TOLD Definitions (USEM Guide)

Question 1

Take-off rated thrust

Answer 1

Take-off rated thrust is the maximum allowable thrust (determined by fan speed, N1). It varies with pressure altitude, ram air temperature, and bleed air usage. Operation of TRT is limited to 5 minutes.

Question 2

Maximum continuous thrust

Answer 2

Maximum continuous thrust is the maximum allowable thrust (determined by fan speed, N1) that may be used without a time limitation. Maximum continuous thrust varies with pressure altitude, ram air temperature, and bleed air usage.

Question 3

Runway available

Answer 3

The runway length minus any unusable portion of the runway such as the aircraft lineup distance or barriers on or above the runway.

Question 4

Runway length

Answer 4

Runway length is the paved surface length excluding any overrun.

Question 5

Critical engine failure speed

Answer 5

Critical engine failure speed is defined as the speed at which one engine can fail and the same distance is required to either continue to accelerate to lift-off speed, or abort and decelerate to a full stop.

Question 6

Critical field length

Answer 6

The critical field length is the total length of the runway required to accelerate on all engines to critical engine failure speed, experience and engine failure, then continue to lift-off or stop. It is used during takeoff planning together with the climbout data to determine maximum gross weight for a safe takeoff and climbout. For a safe takeoff, the critical field length must be no greater than the runway available.

Question 7

Take-off factor

Answer 7

Take-off factor numbers are %N1 settings adjusted for OAT and altitude and are presented on a different scale.

Question 8

Take-off ground run

Answer 8

Take-off ground run is defined as that runway distance normally obtained in service operation at zero wind at the mission-specified weight, pressure altitude, thrust setting, ambient temperature, and appropriate take-off configuration using lift-off speed.

Question 9

Minimum control speed ground (Vmcg)

Answer 9

Ground minimum control speed, Vmcg (88 KIAS), is the minimum controllable speed during the take-off run, at which, when an engine is failed, it is possible to maintain directional control using only primary aerodynamic controls without deviating more than 25 feet laterally with all three wheels on the runway. The speed is established with the remaining engine at the takeoff thrust setting, the aircraft loaded at the most unfavorable weight and center of gravity, and the aircraft is trimmed for takeoff, without exceeding 180 pounds of rudder control force by the pilot with the rudder boost system operating. Conditions of crosswind and RCR may increase Vmcg.

Question 10

Refusal speed (Vr)

Answer 10

Refusal speed, Vr, is the maximum allowable speed that can be attained, with normal acceleration, from which a stop may be completed within the available runway length.

Question 11

Maximum braking speed (Vb)

Answer 11

Maximum braking speed, is the maximum speed from which the aircraft can be brought to a stop without exceeding the maximum brake energy limit (14.8 million foot pounds).

Question 12

Takeoff acceleration check

Answer 12

A takeoff acceleration check provides a speed for a given distance during takeoff ground roll. This speed can be checked against aircraft indicated airspeed at that distance point to ensure that the takeoff is proceeding normally. Takeoff acceleration check speed should be adjusted to be at least 10 KIAS less than S1. Compute takeoff acceleration check whenever S1 is less than Vrot. Effects of wind, runway gradient, and RSC are included in the takeoff ground run. Use 100% of runway wind component for takeoff ground run determination.

Question 13

Go/No Go Speed (S1)

Answer 13

The takeoff is committed at indicated airspeeds at or above S1. If an engine failure occurs prior to obtaining S1 and action is taken to stop the aircraft before obtaining S1, takeoff abort capability is assured. In takeoff planning S1 is equal to or greater than the higher of ground minimum control speed or critical engine failure speed. However, S1 must not be higher than the lowest of refusal speed, rotation speed, or maximum braking speed. If it is higher, the takeoff weight must be reduced until this requirement is met.

Question 14

Rotation speed (Vrot)

Answer 14

Rotation speed is defined as the speed at which the aircraft attitude is increased from the ground run (taxi) attitude to the lift-off attitude. This speed is greater than the ground minimum control speed.

Question 15

Lift-off

Answer 15

Lift-off is the moment at which the main gear lift off the runway.

Question 16

Lift-off speed (Vlof)

Answer 16

Lift off speed is the speed at which lift-off occurs.

Question 17

Takeoff flare

Answer 17

Takeoff flare is the ground distance covered between lift-off and the 50-foot obstacle height.

Question 18

Takeoff speed

Answer 18

Takeoff speed is defined as that speed which permits attaining the obstacle climb out speed at or before reaching the 50 foot obstacle height above the runway.

Question 19

Climbout speed (Vco)

Answer 19

Climbout speed is the scheduled single-engine climbout speed and should be obtained at or prior to reaching the 50-foot obstacle height. Due to excess thrust available with two engines operating, the two-engine climbout speed is 10 knots greater or Vco + 10 knots.

Question 20

Climbout factor

Answer 20

Climbout factor is the variable used to determine take-off/climb performance and obstacle clearance. Minimum climbout factor for all takeoffs is 2.5.

Question 21

Intersection T/O

Answer 21

Intersection takeoffs are authorized as long as the runway remaining is at least 6,000 feet or CFL, whichever is greater (Performance data restrictions apply).

Question 22

Minimum runway length landing

Answer 22

The minimum runway length for full stop landings is 6,000 feet or computed landing distance, whichever is greater.

Question 23

Minimum runway length takeoff

Answer 23

The minimum runway length for takeoff is 6,000 feet, critical field length, or distance to reach reference zero, whichever is greater.