What was unusual about the Ar 64c's propeller?

Short answer

The unusual feature belongs to the first prototype, the Ar 64a, not the c-version: its four-bladed propeller was made by bolting together two two-bladed propellers, with one pair of blades slightly ahead of the other. The Ar 64c carried a 395 kW (530 hp) Jupiter VI and minor structural changes.

Published: November 2, 2026 · Updated: November 2, 2026 · Edited by Above Ten Thousand · Editorial policy

What was unusual about the Ar 64c's propeller?

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Two two-bladed propellers bolted together

The curious detail is documented on the first prototype, the Ar 64a: its four-bladed propeller was created by bolting together two two-bladed propellers, so that one pair of blades sat slightly ahead of the other. That prototype was powered by a 530 hp Jupiter VI engine. The Jupiter VI was an air-cooled radial built by Siemens (Bristol) and drove a four-bladed Schwartz wooden propeller.

What the Ar 64c carried

The Ar 64c was powered by a 395 kW (530 hp) Jupiter VI and featured minor structural changes. Another version repeated the configuration of the 64d, but with a direct-drive variant of the Jupiter VI. All the Ar 64s except two carried the Gnome-Rhône Jupiter radial, built under licence by Siemens.