Weather Theory

Station Pressure Denver 24.92 "Hg Standard Atmosphere Station Pressure New Orleans 29.92 "Hg New Orleans 29.92 "Hg Denver 29.92 "Hg Figure 12-8. Station pressure is converted to and reported in sea level pressure. Altitude and Flight is longer. An aircraft that requires 745 feet of ground run at sea level requires more than double that at a pressure altitude Altitude affects every aspect of flight from aircraft of 8,000 feet. [Figure 12-9]. It is also true that at higher performance to human performance. At higher altitudes, altitudes, due to the decreased density of the air, aircraft with a decreased atmospheric pressure, takeoff and landing engines and propellers are less efficient. This leads to reduced distances are increased, while climb rates decrease. rates of climb and a greater ground run for obstacle clearance. When an aircraft takes off, lift is created by the flow of air Altitude and the Human Body around the wings. If the air is thin, more speed is required to obtain enough lift for takeoff; therefore, the ground run As discussed earlier, nitrogen and other trace gases make up 79 percent of the atmosphere, while the remaining 21 Pressure Altitude: Sea level TAKEOFF DISTANCE MAXIMUM WEIGHT 2,400 LB 0 °C Pressure altitude Ground Total feet (feet) roll to clear (feet) 50 foot obstacle S.L. 745 1,320 1,000 815 1,445 2,000 895 1,585 3,000 980 1,740 745 feet 4,000 1,075 1,920 5,000 1,185 2,125 6,000 1,305 2,360 7,000 1,440 2,635 8,000 1,590 2,960 Pressure Altitude: 8,000 feet 1,590 feet Figure 12-9. Takeoff distances increase with increased altitude. 12-6