Runway length required under standard conditions is 1500 m then actual elevation of the site is 1100 m above M. S. L Runway length corrected for altitude will be

Basic runway length is based on some assumptions:-

a) Derived at Mean Sea level

b) Derived for a standard temperature of 15°C

c) The gradient must be zero.

The actual runway need not follow all these guidelines and hence we must apply some corrections.

The sequential correction is applied in the basic runway length.

The first correction is altitude correction, the second correction is temperature correction and the last correction is gradient correction.

Altitude Correction:

Basic runway length is increased by 7% for every 300 m rise above mean sea level.

This is done due to the decrease in drag force on the aircraft owing to the decrease in density of air as the altitude increases.

Given:

Height above MSL = 1100 m, and Basic Runway length = 1500 m

After applying elevation correction,

\({\rm{Correction}} = 1500 \times \frac{7}{{100}} \times \frac{{1100}}{{300}} = 385{\rm{\;m}}\)

Corrected Runway Length = 1500 + 385 = 1885 m

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