But strafing targets on the ground in fast jets is a practice that dates back more than 70 years. Before the A-10, and even before close air support doctrine was formalized, the German Luftwaffe was working hard to develop an absolutely colossal gun into what would become the very first operational jet fighter.
The Messerschmitt Me-262 Schwalbe (Swallow) marked a turning point in aviation history. It was the product of German science and engineering which was at least five to ten years ahead of Allied technology at certain points in the war.
The brutally fast and agile jet fighter was born from a design first conceived in 1938, before the official start of World War II. The engines that powered it also had their pre-war origins, the venerable Junkers Jumo 004 turbojet engine. The combined thrust of two 004 units propelled the jet to speeds 160 km / h (160 km / h) faster. than any British, Soviet or American piston engine fighter.
As tank battalions on the eastern and western fronts crowded on both sides, the decision was made to mount a cannon on the Me-262 that could meet the ground threat from allied nations. What was needed was a weapon powerful enough to penetrate the hull armor of even the toughest Allied medium tanks. We are talking about the Soviet T-34 and the American Sherman M4. Such a cannon would almost certainly tear an Allied bomber to pieces in one shot.
Messerschmitt’s engineers must have thought that there was no better way to take out a tank than with a gun designed to be mounted in a tank. Enter the colossal 50mm Rheinmetall BK-5 cannon. A brute of a weapon that weighed a scale destroying 1,200 pounds (540 kg) and fired custom 50 × 419 mm cartridges at 45 rounds per minute.
Not that the BK-5 could ever reach this rate of fire, as the magazine drum only held 21 rounds at one point. Its original purpose was mounted in the Panzer III tank as the KwK 39 tank gun as featured in famous tank battles like Operation Barbarossa and the Battle of Kursk.
Let’s compare these numbers to those of the more famous A-10 Thunderbolt. Unlike the 262, the A-10 was designed from the start as a close air support and ground attack aircraft. Its GAU-8 Avenger may not be as huge as the German Me-262, but it makes up for its ammunition capacity well in excess of over 1,000 HE rounds.
Lessons learned in planes like the BK-5 equipped Me-262 have taught engineers that the recoil of such a heavy gun is enough to unbalance the pilot’s aim. The A-10 compensates by having its barrel mounted laterally offset from the axis of the airframe.
Either way, a hit from either of the main guns on these planes is enough to shred just about anything in the sky or on the ground. BK-5 guns were also tested on the twin-engine Messerschmitt 410 attack aircraft. It is believed that more than 100 American bombers towards the end of the war were shot down at his hands.
This came at the cost of pathetic ammo reserves and a muzzle flash bright enough to blind its pilots at night. The cannon protruded at least a meter beyond the nose of the plane, revealing to enemy pilots that this was the slowest and least agile ground attack variant. The gun was also tested on the Junkers Ju-88 as an alternative wartime test stand aircraft.
In the end, no more than 300 MK-5 guns were produced between 1944 and May 1945. Not having made a hard-hitting breach in the invading armored force that ultimately drove the German army into unconditional surrender. Although ahead of their time, the BK-5 and Me-262 were two machines that did not exist fully in harmony at all times. Just hear what Reich Luftwaffe Marshal Hermann Goering said about the project when it was captured by the US military.
“You might find jets with anti-tank guns around Germany. Don’t blame me for such monstrosities. It was done on the explicit orders of the Führer. Hitler knew nothing about the air. “Known to the Army or Navy, but absolutely nothing on the air. He even considered the Me-262 to be a bomber, and he insisted that it be called a bomber.”
Such oversights ultimately led to the fall of the Third Reich. Meanwhile, the idea of attaching a monstrous cannon to a jet attacker took a few more decades to mature. The end result is the phenomenal A-10 that we all know and love today.