AIRCRAFT propeller selection and installation by the airplane designer are best accomplished with the full cooperation of the propeller manufacturer and the engine manufacturer. This period of cooperation should start immediately after the airplane general arrangement has been chosen, approximations to the principal performance characteristics have been made, an engine or a small group of possible engines has been selected, and an indication is available of the general space that can practically be made available for the propeller.
The designer, however, should not wait until this stage to consider the general propeller requirements of the airplane. He should make some preliminary calculations for himself, so that he can be sure that there are propellers that will fill his requirements.
When the propeller manufacturer is consulted, he will normally make his recommendations as a group of possible propellers, any one of which would probably be suitable for the airplane as far as structural strength, angle range, and availability are concerned, but which show variations at the different operating conditions, and differences in weight, diameter, and other properties.
These recommendations will be accompanied by performance estimates for the principal operating conditions that will have to be extended by the airplane designer to cover a wider variety of flight conditions. Methods for making such propeller performance estimates are discussed by Mr. Rhines.
From these estimates, the best propeller is selected and the installation details are definitely settled, again in consultation with the propeller manufacturer, who should review the final selection thoroughly.
