Selecting the proper runway for landing is a fundamental skill in flight training and aviation decision-making. One of the most important factors in that decision is wind direction, which pilots must assess accurately in order to ensure a safe landing. Here’s a great video from Martha King explaining this concept in detail.
Reading the Wind Indicator: The Tetrahedron
In some cases, the FAA may present you with a diagram and ask, “Which runway would you land on, and where is the wind coming from?” To answer this, you’ll need to interpret a common airport wind indicator: the tetrahedron.
A tetrahedron resembles a delta-wing aircraft, and its nose always points into the wind. In the example provided, the tetrahedron is pointing toward the southwest, meaning the wind is coming from the southwest.
Ideal Runway Alignment With the Wind
To minimize the aircraft’s ground speed and ensure better control, pilots should land into the wind whenever possible. With a southwest wind, the most aligned runway would be Runway 22, since it corresponds closely with a 220° heading.
However, Runway 22 is marked with Xs, indicating it is closed and not usable. This is a critical part of interpreting runway availability and status from an airport diagram. Even though Runway 22 would offer a headwind, it’s not an option due to its closure.
Choosing the Next Best Runway
With Runway 22 unavailable, the next consideration is finding a runway that is still as close to the wind direction as possible. Since the wind is from the southwest, and you want to land into the wind, you must choose between Runway 18 or Runway 36.
Runway 18 has a magnetic heading of 180°, meaning you would be landing southbound.
Runway 36 would have you landing northbound, with a tailwind.
The correct choice is Runway 18, because it gives you a headwind component, which is safer and more desirable for landing compared to a tailwind.
Crosswind Considerations
Landing on Runway 18 with wind from the southwest also introduces a crosswind. The wind is not perfectly aligned with the runway, so the aircraft will experience lateral force during approach and landing.
In this case, since the wind is from the southwest and the aircraft is heading south (180°), the crosswind will come from the right side of the aircraft. Pilots must be prepared to apply appropriate rudder and aileron corrections to maintain alignment with the runway centerline.
Avoiding Other Unsuitable Runways
Some airport diagrams may show other closed runways or poorly marked surfaces. Even if a runway appears physically intact, faded or incomplete markings are a signal that the surface is not suitable for landing. Always check runway markings and NOTAMs to verify the operational status of a runway.
Summary
Use the tetrahedron to determine wind direction—it points into the wind.
Aim to land into the wind for safer, slower landings.
Runway X markings indicate the surface is closed and not usable.
When the ideal runway is closed, choose the next best option aligned into the wind.
In this case, Runway 18 is preferred, providing a headwind with a crosswind from the right.
Avoid runways with unclear or degraded markings.
