provided the runway surface is appropriately marked
as usable runway (See FIG 4-3-6). The following
examples clarify the intent of this paragraph.
REFERENCE-
AIM, Paragraph 2-3-3 , Runway Markings
AC 150/5340-1, Standards for Airport Markings

EXAMPLE-
1. The declared LDA for runway 9 must be used when
showing compliance with the landing distance requirements of the applicable airplane operating rules and/or
airplane operating limitations or when making a before
landing performance assessment. The LDA is less than the
physical runway length, not only because of the displaced

4-3-10

threshold, but also because of the subtractions necessary
to meet the RSA beyond the far end of the runway. However,
during the actual landing operation, it is permissible for
the airplane to roll beyond the unmarked end of the LDA.
2. The declared ASDA for runway 9 must be used when
showing compliance with the accelerate-stop distance
requirements of the applicable airplane operating rules
and/or airplane operating limitations. The ASDA is less
than the physical length of the runway due to subtractions
necessary to achieve the full RSA requirement. However, in
the event of an aborted takeoff, it is permissible for the
airplane to roll beyond the unmarked end of the ASDA as
it is brought to a full-stop on the remaining usable runway.

Airport Operations