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It was done in order to retain a balanced airflow over the tail surfaces. The short distance between the propeller shaft centre-line and aft fuselage top-decking led to the use of a small in diamater four-blade prop to take an adventage of the available power. The hub was thus only about ten feet from the intersection of the fin and the tailplane. Therefore the engine nacelle was angled to starboard what was more suitable solution in a low-speed aircraft than more common cambering of a fin and rudder.