Performance Charts

Performance charts allow a pilot to predict the takeoff, climb, cruise, and landing performance of an aircraft. These charts, provided by the manufacturer, are included in the AFM/POH. Information the manufacturer provides on these charts has been gathered from test flights conducted in a new aircraft, under normal operating conditions while using average piloting skills, and with the aircraft and engine in good working order. Engineers record the flight data and create performance charts based on the behavior of the aircraft during the test flights. By using these performance charts, a pilot can determine the runway length needed to take off and land, the amount of fuel to be used during flight, and the time required to arrive at the destination. It is important to remember that the data from the charts will not be accurate if the aircraft is not in good working order or when operating under adverse conditions. Always consider the necessity to compensate for the performance numbers if the aircraft is not in good working order or piloting skills are below average.,, Each aircraft performs differently and, therefore, has different performance numbers. Compute the performance of the aircraft prior to every flight, as every flight is different. (See appendix for examples of performance charts for a Cessna Model 172R and Challenger 605.) Every chart is based on certain conditions and contains notes on how to adapt the information for flight conditions. It is important to read every chart and understand how to use it. Read the instructions provided by the manufacturer. For an explanation on how to use the charts, refer to the example provided by the manufacturer for that specific chart. [Figure 11-20] The information manufacturers furnish is not standardized. Information may be contained in a table format and other information may be contained in a graph format. Sometimes combined graphs incorporate two or more graphs into one chart to compensate for multiple conditions of flight. Combined graphs allow the pilot to predict aircraft performance for variations in density altitude, weight, and winds all on one chart. Because of the vast amount of information that can be extracted from this type of chart, it is important to be very accurate in reading the chart. A small error in the beginning can lead to a large error at the end. The remainder of this section covers performance information for aircraft in general and discusses what information the charts contain and how to extract information from the charts by direct reading and interpolation methods. Every chart contains a wealth of information that should be used when flight planning. Examples of the table, graph, and combined graph formats for all aspects of flight are discussed., Flaps 10° To find the takeoff distance for a pressure altitude of 2,500 feet at 20 °C, average the ground roll for 2,000 feet and 3,000 feet. 1,115 + 1,230 = 1,173 feet 2 sn TAKEOFF Full throttle prior to brake release oiti MAXIMUM WEI dnoC Interpolation Not all of the information on the charts is easily extracted. Some charts require interpolation to find the information for specific flight conditions. Interpolating information means that by taking the known information, a pilot can compute intermediate information. However, pilots sometimes round off values from charts to a more conservative figure. Using values that reflect slightly more adverse conditions provides a reasonable estimate of performance information and gives a slight margin of safety. The following illustration is an example of interpolating information from a takeoff distance chart. [Figure 11-21] Density Altitude Charts Use a density altitude chart to figure the density altitude at the departing airport. Using Figure 11-22, determine the density altitude based on the given information. Sample Problem 1 Airport Elevation...............................................5,883 feet OAT...........................................................................70 °F Altimeter...........................................................30.10 "Hg First, compute the pressure altitude conversion. Find 30.10 under the altimeter heading. Read across to the second column. It reads “–165.” Therefore, it is necessary to subtract 165 from the airport elevation giving a pressure altitude of 5,718 feet. Next, locate the outside air temperature on the scale along the bottom of the graph. From 70°, draw a line up to the 5,718 feet pressure altitude line, which is about twothirds of the way up between the 5,000 and 6,000 foot lines. Draw a line straight across to the far left side of the graph Paved level runway Zero wind Takeoff 0 °C 10 ° speed KIAS Weight Press (lb) ALT Grnd Total feet Grnd T Lift AT (ft) roll to clear roll t off 50 ft (ft) 50 ft OBS (ft) 5 2,400 795 1,460 860 1,000 875 1,605 940 2,000 960 1,770 1,035 3,000 1,055 1,960 1,140 4,000 1,165 2,185 1,260 5,000 1,285 2,445 1,390 6,000 1,425 2,755 1,540 7,000 1,580 3,140 1,710 8,000 1,755 3,615 1,905 and read the approximate density altitude. The approximate density altitude in thousands of feet is 7,700 feet. Takeoff Charts Takeoff charts are typically provided in several forms and allow a pilot to compute the takeoff distance of the aircraft with no flaps or with a specific flap configuration. A pilot can also compute distances for a no flap takeoff over a 50 foot obstacle scenario, as well as with flaps over a 50 foot obstacle. The takeoff distance chart provides for various aircraft weights, altitudes, temperatures, winds, and obstacle heights. Sample Problem 2 Pressure Altitude...............................................2,000 feet OAT..........................................................................22 °C Takeoff Weight.............................................2,600 pounds Headwind...............................................................6 knots Obstacle Height.......................................50 foot obstacle Refer to Figure 11-23. This chart is an example of a combined takeoff distance graph. It takes into consideration pressure altitude, temperature, weight, wind, and obstacles all on one chart. First, find the correct temperature on the bottom left side of the graph. Follow the line from 22 °C straight up until it intersects the 2,000 foot altitude line. From that point, draw a line straight across to the first dark reference line. Continue to draw the line from the reference point in a diagonal direction following the surrounding lines until it intersects the corresponding weight line. From the intersection of 2,600 pounds, draw a line straight across until it reaches the second reference line. Once again, follow the lines in a diagonal manner until it reaches the six knot headwind mark. Follow ISTANCE HT 2,400 LB 20 °C 30 °C 40 °C tal feet Grnd Total feet Grnd Total feet Grnd Total feet clear roll to clear roll to clear roll to clear ft OBS (ft) 50 ft OBS (ft) 50 ft OBS (ft) 50 ft OBS 1,570 925 1,685 995 1,810 1,065 1,945 1,725 1,015 1,860 1,090 2,000 1,170 2,155 1,910 1,115 2,060 1,200 2,220 1,290 2,395 2,120 1,230 2,295 1,325 2,480 1,425 2,685 2,365 1,355 2,570 1,465 2,790 1,575 3,030 2,660 1,500 2,895 1,620 3,160 1,745 3,455 3,015 1,665 3,300 1,800 3,620 1,940 3,990 3,450 1,850 3,805 2,000 4,220 - - - - - - 4,015 2,060 4,480 - - - - - ­ - - - - - - )teef dnasuoht( edutitla ytisned etamixorppA et) (f altit – -18 -12° -7° -1° 4° 10° 16° 21° 27° 32° 38° F 0° 10° 20° 30° 40° 50° 60° 70° 80° 90° 100° gnittes retemitlA )gH"( edutitla erusserP rotcaf noisrevnoc 824 727 630 533 436 340 244 148 053 28.9 957 29.0 863 29.1 768 29.2 673 29.3 579 29.4 485 29.5 392 29.6 298 29.7 205 29.8 112 −73 30.1 −165 30.2 −257 30.3 −348 30.4 −440 30.5 −531 30.6 −622 30.7 −712 30.8 −803 Outside air temperature straight across to the third reference line and from here, draw a line in two directions. First, draw a line straight across to figure the ground roll distance. Next, follow the diagonal lines again until they reach the corresponding obstacle height. In