Weight and Balance Private Pilot Ground School A study tool developed by M.J. Hanwright as part of the development training for CFI certification under the supervision of Joseph J. Zubay, CFI. M J Hanwright
Weight Certified to a maximum gross weight (refer POH) Structural strength of landing gear Power (weight v horse power) Wing loading (strength of the wing) Effects of overloading an aircraft Longer take off and landing roll (major impact with high density altitude) Increased wing loading (maneuvers, turbulence) Requires extra lift to support additional weight Increases stall speed Decreases cruise speed (increased drag) Categories assigned based on weight the wing structure can sustain Normal 3.8G + 1.5G – Straight and level flight is 1G loading 60 degree bank is 2G loading (double the weight supported by the wings)
Weight & Balance CG (center of Gravity) Point where aircraft would balance if suspended CG limits (or envelope) set forward and aft of GC by manufacturer Will have different GC limits if certified in more than one category Loading the aircraft will shift the CG Effects of Forward loading Requires more tail down force and therefore higher angle of attack (reduce cruise speed) Longer take off roll Improved longitudinal (pitch) stability (more tail down force) If past limits - Lack of elevator authority – maybe difficult to flare Effect of Rearward loading Requires less tail down force – lower angel of attack (increased cruise speed) Reduced longitudinal stability (pitch) – if past limits maybe difficult to maintain Higher risk of stall / spin (flat spin) GG limits normal category GG limits utility category
Weight & Balance – Terms Datum Reference point (vertical plane) for measurements of horizontal distances ARM The distance measured from the Datum Measured in inches Can be negative Moment Weight x Arm = Moment (lb- in) CG = Total Moment divided by total Weight Pilot & Front passenger Rear passengers Fuel Baggage 20.2 inches 110.5 inches
Weight & Balance - Terms Basic Empty weight weight of the airplane plus optional equipment includes unusable fuel includes engine oil and operating fluids Every airplane is different – consult the POH Licensed Empty Weight Basic empty weight WITHOUT engine oil Includes undrainable oil only
Weight and Balance Calculations Weight ARM Moment Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight
1. Determine the momement with the following data lbs Moment / 1000 Empty Weight 1350 51.5 Pilot and front passenger 340 Fuel (Std tanks) capacity Oil 8 qts 15 -0.2 A – 69.9 lbs – in B - 74.9 lbs – in C - 77.0 lbs - in
Weight and Balance Calculations Weight ARM Moment Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight
Weight ARM Moment Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight Weight ARM Moment 1350 51500 51.5 x 1000 = 51500 340 Empty Weight …………………...... Front seat occupants............................................ Fuel ( STD Tanks )................................................ Oil …………………………………………………… 1350 51.5 MOM / 1000 340 capacity 15 -0.2 MOM / 1000
Weight ARM Moment -0.2 x 1000 = -200 38gal x 6 = 228 lb Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight Weight ARM Moment 1350 51500 340 228 15 -200 -0.2 x 1000 = -200 Empty Weight …………………...... Front seat occupants............................................ Fuel...................................................................... Oil …………………………………………………… 1350 51.5 MOM / 1000 340 38gal x 6 = 228 lb capacity 15 -0.2 MOM / 1000
12.6
Weight ARM Moment 12.6 x 1000 = 12600 Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight Weight ARM Moment 1350 51500 12600 12.6 x 1000 = 12600 350 228 15 - 200
11
