1. In the July 2021 article “Extending the Glide,” the author makes the statement, “If you lose oil pressure, the prop is going to go flat pitch, so, for many engine failures, coarse pitch might not be available.” Then in the sidebar, “Constant Speed Prop Basics,” the author states, “Higher oil pressure increases blade angle, thereby reducing RPM, and the opposite is true with lower oil pressure.” This is true of MOST constant speed props, not all. For example, certain constant speed counterweighted, non-feathering Hartzell propellers, such as that used on the Helio Courier, work the opposite. The Hartzell HC-B3 series owners manual states, “Counterweighted propellers require governor supplied oil to decrease blade pitch. If the oil supply is lost, the counterweighted propeller will go to high pitch, or low RPM.” The point? Know the systems on your airplane.
    Chuck Daly
    JAARS, Inc.
    Chief Pilot


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