Takeoffs are “easier” because you are gaining speed which is makes crosswind less and less relevant, but surely one would expand the crosswind envelope if one lifted off one wing, once moving fast enough?
Indeed you may take off on one wheel in a crosswind in most light tailwheel aircraft. Crosswind takeoff roll starts with the aileron fully into the wind. If there’s enough of a crosswind you might roll on one wheel for a short time before you lift off, and you keep enough aileron in to continue on one wheel till you get flying speed.
I have been behind a Supermunk accelerating on 1 wheel before take-off.
Peter wrote:
Takeoffs are “easier” because you are gaining speed which is makes crosswind less and less relevant…
Also, at least in singles, the slipstream gives you better rudder authority.
I don’t understand the question. Why should anything be wrong with taking off on one wheel? I once made some >30 knots crosswind training sessions in a microlight. It’s practically impossible to get airborne with all wheels at the same time, if you want to stay on runway centreline.
Normally you don’t “emphasize” or “do” this because it’s simply not as necessary as during landing. Once airborne you put the nose into wind and that’s it.
During landing, to the contrary, you point the nose along the runway heading, which (in strong winds) necessitates crossed rudders and the wing low which points into the wind, in order to keep the roll axis of the aircraft parallel (or identical to) the runway centreline. This is not as such “necessary” during takeoff.
Airborne_Again wrote:
Also, at least in singles, the slipstream gives you better rudder authority.
Although in a tailwheel plane, you still want to avoid side loading the gear, so the one wheel technique is quite important.
I’ve done a few BFRs with Texas Taildraggers (I also did my checkride at this airport) based at Houston Southwest, whose runway direction means they always have a crosswind (the runway is 09/27 with a prevailing wind out the south/southeast). An exercise you’ll always do there when doing your tailwheel BFR is to get the tailwheel up, reduce power, and roll on one wheel for about 3/4 the length of the runway while keeping the plane on the ground. It provides much more practise in one go of doing crosswind correction.
Never had a think about it 
but it’s easier as you start on center-line and you don’t have to narrowly maintain it after lift-off?
Much easier than having to maintain the cent-reline while on approach, during flare and ground roll and being able to stop in the middle of the runway
It’s different if there are trees ahead and runway is short with turbulence around: I think crosswind limit on takeoff is way less than crosswind on landing
Next question why takeoff is easier than landing?
It’s not a limit. It’s just a figure for which landing in that crosswind speed has been demonstrated.
There is no legal reason AFAIK why you can’t land or take off in higher crosswind. On the other hand your insurance company might take a different view.
maybe that’s why…
I do one wheel takeoffs (and landings) regularly, and was training a colleague to do them on Monday in his new Decathlon. Indeed, lifting one wheel off first can be very helpful in soft ground, and can be vital for float or ski plane takeoffs.
It is rare that the crosswind is “limited” for a type. It’s most commonly "demonstrated, and not limiting. I have never seen an airplane for which the demonstrated cross wind value was different takeoff to landing. I do know amphibians where the value is different land or water operation.