this case, foot obstacle. Therefore, draw the diagonal line to the far edge of the chart. This results in a 700 foot ground roll distance and a total distance of 1,400 feet over a 50 foot obstacle. To find the corresponding takeoff speeds at lift-off and over the 50 foot obstacle, refer to the table on the top of the chart. In this case, the lift-off speed at 2,600 pounds would be 63 knots and over the 50 foot obstacle would be 68 knots. Sample Problem 3 Pressure Altitude...............................................3,000 feet OAT.........................................................................30 °C Takeoff Weight............................................2,400 pounds Headwind............................................................18 knots Refer to Figure 11-24. This chart is an example of a takeoff distance table for short-field takeoffs. For this table, first find the takeoff weight. Once at 2,400 pounds, begin reading from left to right across the table. The takeoff speed is in the second column and, in the third column under pressure altitude, find the pressure altitude of 3,000 feet. Carefully follow that line to the right until it is under the correct temperature column of 30 °C. The ground roll total reads 1,325 feet and the total required to clear a 50 foot obstacle is 2,480 feet. At this point, there knot headwind. According to the notes section under point number two, decrease the distances by ten percent for each 9 knots of headwind. With an 18 knot headwind, it is necessary to decrease the distance by 20 percent. Multiply 1,325 feet by 20 percent (1,325 ×.20 = 265), subtract the product from the total distance (1,325 – 265 = 1,060). Repeat this process for the total distance over a 50 foot obstacle. The ground roll distance is 1,060 feet and the total distance over a 50 foot obstacle is 1,984 feet. Climb and Cruise Charts Climb and cruise chart information is based on actual flight tests conducted in an aircraft of the same type. This information is extremely useful when planning a cross-country flight to predict the performance and fuel consumption of the aircraft. Manufacturers produce several different charts for climb and cruise performance. These charts include everything from fuel, time, and distance to climb to best power setting during cruise to cruise range performance. The first chart to check for climb performance is a fuel, time, and distance-to-climb chart. This chart gives the fuel amount used during the climb, the time it takes to accomplish the climb, and the ground distance that is covered during the climb. To use this chart, obtain the information for the departing airport and for the cruise altitude. Using based on the information provided. Sample Problem 4 Departing Airport Pressure Altitude.................6,000 feet Departing Airport OAT............................................25 °C Cruise Pressure Altitude..................................10,000 feet Cruise OAT..............................................................10 °C f e TAKEOFF DISTAN MAXIMUM WEIGHT 2,4 snoitidnoC setoN Takeoff speed Associated c Weight Lift-off 50 ft pounds Power Full throt kts MPH kts MPH Mixture Lean to 2,950 pressure 2,800 Flaps Up 2,600 Landing Retract a 2,400 gear climb est 2,200 Cowl Open flaps Pressure altitude feet ISA -40° -30° -20° -10° 0° 10° 20° 30° 40° 50° 2,800 2,600 Outside air temperature Wei (poun F -40° -20° 0° 20° 40° 60° 80° 100° 120° Flaps 10° Full throttle prior to brake release Paved level runway Zero wind SHORT FIELD 1. Prior to takeoff from fields above 3,000 feet elevation, the mixture should be leaned to 2. Decrease distances 10% for each 9 knots headwind. For operation with tailwind For operation on a dry, grass runway, increase distances by 15% of the “ground roll” fi Takeoff 0 °C 10 °C speed KIAS Press Weight ALT Grnd Total feet Grnd Total feet (lb) Lift AT (ft) roll to clear roll to clear off 50 ft (ft) 50 ft OBS (ft) 50 ft OBS 2,400 795 1,460 860 1,570 1,000 875 1,605 940 1,725 2,000 960 1,770 1,035 