$^{ }$  I N D W  a similar manner. As the air flows down the leeward side of  the mountain, the air follows the contour of the terrain and  is increasingly turbulent. This tends to push an aircraft into  the side of a mountain. The stronger the wind, the greater the  downward pressure and turbulence become.  may “drop in” due to the turbulent air and be too low to clear  obstacles during the approach.  This same condition is even more noticeable when flying in  mountainous regions.  [Figure 12-16]  While the wind flows  smoothly up the windward side of the mountain and the  upward currents help to carry an aircraft over the peak of  the mountain, the wind on the leeward side does not act in  Due to the effect terrain has on the wind in valleys or canyons,  downdrafts can be severe. Before conducting a flight in or  Figure 12-15.  Turbulence caused by manmade obstructions.  Figure 12-16.  Turbulence in mountainous regions.  12-10  WIND 