Cross wind circuits tips

There is nothing more satisfying than landing on the spot you want to land on the runway and having a smooth landing except pulling off a safe cross wind landing when there is a howling gale across the runway.
My next comment may be a bit controversial, but so be it. When looking at the cross wind limit in the POH of an aircraft this is the demonstrated cross wind that was tested during the flight testing of the aircraft and is regarded as the cross wind limit in that aircraft for the average pilot. In my experience this is not the actual limit of the aircraft. So for example depending on the model of the Cessna 172 the limit is apparently 14 knots. However up to 27 knots you can hold the aircraft straight down the runway, but above that speed the aircraft will drift sideways with full rudder applied. To me this is the limit. And even in these circumstances by landing diagonally across a wide runway, such as the runway at Kemble, it is possible to land in an even higher cross wind. The problems start if you mess up and damage the aircraft. What will the insurance company say? I have spoken to an assessor and he was as expected fairly non-committal, but he did say that they do not have hard and fast rules about the numbers, and would look at the circumstances.
These cross wind limits do not tally at all and this confirms my experience. So for example most Pipers have a limit around 15 knots. Yet a similar configuration of aircraft like the Bulldog has a limit of 35 knots. The Tecnam SIRA has a limit of 22 knots, which considering it is so light is very high, but it is so controllable that I have not actually found a limit for it.
However it is all very well talking about numbers, but they mean nothing unless you can actually fly the aircraft safely in these conditions. That means going out with an instructor who is not only skilled enough to fly the aircraft, but is able to let the student fly the aircraft and make mistakes, and be able to recover if the student screws up too much. I once went out with a very good pilot to do circuits in the 172 with about a 25 knot cross wind. I demonstrated a circuit and landing which worked out well landing smoothly down the centre line. The student commented “That looks easy” After his first attempt, he then said “No it’s not!” But by his forth landing he had cracked it. Nearly everything is easy when you know how.
So how to do it? The first thing when going out in strong winds, no matter what direction they are, especially in high wing aircraft is being careful when taxiing. Taxi slowly. Check the aircraft manual and see what the recommended way to hold the controls is. The recommended way in Cessna’s is to dive away from a wind from behind, and climb up to one from the front. Diving away makes sense, as the wind is pushing down on the control surfaces. Climbing up to a wind could be a bit dodgy as if it is too strong there may be a danger of getting airborne if you are taxiiing too fast.
On line up, check the surface wind by looking at the windsock. Depending on the size of the sock you can get a good idea of the strength. All windsocks used to be large and when the sock was parallel to the surface, the wind was 30 knots, and if hanging down at 45 degrees from the horizontal, the wind 15 knots, and obviously if hanging limp there was no wind. The windsocks seem to be a bit smaller nowadays, so maybe the strength of the wind may only be 20 or 25 knots with a horizontal windsock. You can get to know what it is by checking your estimate with what the reported wind is at the airfield at the time. This is very useful as sometimes the reported wind could be very different from what the windsock is indicating in the approximate landing area, and this is what matters.
During the take off run what I find very useful is to hold the ailerons hard down into wind, assuming a very strong wind, not so critical if it is not very strong, but anything helps. So the stronger the wind the more you hold the wing down into wind. Also during the take off run, push the nose down with full forward elevator with a very strong wind. This helps to hold the aircraft firmly on the runway. Otherwise as the wing generates lift, and the grip of the tyres gets less, the aircraft starts to hop sideways. By holding the elevator fully down it is much easier to keep the aircraft running straight down the center line.
On reaching the normal rotate speed keep holding down the nose and on reaching initial climb speed, pull the aircraft sharply into the air. Be careful not to over rotate and hold the nose up too much, just unstick the aircraft sharply so there is no sideways drifting on the runway. At the same time start to roll the ailerons level, but also turn the aircraft into wind to allow for the drift. If possible while the runway is still in sight adjust the drift to stay in line with the runway centre line. This is not only good airmanship, but looks more professional to any watchers on the ground. Drifting rapidly to one side of the centre line does not look very good.
On the crosswind leg, check the runway and make sure you are tracking at right angles to it allowing for the wind. And if the wind is behind you perhaps turn downwind before reaching circuit altitude to avoid making a very wide circuit, and if it is towards you, then fly level for a while before turning. When joining the circuit on a normal rejoin, I fly the crosswind leg until the tailplane is in line with the runway. This can be used to judge the place to turn downwind on any runway anywhere. Use it in these conditions as well. On the downwind leg check for drift. The wind will be stronger up at circuit level so more drift will be needed than needed on initial take off, but that drift is a good starting place. Just adjust your heading to fly a parallel track to the runway.