1,910 3,000 1,055 1,960 1,140 2,120 4,000 1,165 2,185 1,260 2,365 5,000 1,285 2,445 1,390 2,660 6,000 1,425 2,755 1,540 3,015 7,000 1,580 3,140 1,710 3,450 8,000 1,755 3,615 1,905 4,015 2,200 650 1,195 700 1,280 1,000 710 1,310 765 1,405 2,000 780 1,440 840 1,545 3,000 855 1,585 925 1,705 4,000 945 1,750 1,020 1,890 5,000 1,040 1,945 1,125 2,105 6,000 1,150 2,170 1,240 2,355 7,000 1,270 2,440 1,375 2,655 8,000 1,410 2,760 1,525 3,015 2,000 525 970 565 1,035 1,000 570 1,060 615 1,135 2,000 625 1,160 675 1,240 3,000 690 1,270 740 1,365 4,000 755 1,400 815 1,500 5,000 830 1,545 900 1,660 6,000 920 1,710 990 1,845 7,000 1,015 1,900 1,095 2,055 8,000 1,125 2,125 1,215 2,305 6,000 nditions 000 ter positive 000 blished ail 000 Headwind 2,000 1,000 0 2,400 2,200 Wind component Obstacle s) (knots) height (feet) 0 LB give maximum rpm in a full throttle, static runup. 10 knots, increase distances by 10% for each 2 knots. ure. 20 °C 30 °C 40 °C Grnd Total feet Grnd Total feet Grnd Total feet roll to clear roll to clear roll to clear (ft) 50 ft OBS (ft) 50 ft OBS (ft) 50 ft OBS 925 1,685 995 1,810 1,065 1,945 1,015 1,860 1,090 2,000 1,170 2,155 1,115 2,060 1,200 2,220 1,290 2,395 1,230 2,295 1,325 2,480 1,425 2,685 1,355 2,570 1,465 2,790 1,575 3,030 1,500 2,895 1,620 3,160 1,745 3,455 1,665 3,300 1,800 3,620 1,940 3,990 1,850 3,805 2,000 4,220 - - - - - - 2,060 4,480 - - - - - ­ - - - - - - 750 1,375 805 1,470 865 1,575 825 1,510 885 1,615 950 1,735 905 1,660 975 1,785 1,045 1,915 995 1,835 1,070 1,975 1,150 2,130 1,100 2,040 1,180 2,200 1,270 2,375 1,210 2,275 1,305 2,465 1,405 2,665 1,340 2,555 1,445 2,775 1,555 3,020 1,485 2,890 1,605 3,155 1,730 3,450 1,650 3,305 1,785 3,630 1,925 4,005 605 1,110 650 1,185 695 1,265 665 1,215 710 1,295 765 1,385 725 1,330 780 1,425 840 1,525 800 1,465 860 1,570 920 1,685 880 1,615 945 1,735 1,015 1,865 970 1,790 2,145 1,925 1,120 2,070 1,070 1,990 2,405 2,145 1,235 2,315 1,180 2,225 2,715 2,405 1,370 2,605 1,310 2,500 1,410 2,715 1,520 2,950 Pressure ALT feet all o 16,000 - 14,000 F Cruise 12,000 10,000 8,000 6,000 4,000 2,000 Departure Sea level -40° -30° -20° -10° 0° 10° 20° 30° 40°C 0 10 Outside air temperature Fuel, time First, find the information for the departing airport. Find the OAT for the departing airport along the bottom, left side of the graph. Follow the line from 25 °C straight up until it intersects the line corresponding to the pressure altitude of 6,000 feet. Continue this line straight across until it intersects all three lines for fuel, time, and distance. Draw a line straight down from the intersection of altitude and fuel, altitude and time, and a third line at altitude and distance. It should read three and one-half gallons of fuel, 6 minutes of time, and nine NM. Next, repeat the steps to find the information for the cruise altitude. It should read six gallons of fuel, 10.5 minutes of time, and 15 NM. Take each set of numbers for fuel, time, and distance and subtract them from one another (6.0 – 3.5 = 2.5 gallons of fuel). It takes two and one-half gallons of fuel and 4 minutes of time to climb to 10,000 feet. During that climb, the distance covered is six NM. Remember, according to the notes at the top of the chart, these numbers do not take into account wind, and it is assumed maximum continuous power is being used. The next example is a fuel, time, and distance-to-climb table. For this table, use the same basic criteria as for the previous chart. However, it is necessary to figure the information in a different manner. Refer to Figure 11-26 to work the following sample problem. Sample Problem 5 Departing Airport Pressure Altitude..................Sea level Departing Airport OAT............................................22 °C Cruise Pressure Altitude....................................8,000 feet Takeoff Weight.............................................3,400 pounds snoitidnoC setoN utical miles m e nce - Associated conditions Maximum continuous power* 3,600 lb gross weight Flaps up 90 KIAS No wind * 2,700 rpm & (3-blade prop) 2,575 rpm & (2-blade prop) distance to climb To begin, find the given weight of 3,400 in the first column of the chart. Move across to the pressure altitude column to find the sea level altitude numbers. At sea level, the numbers read zero. Next, read the line that corresponds with the cruising altitude of 8,000 feet. Normally, a pilot would subtract these Flaps up Gear up 2,500 rpm NORMAL CLIMB 30 "Hg 120 PPH fuel flow 110 KIAS Cowl flaps open Standard temperature 1. Add 16 pounds of fuel for engine start, taxi, and takeoff allowance. 