Aviation Institute of Maintenance (AIM) Block 16 Practice Exam

Ice on propeller blades disrupts the smooth, balanced flow the propeller relies on. The ice adds uneven weight and a rough surface, which changes the blade’s effective shape and mass distribution. That makes the propeller out of balance and less efficient, so thrust falls and vibration increases as the engine and airframe respond to the imperfect propulsive force. In flight, this imbalance and reduced efficiency are the primary concerns you’d notice.

The other options don’t fit as well. Ice doesn’t cause the propeller to unlock from the hub, and engine oil pressure isn’t typically driven higher by ice on the blades. Fuel consumption wouldn’t decrease—if anything, inefficiency from ice usually leads to higher fuel burn.