Weight and BalanceWeight and Balance
Joey GiangrassoJoey Giangrasso
This is a study tool developed by Joey Giangrasso as part of the development training for CFI certification under the supervision of Joseph J. Zubay, CFI.
Weight and BalanceWeight and Balance
SafetySafety
Calculating Center of Gravity (CG)Calculating Center of Gravity (CG)
Loading configurationsLoading configurations
SafetySafety Stay within the limitationsStay within the limitations
Center of GravityCenter of Gravity Location in airplane where all forces Location in airplane where all forces
are balancedare balanced
All three axes pass through CGAll three axes pass through CG
String analogy String analogy
CG RangeCG Range Check it out one timeCheck it out one time
Weight at a Distance Weight at a Distance Origin (Place to Start) Origin (Place to Start)
Weights are known Weights are known
See Saw See Saw • Middle Middle • Weight on both ends Weight on both ends
INSERT PICTURE HEREINSERT PICTURE HERE
AirplanesAirplanes
Datum Line=imaginary line of Datum Line=imaginary line of referencereference
Arm=distance from datum (InchesArm=distance from datum (Inches
Weight=measured (pounds)Weight=measured (pounds)
Moment Moment
More TermsMore Terms Gross Take Off WeightGross Take Off Weight max max
weight at take offweight at take off
1 gal1 gal AvGas = AvGas = 6 lbs6 lbs 1 gal 1 gal Oil = Oil = 7.5 lbs7.5 lbs
Basic Empty WeightBasic Empty Weight normally normally includes unusable fuel and full oil includes unusable fuel and full oil (Early 1970s) (Early 1970s)
EquationsEquations
Moment=Weight x ArmMoment=Weight x Arm
Center of Gravity = Center of Gravity = Total MomentTotal Moment Total WeightTotal Weight
The TableThe Table
CG=Total Moment/Total Weight=_______________
Limitations
Forward _________(CG or Mom) Aft ______(CG or Mom)
Two ChartsTwo Charts Used to determine moments Used to determine moments
• READ EVERYTHING ON THE CHART READ EVERYTHING ON THE CHART FIRSTFIRST
• Figure 35Figure 35
Table Table
Line Graph Line Graph
Two ChartsTwo Charts Used to determine moments Used to determine moments
• READ EVERYTHING ON THE CHART READ EVERYTHING ON THE CHART FIRSTFIRST
Table Table
Line Graph Line Graph
SAMPLE 1SAMPLE 1 Basic Empty Weight (B.E.W.) 2015lbsBasic Empty Weight (B.E.W.) 2015lbs Moment Moment
155,400 155,400 Front 200lbsFront 200lbs Back 100lbsBack 100lbs Fuel 24gals Fuel 24gals
AND THE ANSWER IS…..AND THE ANSWER IS….. CG=79.75CG=79.75
Total weight 2479Total weight 2479 Total moment 197,720Total moment 197,720
Two ChartsTwo Charts Used to determine moments Used to determine moments
• READ EVERYTHING ON THE CHART READ EVERYTHING ON THE CHART FIRSTFIRST
Table Table
Line GraphLine Graph
Sample 2Sample 2 B.E.W 1350 lbsB.E.W 1350 lbs Empty Moment 51500 inch-lbsEmpty Moment 51500 inch-lbs Front 200lbsFront 200lbs Back 200lbsBack 200lbs Fuel 30 galsFuel 30 gals Oil 15qtsOil 15qts
And the answer is…..And the answer is….. Total moment 81800Total moment 81800
Total weight 1945Total weight 1945
Within limitations…..YESWithin limitations…..YES
Forward and Aft LoadingForward and Aft Loading Forward Forward
AftAft