FREE CPL Aircraft Systems and Aerodynamics Questions and Answers

Question 1

In a conventional twin-engine aircraft with clockwise rotating propellers, which engine is considered the 'critical engine' and why?

Accepted Answer

The left engine, because P-factor and torque from the right engine create the most adverse yawing and rolling moments.

Answer

In a conventional twin-engine aircraft (both propellers rotating clockwise as seen from the cockpit), the failure of the left engine results in the most adverse effects on control and performance. This is due to the combination of asymmetrical thrust (P-factor), which creates a longer arm for the right engine's thrust vector from the aircraft's center of gravity, and torque effects. The resulting yaw and roll towards the dead left engine are more severe than if the right engine had failed.

Question 2

A pilot is flying an aircraft with a constant-speed propeller. During a descent with power reduced, the pilot notices the RPM is increasing. To maintain the desired RPM, the propeller governor will automatically:

Accepted Answer

increase the blade pitch angle, which increases aerodynamic load and slows the propeller.

Answer

In an overspeed condition (RPM higher than selected), the flyweights in the propeller governor are forced outward by centrifugal force. This action directs high-pressure oil to the propeller hub, which increases the blade pitch angle (takes a bigger 'bite' of air). This increased aerodynamic load slows the propeller back to the desired RPM.

Question 3

What is the primary function of a hydraulic accumulator in an aircraft landing gear system?

Accepted Answer

To store hydraulic fluid under pressure to dampen pressure fluctuations and provide emergency pressure.

Answer

A hydraulic accumulator stores hydraulic fluid under pressure from a compressed gas (usually nitrogen). Its primary roles are to absorb pressure surges and shocks in the system, supplement the hydraulic pump during periods of high demand (like gear retraction), and provide a source of stored energy for emergency operation of systems like landing gear or brakes if the main hydraulic pump fails.

Question 4

During a level, coordinated turn, the load factor on an aircraft will:

Accepted Answer

increase as the angle of bank increases.

Answer

In a level turn, the vertical component of lift must still equal the aircraft's weight to maintain altitude. As the bank angle increases, the total lift vector must increase to provide this necessary vertical component. This increase in total lift, which is the sum of the vertical component and the horizontal component (which causes the turn), results in a higher load factor. For example, a 60-degree bank in a level turn produces a load factor of 2 Gs.

Question 5

A pilot of a large, swept-wing aircraft encounters an uncommanded, coupled oscillation of rolling and yawing. This aerodynamic characteristic is known as:

Accepted Answer

Dutch roll.

Answer

Dutch roll is a coupled lateral-directional oscillation that is characteristic of swept-wing aircraft. It consists of an out-of-phase combination of yawing ('tail-wagging') and rolling. It occurs due to an imbalance where dihedral effect (strong lateral stability) is stronger than directional stability. Modern transport aircraft use a yaw damper system to automatically counteract this tendency.

(CPL) Commercial Pilot Licence Practice Test

(CPL) Commercial Pilot Licence Practice Test

FREE CPL Aircraft Systems and Aerodynamics Questions and Answers