Loss of disc area results in what effect?

Loss of disc area results in what effect?

• A. Decrease In Rotor RPM
• B. Increase In Blade Twist
• C. Increase In Forward Speed
• D. Loss Of Total Lift

Answer: (D)

Loss of disc area reduces the amount of air the rotor can move and, therefore, the total lift it can generate. Lift from a rotor scales with the disk area—the bigger the disk, the more air you can accelerate downward for the same rotor speed and blade pitch. If the disc area is reduced, even with the same RPM and pitch, you can’t produce as much thrust, which shows up as a loss of total lift. RPM and forward speed aren’t automatically dictated by a smaller disk, and blade twist is a result of the load and pitch schedule rather than the disk area itself.

Loss of disc area reduces the amount of air the rotor can move and, therefore, the total lift it can generate. Lift from a rotor scales with the disk area—the bigger the disk, the more air you can accelerate downward for the same rotor speed and blade pitch. If the disc area is reduced, even with the same RPM and pitch, you can’t produce as much thrust, which shows up as a loss of total lift. RPM and forward speed aren’t automatically dictated by a smaller disk, and blade twist is a result of the load and pitch schedule rather than the disk area itself.