AFH 4-13

Figure 4-12. The control skills needed to correct total energy and energy distribution errors identified in Figure 4-11 with an additional column giving caution to the “very slow” condition where careful AOA management is needed in addition to energy management. Note that in the scenario depicted in B in Figure 4-13, advancing the throttle forward to increase energy would only succeed if excess thrust is available (PS > 0). This may not be the case if the pilot has badly mismanaged energy and slowed down to a speed where induced drag is so high that even applying full throttle would result in no surplus energy (see column "Cautions When Very Slow" in Figure 4-12). Depending on the flight condition, available excess power at full throttle may be negative (PS < 0). In this case, the only recourse is to first trade altitude for speed by pushing forward on the yoke/stick, reducing AOA and induced drag, and only then advancing the throttle forward to regain total energy. But if the airplane is too close to the ground, there may not be enough room to reverse the negative energy rate and prevent the airplane from striking the ground. Now consider the scenario depicted in C in Figure 4-13, where the airplane has descended below the desired flight path but is flying at the correct speed. Here, even though there is no speed deviation, the pilot is faced with a combination of total energy and distribution errors. Regaining altitude without changing speed requires advancing the throttle forward while easing aft on the yoke/ stick (6 in Figure 4-12). In other words, decoupling altitude and airspeed (i.e. changing one without changing the other) demands the use of both controls simultaneously. In all cases, path and speed should be monitored carefully as they are corrected, adjusting pitch attitude and throttle setting as appropriate. Once short-term deviations are corrected, the airplane will need to be trimmed for long-term control to maintain the desired path-speed profile (5 in Figure 4-12).