34 17 Normal or Steep- Angle Approach Alternating Turns to Lose Altitude Minimum 400 feet AGL Top View Alternating Turns on Runway Centerline Runway Centerline Figure 11-30. Alternating turns used if too high to lose enough altitude to position for a normal or steep-angle approach. planning an approach. The 180° power-off approach from  pattern altitude should be the normal landing procedure in  calm winds. This should become routine and develop the  ability to accurately judge the landing for an engine-out  situation. Remember, the steep approach technique can  always be used if the aircraft is a little high, but do not stretch  a glide by lowering the speed if too low.  With experience and practice, altitudes up to approximately  1,000 feet can be estimated with fair accuracy, while above  this level the accuracy in judgment of height above the  ground decreases since features tend to merge. The best aid  in perfecting the ability to judge height above this altitude is  altimeter indications and associating them with the general  appearance of the Earth. The judgment of altitude in feet, hundreds of feet, or thousands  of feet is not as important as the ability to estimate gliding  angle and its resultant distance. The pilot who knows the  normal glide angle of the aircraft can estimate with reasonable  accuracy the approximate spot along a given ground path  at which the aircraft lands, regardless of altitude. The pilot  who also has the ability to estimate altitude accurately can  judge how much maneuvering is possible during the glide,  which is important to the choice of landing areas in an actual  emergency. The basic procedure in these approaches involves closing  the throttle at a given altitude and gliding to a key position.  This position, like the pattern itself, must not be allowed to  become the primary objective; it is merely a convenient point  in the air from which the pilot can judge whether the glide  safely terminates at the desired spot. The selected key position  should be one that is appropriate for the available altitude  and the wind condition. From the key position, the pilot must  constantly evaluate the situation. It must be emphasized that,  although accurate spot touchdowns are important, safe and  properly executed approaches and landings are vital. The  pilot must never sacrifice a good approach or landing just to  land on the desired spot. All power-off approaches must be practiced to avoid  interfering with normal traffi c flow at busy airports, so the  place and timing must be evaluated by the instructor to  prevent airport traffi c conflicts. This is especially important  for the 360° power-off approach. Unlike a normal approach in which power is available when  needed, for a power-off approach the power is fixed at the  idle setting. Pitch attitude is adjusted to control the airspeed,  which also changes the glide or descent angle. As discussed  in the basic flight maneuvers descents and the steep approach  maneuver, lowering the nose to a speed above the best glide  angle causes the descent angle to steepen. If the airspeed is  too high, raise the nose, and when the airspeed is too low,  lower the nose. If the pitch attitude is raised too high, the  aircraft settles rapidly due to low airspeed and insuffi cient  lift. For this reason, never try to stretch a glide to reach the  desired landing spot. Uniform approach patterns such as the 90°, 180°, or 360°  power-off approaches are described further in this chapter.  Practice in these approaches provides the pilot with a basis  on which to develop judgment in gliding distance and in  The 90° power-off approach is made from a base leg and  requires only a 90° turn onto the final approach. The approach  path may be varied by positioning the base leg closer to or  farther away from the approach end of the runway according  to wind conditions.  [Figure 11-31]  The glide from the key  11-22  90° Power-Off Approach