To prevent icing on the compressor blades, outside air passes through the pre-heaters to be warmed when the ambient air temperature is below 43°F.258,000 cubic feet of air per minute continually passes through the pre-heater and enters the filter banks where it is cleaned. Ambient air must be filtered to keep the engine as clean as possible as a clean engine is an efficient engine.

The filter bank is composed of 120 filters, each filter resembling those used on large diesel engines or semi-tractor trailers.

Filtered air enters the engine through the air intake, passing stationary blades to direct it at "the most efficient angle of attack" for initial compression.