I don't own a Mooney, yet. I came across this thread looking to see if there was a posted crosswind limit in the POH. I have flown, and instructed, in several aircraft in the Air Force. Looking to purchase a Mooney, and it's windy in the places I live and hope to fly to. Hence, my search here. And I realize this is an old post, but just in case anyone else comes here for the same, or similar, reason, I thought I'd elaborate on crosswind limits. Some of what has been said is accurate, some is just missing the rest of the picture.
As mentioned by at least one comment above, for an approach and landing in a crosswind, there is the wing low method. As it was taught to me, and the way I continue to teach, is in a crosswind, you use the rudder to align the nose (to centerline, parallel to the runway) and use aileron to kill the drift. In that order. In effect, this is a slip. Also keep in mind that in so doing you are introducing a lot of drag, so be prepared to add power to compensate. Remember, for short field approaches, (usually to clear an obstacle), you slip the aircraft. This adds a lot of drag which is why you are able to increase descent rate. And If the wind is still strong enough when you get into the ground effect, you will be landing on the upwind main first.
Any aircraft has a limit to what it can handle in terms of crosswind, and it's irrespective of pilot's ability. Also, it's not simply a limit of control authority. One limit is rudder authority. As others have said, if you are in a crosswind, and don't have enough rudder authority to align the nose, you have exceeded the limits of the aircraft. The other is not only aileron authority, but you are limited to wingtip ground clearance. You could be in a crosswind so strong that, even though the nose is aligned using the rudder, your wing might be so low that it contacts the ground on landing. On a KC-135, when they put the new engines on it, the new engines were so much larger than the old ones, that the aircraft crosswind limits were reduced due to the fact that the wing low method in high crosswinds would result in the inboard engine striking the ground.
If you come in on an approach, and there is a crosswind, you step on the rudder to align the nose. And for a second, if you have enough authority, all is well. But if you do nothing else, the aircraft is going to drift. So you bank into the wind. Thus, the wing-low method. And this might be okay, until you are close to the ground. Remember, of the three primary control surfaces, the most effective is the rudder, followed by elevator(s), then ailerons. So you might have enough rudder to align the nose, and you might still have enough aileron to kill the drift, but do you have enough ground clearance on the upwind wingtip?
Flying faster. As mentioned, flying faster gives more rudder authority, but it gives more authority on all the control surfaces. So this only half of the equation. The other half of this equation is if you are flying faster, you are crabbing less, and less rudder is required to actually align the nose. And for those that just resort to flying faster, like really faster, well, that was mentioned above, and that will just result in floating, increasing time exposed to the crappy wind you are trying to get out of! If the above method can't be done at a no-flap approach speed, plus 1/2 of your gust factor if there is one, you have exceeded the limits.
