Only Germany and the USSR deployed aircraft designed exclusively for the purpose of ground attack.
The Luftwaffe had both the Henschel Hs129 and the Stuka -first as dive bomber, later as tank buster-. The soviet fellows launched their IL-2.
Later on the RAF and USAAF found some of their toys had good capabilities in the ground attack mode: P-47, Typhoon and Tempest.
The Germans also deployed some of their planes to perform ground attack tasks: the Bf110 in North Africa, equipped with 3 cm cannon and the very famous Fw190 Fs.
Perhaps the very best ones were the Fw190 and the P-47. Both had radial engines and could endure heavy damage and survive.
The soviets followed a similar path, and the several Yak versions, saw service conducting ground attack missions, sustaining prohibitive losses since the Yaks were extremely vulverable, even to rifle caliber guns.
The IL-2 is, no doubt, the most overrated and overinflated aircraft of the entire conflict.
It is simple: had Germany won the war, the obsolete tag would be belonging to the Shturmovik.
You do not know clumsy until you see footage of Il-2s in flight. Its nearly 1 ton of armor, while of good help against massed light caliber guns greeting it from the ground, turned out to be its own enemy.
Interception was easy, for we are talking about a single engine aircraft, and its massive armor was of very little help against the heavier guns and cannons of German fighters; flak crews also had an easy target to pull the trigger at.
If you are thinking of bringing up the argument of the rear gunner included on the late versions of the IL-2 i will have to tell you it was the same flawed idea as recorded on all planes that carried defensive armament.
If the four engine heavy bombers of the USAAF, with its massive size and massive defensive machine guns were extremely vulnerable to interception, think of the situation of an aircraft the same size of its interceptor, virtuallu uncapable of manouvering, fitted with only ONE defensive MG.
An aircraft that suffered horrific losses, as it is the case of the IL-2, is a true testimony of the actual capabilities of the plane -and of the pilots that flew it as well.-
I am confident when saying this: even if attacking ground targets from the air was a very difficult task i am convinced the Germans were the best at it.
Mr. Zetterling conducted interesting researches on the matter and discovered both the RAF and USAAF failed big time to destroy German armored units in France, prior to the D-Day landings.
Other than causing important delays on the arrival of panzer units to the critical points of the front, the damage they inflicted to German ground units was minimal.
They would claim numbers of panzers destroyed that did not even exist for the entire Normandy campaign of 1944.