Best Direction of Runway

The best direction of a runway is determined by several factors, including wind conditions and geographical considerations. Among the given options, the correct answer is option 'A' - along the direction of the longest line on the wind rose. Let's understand why this is the best choice:

1. Wind Rose
A wind rose is a graphical representation of the frequency and strength of wind from different directions over a specific period. It provides valuable information about prevailing wind patterns and helps in determining the best runway direction.

2. Importance of Wind Direction
The direction and speed of the wind are crucial factors in aviation. Pilots prefer taking off and landing into the wind as it provides better control and reduces the groundspeed during these critical phases of flight.

3. Runway Alignment
The alignment of a runway should be in the direction that minimizes the crosswind component, which is the perpendicular component of the wind blowing across the runway. This reduces the risk of a crosswind affecting the aircraft's stability during takeoff and landing.

4. Longest Line on Wind Rose
The longest line on the wind rose represents the most frequent wind direction in that specific area. Aligning the runway along this direction ensures that the maximum number of aircraft operations can be conducted with minimal crosswind component.

5. Safety and Operational Efficiency
By aligning the runway with the predominant wind direction, pilots can take off and land with a headwind or tailwind, which enhances both safety and operational efficiency. A headwind increases the aircraft's lift, reducing the required takeoff speed, while a tailwind can help reduce the landing distance.

Conclusion
In conclusion, the best direction of a runway is determined by the wind conditions, and aligning it with the longest line on the wind rose ensures optimal safety and operational efficiency. This alignment minimizes the crosswind component and allows pilots to take advantage of headwinds or tailwinds during takeoff and landing.