Aircraft Performance

1. What effect does high density altitude as compare to low density altitude have on propeller efficiency and why?
1. Efficiency is reduced because the propeller exerts less force at high density altitude that at low density altitude
2. What is density altitude?
1. Pressure altitude corrected for nonstandard temperature           
3. if the outside air temperature (OTA) at a given altitude is warmer that standard, the density altitude is?
1. Higher that pressure altitude
4. Which combination of atmospheric conditions will reduce the aircraft takeoff and climb performance?
1. High temperature, high relative humidity, high density altitude
5. What effect does high density altitude have on aircraft performance?
1. Reduce climb performance
6. Refer to figure 8 what is the effect of a temperature increase of 25 to 50 deg F on the density altitude of the pressure altitude remains the same at 5000 feet?
1. 1650 foot increase  (at 25 = 3750 at 50 is 5500)
7. Refer to figure 8 determine the pressure altitude with an indicated altitude of 1380 feet MSL with an altimeter setting of 28.22 at standard temperature?
1. 2991 feet MSL
8. Refer to figure 8 determine the density altitude of the conditions?

-          altimeter setting 29.25

-          Runway temperature + 81 deg F

-          Airport elevation 5,250 feet MSL

 Pressure altitude  29.2 = 673 , 29.3 = 579  .1 = (673-579=94) .05 =94/2 =47 so   29.25=673 +47=626,  Therefore pressure altitude =  5,250 + 626 =8579

From graft go to pressure altitude of 8579 and temperature of  81 deg F at the intersection move across to the density altitude and it will be 8500

9. Refer to figure 8 determine the pressure altitude at an airport that is 3563 feet pressure altitude with an altimeter setting of 29.96
1. 3527    (29.92=0, 30.00= -73, .08= -73, .04=-73/2= -36.5 so 29.26 =-36.5 therefore the actual pressure altitude = 3563 feet -36.5 = 3526.5