Скачать или смотреть Module 13 Questions | EASA Part 66 MCQs | Quiz 6

Explanation 1:
A semi-rigid rotor system typically consists of two blades mounted on a central gimbal or teetering hinge. Here’s why this is the correct answer:
Design:
The two blades are interconnected and pivot as a single unit on a central gimbal, allowing them to flap and teeter. This design is simpler and lighter than a fully articulated rotor system.
Movement:
The semi-rigid rotor allows for flapping (up-and-down movement) and feathering (blade pitch change) but does not have independent horizontal hinges for lead-lag movement.
Comparison:
Rigid rotor (a): No flapping or lead-lag hinges; blades are stiff and rely on flexing.
Fully articulated rotor (c): Allows flapping, feathering, and lead-lag movement with individual hinges for each blade.

Explanation 2:
The autopilot controls roll by adjusting the ailerons, but the bank angle limit sets the maximum roll angle the autopilot can command. This ensures the aircraft does not exceed a safe bank angle during turns, preventing excessive load factors and passenger discomfort. It does not directly limit aileron or rudder deflection, as those are adjusted dynamically to maintain the commanded bank angle.

Explanation 3:
Servo tabs deflect in the opposite direction of the control surface, generating an aerodynamic force that assists in moving it. This reduces the effort needed by the pilot, especially in manually controlled aircraft. They do not actively return the surface to neutral or provide artificial feel.

Explanation 4:
Spring tabs work like servo tabs but are linked to a spring mechanism. They move in response to pilot input, reducing the aerodynamic force needed to deflect the control surface. This helps pilots control large surfaces more easily, especially at high speeds. They do not directly neutralize the surface or simulate artificial feel.

Explanation 5:
Moving the cyclic stick to the right changes the pitch of rotor blades cyclically, causing the main rotor disk to tilt right. This results in a rightward movement of the helicopter. While pitch control arms do adjust blade angles, the direct effect is the tilting of the rotor, making option (a) the clearest choice.

Explanation 6:
Attitude Mode – Maintains a stable approach before landing.
Flare Mode – Reduces the descent rate just before touchdown.
Rollout Mode – Keeps the aircraft aligned with the runway after landing.
Explanation 7:
Spoilers are often used differentially to assist roll control by reducing lift on the down-going wing (same side as the upgoing aileron). This improves roll response, especially at high speeds. They do not act as airbrakes in this case, nor do they move symmetrically with both ailerons.

Explanation 8:
A yaw damper is designed to reduce Dutch roll (a high-frequency oscillation involving both yaw and roll) by automatically adjusting the rudder. It does not directly assist in coordinating turns or managing general aerodynamic response.

Explanation 9:
Moving the elevator tab downward generates a force that helps lift the nose of the aircraft, counteracting a nose-heavy condition. This reduces the control force required by the pilot to maintain the desired attitude. The tab doesn’t directly affect the tail-heavy condition.

Explanation 10:
When a trailing edge flap is lowered and the aircraft encounters rising gusts, the following occurs:
Flap Effect:
Lowering the flap increases the wing’s camber and lift, which can initially increase the angle of attack.
Rising Gusts:
Rising gusts (upward-moving air) increase the relative airflow’s upward component, effectively reducing the angle of attack (the angle between the wing’s chord line and the oncoming air).
Net Effect:
While the flap increases lift, the rising gusts reduce the angle of attack, causing it to tend to decrease.