Presentation on theme: "Keeping the Shiny Side Up"— Presentation transcript:
1 Keeping the Shiny Side Up Weight & BalanceKeeping the Shiny Side UpShow B-52 VideoWritten for the Notre Dame Pilot InitiativeBy the Pilots of the University of Notre Dame“Teaching the Science, Inspiring the Art, Producing Aviation Candidates!”
4 LimitationsAn airplane must only be flown within certificated limits of weight and balance to ensure that it remains controllable, performs adequately and is not overstressed. Correct weight and balance means:Maximum allowable weight is not exceeded; andCenter of gravity (CG) is within a specified range
5 Terms Center of Gravity Center of Lift (Pressure) Basic Empty Weight Point at which the airplane’s entire weight is assumed to be concentratedCenter of Lift (Pressure)Point at which the airplane’s entire lift assumed to be concentratedBasic Empty WeightGenerally, the weight of the airframe, unusable fuel, unusable/full oil, and full hydraulic fluid
6 ForcesThe goal in flying any airplane is to always remain in positive controlKnowing how the forces that act on our airplane balance helps us predict how it will flyAX = BYMoment arm of AMoment arm of BXYABFulcrum
7 Mathematical Treatment “Teaching the Science, Inspiring the Art, Producing Aviation Candidates!”
8 Practical ExerciseJoe (150) and Jeff (200) want to fly to Cocoa Beach. They decide to take Brady (231) with them for some extra practice with them.The golden helmets (15) are in the back seat and footballs (35) are in the baggage compartment.Are we good to go?
9 Weight We want to add up all of the weights in our airplane Start with BEWThen we add usable fuel (and oil), passengers, and cargoFAA standard passenger is 170 lbsAlways ascertain the proper weight of pax and cargoAVGAS is 6 pounds per gallonOil is 7.5 pounds per gallonWater is 8.35 pounds per gallon
11 BalanceThe aircraft can only be controlled if it is positively stable.Maintaining the proper center of gravity assures us that the airplane will be controllable upon liftoffThe Center of Gravity must be forward of the Center of Lift (Pressure) in order to achieve positive dynamic stability
17 Center of Gravity Envelope Very similar to previous slide, x axis is inches instead of pound-inches
18 Stability & Control Center of Gravity concerns: Unable to compensate with elevator in pitch axisWeight and Balance becomes critical – stalls & landingToo much weight in the front of the airplane will cause it to pitch downwardToo much weight in rear of aircraft will cause aircraft to pitch upward
19 Tricks of the TradeFlying with a rear CG is more efficient but decreases stabilityFlying with a forward CG decreases performance and makes flaring for landing more difficult, yet makes for a quick stall recoveryFlying over gross weight may overstress the airplane and cause it to self-destruct
20 ConclusionsIt is very easy to make an airplane unflyable by misloading it.When you fly outside of tolerance, you become a test pilot.Understanding weight and balance will allow you to maximize performance and understand poor performance
21 Say IntentionsOne Passenger, No baggage, Full Fuel, Calm Winds, No Ceiling, PIC-25 hoursGo for itThree Passengers, Full Fuel, Golf Clubs for 4 (10 each), Scattered T-storms, PIC-500 hoursCalculations bring you right to max GW and a rear CGGo for it with that experienceSecond scenario again (Passengers are his grandmother, girlfriend, and the bosses 3 year old daughter), PIC-50 hours, 5 hours in an ArcherNo go, passengers are not easy to deal with, pilot has little experience in type, and the airplane will be difficult to control in turbulence
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