Weight & Balance for CESSNA 172E SKYHAWK

To taxi great distances, it may be advisable to taxi on the step with the water rudder retracted. Turns on the step may be made with safety providing they are not too sharp and if ailerons are used to counteract the overturning tendency. MINIMUM RUN TAKE-OFF. To shorten the take-off run, the following procedure is recommended: With the airplane in the planing position, allow the airspeed to build up to 40 MPH IAS, at which speed one float can be raised out of the water by slowly applying full aileron. When one float leaves the water, apply slight elevator back pressure to complete the take-off. Care must be taken to stop the rising wing as soon as the float is clear of the water, and in crosswinds, raise only the downwind wing. With one float out of the water, the airplane accelerates to take-off speed almost instantly. If porpoising is encountered while on the step, apply additional con- trol wheel back pressure to correct the excessively nose-low attitude. CROSSWIND TAKE-OFF. Start the take-off run with the flaps up and the water rudder extended for better directional control. Flaps are lowered to 10° and the water rudder retracted when the airplane is on the step; the remainder of the take-off is normal. If the floats are lifted from the water one at a time, the down-wind float should be lifted first. TAKE-OFF. NORMAL TAKE-OFF. The use of 10° flaps throughout the take-off run is recommended (take-off distances are given in figure 4-3). Apply full throttle smoothly and hold the control wheel full back. Watch the point where the bow wave leaves the float, and move the con- trol wheel forward slowly as this point moves aft of the wing strut. Slow control movement and light control pressures produce the best results. Attempts to force the airplane into the planing attitude will generally result in loss of speed and delay in getting on the step. The airplane will assume a planing attitude which permits acceleration to take-off speed (50 to 60 MPH IAS) at which time the airplane will fly off smoothly. 2-2 CLIMB. The best rate of climb is obtained with the floatplane at 71 MPH IAS (see figure 4-3) with the flaps up and full throttle. Full rich mixture is used below 5000 feet for engine cooling. For obstruction clearance with 10° flaps, climb at 61 MPH IAS. Such climbs should be of short duration due to reduced cooling at less than best rate-of-climb speeds. In a balked landing (go-around) climb, retract wing flaps immediately to 10°. CRUISE. Observe the same engine speed limits as for the landplane. This allows 69% power for a floatplane equipped with a McCauley 1A175/ATM 8042 propeller. Speed, range and endurance are shown on the Cruise and Range Performance chart, figure 4-4. 2-3 Section III WEIGHT AND BALANCE The following information will enable you to operate your floatplane within the prescribed weight and center of gravity limitations. In figuring your loading problems, be certain that you use the Licensed Empty Weight of your particular floatplane as shown on its Weight and Bal- ance Data Sheet. This sheet, plus an Equipment List, is included with each floatplane as it leaves the factory. When the floats have been installed by anyone other than the factory, the Repair and Alteration Form FAA-337 must be consulted for proper weight and balance information. The loading instructions given in the 172 Owner's Manual for the land- plane should be used as a guide when figuring floatplane weight and balance problems. In conjunction with these instructions, use the Sample Problem, Loading Graph, and Center of Gravity Moment Envelope in this supplement. SAMPLE LOADING PROBLEM Sample Airplane Weight Moment (lbs) (lb-ins. /1000) Your Airplane Weight Moment FLOATPLANE 1. Licensed Empty Weight (Sample Airplane) ... 1471 53.7 2. Oil 8 Qts.* 15 .0.3 25 15 -0.3 3. Pilot & Front Passenger 340 12.2 4. Fuel (30 Gal. at 6#/Gal.) 180 8.6 5. Rear Passenger (1) 170 11.9 6. Baggage 7. Total Aircraft Weight (Loaded). 44 4.2 2220 90.3 8. Locate this point (2220 at 90.3) on the center of gravity envelope, and since this point falls within the envelope the loading is acceptable. Note: Normally full oil may be assumed for all flights. 