The A-10 is a legend. But it was built upon the wings of even greater legends.

It’s a good thing that the Air Force generals who want to retire the beloved A-10 Warthog were not around 70 years ago.

If they were, Josef Stalin might have had them shot.

The Soviet dictator loved the A-10 of his day, otherwise known as the Ilyushin Il-2 Sturmovik. “They are as essential to the Red Army as bread and water,” he said.

It is the Sturmovik, along with the German Ju-87 Stuka dive bomber, that fathered the A-10. “The World War II close air support successes of both the Stuka and the Sturmovik had a major—and inspiring—influence in convincing all of us early A-X/A-10 proponents that close support was by far the most important mission of air power, certainly more so than strategic bombing,” A-10 designer Pierre Sprey tells War is Boring.

“I felt that the combat specifics, such as tactics, targets, aerial cannon effectiveness, austere field operations, surge sortie rates, air-ground communications and coordination, of the World War II close support experience were so relevant to designing a first-rate CAS [close air support] plane that I required every member of the A-X concept design team to read Hans-Ulrich Rudel’s Stuka Pilot.”

The Stuka connection

The Stuka and the Sturmovik symbolize different branches of the A-10 family tree. The Warthog gets its ferocious anti-tank firepower from the Stuka.

Most people think of Stukas as the clumsy-looking dive bombers in History Channel documentaries, pouncing with a terrifying screech—thanks to the sirens installed in their wings—on their hapless prey. Desperate to stop the hordes of Soviet T-34 tanks that were overwhelming the Wehrmacht on the Eastern Front, Germany also built a special tank-buster version of the dive-bomber.

The Ju-87G was armed with a converted 37-millimeter anti-aircraft cannon in a pod under each wing. As seen in the photo above, the cannon barrels stuck out almost as far as the Stuka’s propeller.

Firing armor-piercing tungsten-carbide ammunition, these guns could penetrate a tank’s thin overhead and engine compartment armor. In effect, the Ju-87G’s cannon was the World War II predecessor of the A-10's far more devastating 30-millimeter Gatling gun, whose depleted uranium shells sliced up Iraqi tanks in 1991 and 2003.

Rudel, the legendary Stuka pilot and unrepentant Nazi who flew the Ju-87G, claimed to have destroyed 519 Soviet tanks. But Rudel was also shot down or forced to land 32 times, which pointed to the Stuka’s major weakness. With fixed landing gear and a level speed of less than 250 miles per hour, it was very vulnerable to defending fighters and flak.

Against the hapless Poles and French, who lacked air defenses, the Stuka was devastating. Used as a strategic bomber in the Battle of Britain, it was mincemeat for the Royal Air Force Hurricanes and Spitfires.

Flying tank

The Il-2 Sturmovik ground attack aircraft, nicknamed “Flying Tank,” is not as well known as the Stuka, at least outside of Russia. But if anyone wonders where the A-10 got its 1,200 pounds of armor from, just look at the Il-2.

The Sturmovik was not heavily armed. Two forward-firing 23-millimeter cannons and two 7.62-millimeter machine guns, as well as 1,300 pounds of bombs or eight air-to-ground rockets, sounds like a potent punch. But it is actually less firepower than a late-war fighter-bomber like the P-47 Thunderbolt, with eight .50-caliber machine guns and 2,500 pounds of bombs, or the devastating Hawker Typhoon with four 20-millimeter cannons, two tons of bombs and eight rockets.

But, oh, the Sturmovik could take damage, as befitted what was essentially a slab of armor with wings. Not only was armor plate an integral part of the airframe, but an armored “bathtub” protected the engine, cockpit, water and oil radiators and fuel tanks.

The Il-2 needed every bit of protection. The Soviets estimated that a Sturmovik attacking a defended target faced 8,000 large-caliber and 200 small-caliber flak rounds every second, according to Il-2 Sturmovik Guards Units of World War II.

