RAM AIR TURBINES
UNDERSTANDING TRANSIENT EFFECTS OF DEPLOYMENT
Ram Air Turbines are typically stowed within an aircraft airframe. When needed, they are deployed with the vehicle in flight. Often, they are deployed from the underside of an airframe but can also be deployed from side panels or other areas. Deployment of a Ram Air Turbine can create potentially damaging transient effects, such as shock loads and vibrations. Upon deployment, the RAT requires time to achieve a steady rotational rate. This time can vary for different points in the operational envelope and for different simulated loads. At Calspan, our uniquely designed test section allows a Ram Air Turbine to be stowed in a variety of ways. The customer can simulate a deployment from a sidewall, ceiling, or floor installation depending on how the RAT is intended to be deployed from the airframe. Auxiliary instrumentation such as strain gauges and accelerometers allow the customer to measure the transient effects of a deployment. Through this test, Calspan can ensure that the RAT is able to withstand deployments throughout the flight envelope and we are able to measure the time it takes to spin up the rotor for a variety of simulated loads.