What occurs to the pitch of a variable pitch propeller to maintain constant rpm when IAS is increased?

To maintain a constant RPM when indicated airspeed (IAS) increases, the pitch of a variable pitch propeller must be adjusted to counteract the effects of the increased airflow and thrust demand. As IAS increases, the propeller encounters more air and the engine may risk overspeeding if the pitch does not change.

When maintaining constant RPM, the propeller's pitch is typically adjusted to a lower setting (decreased pitch) to allow the blades to grab less air, thereby preventing an increase in engine speed beyond the desired operating range. Therefore, the misconception of the pitch staying constant under increasing IAS is incorrect in this context.

Thus, for the system to effectively handle the increased demand for thrust without exceeding the RPM limits, the propeller's pitch must be changed, which results in a decreased pitch setting.