There are two measurements of the a

There are two measurements of the atmosphere that affect performance and instrument calibrations :
1. Pressure altitude is the height above the standard datum pressure (SDP) (29.92”Hg, sea level under ISA). And is used for standardizing altitudes for flight levels (FL).
2. Density altitude is pressure altitude corrected for nonstandard temperatures. And is used for determining aerodynamic performance in the nonstandard atmosphere. If a chart is not available the density altitude can be estimated by adding 120 feet for every degree Celsius above the ISA. For example, at 3,000 feet pressure altitude (PA), the ISA prediction is 9°C (15° C – [lapse rate of 2° C per 1,000 feet x 3 = 6° C]). How ever, if the actual temperature is 20° C (more than that predicted by ISA) then the difference of 11° C is multiplied by 120 feet equaling 1,320. Adding this figure to the original 3,000 feet provides a density altitude of 4,320 feet (3,000 feet + 1,320 feet).
LIFT
Lift always acts in a direction perpendicular to the relative wind and to the lateral axis of the aircraft. The fact that lift is referenced to the wing, not to the earth’s surface, is the sourece of many errors in learning flight control. Lift is not always “up” its direction relative to the earth’s surface changes as the pilot maneuvers the aircraft.
The magnitude of the force of ligt is directly proportional to the density of the air, the area of the wings, and the airspeed. It also depend upon the type of wing and the angle of attack. Lift is therefore controlled by varying the angle of attack and speed.

Pitch/power relationship
The pilot control pitch through the elevators, whitch control the angle of attack. Under most conditions the elevator is placing downward pressure on the tail. This pressure requires energy that is taken from aircraft performance(speed). When the CG is closer to the aft portion of the aircraft the elevator downward forces are less. This results in less energy used for downward forces, in turn resulting in more enrgy applied to aircraft performance.
Thrust is controlled by using the throttle to establish or maintain desired airspeeds.the most precise method of controlling flight path is to use pitch control while simultaneously using power(thrust) to control airspeed.
If the pilots wants the aircraft to accelerate while maintaining altitude, thrust must be increased to overcome drag.as the aircraft speeds up, lift is increased. As aircraft slow down, lift is reduced.
Drag curves
Understanding the drag curve can provide valueable insight into the various performance parameters and limitations of the aircraft. Because power must equal drag to maintain a steady airspeed, the curve can be either a drag curve or a power required curve.
The propellers used on most reciprocating engines achieve peak propeller efficiencies in the range of 80 to 88 percent. An engine that produces 160 HP will have only about 80 percent of that power converted into available horsepower, approxiamately 128 horsepower. The remainder is lost energy. This is the reason the thrust and power available curves change with speed.

Hasil (Bahasa Indonesia) 1:

There are two measurements of the atmosphere that affect performance and instrument calibrations :1. Pressure altitude is the height above the standard datum pressure (SDP) (29.92”Hg, sea level under ISA). And is used for standardizing altitudes for flight levels (FL).2. Density altitude is pressure altitude corrected for nonstandard temperatures. And is used for determining aerodynamic performance in the nonstandard atmosphere. If a chart is not available the density altitude can be estimated by adding 120 feet for every degree Celsius above the ISA. For example, at 3,000 feet pressure altitude (PA), the ISA prediction is 9°C (15° C – [lapse rate of 2° C per 1,000 feet x 3 = 6° C]). How ever, if the actual temperature is 20° C (more than that predicted by ISA) then the difference of 11° C is multiplied by 120 feet equaling 1,320. Adding this figure to the original 3,000 feet provides a density altitude of 4,320 feet (3,000 feet + 1,320 feet).LIFTLift always acts in a direction perpendicular to the relative wind and to the lateral axis of the aircraft. The fact that lift is referenced to the wing, not to the earth’s surface, is the sourece of many errors in learning flight control. Lift is not always “up” its direction relative to the earth’s surface changes as the pilot maneuvers the aircraft.The magnitude of the force of ligt is directly proportional to the density of the air, the area of the wings, and the airspeed. It also depend upon the type of wing and the angle of attack. Lift is therefore controlled by varying the angle of attack and speed.Pitch/power relationshipThe pilot control pitch through the elevators, whitch control the angle of attack. Under most conditions the elevator is placing downward pressure on the tail. This pressure requires energy that is taken from aircraft performance(speed). When the CG is closer to the aft portion of the aircraft the elevator downward forces are less. This results in less energy used for downward forces, in turn resulting in more enrgy applied to aircraft performance.Thrust is controlled by using the throttle to establish or maintain desired airspeeds.the most precise method of controlling flight path is to use pitch control while simultaneously using power(thrust) to control airspeed.If the pilots wants the aircraft to accelerate while maintaining altitude, thrust must be increased to overcome drag.as the aircraft speeds up, lift is increased. As aircraft slow down, lift is reduced.Drag curvesUnderstanding the drag curve can provide valueable insight into the various performance parameters and limitations of the aircraft. Because power must equal drag to maintain a steady airspeed, the curve can be either a drag curve or a power required curve.Baling-baling yang digunakan pada kebanyakan mesin bolak-balik mencapai puncak baling-baling efisiensi dalam kisaran 80-88 persen. Mesin yang memproduksi 160 HP akan memiliki hanya sekitar 80 persen dari kekuatan itu diubah menjadi tenaga kuda tersedia, approxiamately tenaga kuda 128. Sisanya adalah kehilangan energi. Ini adalah alasan dorong dan kekuatan tersedia kurva berubah dengan kecepatan.