background image

AIM

10/12/17

4−3−9

Airport Operations

(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

3/29/18

AIM

3/29/18

AIM