(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 considera-
tion 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.
(c) Runway design standards may impose
restrictions on the amount of runway available for
use in takeoff and landing that are not apparent
from the reported physical length of the runway or
from runway markings and lighting. The runway
elements of Runway Safety Area (RSA), Runway

Object Free Area (ROFA), and Runway Protection

Zone (RPZ) may reduce a runway's declared

distances to less than the physical length of the

runway at geographically constrained airports (See

FIG 4-3-6). When considering the amount of

runway available for use in takeoff or landing

performance calculations, the declared distances

published for a runway must always be used in lieu

of the runway's physical length.

REFERENCE-
AC 150/5300-13, Airport Design

(d) While some runway elements associated

with declared distances may be identifiable through
runway markings or lighting (for example, a
displaced threshold or a stopway), the individual
declared distance limits are not marked or otherwise

identified on the runway. An aircraft is not

prohibited from operating beyond a declared

distance limit during the takeoff, landing, or taxi
operation provided the runway surface is appropri-
ately marked as usable runway (See FIG 4-3-6). The