Weight ARM Moment 11 x 1000 = 11000 Answer A – 69.9 lbs – in Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total Weight ARM Moment 1350 51500 340 12600 228 11000 11 x 1000 = 11000 15 - 200 1933 74900 Answer A – 69.9 lbs – in B - 74.9 lbs – in C - 77.0 lbs - in 74900 / 1000 74.9 lbs - in
2. What is the maximum amount of fuel that may be aboard the airplane on takeoff if it is loaded as follows? lbs Moment / 1000 Empty Weight 1350 51.5 Pilot and front passenger 340 Rear passengers 310 Baggage 45 Oil 8qts 15 -0.2 A – 24 gal B – 34 gal C – 40 gal
Weight and Balance Calculations Weight ARM Moment Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight
Weight ARM Moment Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight Weight ARM Moment 51500 51.5 x 1000 = 51500 1350 340 310 45 15 -200 2060 Empty Weight ………………….......................... Pilot and front passenger..................................... Rear passengers ....................................... Baggage................................................................ Oil …………………………………………………… Fuel.....................................................................???. 1350 51.5 MOM / 1000 340 310 45 15 -200
Weight ARM Moment Answers A – 24 gal B – 34 gal C – 40 gal Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total Weight ARM Moment 1350 51500 340 310 45 15 -200 2060 Max Weight 2300 lb Current weight 2060 lb Weight below gross 240 lb Answers A – 24 gal B – 34 gal C – 40 gal Is the CG OK ????? 240 lb / 6 lb = 40 gal
Weight ARM Moment Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total Weight ARM Moment 1350 51500 340 310 45 240 15 -200 2300 Max Weight 2300 lb Current weight 2060 lb Weight below gross 240 lb
12.6
Weight ARM Moment 12.6 x 1000 = 12600 Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total Weight ARM Moment 1350 51500 12600 12.6 x 1000 = 12600 340 310 45 240 15 - 200 2300
22.7
Weight ARM Moment 22.7 x 1000 = 22700 Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total Weight ARM Moment 1350 51500 340 12600 310 22700 22.7 x 1000 = 22700 45 240 15 - 200 2300
4
Weight ARM Moment 4 x 1000 = 4000 Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total Weight ARM Moment 1350 51500 340 12600 310 22700 45 4000 4 x 1000 = 4000 240 15 - 200 2300
11.6
Weight ARM Moment 11.6 x 1000 = 11600 102200 /1000 = 102.2 lb - in Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total Weight ARM Moment 1350 51500 340 12600 310 22700 45 4000 240 11600 11.6 x 1000 = 11600 15 - 200 2300 102200 102200 /1000 = 102.2 lb - in
3. What is the maximum amount of baggage that may be loaded aboard the airplane for the CG to remain within the loading envelope? lbs Moment / 1000 Empty Weight 1350 51.5 Pilot and front passenger 250 Rear passengers 400 Baggage ? Fuel 30 gal Oil 8qts 15 -0.2 A – 120 lb B – 105 lb C – 90 lb
Weight and Balance Calculations Weight ARM Moment Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight
Weight ARM Moment Fuel 30 x 6 = 180 lb Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight Weight ARM Moment 1350 51500 51.5 x 1000 = 51500 250 400 180 15 -200 2195 Empty Weight ………………….......................... Pilot and front passenger..................................... Rear passengers ....................................... Baggage................................................................ Oil …………………………………………………… Fuel..................................................................... 30 Gal 1350 51.5 MOM / 1000 250 400 ???? 15 -0.2 Fuel 30 x 6 = 180 lb
Weight ARM Moment Answers A – 120 lb B – 105 lb C – 90 lb Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total Weight ARM Moment 1350 51500 250 400 180 15 -200 2195 Max Weight 2300 lb Current weight 2195 lb Weight below gross 105 lb Answers A – 120 lb B – 105 lb C – 90 lb Is the CG OK ?????
