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6/17/21 

AIM 

(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

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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 

Airport Operations 

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