3-1 3-3 LOADED AIRCRAFT WEIGHT (POUNDS) 3-2 LOAD WEIGHT (POUNDS) 400 350 300 250 200 150 100 50 PILOT & FRONT PASSENGER. 30 FUEL (6 LBS/GAL) 38 GAL MAX- REAR PASSENGERS 20 BAGGAGE OR PASSENGERS ON AUXILIARY SEAT (120# MAX) LOADING GRAPH 0 5 2200 2100 2000 1900 1800 1700 1600 1500 50 10 10 15 20 LOAD MOMENT/1000 (POUND - INCHES) CENTER OF GRAVITY MOMENT ENVELOPE FLOATPLANE 60 70 25 25 80 90 100 LOADED AIRCRAFT MOMENT/1000 (POUND-INCHES) 30 30 НЕИД БИЛЕГОВЕ CELEB OE CEVALLA Section IV OPERATIONAL DATA In the Cruise and Range Performance chart, figure 4-4, range and endurance are given for lean mixture, from 2500 feet to 12, 500 feet. All figures are based on zero wind, 38 gallons of fuel for cruise, McCauley 1A175/ATM 8042 propeller, 2220 pounds gross weight, and standard at- mospheric conditions. For lean mixture figures, the mixture was leaned to maximum RPM. Allowances for fuel reserve, headwinds, take-off and climb, and vari- ations in mixture leaning technique should be made and are in addition to those shown on the charts. Other indeterminate variables such as carbu- retor metering-characteristics, engine and propeller conditions, and tur- bulence of the atmosphere may account for variations of 10% or more in maximum range. 4-1 4-2 AIRSPEED CORRECTION TABLE FLAPS UP FLOATPLANE. 140 FLAPS DOWN CAS 45 54 62 71 80 90 99 •••• CAS 48 54 62 70 79 88 98 107 117 126 136 IAS 40 50 60 70 80 90 100 110 120 130 140 Figure 4-1. POWER OFF STALLING SPEEDS MPH CAS FLOATPLANE 0° 20° EANGLE OF BANK 40° 60° CONDITION FLAPS UP 59 61 67 20 WEIGHT GROSS 2220 LBS. FLAPS 10° 56 58 64 FLAPS 30° 52 53 53 59 59 Figure 4-2. 73 73 79 83 GROSS HEAD IAS WEIGHT POUNDS WIND MPH AT TO CLEAR FLOATPLANE TAKE-OFF DATA TAKE-OFF DISTANCE WITH 10° FLAPS AT SEA LEVEL & 59° F WATER AT 2500 FT. & 50° F WATER TO CLEAR TO CLEAR AT 5000 FT. & 41° F WATER 50 FT RUN 50' OBS. RUN 50' OBS. RUN 50' OBS. AT 7500 FT. & 32° F WATER RUN TO CLEAR 50' OBS, 1700 30 60 1950 30 150 150 58 805 1260 985 1515 1215 1840 1530 2300 425 745 535 915 670 1130 870 1440 155 350 210 445 280 575 385 760 60 1135 1715 1405 2105 1750 2625 2240 3390 625 1045 775 1290 1010 1665 1320 2190 255 520 345 675 460 895 635 1230 2220 15 30 150 19 64 1620 2390 2020 3010 2570 3900 3360 5370 930 420 1505 800 1190 565 1940 1545 2560 2070 3625 NOTE: INCREASE DISTANCES 10% FOR EACH 25°F ABOVE STANDARD TEMPERATURE FOR PARTICULAR ALTITUDE. 2170 1070 770 1470 1070 FLOATPLANE MAXIMUM RATE-OF-CLIMB DATA AT SEA LEVEL & 59° F AT 5000 FT. & 41° F GROSS IAS WEIGHT POUNDS MPH RATE OF CLIMB GALS. OF IAS MPH RATE FROM OF S. L. IAS MPH AT 10,000 FT. & 23° F RATE OF FROM AT 15,000 FT. & 5° F IAS RATE FROM S. L. MPH OF S. L. FUEL CLIMB FUEL CLIMB FUEL CLIMB FPM USED FPM USED FPM USED FPM FUEL USED 1700 960 1.0 65 720 2.1 64 475 3.3 63 240 5.6 1950 68 760 1.0 540 2.4 66 320 4.1 66 100 7.6 2220 71 580 1.0 70 380 2.9 69 175 5.6 • 4-3 NOTES: 1. FLAPS UP, FULL THROTTLE, MIXTURE LEANED FOR SMOOTH OPERATION ABOVE 5000 FT. 2. FUEL USED INCLUDES WARM UP AND TAKE-OFF ALLOWANCE. 3. FOR HOT WEATHER, DECREASE RATE OF CLIMB 20 FT/MIN. FOR EACH 10°F ABOVE STANDARD DAY TEMPERATURE FOR PARTICULAR ALTITUDE. Figure 4-3. CRUISE & RANGE PERFORMANCE 172 & SKYHAWK Gross Weight - 2220 Lbs. Standard Conditions Zero Wind Lean Mixture 38 Gal. of Fuel (No Reserve) MAXIMUM RECOMMENDED CRUISE IS 75% BHP FLOATPLANE ALT. RPM % BHP TAS GAL / ENDR. MPH HOUR HOURS RANGE MILES 2500 2700 2600 2500 2400 2300 2200 8.8 4.3 460 7.9 4.8 490 7.3 5.2 505 6.8 5.6 510 6.4 5.9 510 6.0 6.3 495 5000 2700 8.2 2600 7.5 2500 7.0 2400 99 2300 25062 7500 10,000 12,500 2700 2600 2500 4-4 51 9944 68481 455 5.8 6.1 8284 4052 ខ្ន៖ គ្លីន 9941 4.9 510 5.3 525 5.6. 525 6.0 515 813 Figure 4-4. 5555 1582 370 555 540 515 515 590 1345 620 1420 655 1500 695 1585 GROSS WEIGHT POUNDS FLOATPLANE LANDING DISTANCE LANDING DISTANCE WITH 30° FLAPS AND POWER OFF APPROACH SVI MPH @ SEA LEVEL & 59° F WATER TOTAL TO CLEAR @ 2500 FEET & 50°F @ 5000 FEET & 41° F @7500 FEET & 32° F RUN 50 FT. OBS. WATER RUN TO CLEAR TOTAL 50 FT. OBS. RUN WATER TOTAL TO CLEAR 50 FT. OBS. RUN WATER TOTAL TO CLEAR 50 FT. OBS. Figure 4-5. NOTE: Reduce landing distances 10% for each 5 knots headwind. 99 2220 4-5 essna. SALES AND SERVICE "TAKE YOUR CESSNA HOME FOR SERVICE AT THE SIGN OF THE CESSNA SHIELD". DE11-13 CESSNA AIRCRAFT COMPANY WICHITA, KANSAS