2. Increase time, fuel, and distance by 10% for each 7 °C above standard temperature. 3. Distances shown are based on zero wind. From sea level Press Rate of Weight ALT climb (pounds) Distance (feet) fpm Time Fuel used (nautical (minutes) (pounds) miles) 4,000 S.L. 605 000 570 000 530 000 485 000 430 000 365 700 S.L. 700 000 665 000 625 000 580 000 525 000 460 810 000 775 400 8,000 735 000 690 000 635 000 565 two sets of numbers from one another, but given the fact that the numbers read zero at sea level, it is known that the time to climb from sea level to 8,000 feet is 10 minutes. It is also known that 21 pounds of fuel is used and covered during the climb. However, the temperature is 22 °C, which is 7° above the standard temperature of 15 °C. The notes section of this chart indicate that the findings must be increased by ten percent for each 7° above standard. Multiply the findings by ten percent or.10 (10 ×.10 = 1, 1 + 10 = 11 minutes). After accounting for the additional ten percent, the findings should read 11 minutes, 23.1 pounds of fuel, and 22 NM. Notice that the fuel is reported in pounds of fuel, not gallons. Aviation fuel weighs six pounds per gallon, pounds of fuel is equal gallons of fuel (23.1 ÷ 6 = 3.85). The next example is a cruise and range performance chart. This type of table is designed to give TAS, fuel consumption, endurance in hours, and range in miles at specific cruise configurations. Use Figure 11-27 to determine the cruise and range performance under the given conditions. Sample Problem 6 Pressure Altitude...............................................5,000 feet RPM..................................................................2,400 rpm Fuel Carrying Capacity..................38 gallons, no reserve Find 5,000 feet pressure altitude in the first column on the left side of the table. Next, find the correct rpm of 2,400 in the second column. Follow that line straight across and read the TAS of 116 mph and a fuel burn rate gallons per hour. As per the example, the aircraft is equipped with a fuel carrying capacity of 38 gallons. Under this column, read that the endurance in hours hours and the range in miles is 635 miles. Cruise power setting tables are useful when planning crosscountry flights. The table gives the correct cruise power settings, as well as the fuel flow and airspeed performance numbers at that altitude and airspeed. Sample Problem 7 Pressure Altitude at Cruise................................6,000 feet OAT..................................................36 °F above standard Refer to Figure 11-28 for this sample problem. First, locate the pressure altitude of 6,000 feet on the far left side of the table. Follow that line across to the far right side of the table under the 20 °C (or 36 °F) column. At 6,000 feet, the rpm setting of 2,450 will maintain 65 percent continuous power "Hg with a fuel flow rate gallons per hour and airspeed of 161 knots. snoitidnoC setoN Gross weight—2,300 lb. Standard conditions Zero wind Lean mixture Maximum cruise is normally limited to 75% power. 