The
Henschel Hs 129 was a
World War IIWorld War II, or the Second World War , was a global military conflict which involved a majority of the world's nations, including all great powers, organized into two opposing military alliances: the Allies and the Axis...
ground-attack aircraft fielded by the
GermanGermany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium,...
LuftwaffeLuftwaffe is a generic German term for an air force. It is also the official name for two of the four historic German air forces, the Wehrmacht air arm founded in 1933 and disbanded in 1946; and the current Bundeswehr air arm founded in 1956.Schweizer Luftwaffe is also the name of the Swiss Air...
. Its nickname, the
Panzerknacker (tank cracker), is a deliberate pun—in German, it also means
"safe cracker"Safe-cracking is the process of opening a safe, generally without the combination. It may also refer to a computer hacker's attempts to break into a secured computer system, in which case it may be shortened to "cracking" or black hat hacking.-History:...
. The Hs 129 never really had a chance to prove itself in any way; the plane was produced only in small numbers and deployed during a time when the Luftwaffe was unable to protect them from attack.
Design and development
By the middle of the 1930s, the idea of using aircraft against ground targets had been "well understood" to be of little use other than hurting enemy morale. Experiences during
World War IWorld War I , also known as the First World War, the Great War, and the War to End All Wars, was a global military conflict which involved most of the world's great powers, assembled in two opposing alliances: the Triple Entente and the Triple Alliance...
had demonstrated that attacking the combatants was generally much more dangerous to the aircraft than the troops on the ground, a problem that was only becoming more acute with the introduction of newer weapons. For much of the 1920s and 1930s, the use of aircraft was seen primarily in the
strategicStrategic bombing is a military strategy used in a total war with the goal of defeating an enemy nation-state by destroying its economic ability to wage war rather than destroying its land or naval forces...
and
interdictionThe purpose of interdiction is to delay, disrupt, or destroy enemy forces or supplies en route to the battle area. A distinction is often made between strategic and tactical interdiction. The former refers to operations whose effects are broad and long-term; tactical operations are designed to...
roles, where their targets were less likely to be able to fight back with any level of coordination. For high-value point targets, the
dive bomberA dive bomber is a bomber aircraft that dives directly at its targets in order to provide greater accuracy and limit the exposure to and effectiveness of anti-aircraft fire...
was the preferred solution.
The German
Condor LegionThe Condor Legion was a unit composed of "volunteers" from the German Air Force and from the German Army which served with the Nationalist side during the Spanish Civil War of July 1936 to March 1939...
experience during the
Spanish Civil WarThe Spanish Civil War was a major conflict that devastated Spain from 17 July 1936 to 1 April 1939. It began after an attempted coup d'état by a group of Spanish Army generals against the government of the Second Spanish Republic, then under the leadership of president Manuel Azaña...
turned this idea on its head. Although armed with generally unsuitable aircraft such as the
Hs 123The Henschel Hs 123 was a single-seat biplane dive bomber and close-support attack aircraft flown by the German Luftwaffe during the Spanish Civil War and the early to mid-point of World War II...
and cannon-armed versions of the
Heinkel He 112The Heinkel He 112 was a fighter aircraft designed by Walter and Siegfried Günter. It was one of four aircraft designed to compete for the Luftwaffes 1933 fighter contract, which was eventually won by the Messerschmitt Bf 109...
, their powerful armament and fearless pilots proved that the aircraft was a very effective weapon even without bombs. This led to some support within the
Luftwaffe for the creation of an aircraft dedicated to this role, and eventually a contract was tendered for a new "attack aircraft".
Since the main source of damage would be from
rifleA rifle is a firearm designed to be fired from the shoulder, with a barrel that has a helical groove or pattern of grooves cut into the barrel walls. The raised areas of the rifling are called "lands," which make contact with the projectile , imparting spin around an axis corresponding to the...
and
machine gunA machine gun is a fully automatic mounted or portable firearm, usually designed to fire rifle bullets in quick succession from an ammunition belt or large-capacity magazine, typically at a rate of several hundred rounds per minute...
fire from the ground, the plane had to be heavily
armoredMilitary vehicles are commonly armoured to withstand the impact of shrapnel, bullets, missiles, or shells, protecting the personnel inside from enemy fire. Such vehicles include tanks, aircraft, and ships.Civilian vehicles may also be armoured...
around the
cockpitA cockpit or flight deck is the area, usually near the front of an aircraft, from which a pilot controls the aircraft. Most modern cockpits are enclosed, except on some small aircraft, and cockpits on large airliners are also physically separated from the cabin.It is a place where from which flight...
and engines. They also required the same protection in the
windscreenThe windshield or windscreen of an aircraft, automobile, bus, motorcycle, or tram is the front window. Modern windshields are generally made of laminated safety glass, a type of treated glass, which consists of two curved sheets of glass with a plastic layer laminated between them for safety, and...
