Designed to an official requirement for a dive-bomber, issued in 1933, the Henschel Hs 123 single-bay biplane was of all-metal construction, with fabric covering used only for the rear portions of the wings and the control surfaces. Powered by a 650 hp (485 kW) BMW 132A-3 radial engine, the prototype flew in 1938 and quickly established its superiority over the rival Fieseler Fi 98. The third prototype was the first to be armed, carrying two fixed forward-firing 7.92 mm (0.31 in) MG 17 machine-guns in the fuselage top decking. The first three aircraft were flown to Rechlin for testing in August 1935, in the course of which activity two of them were destroyed when their wings came off in dives. A fourth prototype tested successfully the structural changes introduced to overcome this problem and initial production orders were placed for the Hs 123A-1, which retained the blistered cowling of the second and third prototypes, rather than the NACA cowling of the first. Power was provided by the BMW 132De radial engine and, in addition to the two fixed MG 17 machine-guns, a mounting for a 551 lbs (250 kg) bomb or an external fuel tank was included beneath the fuselage, and four 110 lbs (50 kg) bombs could be carried on underwing racks.

The Hs 123 was built at Henschel's Schonefeld and Johannisthal factories in Berlin, but although the company built two prototypes, the first, an improved Hs 123B version with the 960 hp (716 kW) BMW 132K engine, the second, designated Hs 123C, differed by having two additional MG 17 machine-guns and an enclosed cockpit for use as an intended ground attack aircraft, the Luftwaffe expressed its satisfaction with the Junkers Ju 87 and production ended. The Hs 123A first entered service with 1./StG 162 in the autumn of 1936, although its career as a front-line dive-bomber was short-lived because the Junkers Ju 87A Stuka began to replace it in 1937. Five Hs 123As were supplied to the Legion Condor in Spain in December 1936


; the type also saw operational service as a close support aircraft in Poland during the closing months of 1939 and in the campaigns in France and Belgium during the spring of 1940. It was withdrawn finally in 1944.

The Hs 123 soon gained a reputation for being a rugged, dependable and harsh weather aircraft. Although the Luftwaffe replaced it with the Ju 87, which was a technically superior aircraft, in operational use, it performed no better than the Hs 123. There were those in the Luftwaffe who, as late as Spring 1944, called for the Hs 123 to be put back into production.
Close Support Role
Back in Germany, the Ju 87 Stuka had started to replace the Hs 123 with the Stukagruppen in 1937, and the Hs 123 was diverted to the close support units, equipping two of the five to form. Debate was raging in the Luftwaffe over the respective merits of the dedicated dive bomber and the close support aircraft. The dive-bomber protagonists won, and the Ju 87 Stuka was also given a close support role, signalling the end of production for the Henschel Hs 123. Two variants built in prototype form were the Hs 123B (V5 prototype) with a BMW 132K engine under a long chord cowling, and the Hs 123C (V6 prototype) which had additional machine-guns under the wings and an armoured headrest with a sliding hood. The latter feature was adopted by service Hs 123As.

In late 1938, after the Sudeten crisis had passed, the close support units were officially disbanded. Nevertheless, one (Schlachtfliegergruppe 10) survived the axe and was incorporated into Lehrgeschwader 2 as II (Schlacht)/LG 2. In September 939 it was the only front-line Hs 123 unit, all other aircraft having been passed to training units. II (Schlacht)/LG 2 was in the lead air assault against Poland on 1 September 1939 that opened World War II. Armed with 110 lbs (50 kg) bombs on the wing racks and the 7.92 mm (0.31 in) MG 17 machine-guns, the Hs 123s flew just feet above the heads of the Polish cavalry brigades for 10 days. More effective than the armament was the terrifying noise of the BMW radial, which was every bit as effective at dispersing mounted columns as explosives. So effective was the Hs 123 in the lightning Polish campaign that plans to re-equip II (Schlacht)/LG 2 were immediately reversed.

For the unit, the next target was Belgium, supporting the 6th Army as it smashed through from 10 May 1940. The first action was to ward off Belgian sappers attempting to destroy brdige crossings over the Albert Canal. Sweeping through Luxembourg and the Ardennes, Hs 123s were soon in France, and by 21 May were the most forward based Lufwtaffe unit when they reached Cambrai. With victory in France achieved, II (Schlacht)/LG 2 was withdrawn to Germany for re-equipment with the Bf 109E, but the Hs 123 had by now built a legendary reputation for its ability to absorb battle damage, and the Gruppe only partially equipped with the Messerschmitt fighter.
The Eastern Front
After a spell in the Balkans from April 1941, the unit joined the fight against the Soviet Union, operating on the southern front. It was incorporated into the newly-formed Schlachtgeschwader 1 and again proved the considerable capability of the Hs 123 in the close support role. Armed with either four SC 50 100 lbs (50 kg) bombs, twin 20 mm MG FF cannon or containers each bearing 92 SC 2 anti-personnel bombs under the wings, and with a fuel tank on the centreline, the Hs 123 proved so effective and dependable that there were calls even as late as 1943 for its reinstatement into production. When conditions were so wet that other aircraft could not take off from the quagmire-like advanced fields, Hs 123s could get aloft once the wheel spats had been removed.