38 gal 48 gal ALT RPM % TAS GAL/ (no reserve) (no reserve) BHP MPH Hour Endr. Range Endr. Range hours miles hours miles 2,500 2,700 86 134 525 4.9 660 2,600 79 129 570 5.6 720 2,500 72 123 600 6.2 760 2,400 65 117 620 6.7 780 2,300 58 111 630 7.2 795 2,200 52 103 625 7.7 790 5,000 2,700 82 134 565 5.3 710 2,600 75 128 600 5.9 760 2,500 68 122 625 6.4 790 2,400 61 116 635 6.9 805 2,300 55 108 635 7.4 805 2,200 49 100 630 7.9 795 7,500 2,700 78 133 600 5.7 755 2,600 71 127 625 6.2 790 2,500 64 121 645 6.7 810 2,400 58 113 645 7.2 820 2,300 52 105 640 7.7 810 10,000 2,650 70 129 640 6.3 810 2,600 67 125 650 6.5 820 2,500 61 118 655 7.0 830 2,400 55 110 650 7.5 825 2,300 49 100 635 8.0 800 Another type of cruise chart is a best power mixture range graph. This graph gives the best range based on power setting and altitude. Using Figure 11-29, find the range at 65 percent power with and without a reserve based on the provided conditions. Sample Problem 8 OAT....................................................................Standard Pressure Altitude...............................................5,000 feet First, move up the left side of the graph to 5,000 feet and standard temperature. Follow the line straight across the graph until it intersects the 65 percent line under both the reserve and no reserve categories. Draw a line straight down from both intersections to the bottom of the graph. At 65 percent power with a reserve, the range is approximately 522 miles. At 65 percent power with no reserve, the range should be 581 miles. The last cruise chart referenced is a cruise performance graph. This graph is designed to tell the TAS performance of the airplane depending on the altitude, temperature, and power setting. Using Figure 11-30, find the TAS performance based on the given information. 14 -13° 12 -9° 10 -5° 8 -1° 6 3° 4 7° 2 11° S.L. 15° 450 500 550 600 500 550 600 650 Range (nautical miles) (Includes distance to climb and descend) )teef 000,1( TLA erusserP C° erutarepmeT dradnatS % % % % % % Associated conditions setoN Range may be reduced 7% if wheel fairings are not installed setoN CRUISE PO 65% MAXIMUM CONTINUOUS 2,800 ISA –20° (–36 °F) Sta Fuel Engine Man. Engine Press IOAT flow per TAS IOAT speed press speed ALT engine °F °C RPM "HG PSI GPH kts MPH °F °C RPM –3 2,450 147 169 450 2,000 19 –7 2,450 149 171 450 4,000 12 –11 2,450 152 175 450 6,000 5 –15 2,450 155 178 450 8,000 –2 –19 2,450 157 181 450 10,000 –8 –22 2,450 160 184 28 –2 2,450 12,000 –15 –26 2,450 162 186 21 –6 2,450 14,000 –22 –30 2,450 159 183 14 –10 2,450 16,000 –29 –34 2,450 156 180 7 –14 2,450 1. Full throttle manifold pressure settings are approximate. 2. Shaded area represents operation with full throttle. 45 minutes reserve at 55% power best economy mixture No reserve Add for each degree Celsius above standard temperature and subtract 1 NM for each degree Celsius below standard temperature. setoN Sample Problem 9 OAT.........................................................................16 °C Pressure Altitude...............................................6,000 feet Power Setting................................65 percent, best power Wheel Fairings..............................................Not installed Begin by finding the correct OAT on the bottom left side of the graph. Move up that line until it intersects the pressure altitude of 6,000 feet. Draw a line straight across to the Mixture Leaned per section 4 Weight 2,300 lb. Wings No Fuel 48 gal usable Wheel Fairings installed Cruise Mid cruise ER SETTING POWER (OR FULL THROTTLE) OUNDS dard day (ISA) ISA +20° (+36 °F) Fuel Fuel Man. Engine Man. flow per TAS IOAT flow per TAS press speed press engine engine "HG PSI GPH kts MPH °F °C RPM "HG PSI GPH kts MPH 150 173 450 153 176 153 176 450 156 180 156 180 450 159 183 158 182 450 161 185 161 185 450 164 189 163 188 450 166 191 163 188 450 163 188 160 184 450 160 184 156 180 450 155 178 65 percent, best power line. This is the solid line, that represents best economy. Draw a line straight down from this intersection to the bottom of the graph. The TAS at 65 percent best power is 140 knots. However, it is necessary to subtract 8 knots from the speed since there are no wheel fairings. This note is listed under the title and conditions. The TAS is 132 knots. Crosswind and Headwind Component Chart Every aircraft is tested according to Federal Aviation Administration (FAA) regulations