Editing Heinkel He 100 (section)

=== Pre-production series ===
Throughout the prototype period, the various prototypes were presented to the RLM as the basis for series production. The Luftwaffe never took Heinkel up on their offer, although the company decided to build a total of 25 of the aircraft one way or the other, so with 10 down, there were another 15 of the latest model to go. In keeping with general practice, any series production is started with a limited run of "zero series", resulting in the He 100 A-0 (postwar designation: He 100 D-0).

The A-0 was similar to the earlier prototype models, with a few notable changes. Primary among these was a larger vertical tail in order to finally solve the stability issues. In addition, the [[cockpit]] and canopy were slightly redesigned, with the pilot sitting high in a large canopy with excellent vision in all directions. The armament was reduced from the V8 model to one {{convert|20|mm|abbr=on}} MG FF/M in the engine V firing through the propeller spinner, and two 7.92&nbsp;mm (.30-caliber) MG 17s in the wings close to the fuselage.

The three pre-production aircraft were completed by the summer of 1939 and stayed at the Heinkel Marienehe plant for testing. They were later sold to the [[Japanese Imperial Navy]] to serve as pattern aircraft for a production line, and were shipped there in 1940. They received the designation '''AXHe1'''.