What happens if the elevator trim tabs on an airplane are lowered?

Lowering the elevator trim tabs on an airplane adjusts the aerodynamic forces acting on the tail of the aircraft. When you lower the trim tabs, they create an upward force on the tail, which in turn allows the elevators to move the tail down. This action results in the nose of the airplane pitching up due to the change in angle of attack. By providing this upward force, the plane becomes more stable in a nose-up attitude, making it easier to maintain level flight or to climb without constantly applying back pressure on the control yoke or stick.

Understanding this action is essential for pilots as it helps in managing the aircraft's pitch attitude more effectively, particularly during different flight phases such as takeoff and landing. The other options reflect misunderstandings of the relationship between trim settings and the aircraft’s attitude in flight.