prior to certification. The aircraft is tested by a pilot with average piloting skills in 90° crosswinds with a velocity two-tenths S0 of the aircraft’s stalling speed with power off, gear down, and flaps down. This means that if the stalling speed of the aircraft is 45 knots, it must be capable of landing in a 9-knot, 90° crosswind. The maximum demonstrated crosswind component is published in the AFM/POH. The crosswind and headwind component chart allows for figuring the headwind and crosswind component for any given wind direction and velocity. Sample Problem 10 Runway..........................................................................17 Wind........................................................140° at 25 knots Refer to Figure 11-31 to solve this problem. First, determine how many degrees difference there is between the runway and the wind direction. It is known that runway 17 means a direction of 170°; from that subtract the wind direction of 140°. This gives a 30° angular difference or wind angle. Next, locate the 30° mark and draw a line from there until it intersects the correct wind velocity of 25 knots. From 2 0,000 18,000 Pressure ALT (feet) 10,000 8,000 6,000 4,000 2,000 Sea level –40° –30° –20° –10° 0° 10° 20° 30° 40° 100 120 Outside air temperature (°C) there, draw a line straight down and a line straight across. The headwind component is 22 knots and the crosswind component is 13 knots. This information is important when taking off and landing so that, first of all, the appropriate runway can be picked if more than one exists at a particular airport, but also so that the aircraft is not pushed beyond its tested limits. Landing Charts Landing performance is affected by variables similar to those affecting takeoff performance. It is necessary to compensate for differences in density altitude, weight of the airplane, and headwinds. Like takeoff performance charts, landing distance information is available as normal landing information, as well as landing distance over a 50 foot obstacle. As Crosswind component tnenopmoc dniwdaeH 0° 10° 70 20° 30° 60 W ind 40° 50 velocity 50° 40 60° 30 70° 20 80° 10 90° % % % Associated conditions Weight 3,600 lb. gross weight Flaps Up Best power Mixture leaned to 100° rich of peak EGT Best economy Mixture leaned to peak EGT 1,650° Max allowable EGT Wheel Fairings installed 140 160 180 200 True airspeed (knots) setoN Subtract 8 knots if wheel fairings are not installed. p Best power o p Best economy 2bl – 3- P. – usual, read the associated conditions and notes in order to ascertain the basis of the chart information. Remember, when calculating landing distance that the landing weight is not the same as the takeoff weight. The weight must be recalculated to compensate for the fuel that was used during the flight. Sample Problem 11 Pressure Altitude...............................................1,250 feet Temperature.........................................................Standard Refer to Figure 10-32. This example makes use of a landing distance table. Notice that the altitude of 1,250 feet is not on this table. It is, therefore, necessary to interpolate to find the correct landing distance. The pressure altitude of 1,250 is halfway between sea level and 2,500 feet. First, find the column for sea level and the column for 2,500 feet. Take the total distance of 1,075 for sea level and the total distance of 1,135 for 2,500 and add them together. Divide the total by two to obtain the distance for 1,250 feet. The distance is 1,105 feet total landing distance to clear a 50 foot obstacle. Repeat this process to obtain the ground roll distance for the pressure altitude. The ground roll should be 457.5 feet. Sample Problem 12 OAT.......................................................................... 57 °F Pressure Altitude.............................................. 4,000 feet Landing Weight...........................................2,400 pounds Headwind.............................................................. 