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).

Jet engines are designed to achieve their best specific fuel consumption at high rpm, which can only be achieved at high altitudes where the air density is low.

Thrust produced will be low enough to equal the required cruising thrust. Also high altitude gives the best operating conditions for the airframe i.e. minimum drag during the cruise.

Turboprops need relatively dense air for the propellers to work efficiently and at high altitude the density would be too low.

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

The track changes constantly.

Mcrit is the aircraft’s Mach speed at which the airflow over a wing becomes sonic.

Fusible plugs offer protection from tire blowouts caused by thermal expansion that is generated in the tire under extra hard braking conditions.

TORA= Takeoff Run Available, the length of runway declared available and suitable for the ground run of an aeroplane taking off.

TODA= Takeoff Distance Available, the length of the take off run available (TORA) plus the length of the clearway, if available.

ASDA= Accelerated Stop Distance Available, the length of the takeoff run plus the length of the stopway, if available.

A clearway is an area beyond the paved runway, free of obstructions and under the control of the airport authorities. The length of the clearway may be included in the length of the takeoff distance available (Take Off Distance Available (TODA)). For example, if a paved runway is 2000 m long and there are 400 m of clearway beyond the end of the runway, the takeoff distance available is 2400 m long.

The stopway is an area beyond the runway which can be used for deceleration in the event of a rejected takeoff.

Screen height: TODR is the distance from the brake release point to the point where the aircraft gains a height of 35 ft above the ground. This 35 ft is what we call the screen height. While 35 ft is the screen height for class A airplanes, it is 50 ft for class B airplanes.

On a wet runway, the screen height is reduced to 15 ft.

Basic Empty Mass (BEM) is the mass of the aircraft with the basic equipment, unconsumable fluids and unusable fuel and oil.

A swept wing makes the velocity vector normal to the leading edge a shorter distance than the chordwise resultant.

When considering a volume of air, adiabatic lapse rate is the temperature change that is caused by the vertical movement of the volume, andThe Lapse Rate is the rate at which temperature changes with height in the atmosphere.

The Environmental Lapse Rate (ELR) is according to ISA 2°C per 1000 feet increasing altitude.

For unsaturated air, the lapse rate is 3°C per 1000 feet, this is called the Dry Adiabatic Lapse Rate (DALR).

The Saturated Adiabatic Lapse Rate (SALR) is the rate at which saturated air cools with height and is, at low levels and latitudes, 1.8°C per 1000 feet.