Unpressurized Navajo Air Conditioning System

It has been obvious for some time that an air conditioning system is a desirable option for general aviation aircraft. This paper discusses the more important details of the design and development program for the unpressurized Piper Navajo air conditioning system.

The final system weighs 97.6 lb and provides a maximum ground cooling capacity of 18,000 Btu/h on a 100 F day at 1000-1500 engine rpm. Flight testing failed to reveal measurable aircraft performance change with the system off.

Since the basic system is closely related to existing automobile systems, emphasis to be placed on the problems unique to the aircraft installation.