TM 1-1520-238-10 Change 9 5-11 LINE AND READ TRUE MOVE DOWN, READ INDICATED FEET DENSITY ALTITUDE. AND MOVE TO RIGHT TO 1500 164 KNOTS TRUE AIRSPEED ON SHEET 2 ENTER AT ALTITUDE = 1500 FEET MOVE DOWN, READ DENSITY AIRSPEED = 166 KNOTS FIRST. MOVE LEFT AT -30 5C MACH LIMIT IS ENCOUNTERED FIRST. IN THIS CASE, THE FAT, WHICHEVER IS ENCOUNTERED GROSS WEIGHT OR MACH LIMIT MOVE DOWN TO 18,000 POUND MOVE RIGHT TO FAT = -30 5C PRESSURE ALTITUDE ENTER AT 6000 FEET MAXIMUM TRUE AND INDICATED AIRSPEED FAT = -30 5C PRESSURE ALTITUDE = 6000 FEET AH-64A 180 DERIVED FROM FLIGHT TEST DENSITY ALTITUDE ~ FEET 20000 15000 10000 200 0 170 -5000 190 5000 MACH NO. LIMITS -50 20000 15000 10000 5000 0 -5000 160 150 AIRSPEED = 156 KNOTS. METHOD GROSS WEIGHT = 18,000 POUNDS KNOWN AND DENSITY ALTITUDE WANTED EXAMPLE 110 100 120 130 140 90 0 5000 10000 20000 15000 100% ROTOR RPM AIRSPEED OPERATING LIMITS LEVEL FLIGHT AIRSPEED OPERATING LIMITS -20 -30 -40 -10 M01-231-1 DATA BASIS: 5 FAT ~ 5C -60 Figure 5-2. Airspeed Operating Limits Chart (Sheet 1 of 2)