# Distribution

The distribution provides ram air ventilation to the cabin. It consists of the components that follow:

* [Inlet duct](#inlet-duct)
* [Plenum assembly](#plenum-assembly)
* [Outlet duct](#outlet-duct)
* [Fresh air control assembly](#fresh-air-control-assembly)

## Inlet duct

The inlet duct takes outside air and directs it to the plenum. It consists of a screen and a duct made from thermoplastic resin. It is located in the nose cone assembly with the screen holding it on the intake hole from the outside.

## Plenum assembly

The plenum assembly is located at the forward end of the pedestal. It consists of the plenum, damper, back cover and outlet, all made from thermoplastic resin. A spring, made from corrosion resistant steel, maintains a tension to close the damper.

The plenum assembly collects the air and directs it to the outlet duct. The damper controls the flow of air.

## Outlet duct

The outlet duct is located on the top of the plenum at the forward end of the pedestal. It is made from thermoplastic resin.

The outlet duct distributes the air in the cabin.

## Fresh air control assembly

The fresh air control assembly controls the position of the damper. It consists of the control knob, control bushing, control shaft, cable assembly, end fitting stud, wire plug, and clevis. It is located in the pedestal and offers easy access for the operator to control airflow in the cockpit.

## Operation

The inlet duct takes ram air from the main rotor and the forward movement of the helicopter and routes it to the plenum assembly. The plenum assembly routes the air to the outlet. The air from the outlet is diffused in the cabin by the outlet duct. The fresh air control assembly positions the damper to control the flow of air.
