1 and 2 are correct
2 and 3 are correct
1 and 3 are correct
1, 2 and 3 are correct
Answer is Right!
Answer is Wrong!
The correct answer is D. 1, 2 and 3 are correct.
ICAO recommendation for correction to basic runway length is as follows:
- The basic runway length should be increased at the rate of 7 percent per 300 m rise in elevation above the mean sea level.
- The basic runway length after having been corrected for elevation should be further increased at the rate of 1 percent for every 1°C rise in airport reference temperature above the standard atmospheric temperature at that elevation.
- The runway length after having been corrected for elevation and temperature should be further increased at the rate of 20% for every 1 percent of effective gradient.
The following are the reasons for these corrections:
- The higher the elevation, the thinner the air and the less lift the aircraft can generate. This means that the aircraft will need a longer runway to take off and land.
- The higher the temperature, the less dense the air and the less lift the aircraft can generate. This means that the aircraft will need a longer runway to take off and land.
- The effective gradient is the slope of the runway from the beginning to the end. A higher effective gradient means that the aircraft will need to accelerate more quickly in order to take off and land. This means that the aircraft will need a longer runway.