Question

The length of runway under standard conditions is 2000 m. The elevation of airport site is 300 m. Its reference temperature is 33.05${}^o$C. If the runway is to be constructed with an effective gradient of 0.25%, the corrected runway length will be _______m.

• A. 2696.4

Answer 1

The correct option is A 2696.4
For standard conditons,

Length of runway = 2000 m

Correction for elevation $=\frac{7}{100}\times 2000\times \frac{300}{300}$
= 140 m

$\therefore$ Corrected length of runway = 2000 + 140 = 2140 m
Standard atmospheric temperature at given elevation = 15 - 0.0065 $\times$ 300
= 13.05${}^o$C
$\therefore$ Correction for temperature $=\frac{2140}{100}\times (33.05-13.05)=428$ m
$\therefore$Corrected length of runway = 2140+428=2568 m

Correction for gradient $=\frac{20}{100}\times 2568\times 0.25=128.4m$

$\therefore$ Corrected length of runway = 2568 + 128.4 m

= 2696.4 m