6 knots Obstacle Height..................................................... 50 feet Using the given conditions and Figure 11-33, determine the landing distance for the aircraft. This graph is an example etoN LANDING snoitidnoC Flaps lowered to 40° Power off Hard surface runway Zero wind At sea level & 59 °F Gross Approach speed weight IAS, MPH Total to clear lb Ground roll Ground roll 50 ft OBS 1,600 60 445 1,075 470 1. Decrease the distances shown by 10% for each 4 knots of headwind. 2. Increase the distance by 10% for each 60 °F temperature increase above sta 3. For operation on a dry, grass runway, increase distances (both “ground roll” a a combined landing distance graph and allows compensation for temperature, weight, headwinds, tailwinds, and varying obstacle height. Begin by finding the correct OAT on the scale on the left side of the chart. Move straight line to the correct pressure altitude of 4,000 feet. From this intersection, move straight across to the first dark reference line. Follow the lines in the same diagonal fashion until the correct landing weight is reached. At 2,400 pounds, continue in a straight line across to the second dark reference line. Once again, draw a line in a diagonal manner to the correct wind component and then straight across to the third dark reference line. From this point, draw a line in two separate directions: one straight across to figure the ground roll and one in a diagonal manner to the correct obstacle height. This should be 975 feet for the total ground roll and 1,500 feet for the total distance over a 50 foot obstacle. Associated conditions W (po Power Retarded to maintain 900 feet/on final approach 2 Flaps Down 2 Landing gear Down Runway Paved, level, dry surface 2 Approach speed IAS as tabulated 2 Braking Maximum 2 Pressure altitude (feet) 000 ISA C –40° –30° –20° –10° 0° 10° 20° 30° 40° 50° 2,800 Outside air temperature F –40° –20° 0° 20° 40° 60° 80° 100° 120° DISTANCE ft & 50 °F At 5,000 ft & 41 °F At 7,500 ft & 32 °F Total to clear Total to clear Total to clear Ground roll Ground roll 50 ft OBS 50 ft OBS 50 ft OBS 1,135 495 1,195 520 1,255 dard. d “total to clear 50 ft obstacle”) by 20% of the “total to clear 50 ft obstacle” figure. Stall Speed Performance Charts Stall speed performance charts are designed to give an understanding of the speed at which the aircraft stalls in a given configuration. This type of chart typically takes into account the angle of bank, the position of the gear and flaps, and the throttle position. Use Figure 11-34 and the accompanying conditions to find the speed at which the airplane stalls. Sample Problem 13 Power........................................................................ OFF Flaps....................................................................... Down Gear........................................................................ Down Angle of Bank............................................................. 45° First, locate the correct flap and gear configuration. The bottom half of the chart should be used since the gear and 3,500 ) 000 800 600 500 R R 400 200 60 69 ail T 2,000 1,500 ead 1,000 500 2,600 2,400 2,200 eight Wind component Obstacle (pounds) (knots) height (feet) Angle of bank Gross weight Level 30° 45° 60° 2,750 lb Gear and flaps up rewoP MPH knots MPH 106 Off knots Gear and flaps down rewoP MPH knots MPH Off knots flaps are down. Next, choose the row corresponding to a power-off situation. Now, find the correct angle of bank column, which is 45°. The stall speed is 78 mph, and the stall speed in knots would be 68 knots. Performance charts provide valuable information to the pilot. By using these charts, a pilot can predict the performance of the aircraft under most flying conditions, providing a better plan for every flight. The Code of Federal Regulations (CFR) requires that a pilot be familiar with all information available prior to any flight. Pilots should use the information to their advantage as it can only contribute to safety in flight.