from an irregularly running engine; however, it is generally  better to switch the engine and fuel off just before touchdown.  This not only ensures the pilot’s initiative over the situation,  but a cooled-down engine reduces the fire hazard considerably. When the pilot has time to maneuver, the planning of the  approach should be governed by the following three factors: These three factors are seldom compatible. When compromises  have to be made, the pilot should aim for a wind/obstacle/ terrain combination that permits a final approach with some  margin for error in judgment or technique. A pilot who  overestimates the gliding range may be tempted to stretch the  glide across obstacles in the approach path. For this reason, it  is sometimes better to plan the approach over an unobstructed  area, regardless of wind direction. Experience shows that a  collision with obstacles at the end of a ground roll or slide is  much less hazardous than striking an obstacle at flying speed  before the touchdown point is reached. Since an emergency landing on suitable terrain resembles  a situation in which the pilot should be familiar through  training, only the more unusual situations are discussed. The natural preference to set the airplane down on the ground  should not lead to the selection of an open spot between trees  or obstacles where the ground cannot be reached without  making a steep descent. Once the intended touchdown point is reached, and the  remaining open and unobstructed space is very limited,  it may be better to force the airplane down on the ground  than to delay touchdown until it stalls (settles). An airplane  decelerates faster after it is on the ground than while airborne.  Thought may also be given to the desirability of ground- looping or retracting the landing gear in certain conditions. A river or creek can be an inviting alternative in otherwise  rugged terrain. The pilot should ensure that the water or creek  bed can be reached without snagging the wings. The same  concept applies to road landings with one additional reason  for caution: manmade obstacles on either side of a road may  not be visible until the final portion of the approach. When planning the approach across a road, it should be  remembered that most highways and even rural dirt roads are  paralleled by power or telephone lines. Only a sharp lookout for  the supporting structures or poles may provide timely warning. Although a tree landing is not an attractive prospect, the  following general guidelines help to make the experience  survivable. Approach Trees (Forest) Terrain Types Confined Areas • Wind direction and velocity • Dimensions and slope of the chosen field • Obstacles in the final approach path • Use the normal landing configuration (full flaps, gear  down). • Keep the groundspeed low by heading into the wind. • Make contact at minimum indicated airspeed, but not  below stall speed, and “hang” the airplane in the tree  branches in a nose-high landing attitude. Involving  the underside of the fuselage and both wings in the  initial tree contact provides a more even and positive  cushioning effect, while preventing penetration of the  windshield.  [Figure 17-4] • Avoid direct contact of the fuselage with heavy tree  trunks. • Low, closely spaced trees with wide, dense crowns  (branches) close to the ground are much better than  tall trees with thin tops; the latter allow too much free  fall height (a free fall from 75 feet results in an impact  speed of about 40 knots, or about 4,000 fpm). • Ideally, initial tree contact should be symmetrical;  that is, both wings should meet equal resistance in the  tree branches. This distribution of the load helps to  maintain proper airplane attitude. It may also preclude  the loss of one wing, which invariably leads to a more  rapid and less predictable descent to the ground.  Figure 17-4.  Tree landing. 17-5