, which required 75 mm (2.95 in) thick
armored glassBulletproof glass is a colloquial term for glass that is particularly resistant to being penetrated when struck by bullets. Since manufacturing glass of usable thicknesses capable of fully stopping most bullets cannot currently be done, the industry generally refers to it as bullet-resistant glass...
. Since the aircraft was expected to be attacking its targets directly in low-level
strafingStrafing is the practice of attacking ground targets from low-flying aircraft. The term is usually applied to attacks with aircraft-mounted automatic weapons, but may be applied to attacks with bombs, though not high-level bomb delivery...
runs, the cockpit had to be located as close as possible to the nose in order to see the ground. One last requirement, a non-technical one, ended up dooming the designs; the RLM demanded that the aircraft be powered by "unimportant" engines of low power that were not being used in other designs, so the plane's production would not interfere with that of other types deemed more essential to the war effort.
Four companies were asked to respond, and only two of the resulting three entries were considered worthy of consideration; Focke-Wulf's conversion of their earlier
Fw 189The Focke-Wulf Fw 189 Uhu was a German twin-engine twin-boom three-seat tactical reconnaissance and army cooperation aircraft...
reconnaissanceReconnaissance is a military and medical term denoting exploration conducted to gain information. Militarily, its shorthand Canadian and British form is recce , its American usage form is recon...
plane, and Henschel's all new Hs 129.
Prototypes
The Hs 129 was designed around a single large "bathtub" of steel sheeting that made up the entire nose area of the plane, completely enclosing the
pilotAn aviator is a person who flies aircraft for pleasure or as a profession. The first recorded use of the term was in 1887 as a variation of the French 'aviation', from the latin 'avis', coined 1863 by G. de la Landelle in "Aviation ou Navigation Aérienne"...
up to head level. Even the canopy was steel, with only tiny windows on the side to see out of and two angled blocks of glass for the windscreen. In order to improve the armor's ability to stop bullets, the
fuselageThe fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...
sides were angled in forming a triangular shape, resulting in almost no room to move at shoulder level. There was so little room in the cockpit that the instrument panel ended up under the nose below the windscreen where it was almost invisible; some of the engine instruments were moved outside onto the engine nacelles, as on some models of Messerschmitt's
Bf 110The Messerschmitt Bf 110, often called Me 110, was a twin-engine heavy fighter in the service of the Luftwaffe during World War II. Hermann Göring was a proponent of the Bf 110, and nicknamed it his Eisenseiten...
heavy fighter, and the gunsight was mounted outside on the nose.
In the end, the plane came in 12% overweight and the engines 8% underpowered, and it understandably flew poorly. The
controlsAn aircraft flight control system consists of flight control surfaces, the respective cockpit controls, connecting linkages, and the necessary operating mechanisms to control an aircraft's direction in flight. Aircraft engine controls are also considered as flight controls as they change speed.The...
proved to be almost inoperable as speed increased, and in testing, one plane flew into the ground from a short dive because the
stickA joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. Joysticks are often used to control video games, and usually have one or more push-buttons whose state can also be read by the computer...
forces were too high for the pilot to pull out. The Fw design proved to be no better. Both planes were underpowered with their
Argus As 410The Argus 410 was an inverted air cooled V 12 light aircraft engine first produced in 1938.-Design and development:The engine marked a departure from earlier Argus engines in that it had new construction techniques which gave the engine greater operating speeds and power...
engines, and very difficult to fly.
The RLM nevertheless felt they should continue with the basic concept. In the end, the only real deciding factor between the two was that the Henschel was smaller and cheaper. The Focke-Wulf was put on low priority as a backup, and testing continued with the Hs 129 A-0. A series of improvements resulted in the
Hs 129 A-1 series, armed with two 20 mm
MG 151/20 cannonThe MG 151 was a 15 mm autocannon produced by Waffenfabrik Mauser starting in 1940. It was in 1941 developed into the 20 mm MG 151/20 cannon which was widely used on many types of German Luftwaffe fighters, fighter bombers, night fighters, ground attack and even bombers as part of or as...
s and two 7.92 mm (.312 in)
MG 17 machine gunThe MG 17 was a 7.92 mm machine gun produced by Rheinmetall-Borsig for use at fixed mountings in many World War II Luftwaffe aircraft.- History :...
s, along with the ability to carry four 50 kg (110 lb) bombs under the fuselage midline.
