A variable pitch propeller provides an optimum angle of attack for the propeller blades for a longer range which reduces fuel usage, fixed pitch propellers only have a certain rpm.

New York to London (flying east) would take less time because of the Polar front westerly jet stream.

To increase the strength of the surfaces.

The same strategy is employed by plastic water bottles, by adding ridges to a surface you increase it's structural rigidity

V1 is lower when the runway is wet than when the runway is dry, because of the longer ASDR on a wet runway.

Meridians converge from their maximum distance apart (at the equator) to the poles where they meet.

Great circles are the shortest distance between two points and convergency represents the change in direction experienced between those points.

V1 is the decision speed (sometimes referred to as critical engine speed or critical engine failure speed) by which any decision to reject a takeoff must be made.

V2 is the takeoff safety speed which must be attained at the 35 ft height at the end of the required runway distance. This is essentially the best one-engine inoperative angle of climb speed for the airplane and is a minimum speed for flight in that condition until at least 400 ft above the ground. V2 shall be at least 1.1 times VMCA, and no less than 1.2 times VS.

Vr is defined as the speed at which the rotation of the aircraft should be initiated to takeoff attitude.

VMCA is the minimum control speed in the air and is defined as the minimum speed, whilst in the air, that directional control can be maintained with one engine inoperative (critical engine on two engine aerolanes), operating engine(s) at takeoff power and a maximum of 5 degrees of bank towards the good engine(s).

VMCG is the minimum control speed on the ground and is defined as the minimum speed, whilst on the ground, that directional control can be maintained, using only aerodynamic controls, with one engine inoperative (critical engine on two engine airplanes) and takeoff power applied on the other engine(s).

Antiskid has a detection system that senses the moment a wheel stops rotating.

Once it senses that the wheel is not rotating, the antiskid system releases brake pressure. This allows the wheel to regain traction with the surface, so that break application can be resumed and prevents complete loss of controllability.

Dutch roll is an aircraft stability issue involving oscillations of rolling and yawing motions. It occurs when the aircraft's nose deviates from its path, causing rolling in the opposite direction due to the vertical fin's side force. This generates a yawing moment, resulting in a cycle of yawing and rolling motions. Dutch roll can be problematic for passenger comfort and pilot control. Measures like tail fin design, yaw dampers, and control inputs are used to counteract it and maintain stability.

First continue on the SID and try all available resources to check if you have a complete radio failure.

If so, squawk 7600 and return towards the airport.

Boots on the leading edges inflate (6 seconds) to break the ice dissipating it into the airflow.

Powered by the gyro pressure system.