Operational History
Prior to World War II
A small pre-production batch of Hs 123A-0s was completed in 1936 for service evaluation by the Luftwaffe. This initial group was followed by the slightly modified Hs 123A-1 series, the first production examples. The service aircraft flew with an armoured headrest and fairing in place (a canopy was tested in the Hs 123V6) as well as removable main wheel spats and a faired tailwheel. The main weapon load of four SC50 110 lb (50 kg) bombs could be carried in lower wing racks along with an additional SC250 550 lb (250 kg) bomb mounted on a "crutch" beneath the fuselage. The usual configuration was to install an auxiliary fuel "drop" tank at this station that was jettisoned in emergencies. Two 7.92 mm MG 17 machine guns were mounted in the nose synchronized to fire through the propeller arc.

Henschel Hs 123 with the Condor Legion
Spanish Civil War
During the same time, at the request of Oberst (later Generalfeldmarschall) Wolfram Freiherr von Richthofen, chief of staff of the Legion Kondor, five aircraft had been deployed to Spain as a part of the Condor Legion, intended to be used as tactical bombers.

Henschel Hs 123A-1 with the Condor Legion.
Second Sino-Japanese War Twelve Hs 123s were also exported to China, where they were used extensively as dive bombers against Japanese warships along the Yangtze River, especially in 1938.
World War II (service from Poland to Greece)
At the outbreak of hostilities, the surviving 39 Hs 123s assigned to II. (Schl)/LG 2, were committed to action in the Polish Campaign. This single unit proved to be particularly effective. Screaming over the heads of enemy troops, the Hs 123s delivered their bombs with devastating accuracy. A frightening aspect of an Hs 123 attack was the staccato noise of its engine that a pilot could manipulate by changing rpm to create "gunfire-like" bursts. The Hs 123 proved rugged and able to take a lot of damage and still keep on flying. Operating from primitive bases close to the front lines, ground crews considered the type reliable in field conditions, being easy to maintain.The Polish campaign was a success for an aircraft considered obsolete by the Luftwaffe high command. Within a year, the Hs 123 was again in action in the blitzkrieg attacks through the Netherlands and France. General Guderian was continually impressed by the quick turnaround time offered by II.(Schl)/LG 2. Often positioned as the Luftwaffe's most-forward based combat unit, the Hs 123 flew more missions per day than other units, and again proved their worth in the close-support role. With Ju 87s still being used as tactical bombers rather than true ground support aircraft and with no other aircraft capable of this mission in the Luftwaffe arsenal, the Hs 123 was destined to continue in service for some time more, although numbers were constantly being reduced by attrition.

Henschel Hs 123.
At the beginning of the Balkans Campaign, the 32 examples of the Hs 123 that had been retired after the fall of France were taken back into service to equip 10.(Schl)/LG 2. The aircraft performed well enough to warrant its use in Operation Barbarossa.
World War II (Eastern Front)
At the start of Operation Barbarossa, the single Gruppe of the Luftwaffe that was dedicated to ground support was II.(Schl)/LG 2, operating 38 Bf 109Es and 22 Hs 123s. In service use on the Eastern Front, the remaining aircraft had been "field" modified with the main wheel spats removed, additional armour and extra equipment fitted as well as mounting extra machine guns and even cannons in under-wing housings.

Crashed Henschel Hs 123 with winter camo on the Eastern Front.
During the initial drive, the unit participated in action along the central and northern parts of the front, including a brief time in support of the fighting around Leningrad, and participating in the battles for Bryansk and Vyazma. The first weeks revealed problems associated with using the Bf 109E which was plagued by undercarriage and engine problems in the fighter-bomber role. Its liquid-cooled inline engine was also more vulnerable to small arms fire than the Hs 123's radial.

Henschel Hs 123 in winter camoflage.
This "new" unit participated in operations in Crimea in May 1942, after which it operated on the southern sector for some time, participating in the Second Battle of Kharkov and going on to take part in the Battle of Stalingrad. In the meantime, the small number of operational Hs 123 continued to slowly dwindle. Aircraft had been salvaged from training schools and even derelict dumps all over Germany to replace losses. The aircraft that had supposedly replaced the Hs 123, the Ju 87, also started to be assigned to ground support units, leaving tactical bombing to newer aircraft.
The greatest tribute to the Hs 123 usefulness came in January 1943 when Generaloberst Wolfram Freiherr von Richthofen, then commander-in-chief of Luftflotte 4, asked whether production of the Hs 123 could be restarted because the Hs 123 performed well in a theater where mud, snow, rain and ice took a heavy toll on the serviceability of more advanced aircraft. However, the Henschel factory had already dismantled all tools and jigs in 1940.

Henschel Hs 123 of SG.1
By 1945, the Hs 123s that remained serviceable were reassigned to secondary duties such as supply dropping and glider towing.
Gunston, Bill - The Encyclodepia of the Worlds Combat aircraft, 1976, Chartwell Books, Inc., New York
Brown, Eric, Captain - Wings of the Luftwaffe
Gunston, Bill & Wood, Tony - Hitler's Luftwaffe
Donald, David - The Complete Encyclopedia Of World Aircraft, 1997, Brown Packaging Books Ltd., London
Wikipedia - Henschel Hs 123