Hs 129 B-1
Even before the A-1s were delivered, the plane was redesigned with the
Gnome-Rhône 14MThe Gnome-Rhône 14M was a small 14-cylinder two-row air-cooled radial engine that was used on several French and German aircraft of World War II.-Applications:*Breguet 693*Hanriot NC 530*Hanriot NC 600*Potez 631*Potez 633*Potez 637*Potez 662...
radial engineThe radial engine is a reciprocating type internal combustion engine configuration in which the cylinders point outward from a central crankshaft like the spokes on a wheel. This configuration was very commonly used in large aircraft engines before most large aircraft started using turbine engines...
, which were captured in some number when
France fellIn World War II, the Battle of France, also known as the Fall of France, was the German invasion of France and the Low Countries, executed from 10 May 1940, which ended the Phoney War. The battle consisted of two main operations...
. This engine supplied 522 kW (700 hp) for takeoff compared to the Argus at 347 kW (465 hp). The Gnome-Rhone radials were also made in versions with opposite rotation for the propeller, and were installed on the Hs 129 with the port engine rotating clockwise and the starboard rotating counterclockwise—as seen from nose-on—thus eliminating engine torque problems. The A-1 planes were converted into
Hs 129 B-0s for testing (although some claim that some As were sold to
RomaniaRomania is a country located in Southeastern and Central Europe, North of the Balkan Peninsula, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea. Almost all of the Danube Delta is located within its territory...
) and the pilots were reportedly much happier. Their main complaint was the view from the canopy, so a single larger windscreen and a new canopy with much better vision were added, resulting in the production model
Hs 129 B-1.
B-1s started rolling off the lines in December 1941, but they were delivered at a trickle. In preparation for the new plane, I./Sch.G 1 had been formed up in January with Bf 109 E/Bs (fighter-bomber version of Bf 109 E) and Hs 123s, and they were delivered B-0s and every B-1 that was completed. Still, it wasn't until April that 12 B-1s were delivered and its 4th
staffel (squadron) was ready for action. They moved to the
Eastern FrontThe Eastern Front of World War II was a theatre of war between the European Axis powers, Nazi Germany, Fascist Italy, Hungary, Romania, Slovakia, Croatia and Finland , and the Soviet Union which encompassed central and eastern Europe from 22 June 1941 to 9...
in the middle of May, and in June, they received a new weapon, the 30 mm (1.2 in)
MK 101 cannonThe MK 101 is the designation of a 30 mm autocannon used in German combat aircraft during World War II. Although accurate and powerful, with a high muzzle velocity, it was very heavy, with a slow rate of fire, which limited its production....
with armor-piercing ammunition in a midline pod.
Hs 129 B-2
By May 1942, after only 50 of the planes had been delivered, they started to deliver the new
Hs 129 B-2 model side-by-side with the B-1. The only difference between the two were changes to the fuel system – a host of other minor changes could be found almost at random on either model. As time went on, these changes accumulated in the B-2 production line until they could finally be told them apart at a glance, the main differences being the removal of the mast for the radio antenna, the addition of a direction-finding radio antenna loop, and shorter exhaust stacks on the engines.
In the field, the differences seemed to be more pronounced. The R-kits were renumbered and some were dropped, and in general, the B-2 planes received the upgraded cannon pack using a 30 mm
MK 103 cannonThe Rheinmetall-Borsig MK 103 was a German 30 mm caliber autocannon that was mounted in German combat aircraft during World War II. Intended to be a dual purpose weapon for anti-tank and air-to-air fighting, it was a development of the heavy MK 101. Compared to the MK 101, it was lighter,...
instead of the earlier MK 101. These guns both fired the same ammunition, but the 103 did so at almost twice the rate.
Hs 129 B-3
Even by late 1942, complaints started about the effectiveness of the MK 103 against newer versions of the
SovietThe Union of Soviet Socialist Republics was a constitutionally socialist state that existed in Eurasia from 1922 to 1991. The name is a translation of the , tr. Soyuz Sovetskikh Sotsialisticheskikh Respublik, abbreviated СССР, SSSR. The common short name is Soviet Union, from , Sovetskiy Soyuz...
