Best angle-of-climb airspeed (V$_{X}$) gives the greatest altitude gain in  the shortest horizontal distance. Best rate-of-climb airspeed (V$_{Y}$) gives the greatest altitude gain  in the shortest time. Figure 3-19.  Best angle of climb verses best rate of climb. (AFM/POH) must be consulted to ensure that the correct  airspeed is used for the desired climb profile at the given  environmental conditions. There is a point at which the best  angle of climb airspeed and the best rate of climb airspeed  intersect. This occurs at the absolute ceiling at which the  airplane is incapable of climbing any higher.  [Figure 3-20] The power should be advanced to the recommended climb  power. On airplanes equipped with an independently  controllable-pitch propeller, this requires advancing the  propeller control prior to increasing engine power. Some  airplanes may be equipped with cowl flaps to facilitate  effective engine cooling. The position of the cowl flaps  should be set to ensure cylinder head temperatures remain  within the manufacturer’s specifications.  Engines that are normally aspirated experience a reduction  of power as altitude is gained. As altitude increases, air  density decreases, which results in a reduction of power.  The indications show a reduction in revolutions per minute  (rpm) for airplanes with fixed pitch propellers; airplanes  that are equipped with controllable propellers show a  decrease in manifold pressure. The pilot should reference  the engine instruments to ensure that climb power is being  A straight climb is entered by gently increasing back  pressure on the elevator flight control to the pitch attitude  referencing the airplane’s nose to the natural horizon while  simultaneously increasing engine power to the climb power  setting. The wingtips should be referenced in maintaining the  climb attitude while cross-checking the flight instruments to  verify performance. In many airplanes, as power is increased,  an increase in slipstream over the horizontal stabilizer causes  the airplane’s pitch attitude to increase greater than desired.  The pilot should be prepared for slipstream effects but also  for the effect of changing airspeed and changes in lift. The  pilot should be prepared to use the required flight control  pressures to achieve the desired pitch attitude. If a climb is started from cruise flight, the airspeed gradually  decreases as the airplane enters a stabilized climb attitude.  The thrust required to maintain straight-and-level flight at a  given airspeed is not sufficient to maintain the same airspeed  in a climb. Increase drag in a climb stems from increased lift  demands made upon the wing to increase altitude. Climbing  requires an excess of lift over that necessary to maintain level  flight. Increased lift will generate more induced drag. That  increase in induced drag is why more power is needed and  why a sustained climb requires an excess of thrust. For practical purposes gravity or weight is a constant.  Even using a vector diagram to show where more lift is  necessary because the lift vector from the wings is no longer  perpendicular to the wings, therefore more lift is needed from  the wings which requires more thrust from the powerplant. Figure 3-20.  Absolute ceiling. 3-17 Establishing a Climb Standard altitude (feet) Indicated airspeed (knots) Best angle of climb(V X ) Best rate of climb(V Y ) 22,000 20,000 18,000 16,000 14,000 12,000 10,000 8,000 6,000 4,000 2,000 S.L. Absolute ceiling Service ceiling 80 90 100 110 120