The Luftwaffe’s Warthog

When Germany’s Luftwaffe began laying its future plans in 1935, contributing directly to the land battle was not considered one of its major missions. World War I had shown aircraft operating at a low level close to the front were highly vulnerable, and the aircraft’s limited fire power seemed to make ground attack operations of limited use.

This all changed with the Luftwaffe’s participation in the Spanish Civil War from 1936 to 1939, when attack aircraft proved not only to be effective but, in some cases, decisive. Though the poster child for attack aircraft was the Junkers Ju-87 Stuka dive bomber with its accurate strikes on point targets, it was also clear the Luftwaffe needed some type of tough, modern aircraft for strafing and repetitive attacks in support of ground troops.

In April 1937, the Luftwaffe issued a requirement for a heavily armed and armored close air support aircraft, but it had to be both small and use two low power 465 horsepower engines. The Henschel Company submitted a conventional twin engine aircraft, the Hs 129, with a slim, triangular fuselage, broad at the bottom and narrow on top. Its competitor was Focke-Wulfe’s modified version of its twin boom reconnaissance aircraft, the Fw-189. Both aircraft proved to be terrible; they were sluggish, slow and unmaneuverable, and the Henschel aircraft was so cramped the engine instruments had to be mounted on the nacelles because there was no room for them on the instrument panel.

Because the Hs 129 was much smaller, it was chosen. The production version, the Hs 129A, had more than 2,300 pounds of armor and armored glass and carried two 20 millimeter cannons and two 7.62 millimeter machine guns in the nose, and the weight made it too underpowered to contribute to the German invasion of the West in May 1940.

Then, with the capture of France, Henschel engineers decided to re-engine the Hs 129 with a French engine, the 700 horsepower Gnome-Rhome 14M. The change provided an increase in performance, but while the Hs 129 was still slower, less maneuverable and had shorter range than the Stuka, its armor was expected to offset the low performance.

With the invasion of Russia in June 1941 and fighting in the desert, there was a need for the Hs 129s as quickly as possible, but there were production difficulties and the aircraft dribbled out and only reached enough to equip a full squadron in mid-1942.

Once in the combat units, problems appeared with the French Gnome-Rhome engines. The engines had been designed for Western Europe and proved intolerant of the dust of the Eastern Front steppes, and even less tolerant of the sand in North Africa. Filters eventually reduced the problems in Russia, but the sand problem proved intractable and eventually all the Hs 129s were abandoned in the desert.

With proper engine performance, the Hs 129 was an effective combat aircraft, though it suffered high attrition. It could carry a variety of small cluster bomb-type weapons and, more importantly, as Soviet tanks became larger and more heavily armored, the Hs 129 proved amenable to a variety of heavier cannons carried under the fuselage. First was the 30 millimeter Mk 101, then the armor-piercing Mk 103 30 millimeter, and then the 37 millimeter BK 3,7 gun.

As Soviet tanks grew more powerful and numerous, the Luftwaffe was forced to develop new weapons. The most useful new weapon for the Hs 129 was the 3,300-pound PaK 40 75 millimeter anti-tank cannon in an enormous tub under the fuselage. The gun was very accurate and fired a 7 pound shell that could penetrate the heaviest Soviet armor at a range of half a mile.

Called the Hs 129B-3/Wa, this awkward aircraft could make several passes firing three or four rounds a pass, but even with a 4-foot-long muzzle bake, the cannon was almost too much for the little Henschel and it was only provided to two squadrons.

Production of the Hs 129 ended in mid-1944 when Germany moved entirely to fighter production, but the Hs 129, like the Soviet Il-2 Shturmovik, contributed to the concept of a cannon armed armored ground attack aircraft seen today in the U.S. Air Force’s A-10.

(For questions or comments, contact Dr. Michel at  marshall.michel@ramstein.af.mil.)