T-34 tanks. One obvious solution would be to use the larger 37 mm
Bordkanone BK 37The Bordkanone BK 37 was a 37mm anti-tank/bomber autocannon based on the earlier 37 mm Flak 18 made by Rheinmetall. It was mounted on World War II Luftwaffe aircraft such as the anti-tank or bomber-destroyer versions of the Junkers Ju 87D-3 and G-2, Henschel Hs 129B-2/R3, Messerschmitt Bf...
gun, adapted from an anti-tank gun that had recently been abandoned by the army. These guns had already been converted into underwing pod-mounted weapons for the Ju 87 and found to be a fearsome weapon. When mounted on the Hs 129, the empty area behind the cockpit could be used for ammunition storage, which would address the only problem with the Ju 87's mounting, a limited ammunition supply.
But for some reason the
Luftwaffe decided to skip over this gun for the Hs 129, and as had been done with the heavy-gunned Ju 88P-1, the Rheinmetall firm decided to adapt their already semi-automatic loading PaK 40 anti-tank gun into a lighter-weight, fully-automatic aircraft-mountable version, with a completely different, more aerodynamic muzzle brake, to produce the
Bordkanone BK 7.5 model. A huge hydraulic system was used to dampen the recoil of the gun, and an auto-loader system with 12 rounds, easier to design and fit because of the PaK 40's already semi-automated loading, was fitted in the large empty space behind the cockpit, with the gun and its magazine occupying a
gun podA gun pod is a detachable pod or pack containing machine guns or automatic cannon and ancillaries, mounted externally on a vehicle such as a military aircraft which may or may not also have its own guns....
under the fuselage, with a hole in the rear end of the pod to allow spent cartridges to be ejected. The resulting system was able to knock out any tank in the world, but the weight slowed the already poor performance of the plane to barely flyable in this new
Hs 129 B-3 version.
B-3s finally started arriving in June 1944, and only 25 were delivered by the time the lines were shut down in September. A small number were also converted from older B-2 models. In the field, they proved deadly weapons, but with only 25 of them, they had no effect on the war effort.
The
Bordkanone BK 7,5 cannon installation in the Hs 129B-3, at some 1,200 kg (2,645 lb) was the heaviest forward-firing "big-gun" installation ever produced for a series production military aircraft, until the 1970s-era General Electric
GAU-8 AvengerThe General Electric GAU-8/A Avenger is a 30 mm, hydraulically-driven seven-barrel Gatling-type rotary cannon that is mounted on the United States Air Force's A-10 Thunderbolt II...
seven barrel 30mm caliber anti-tank Gatling cannon was introduced, as the A-10's main armament, at a total weight with ammunition of up to 1,830 kg (4,030 lb).
Hs 129 C
In order to address the poor performance of the aircraft, plans had been underway for some time to fit the plane with newer versions of the
ItalianItaly , officially the Italian Republic , is a country located on the Italian Peninsula in Southern Europe and on the two largest islands in the Mediterranean Sea, Sicily and Sardinia. Italy shares its northern, Alpine boundary with France, Switzerland, Austria and Slovenia...
Isotta-Fraschini DeltaThe Delta was a 12-cylinder inverted-V aircraft engine built by Isotta-Fraschini prior to and during World War II.-Design and development:The Delta is a fairly rare example of a large air-cooled inline engine, which normally have cooling problems with the rearmost cylinders. It produced about...
engine that delivered 630 kW (850 hp). However, the engine ran into a number of delays, and was still not ready for production when the plant was overrun by the Allies in 1945.
Operators
Germany
- Luftwaffe
Luftwaffe is a generic German term for an air force. It is also the official name for two of the four historic German air forces, the Wehrmacht air arm founded in 1933 and disbanded in 1946; and the current Bundeswehr air arm founded in 1956.Schweizer Luftwaffe is also the name of the Swiss Air...
Hungary
- Hungarian Air Force
The Hungarian Air Force is the air force branch of the Hungarian Army.-1918 - Pre-World War II:Following the dissolution of the Austro-Hungarian Monarchy in 1918, a small air arm was established operating surviving aircraft from Hungarian factories and training schools...
Romania
- Romanian Air Force
The Romanian Air Force is the air force branch of the Romanian Armed Forces It has an air force headquarters, an operational command, four air bases and an air defense brigade...
Specifications (Hs 129 B-1)
See also