Weight ARM Moment Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total Weight ARM Moment 1350 51500 250 400 105 180 15 -200 2300 Max Weight 2300 lb Current weight 2195 lb Weight below gross 105 lb
9.5
Weight ARM Moment 9.5 x 1000 = 9500 Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total Weight ARM Moment 1350 51500 9500 9.5 x 1000 = 9500 250 400 105 180 15 - 200 2300
29.5
Weight ARM Moment 29.5 x 1000 = 29500 Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total Weight ARM Moment 1350 51500 250 9500 400 29500 29.5 x 1000 = 29500 105 180 15 - 200 2300
10
Weight ARM Moment 10 x 1000 = 10000 Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total Weight ARM Moment 1350 51500 250 9500 400 29500 105 10000 10 x 1000 = 10000 180 15 - 200 2300
8.7
Weight ARM Moment 8.7 x 1000 = 8700 109000 /1000 = 109 lb - in Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total Weight ARM Moment 1350 51500 250 9500 400 29000 105 10000 180 8700 8.7 x 1000 = 8700 15 - 200 2300 109000 109000 /1000 = 109 lb - in
4. Calculate the moment of the airplane and determine which category is applicable. lbs Mom / 1000 Empty weight 1350 51.5 Pilot and front passenger 310 Rear passenger 96 Fuel 48 gal. Oil 8qt -0.2 A – 79.2 utility category B – 80.8 utility category C – 81.2 normal category
Weight and Balance Calculations Weight ARM Moment Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight
Weight ARM Moment 48 x 6 = 288lb Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight Weight ARM Moment 51.5 x 1000 = 51500 1350 51500 310 96 288 Empty Weight …………………...... Front seat occupants............................................ Rear seat occupants............................................. Fuel...................................................................... Oil ………………………………………………….. 1350 51.5 MOM / 1000 310 96 48 gallons 48 x 6 = 288lb 8 qts
Weight ARM Moment 48 x 6 = 288lb Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight Weight ARM Moment 1350 51500 310 96 288 15 - 200 Front seat occupants............................................ Rear seat occupants............................................. Fuel...................................................................... 310 96 288 48 x 6 = 288lb
11.6
Weight ARM Moment 11.6 x 1000 = 11600 Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight Weight ARM Moment 1350 51500 11.6 x 1000 = 11600 310 11600 96 288 15 - 200 Front seat occupants............................................ Rear seat occupants............................................. Fuel...................................................................... 310 96 288
6.9
Weight ARM Moment 6.9 x 1000 = 6900 Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight Weight ARM Moment 1350 51500 310 11600 96 6900 6.9 x 1000 = 6900 288 15 - 200 Front seat occupants............................................ Rear seat occupants............................................ Fuel...................................................................... 310 96 288
13.75
Weight ARM Moment 13.75 x 1000 = 13750 Answer Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total Weight ARM Moment 1350 51500 310 11600 96 6900 288 13750 13.75 x 1000 = 13750 15 - 200 2059 83550 Answer A – 79.2 utility category B – 80.8 utility category C – 81.2 normal category 83550 / 1000 = 83.5 lb – in
5. Determine if the airplane Weight and balance are within limits Front seat Occupants 340 lb Rear seat Occupants 295 lb Fuel 44 gal. Baggage 56 lb A – within limits B – 20lb overweight, CG within limits C – Weight within limits, CG out of limits forward
Weight and Balance Calculations Weight ARM Moment Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight
Weight ARM Moment Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight Weight ARM Moment Front seat occupants............................................ Rear seat occupants............................................ Fuel...................................................................... Baggage …………………………………………… 56 lb 340 lb 295 lb 44 gal
Weight ARM Moment 1554 x 100 = 155400 44 x 6 = 265 lb Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight Weight ARM Moment 1554 x 100 = 155400 2015 155400 340 295 56 264 2970 Front seat occupants............................................ Rear seat occupants............................................ Fuel...................................................................... Baggage …………………………………………… 56 lb 340 lb 295 lb 44 gal 44 x 6 = 265 lb
340 lb 119 + 170 = 289