On the base leg, depending on the aircraft type and the normal way of setting up an approach, the wind is going to affect when the aircraft is configured. So for example on most light training aircraft with no wind, I teach to pull the power back to 1500 RPM and set half flap when the chosen landing point is at 45 degrees between the nose and leading edge of the wing. Due to the drift angle if the power is pulled back at the same 45 degrees, the power will come off closer to the runway if there is a strong wind down the runway. This is what is wanted, there is no point in reducing power too early and having to use a lot of power to maintain height on final. However with a strong crosswind there is another consideration. If the wind is behind you then you need to configure the aircraft and start descending early. Conversely if it is against you, then leave this till later. When turning onto final, with the wind behind you start your turn early and keep turning to set up the approximate drift angle on reaching the extended centerline and let the wind push you onto final. There is a lot of turning required to do this compared to a calm day. If the wind is against you, leave the turn till almost on the center line. This does not require much of a turn in any case due to the drift angle into wind.
On final the type of approach depends on the type of landing you are going to do. I like the crab approach with a sideslip landing after lining up on the center line. If a side slip is chosen all the way down on final, there is constant adjustment needed as the wind strength drops off. I like to get my students to do this a couple of times to get the feel of the sideslip hold off, and also to see the difference between this approach and the crab approach. Don’t forget that with any strong wind allow extra speed to compensate for any wind shear. An approximate amount is to add half the wind speed to the approach speed when the wind gets above 10 knots. And especially with high wing aircraft do not use too much flap. So with a very strong crosswind it may be worth landing with no flap if the runway is long enough, but in any case in something like a Cessna 172 do not land with more than 20 degrees of flap. Using too much flap causes an unstable approach and potential problems on the hold off.
Now going back to the approach and landing. I like to approach using the crab method of turning into wind and compensating for drift all the way down the approach. Then when you think you are about to hit the runway, if you are very skilled and know your aircraft, kick is straight just as is is about to touch down. However this is difficult to judge if the wind is gusty. So I prefer to kick it straight then stay on the centerline using the rudder to keep the aircraft pointed straight down the runway centreline as though you are taxiing, and using enough bank to stay on the centerline with aileron almost as though you are steering a car. If you can hold off in this way, do not try to hold off for too long, but as soon as the aircraft is stable let it sink on to the runway firmly with the upwind wheel touching down first, then lower the other wing and as that wheel touches down lower the nose and then immediately hold the nose down hard and turn hard into wind with full down aileron as described for the take off to hold the aircraft onto the centerline. Holding the aileron into wind especially is very effective to keep control. If you forget to do this then with a high wing aircraft it is easy for the wind to get under the wing and lift if up potentially causing a loss of control.
Finally how are you going to know what to expect with the effect of the wind? It is necessary to be able to quickly work out the actual cross wind to see whether you are within the aircraft’s demonstrated crosswind limit, and to make sure the wind is within your own limits and the actual limit of the aircraft.
If the wind strength is below the demonstrated crosswind limit in any direction, then the average pilot is not going to have any problem unless it is gusty. But in any case it is nice to know the limit. There are several ways of doing this. In any case look at the windsock and judge the angle that the wind is off the runway, and if you are given a wind direction and strength, check the direction on the DI and work out the angle between the wind and the runway direction.
The RAF way of calculating the actual cross wind is to use the clock method. They assume that any wind more than 60 degrees off the runway is all cross wind. Then using an analogue clock face, the number of degrees off the runway is matched with the number of minutes past the hour. Then depending how far round the clock face this is, the proportion of the way round the clock face relates to the proportion of the wind strength that is cross wind. So for example on runway 27 if the wind is 250/20 knots, the difference between the runway heading and the wind direction is 20 degrees. 20 degrees equates to 20 minutes, which is 1/3 of the way round the clock face, so the crosswind is 1/3 of 20 which is approximately 7 knots.
The other method is to use sines. For this I imagine an angle of 30, 45, 60 and 90 degrees from the centerline of the runway. Obviously if the wind is straight down the runway there is no cross wind, and if it is at 90 degrees to the runway then it is all cross wind. But how to work out the angles in between? Simple, 30 degrees is .5 or half the wind strength, 45 degrees is .7 or roughly 3/4 the wind strength, and 60 degrees off is .9 or nearly all the wind strength.

How to calculate a cross wind.

How to calculate a cross wind.

Doing the sums is very simple if you learned your multiplication tables when you were at school. More difficult if not. But remembering the approximate angle related to the approximate cross wind is enough. The wind is never constant so I always take the wind to the nearest 10 knots. Then for example if the wind is 30 degrees off the runway at 30 knots a quick multiplication of .5 X 30 ( 5 threes are 15) or half the wind strength is 15, the cross wind is 15 degrees. At 45 degrees .7 X 30 ( 3 sevens are 21) or about 3/4 of 30 gives us a 21 knot crosswind. I like this as you can also use it to work out head wind and tail winds to get a groundspeed by reversing the decimal points. So a wind on the nose is all headwind, and at 90 degrees there is no headwind.