2. SPEEDS AND DISTANCES2. SPEEDS AND DISTANCES

Performance JAR 23Performance JAR 23

SPEEDS AND DISTANCESSPEEDS AND DISTANCES

Speeds: Definitions

• VS: Stall speed

• VS0: Stall speed in landing configuration

• VS1: Stall speed in a specified configuration

• VLE: Maximum Landing Gear Extended speed

• VLO: Maximum Landing Gear Operating speed

• VFE: Maximum Flap Extended speed

• VA: Maneuvering speed

• VNO: Maximum Structural Cruising speed

• VNE: Never Exceed speed

• VR & V2: Operative speeds

Declared distances

Takeoff requirements

SPEEDS: DEFINITIONSSPEEDS: DEFINITIONS

STALL SPEED (VS)

It is the minimum steady flight speed at which the aeroplane is controllable.

Stall condition

SPEEDS: DEFINITIONSSPEEDS: DEFINITIONS

STALL SPEED IN LANDING CONFIGURATION (VS0)

It is the minimum steady flight speed at which the aeroplane is controllable under the following conditions:

• Propeller in takeoff position.

• Engine controls set at zero thrust.

• Landing gear down and cowl flaps closed.

• Full flaps.

• CG in the most unfavourable position (forward).

• Maximum Take Off Mass (MTOM).

SPEEDS: DEFINITIONSSPEEDS: DEFINITIONS

STALL SPEED IN A SPECIFIED CONFIGURATION (VS1)

It is the minimum steady flight speed at which the aeroplane is controllable under the following conditions:

• Propeller in takeoff position.

• Engine controls set at zero thrust.

• Specified configuration (the same for which the speed found will be used).

For single engined landplanes, VR must not be less than VS1.

SPEEDS: DEFINITIONSSPEEDS: DEFINITIONS

MAXIMUM LANDING GEAR EXTENDED SPEED (VLE)

It is the maximum calibrated airspeed at which the airplane can be safely flown with the landing gear extended. This is a problem involving stability and controllability.

MAXIMUM LANDING GEAR OPERATING SPEED (VLO)

It is the maximum calibrated airspeed at which the landing gear can be safely extended or retracted. This is a problem involving the air loads imposed on the operating mechanism during extension or retraction of the gear.

SPEEDS: DEFINITIONSSPEEDS: DEFINITIONS

MAXIMUM FLAP EXTENDED SPEED (VFE)

It is the highest calibrated airspeed permissible with the wing flaps in a prescribed extended position. This is because of the air loads imposed on the structure of the flaps.

MANEUVERING SPEED (VA)

It is the maximum speed at which the limit load can be imposed (either by gusts or full deflection of the control surfaces) without causing structural damage.

SPEEDS: DEFINITIONSSPEEDS: DEFINITIONS

MAXIMUM STRUCTURAL CRUISING SPEED (VNO)

It is the speed that should not be exceeded except in smooth air and then only when caution.

NEVER EXCEED SPEED (VNE)

It is the speed limit that may not be exceeded at any time. It is indicated by a red line in the airspeed indicator.

SPEEDS: DEFINITIONSSPEEDS: DEFINITIONS

VNE

VNO

VFE

VS

VS0

SPEEDS: DEFINITIONSSPEEDS: DEFINITIONS

ROTATION SPEED (VR)

The rotation speed VR is the speed at which rotation must be initiated

in order to attain V2 not later than at 50 ft.

SPEEDS: DEFINITIONSSPEEDS: DEFINITIONS

TAKEOFF SAFETY SPEED (V2)

The takeoff safety speed V2 is the speed that will allow the initial climb to be continued with a safe margin to stall. For single-engined aeroplanes (JAR 23), this speed is the higher of:

a) A speed that is shown to be safe under all reasonably expected conditions, including turbulence and complete engine failure.

b) V2 ≥ 1.2 · VS1

DISTANCESDISTANCES

DECLARED DISTANCES

TORA: Takeoff Run Available

TODA: Takeoff Distance Available

ASDA: Accelerate-Stop Distance Available

LDA: Landing Distance Available

Declared distances can be found in the AIP (AD section), and they are also included in the aerodrome charts.

DISTANCESDISTANCES

TORA (Takeoff Run Available)

It is the distance available as takeoff run, which is basically the length of the runway.

DISTANCESDISTANCES

TORA

DISTANCESDISTANCES

TODA (Takeoff Distance Available)

It is the TORA plus any clearway, which is an area beyond the runway, free of obstacles and under the Airport Authority Control. A typical clearway is the sea.

DISTANCESDISTANCES

TORA

CWY

TODA

DISTANCESDISTANCES

ASDA (Accelerate-Stop Distance Available)

It is the TORA plus any stopway. A stopway is an area beyond the runway which can be used for decelerating the aeroplane during an aborted takeoff, without the aeroplane being damaged.

Stopway CANNOT be used for landing calculations.

DISTANCESDISTANCES

STOPWAY

DISTANCESDISTANCES

SWY

TORA

ASDA

DISTANCESDISTANCES

LDA (Landing Distance Available)

It is the length of runway which is declared available and suitable for the ground run of an aeroplane landing.

It is also a declared distance, and it will be equal to the TORA if there is no displaced threshold. Stopways are not included in the LDA.

DISTANCESDISTANCES

TORA

LDA

DT

DISTANCESDISTANCES

CWY = 100 m

DISTANCESDISTANCES

NO SWY

DISTANCESDISTANCES

DISTANCESDISTANCES

DISTANCESDISTANCES

RWY

CWY

SWYDT

TORA

ASDA

TODA

LDA

TAKEOFF REQUIREMENTSTAKEOFF REQUIREMENTS

FIELD-LENGTH REQUIREMENTS

NO STOPWAY OR CLEARWAY TOD ≤ 0.8 · TORA

50 ft

Takeoff distance = 80 % TORA Safety margin

TAKEOFF REQUIREMENTSTAKEOFF REQUIREMENTS

FIELD-LENGTH REQUIREMENTS

TORA

SWY OR CWY AVAILABLE 0.77 · ASDA

0.87 · TODA

In other terms:

TOD ≤ TORA

1.30 · TOD ≤ ASDA

1.15 · TOD ≤ TODA

TOD ≤ the most restrictive of