Arlington Municipal Airport Development Plan Arlington Airport Development Plan | Page 174
RPZ incompatibilities to the runway environment. Declared distances are the effective runway length
that the airport operator declares available for takeoff run, takeoff distance, accelerate‐stop distance,
and landing distance requirements. Pilots utilize these measurements in their runway length calcula‐
tions. The four declared distances are defined as the following:
Takeoff run available (TORA) ‐ The length of the
Alternative 2 includes a 700‐foot nor‐
runway declared available and suitable to accel‐
erate from brake release to lift‐off, plus safety
therly extension to Runway 16‐34 and
factors.
proposes a displaced landing threshold
and the use of declared distances in or‐
Takeoff distance available (TODA) ‐ The TORA
der to mitigate RSA and RPZ incompat‐
plus the length of any remaining runway or
ibilities to the runway environment.
clearway beyond the far end of the TORA availa‐
ble to accelerate from brake release past lift‐off,
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 take‐off decision speed, and then decelerate to a stop,
plus safety factors.
Landing distance available (LDA) ‐ The distance from the threshold to complete the approach, touch‐
down, and decelerate to a stop, plus safety factors.
The TORA and TODA are often equal to the actual runway length. The ASDA and the LDA are the pri‐
mary considerations in determining the runway length available for use by aircraft, as these calcula‐
tions must consider providing the full RSA and ROFA to standard in operational calculations. The ASDA
and LDA can be figured as the usable portions of the runway length less the distance required to main‐
tain adequate safety areas beyond the ends of the runway or prior to the landing threshold. By regula‐
tion, a full 1,000 feet of RSA and ROFA must be available at the far end of a departure operation in the
ASDA calculation. For LDA calculations, 600 feet of RSA and ROFA is required prior to the landing
threshold, and 1,000 feet of RSA and ROFA is required beyond the far end of the landing operation.
In contrast to the previous alternative, a 700‐foot displaced threshold is proposed on Runway 16. Ac‐
cording to AC 150/5300‐13A, Change 1, a runway’s threshold is located to provide proper clearance for
landing aircraft over existing obstacles while on approach to landing. Runway thresholds can be dis‐
placed to provide:
1) A means for obtaining RSA prior to the threshold;
2) A means for obtaining additional ROFA prior to the threshold;
3) A means for locating the RPZ to mitigate unacceptable incompatible land uses; and
4) Mitigation of environmental impacts.
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