airport/documents/Mesquite Master Plan Final.pdf - The City of ...

AIRFIELD ALTERNATIVE 1
Alternative 1, depicted on Exhibit 4C,
considers the recommended
development concept of the previous
master plan. As depicted, this
alternative proposed the extension of
Runway 17-35 1,370 feet to the south,
achieving a pavement length of 7,370
feet. This extension, in conjunction
with a three-quarter-mile visibility
minimum for Runway 35, is the
maximum length available when
considering meeting all safety area
standards, as the RSA and OFA would
remain on existing airport property and
the southern RPZ is capable of being
free of incompatible land uses.
As discussed, the previous RSA
standard required 1,000 feet prior to the
runway and beyond the far end of the
runway for critical aircraft in ARC C/D-
II. In order to accommodate this
standard, the north end of the runway
was recommended to be displaced by
370 feet. Displacing a threshold for
limited RSA requires the application of
declared distances. Declared distances
are the effective runway distances that
the airport operator declares available
for take-off run, take-off distance,
accelerate-stop distance, and landing
distance requirements. These are
defined by the FAA as:
Take-off run available (TORA) - The
length of the runway declared available
and suitable to accelerate from brake
release to lift-off, plus safety factors.
Take-off distance available (TODA)
- The TORA plus the length of any
4-11
remaining runway or clearway beyond
the far end of the TORA available to
accelerate from brake release past liftoff
to start of take-off climb, plus safety
factors.
Accelerate-stop distance available
(ASDA) - The length of the runway plus
stopway declared available and suitable
to accelerate from brake release to takeoff
decision speed, and then decelerate
to a stop, plus safety factors.
Landing distance available (LDA) -
The distance from threshold to complete
the approach, touchdown, and
decelerate to a stop, plus safety factors.
The ASDA and LDA are the overriding
considerations in determining the
runway length available for use by
aircraft because safety areas must be
considered. The ASDA and LDA can be
figured as the useable portions of the
runway minus the area required to
maintain adequate RSA and OFA
beyond the end of the runway.
With the predominant wind direction
being from the south, a 1,370-foot
extension was necessary, as
recommended in the previous plan, to
provide at least 7,000 feet of operational
length for landings and take-offs in both
directions. The new FAA standard calls
for only 600 feet for RSA prior to
landing. As a result, there is no longer
a need to displace the north end
threshold for landing operations to
Runway 17. In this alternative, the
operational length available for
ASDA/LDA calculations utilizing
Runway 17 would be 7,370 feet.