Without new production aircraft to replace losses, attrition slowly took its toll on the Hs 123 squadrons, which ended its days in mid-1944, the remaining aircraft having been grouped in II/Schlachtgeschwader 2.
Variants
Hs 123 V1 - In 1934 the Luftwaffe issued a two-stage requirement for a dive bomber. While the second phase would be filled by a new technology design, the first phase highlighted immediacy as the main goal. Henschel and Fieseler were asked to develop the first phase aircraft, both teams choosing the 725 hp (541 kW) BMW 132A-3 9-cylinder air-cooled radial engine for their designs. Both designs flew in early 1935, the Hs 123 V1 showing a marked superiority over the Fi 98 from the outset of flight trials. The Hs 123 V1 was an ungainly biplane, featuring a wide-chord NACA-style cowling, unequal-span wings and virtually no interplane bracing, most of the loads being borne by two large outward-canted struts.


Hs 123 V1 beefed-up' strut supports on the wing under-surfaces and the rather clumsy and overly large main wheel fairings



Hs 123 V2 - The Hs 123 V2 prototype introduced a shorter-chord, narrower cowl with 18 fairings to house the valves.

Hs 123 V3 - The Hs 123 V3 was similar except for substituting a two-bladed, variable-pitch propeller for the three-bladed adjustable-pitch unit of the preceding aircraft.


Hs 123 V4 - All three prior prototypes went to Rechlin for trials, where two were lost within three weeks. Both had shed the upper wing, and so hasty strengthening of the centre-section struts was introduced from the Hs 123 V4 prototype onwards. With this modification the Hs 123 V4 demonstrated adequate performance, including pulling out of dives at near-vertical angles.

Hs 123A-1 - First deliveries of production Hs 123A-ls were made in the summer of 1936, the initial unit being Stukagruppe 1./162 'Immelmann'. Power came from a 880 hp (656 kW) BMW 132Dc 9-cylinder radial engine and armament consisted of two 7.92 mm (0.31 in) MG 17 machine-guns in the upper fuselage decking. A 551 lbs (250 kg) bomb was carried on a crutch which swung forward from between the main wheels, and four 110 lbs (50 kg) bombs could be carried on wing racks. Five Hs 123A-1s were dispatched to Spain for combat evaluation, but from their debut in early 1937 they were mainly used in a ground attack role. In this they proved remarkably successful, flying close support over the battlefield despite the lack of any communications with ground forces. Spain acquired all five aircraft, and ordered another 11. This type served up until 1943, when virtually all aircraft had been destroyed.















Hs 123B (V5 prototype) - An improved version with the 960 hp (716 kW) BMW 132K engine. Never saw production.

Hs 123C (V6 prototype) - Same as the Hs 123B but differed by having two additional 7.92 mm (0.31 in) MG 17 machine-guns under the wings and an armoured headrest with a slider hood. It was never put into production but the headrest and slider hood was adopted into Hs 123A-1 production.
Specifications (Hs 123A-1)
Crew: 1
Length: 8.33 m (27 ft 4 in)
Wingspan: 10.5 m (34 ft 5 in)
Height: 3.2 m (10 ft 6 in)
Wing area: 24.85 m2 (267.5 sq ft)
Empty weight: 1,500 kg (3,307 lb)
Gross weight: 2,215 kg (4,883 lb)
Powerplant: 1 × BMW 132Dc nine-cylinder air-cooled radial piston engine, 660 kW (880 hp)
Propellers: 2-bladed metal variable-pitch propeller
Performance
Maximum speed: 341 km/h (212 mph, 184 kn) at 1,200 m (3,900 ft)
Range: 860 km (530 mi, 460 nmi) with drop tank
Combat range: 480 km (300 mi, 260 nmi) with 200 kg (440 lb) of bombs
Service ceiling: 9,000 m (30,000 ft)
Rate of climb: 15 m/s (3,000 ft/min)
Armament
2× 7.92 mm MG 17 machine guns, 400 rpg (field modification of 2× 20 mm (0.79 in) MG FF cannon)
Up to 450 kg (992.1 lb) of bombs (1 x SC250 bomb under fuselage and 4 x SC50 bombs under wings)