Every flight we've been on at St. Martin the past 10 years has arrived eastward over Maho and departed eastward toward the mountain. Last Wednesday the 24th, as our plane got ready to taxi for takeoff, I saw another airliner land eastward toward the mountain. However, our plane turned left, taxied to the east end of the runway, and departed westward over Maho. I had read somewhere that about 98% of takeoffs at PJIA are to the east, based on prevailing winds. I could see palm trees blowing to the west, consistent with the landing approach of the other airliner I saw. Could a sudden change in wind direction cause a sudden change in take-off direction ?