Question

A runway is being constructed in a new airport as per the international Civil Aviation Organization (ICAO) recommendations. The elevation and the airport reference temperature of the airport are 535 m above the mean sea level and $22.65{}^{o}C$, respectively. Consider the effective gradient of runway as 1%. The length of the runway required for a design-aircraft under the standard conditions is 2000 m. Within the framework of applying sequential corrections as per the ICAO recommendations, the length of runway corrected for the temperature is

• A. 2500 m
• B. 2750 m
• C. 2223 m
• D. 2250 m

Answer 1

The correct option is A 2500 m

Correction for elevation;
7% increase per 300 m
So, correction $=\frac{7}{100}\times \frac{535}{300}\times 2000=249.66m$
Corrected length $=2000+249.66=2249.66m$
Correction for temperature :
Standard atmospheric temperature
$=15-0.0065\times 535={11.5225}^{o}C$
Rise of temp,$={22.65}^{o}C-{11.523}^{o}C={11.127}^o$
Correction $=\frac{2249.66}{100}\times 11.127=250.320m$
Correct length $=2249.66+250.320=2499.98m$
Check for total correction for elevation plus temperature
Total correction %$=\frac{2299.98-2000}{2000}\times 100=24.99$
According to ICAO, this should not exceed by 35%