A propulsion engine, using the speed control circuit shown in the illustration, fails to function at speeds lower than the low end of the critical speed range. Which of the following statements describes what should be done to correct this malfunction? Illustration MO-0114

Correct Answer: Option A — Device 17A needs to be replaced, repaired, or reset to the setpoint coinciding with the RPM value for the low end of the critical speed range.

Bypassing or operating within critical speed ranges requires precise tachometer relay or switch settings. Device 17A must be reset or repaired to match the exact RPM threshold defining the lower boundary of the engine critical speed range.