****Why does the 744 have a max autoland headwind component of 25kts? Just in case there's shear or somethin? I've just never seen a plane have a max headwind component.. autoland or no.*****
Per FAA regulations, the aircraft operation in winds has to be demonstrated (i.e. == flight tested) to at least 150% of the winds (cross and tail/head winds) for which credit is sought. For the above example, in order to have a 25knts limit, the aircraft must have been exposed to 37.5 knts headwind. Regardless of aircraft/autoland actual performance, it is pretty tough to find that kind of winds to demonstrate your system on, especially when the flight testers only have a window of 1 or 2 weeks. The test crew literally would have to fly all over the country to find the right winds at airports that are not too busy to allow you to do multiple go-arounds/landings and not make you wait hours for your turn.