The crosswind limit is usually stated as a "Demonstrated" limit. The FAA, for instance does not require manufacturers to even state one in their Flight Manual. Look at the DC-9 and the Dornier 328J. The airline can make a limit, and probably would if they were wise, but it is not a requirement.. .The other limit is for ground handling as the wind hits the fin and the nosewheel loses traction. That again could be a manufacturers recomendation or a company imposed limit.. .If the JAR requirements are for the manufacturers to test and certify a limit we will have found at least one thing that the JAR's are good for.. .Line pilots should not be expected to be test pilots.