That was why strafing was so dangerous for World War II fighter pilots. Lacking smart bombs, they had had to go in low to shoot up ground troops and airfields, yet the liquid-cooled engine of a P-51 Mustang could seize up after being hit by a single bullet. “The main thing was that it was reliable and hardy,” recalled a Sturmovik pilot. “Precisely the qualities required of an assault aircraft.”

The Sturmovik was also prolific. Some 36,000 were built, making it the most produced warplane in history. Operating in large formations, the Sturmoviks used a tactic known as the “circle of death,” in which they would orbit over German tanks and then dive on the vehicles’ thinly-armored rears. “The other preferred tactic was ‘shaving flight,’ or nap-of-the-earth flying,” says James Sterrett, author of Soviet Air Force Theory, 1918-1945.

“They would pop over some ridge or forest and plaster a target without warning,” Sterrett continues. “Though this made navigation critical and difficult to spot the target early, so inevitably there were medium altitude approaches to find targets, followed by shallow dives to strafe, bomb or rocket.”

Sterrett rates the Sturmovik as the best close support aircraft of the war. It was certainly the most expendable. Some 20,000 were destroyed. Facing elite German fighter aces and thick German flak defenses, and flown by inexperienced crews, they took staggering losses, especially in the early years of the war.

“During the spring and summer of 1942, one Il-2 was lost for every 24 combat sorties, and in the Battle of Stalingrad the ratio increased to one aircraft per 10-to-12 combat sorties,” notes the Guards Units book. Perhaps that is why there is a story, likely apocryphal, that some Sturmovik rear gunners were prisoners drafted into special penal battalions.

Whatever the flaws of the Sturmovik, it was what the Soviets needed. The Western Allies, safe behind the English Channel and the Atlantic Ocean, could lavish vast resources on strategic bombing. The Soviet Union was engaged in a life-and-death struggle against the bulk of Hitler’s army, and the ground troops needed close air support in Russia, not a tank factory bombed in Berlin.

Just as modern U.S. troops fighting for their lives in a firefight need close air support now, not stealth bombers blowing up enemy truck convoys far to the rear.

The Warthog is the star of the family

Fortunately, Sprey and his design team didn’t just copy the Stuka and Sturmovik for the A-10. They thought hard about what improving the qualities that made the older planes useful. Sprey says the World War II aircraft provided inspirations for the best aspects of the Warthog’s design:

• High maneuverability and acceleration for a fully-loaded close-support aircraft operating at speeds from 150 to 300 knots. That was for “staying within sight of extremely hard-to-see camouflaged targets and for operating under 500-foot to 1,000-foot ceilings,” says Sprey. Neither the Stuka nor Sturmovik could do this, but the A-10 can.

• Aircraft survivability, including fire-suppression systems and bulletproof, fully redundant controls plus lots of cockpit armor. Not only could this protection save a pilot’s life, but it also boosts a pilot’s morale as he flies into heavy ground fire, Sprey notes.

• High sortie rates from austere and unpaved airfields. “The ability of the Stuka and Sturmovik, operating out of dirt fields up near the troops, to fly five sorties or more per day under combat crisis conditions proved to be an enormous force multiplier,” Sprey says.

• Multiple radios that enable pilots to communicate with ground troops. Sturmovik units were hampered by having radios only in the flight leaders’ planes. And those radios couldn’t talk to Red Army ground troops. But it wasn’t just the Soviets who couldn’t communicate. Before the A-10, no U.S. fighter had all the necessary radios, according to Sprey.

• A cannon large enough to kill tanks and with enough ammunition for 12 firing passes, plus sufficient fuel for two to three hours supporting ground troops. The Ju-87G’s 37-millimeter guns were the best airborne tank-killing cannons of World War II, Sprey says, but they only had enough ammunition for six passes.

The A-10 is a legend. But it was built upon the wings of even greater legends.

This article by Michael Peck originally appeared at War is Boring in 2013.

Image: Wikimedia