AIM

4/20/23

4

−

3

−

9

Airport Operations

Supplement U.S. For runways without published declared distances, the declared distances may be assumed to
be equal to the physical length of the runway unless there is a displaced landing threshold, in which case the
Landing Distance Available (LDA) is shortened by the amount of the threshold displacement.

NOTE

−

A symbol 

 is shown on U.S. Government charts to indicate that runway declared distance information is available (See

appropriate Chart Supplement U.S., Chart Supplement Alaska or Pacific).

(a)

The FAA uses the following definitions for runway declared distances (See FIG 4

−

3

−

5):

REFERENCE

−

Pilot/Controller Glossary Terms: “Accelerate

−

Stop Distance Available,” “Landing Distance Available,” “Takeoff Distance Available,” “Takeoff Run

Available,” ” Stopway,” and “Clearway.”

(1)

Takeoff Run Available (TORA) – The runway length declared available and suitable for the ground

run of an airplane taking off.

The TORA is typically the physical length of the runway, but it may be shorter than the runway length if necessary
to satisfy runway design standards. For example, the TORA may be shorter than the runway length if a portion
of the runway must be used to satisfy runway protection zone requirements.

(2)

Takeoff Distance Available (TODA) – The takeoff run available plus the length of any remaining

runway or clearway beyond the far end of the takeoff run available.

The TODA is the distance declared available for satisfying takeoff distance requirements for airplanes where the
certification and operating rules and available performance data allow for the consideration of a clearway in
takeoff performance computations.

NOTE

−

The length of any available clearway will be included in the TODA published in the entry for that runway end within the
Chart Supplement U.S.

(3)

Accelerate

−

Stop Distance Available (ASDA) – The runway plus stopway length declared available

and suitable for the acceleration and deceleration of an airplane aborting a takeoff.

The ASDA may be longer than the physical length of the runway when a stopway has been designated available
by the airport operator, or it may be shorter than the physical length of the runway if necessary to use a portion
of the runway to satisfy runway design standards; for example, where the airport operator uses a portion of the
runway to achieve the runway safety area requirement. ASDA is the distance used to satisfy the airplane
accelerate

−

stop distance performance requirements where the certification and operating rules require

accelerate

−

stop distance computations.

NOTE

−

The length of any available stopway will be included in the ASDA published in the entry for that runway end within the Chart
Supplement U.S.

(4)

Landing Distance Available (LDA) 

−

 The runway length declared available and suitable for a

landing airplane.

The LDA may be less than the physical length of the runway or the length of the runway remaining beyond a
displaced threshold if necessary to satisfy runway design standards;for example, where the airport operator uses
a portion of the runway to achieve the runway safety area requirement.

Although some runway elements (such as stopway length and clearway length) may be available information,
pilots must use the declared distances determined by the airport operator and not attempt to independently
calculate declared distances by adding those elements to the reported physical length of the runway.

(b)

The airplane operating rules and/or the airplane operating limitations establish minimum distance

requirements for takeoff and landing and are based on performance data supplied in the Airplane Flight Manual
or Pilot’s Operating Handbook. The minimum distances required for takeoff and landing obtained either in
planning prior to takeoff or in performance assessments conducted at the time of landing must fall within the
applicable declared distances before the pilot can accept that runway for takeoff or landing.