instantly lethal burst. Captain Robert Swain demonstrated the A-10's air-to-air potential during the Gulf War when he shot down an Iraqi helicopter with the GAU-8—a far less threatening target, but proof the weapon system can track and engage aircraft.

The WWII pilot's best chance would be a lucky cockpit shot through the canopy or disabling both engines in a single pass. Possible, but improbable against an aircraft that was built from the ground up to keep flying after taking severe battle damage.

It is possible. Given the Warthog’s good general manoeuverability and small turn radius, and despite its size and lack of outright power, it can employ a few AIM 9 Sidewinder missiles to take down other airplanes in close quarters. This is especially true if the adversaries are WW2 airplanes, since the armament suite is less advanced (guns and cannon) and rarely rockets (which were used primarily for air-to-ground operations in WW2). The A-10’s robust construction which can survive direct fire from guns and cannon will help too. The A-10’s own 30-mm 7-barrel Gatling cannon can take down frail WW2 airframes in a few rounds.