Final answer:
In a constant power dive, the blade angle of a constant speed propeller increases to maintain a consistent engine RPM despite increased air resistance.
Step-by-step explanation:
During a constant power dive with a constant speed propeller, the blade angle of the propeller increases. This adjustment is made to maintain a consistent engine RPM. As the aircraft gains speed in the dive, the propeller experiences more air resistance, naturally wanting to spin faster. The constant speed propeller system counters this by increasing the blade angle, making the blades more perpendicular to the oncoming air, which increases their aerodynamic resistance and prevents the RPM from increasing, thereby maintaining constant engine power.