One of the most challenging flight situations for pilots is the crosswind landing. It’s a bit worrisome when you approach your destination and find the winds of 23 knots, and 50 or 60 degrees (or even more) off course. Well, depending on the aircraft that is operating the landing can become more stressful, especially if you are at times without practicing this situation, or even is a pilot student in initial training.
When we talk about crosswind landing situations, we basically have two approaches: crab or the ‘wing-low’ technique. However both methods have advantages and disadvantages.
The technique is simple: just point the nose of your aircraft to the side where the wind comes, shifting your nose a few degrees from the course. This will prevent your aircraft from drifting to the left or right of the center line. Basically, we keep this configuration during all approach, and shortly before landing, we step on the rudder to align the nose with the lane and we use the ailerons to avoid drifting with the wind.
The crab technique is the simplest but requires attention and perfect timing to align the aircraft just before the touch. This technique is a good request, as it applies to both single-piston and commercial jets.
But of course, each aircraft has its peculiarities with respect to the inertia of the alignment. We should stick to the condition at the moment. This technique requires a greater dominance of the aircraft, since it involves a sudden change of configuration at low altitude, and a gust accompanied by an inattentive pilot can generate a CFIT (Controlled Flight Into Terrain), or in the good Portuguese, collision with the ground in controlled flight.
The wing-low method is one of the easiest ways to achieve a beautiful landing touch with crosswind, that is, most cases in light aircraft. To do this is simple: you use your rudder to align the nose with the lane, and the ailerons to correct drift left or right, throughout the final trajectory. Essentially, you are glissando laterally.
This method can become a bit complicated because the intention is to cross commands in order to stay in line with the track. When it’s starting, it’s a bit difficult to understand the functionality of each item but over time and improvement is understood:
- Look for track alignment with the rudder;
- Use the ailerons to drift left or right;
This technique is also ideal to keep the axle in takeoff with crosswind. However this technique has a very important detail: when the aircraft begins to decelerate, the flight commands become less effective. This is because essentially there is no more airflow passing through them. This will make you have to apply more rudder to keep in line with the lane, and then aileron to keep the wing low, preventing windward lift wings.
‘You’re going to want to kiss the ground … just a little bit’
Who has watched the animation Madagascar 2 remembers the emblematic scene of the penguins landing their (pseud) Douglas DC-3. The touch of a wing-low trajectory can become a real disaster depending on weather conditions.
Soon the correct touch sequence is:
- Touch the wheel of the landing gear on the side of the low wing, where the windward occurs;
- Touch the high wing landing gear wheel;
- Then.. Touch the nose landing gear wheel;
- Control the aircraft of the runway with the rudder, maintaining the application of aileron;
On the ground
The yaw provided by the crosswind can get you off track, so it is very important to maintain the ailerons’ continuous and slow deflection as the aircraft travels the track in deceleration. The goal is that in full stop of the aircraft, the aileron is completed deflected to the wind side. This makes your aircraft firmer on ground, even preventing bursts from pulling you off the ground again, or your ground control.
What is the safe speed for a crosswind landing?
According to the FAA, aircraft should be controllable with little degree of expertise or additional concentration on the part of the pilots, in 90 degree crosswind, at a velocity equal to 0.2 Vso (Stall Speed / Minimum Speed in Landing Configuration).
This means that when the wind speed has at least 20% of the speed of loss of the airplane, with landing gear and flaps lowered (according to the FAA) you must present an exceptional degree of ability to safely land the aircraft.
However common sense is essential: if you are flying and it is impossible to keep your nose aligned using the techniques above, the conditions will be well beyond the capabilities of the aircraft, and why not yours. If this is the case, choose a more favorable lane, or even a different aerodrome.
Remember: “A great driver is one who avoids the conditions that a good driver can get out of.”
Flaps: use or not use, that’s the question …
When landed with a crosswind, flaps generally help stabilize the aircraft, making landing and touch easier. Whoever has landed without a flap, whether by choice or even necessity, knows how hard it is to get a hand.
One of the few days you will not want to use ‘full flap’ is on days of gusts of wind. The use of less flap helps us with two advantages: a higher pitch that helps us to stabilize the speed, and have fewer attitude changes until the touch, and a landing with a speed slightly above, which will give you greater ground control after the touch.
Fly safe, folks.