If it’s a plane with good control authority, e.g. something aerobatic, you can counteract very strong crosswinds with a slip. If it has limited control authority, you’d more likely use a crab. If it has something in between, you can slip enough to counteract e.g. 20 knots of crosswind and crab to take out the rest until it is gone due to proximity to the ground. Or start your final approach laterally displaced from the runway, let it drift into line and see how the slip works when you closer to the ground.
Overall I think it’s better to use your brain versus flying by formula: all you have to do on approach is get it to the end of the runway by whatever means, and then you reconfigure as required to eliminate any crab before touchdown. At that point if you can’t keep it aligned with the runway axis without crabbing or dragging a wingtip, then you need to find another runway. And while it’s not generally advisable, some planes (e.g. airliners and Ercoupes) can be landed in a crab by design.
@UdoR I should have guessed what you meant by cross rudder. But I thought maybe it was something I hadn’t heard of.
I think the straightening in the flare and applying into wing aileron at the same time ie 3 things at the same time pedal, pull back a little on stick and apply a little into wing aileron all at the same time. There’s a feel to getting it right which is very satisfying and touch down is with no skid or slip.
It might be that my early flying days were on planes with a stick. The Robin for instance is not as sensitive to the amount of aileron deflection as many other aircraft. In fact when you de crab and apply into wind aileron you can just about apply full aileron and leave it there until you stop. I haven’t tried a 40kt crosswind in the Super Guépard yet and I think if I were to need to I would shape up diagonally across the runway.🙂 But I think I would need to build up to it a few knots at a time. At the moment I am at half that without particular problem. And that is on grass.
One of the club rules is to demonstrate a crosswind landing with instructor once a year. This was started following a member damaging the landing gear due to a bad crosswind landing and doing €3000 worth of damage.☹
The advantage of crabbing all the way to the runway is that you get an indication of whether the crosswind component will be excessive, all the way down.
If you are at 20ft and the plane is still pointing 45 degrees off, then that’s not so great 
If it’s a plane with good control authority, e.g. something aerobatic, you can counteract very strong crosswinds with a slip.
That’s why I gave my today’s approach as an example – I can’t imagine slipping in 40 kts of crosswind, regardless the authority available.
Or start your final approach laterally displaced from the runway, let it drift into line and see how the slip works when you closer to the ground.
I’m not sure this is appreciated technique during instrument approach.
Silvaire wrote:
Overall I think it’s better to use your brain versus flying by formula
That includes considering all the techniques appropriate to the plane, the operation and the skill level of the pilot. And downselecting to the one of likely several possibilities that works best.
it’s better to use your brain
That helps in general 
Emir wrote:
it’s better to use your brainThat helps in general
But not for crosswind landings.
It’s about getting the feeling for it. A standard brain is not capable of prethinking the movements and coordination necessary to perform a crosswind landing, let aside a gusty crosswind landing. It’s hand-eye-coordination and feeling. That equals to experience and training.
What I actually said twice was:
Silvaire wrote:
I think it’s better to use your brain versus flying by formula
Obviously that includes using the parts of your brain that allow you to exercise a selected method/technique due to experience and training.
gallois wrote:
So when you arrive at your destination and the controller gives you the wind speed using Vw which has just been given you and multiplying that by you Fb which you know will give you a maximum. If this is above your crosswind limits instead of tormenting your brain at a critical time you can have time to go away and either land elsewhere or just do some recalculations. If the maximum is below your crosswind landing limits then you know you are okay.
This is where you lose me. Assume the POH says max crosswind 25 kt (let’s forget for a moment that a demonstrated crosswind is not a limit – that’s not relevant for this discussion). You are flying the approach at 100 kt (i.e. Fb = 0.6) and ATC gives the wind as 30 kt (i.e., Vw = 30) at right angle to the runway. You seem to say that as Vw x Fb = 18 which is less than 25, it is ok to land. That’s obviously not true, so that can’t be what you actually mean.
“It’s about getting the feeling for it. A standard brain is not capable of prethinking the movements and coordination necessary.”
Yes! And currency.
I think Mass has an effect on technique used – I find I crab and de-crab a Pa28 but sideslip a Jodel to touchdown. I always crab till near the threshold.
Returning to Inverness EGPE there’s usually no option to divert, as there’s no VFR alternate both near enough and better. Fortunately there are 2 runways.
At the limit, the⁰ runway must be smooth to avoid getting airborne again in a gust at too low speed to control.
