In order to prevent trouble with the operating oil in the controllable-pitch airscrew hub developed by Junkers, it consists of two coaxial shells which surround the hub. Warm air fed from the engine cowling into the space between hub and inner shell, flows through a forward opening into the space between the shells and leaves through slits in the outer shell. The airscrew hub is thus surrounded by two layers of warm air.
The Junkers controllable pitch propeller is a copy of Hamilton designs, operated by oil pressure from a separate oil pump via a governor. The Junkers system is entirely independent in its operation. and wear of parts is slight.
This news clip was originally published in the "Aviation Abroad" column in the October, 1942, issue of Aviation magazine, vol 41, no 10, p 268.