Weight ARM Moment 289 x 100 = 28900 Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight Weight ARM Moment 2015 155400 289 x 100 = 28900 340 28900 295 56 264 2970 Front seat occupants............................................ Rear seat occupants............................................ Fuel...................................................................... Baggage …………………………………………… 56 lb 340 lb 295 lb 44 gal
340 lb 340 x 85 = 28900
Weight ARM Moment 340 x 85 = 28900 Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight Weight ARM Moment 2015 155400 340 x 85 = 28900 340 85 28900 295 56 264 2970 Front seat occupants............................................ Rear seat occupants............................................ Fuel...................................................................... Baggage …………………………………………… 56 lb 340 lb 295 lb 44 gal
Weight ARM Moment Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total Weight ARM Moment 2015 155400 340 85 28900 295 121 35695 56 140 7840 264 75 19800 2970 247635
B – 20lb overweight, CG within limits Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total Weight ARM Moment 2015 155400 340 85 28900 295 121 35695 CG = MOM / Weight 247635 / 2970 = 83.37 56 140 7840 264 75 19800 2970 247635 Max weight 2950 Actual Weight 2970 - 20 Answer A – within limits B – 20lb overweight, CG within limits C – Weight within limits, CG out of limits forward Mom Limits @ 2950lb Min 2422 x 100 = 242200 Max 2499 x 100 = 249900
6. Which action can adjust the airplane’s weight to max gross weight and the CG within limits for takeoff? Front seat Occupants 425 lb Rear seat Occupants 300 lb Fuel 44 gal A – Drain 12 gallons of fuel B – Drain 9 gallons of fuel C – Transfer 12 gallons of fuel from the main Tanks to the auxiliary tanks
Weight ARM Moment Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight Weight ARM Moment Front seat occupants............................................ Rear seat occupants............................................ Fuel...................................................................... 425 lb 300 lb 44 gal
Weight ARM Moment 1554 x 100 = 155400 44 x 6 = 265 lb Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total CG = Moment / Weight Weight ARM Moment 1554 x 100 = 155400 2015 155400 425 85 36125 300 121 36300 264 75 19800 3004 247625 Front seat occupants............................................ Rear seat occupants............................................ Fuel...................................................................... 425 lb 300 lb 44 gal 44 x 6 = 265 lb
A – Drain 12 gallons of fuel B – Drain 9 gallons of fuel Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total Weight ARM Moment 2015 155400 425 85 36125 300 121 36300 264 75 19800 CG = mom / weight 247625 / 3004 = 82.43 3004 247625 Max Weight 2950 lb Actual weight 3004 lb 54 lb Answer A – Drain 12 gallons of fuel B – Drain 9 gallons of fuel C – Transfer 12 gallons of fuel from the main Tanks to the auxiliary tanks CG limits Fwd 82.1 Aft 84.7 Actual 82.43
A – Drain 12 gallons of fuel B – Drain 9 gallons of fuel Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total Weight ARM Moment 2015 155400 425 85 36125 300 121 36300 210 264 75 15750 19800 CG = mom / weight 243575 / 2950 = 82.56 3004 2950 243575 247625 Max Weight 2950 lb Actual weight 2950 lb Max Weight 2950 lb Actual weight 3004 lb 54 lb Answer A – Drain 12 gallons of fuel B – Drain 9 gallons of fuel C – Transfer 12 gallons of fuel from the main Tanks to the auxiliary tanks CG limits Fwd 82.1 Aft 84.7 Actual 82.56
7. What effect does a 35 gallon fuel burn have on the weight and balance if the airplane weighed 2890 pounds and the moment / 100 was 2452 at takeoff? A – Weight is reduced by 210 lbs and the CG is unaffected B – Weight is reduced to 2680 lbs and the CG moves forward C – Weight is reduced by 210 lbs and the CG is aft of limits
Weight 2890 lb Mom / 100 2452
Weight ARM Moment Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total Weight ARM Moment 2890 245200 Weight change 35 gal x 6 = 210 lbs 2890 – 210 = 2680 lbs Mom change ?
Weight ARM Moment Weight and Balance Calculations Empty weight Pilot & Front Passenger Rear Passengers Baggage area 1 Baggage area 2 Fuel main tanks Fuel Aux tanks Oil Total Weight ARM Moment 2680 2890 229400 245200 Weight change 35 gal x 6 = 210 lbs 2890 – 210 = 2680 lbs Mom change 245200 – 15800 = 229400
Weight 2680 lb Mom / 100 2294
7. What effect does a 35 gallon fuel burn have on the weight and balance if the airplane weighed 2890 pounds and the moment / 100 was 2452 at takeoff? A – Weight is reduced by 210 lbs and the CG is unaffected B – Weight is reduced to 2680 lbs and the CG moves forward C – Weight is reduced by 210 lbs and the CG is aft of limits