Heinkel He 51 C-1 single-engine fighter/light ground-attack aircraft
The combat début of the He 51 fighter took place in 1936 during the Spanish Civil War. Heinkel fighters were flown both by Spanish Nationalists, including Joaquin Garcia-Morato, the best ace of the Spanish War, and by German fighter pilots of the famous Condor Legion.
In November 1936, General Franco's pilots and German volunteers met in the air for the first time with Polikarpov I-15 fighters supplied to the Republicans by the Soviet government. The appearance of the Soviet planes was a shock for the German pilots, who had believed that their He 51B was superior to foreign fighters in every respect. The superiority of the I-15 over the He 51 in speed, manoeuvrability, and rate of climb was indisputable. Although the Soviet fighter's four PV-1 machine guns had a slower rate of fire, they provided fire superiority over the German's two MG 17s. In addition, the He 51's magazine capacity was three times less.
When the experience of the He 51's combat employment in Spain showed the complete superiority of the Soviet fighters, it was decided to use the plane as a ground-attack aircraft to provide direct air support to ground forces.
The He 51 C-1 variant was launched into full-scale production. These aircraft were notable for their bomb racks, which were able to suspend six 10 kg fragmentation bombs. The bomb racks were mounted under the lower wing panels.
He 51 fighters of early variants were modified by the troops on site, fitted to carry bombs. The experience of combat with the He 51 during strike missions against ground targets had an enormous influence on the future development of the Luftwaffe, particularly on its tactical deployment of the Hs 123 and Ju 87 dive bombers.
A combined total of 725 He 51 fighters were built. 135 aircraft of the "A", "B", and "C" variants were delivered to Spain. When the Civil War was over in April 1939, only 46 He 51s remained in good enough condition for flying.
Spanish He 51s served as light ground-attack aircraft and then as training planes until 1946.