Subsequently, autoland systems became available on a number of aircraft types but the primary customers were those mainly European airlines whose networks were severely affected by radiation fog. Early autoland systems needed a relatively stable air mass and could not operate in conditions of turbulence and in particular gusty crosswinds. In North America, it was generally the case that reduced but not zero visibility was often associated with these conditions, and if the visibility really became almost zero in, for example, blowing snow or other precipitation then operations would be impossible for other reasons.