The Collaborative International Dictionary of English v.0.48:

Aviatress \A"vi*a`tress\, Aviatrix \A`vi*a"trix\, n.
   A woman aviator (in senses 1 or 3).
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

aviatrix
    n 1: a woman aviator [syn: aviatrix, airwoman, aviatress]