1. READ GLEIM CHAPTER 5 (5.7-5.9) 17 QUESTIONS
JEP CHAPTER 8 SECTION B (8-29 TO 8-47)
PHAK CHAPTER 9
ASA Chapter 8-1 through 8-20

2. Private Pilot Ground School Weight & Balance Class #5

3. Content of Lesson Terms used in weight and balance calculations.
Effects of weight and the distribution of weight
Various Manufacturers display of weight and balance info and use of
B-19 weight and balance computations sample and actual problems

4. Weight and Balance Terminology
Reference Datum- imaginary vertical plane from which all horizontal distances are measured for balance purposes

5. Different Datum Locations

6. Weight and Balance Terminology
Standard Empty Weight - the weight of a standard airplane including unusable fuel, full operating fluids and full oil.
Basic empty weight - Standard empty weight plus optional equipment

7. Weight and Balance Terminology
Max ramp weight - max weight of aircraft for taxi operations (it includes start taxi and run-up fuel)
Max takeoff weight - max weight approved for the start of the takeoff run
Max landing weight - max weight approved for the landing touchdown

8. Weight and Balance Terminology
Useful load - Difference between take off weight and basic empty weight
Payload - Weight of the occupants, cargo and baggage
Zero fuel weight - weight exclusive of usable fuel useful for calculations when fuel is a variable

9. Weight and Balance Terminology
Tare - Weight of chocks, blocks, stands ect used when weighing an aircraft
Arm - the horizontal distance from the reference datum
Moment - the force exerted by a weight using an arm usually measured in in/lbs or foot/lbs
Station- a designated location on the fuselage measured from the reference datum

10. Weight and Balance Terminology
Center of Gravity - The point at which an airplane would balance if suspended from that point
C. G. Arm (center of gravity)- The arm obtained by adding the airplane’s individual moments and dividing the sum by the total weight

11. Weight and Balance Terminology
C. G. Limits - The extreme center of gravity location within which the airplane must be operated at a given weight.
Useable Fuel - Fuel available for flight planning

12. Weight and Balance Terminology
Unusable Fuel - Fuel remaining after a runout test.
Falcrum - Support point

13. Principles of Weight and Balance
Weight x Arm = Moment
Arm = Moment/Weight
Weight=Moment/Arm

14. WAM

15. A balanced teeter-totter

16. - ARMS

17. Determining Gross Weight & Center of Gravity
Three ways
Computation method,
Tabular method, and
Graphical method

18. Computation method (p135)

19. Tabular method (p136)
Like B-19, uses tables to quickly determine arm and moment.

21. Graphical method (p136)
Also used for B-19 to determine gross weight moment limits (6-12)
Loading graphs commonly found in cessna POH’s
Easy way to determine if aircraft is in the envelope.

22. Graphical method (p136)

25. High gross weights

26. High gross weights Added wear on engine Increased fuel consumption
Overheating in climb

27. High gross weights
It is a violation of FARs to exceed gross weight limits

28. LLF
Limit load factors normal utility aerobatic

29. High gross weights
Over loading may accelerate metallic fatigue failures
Baggage floor may have limits on weight for structural reasons
Stability may be effected to the negative if overloaded

30. High gross weights
The higher the gross weight the higher the stall speed
Less reserve angle of attack
Load distribution

31. Safety Manufacturer set limits for controllability and maneuverability
Certification procedures demand a certain amount of oscillations before dampening out this determines where the aft cg is located

32. Forward CG gives: Higher stall speed,
Higher elevator control forces (critical in takeoff and landing phase),
Slower cruise, (higher angle of attack need more tail down force.)
More overall stability,
Longer takeoff and landing distance,

33. Aft C of G
With an aft cg recovery from a stall spin harder or impossible.
Lower stall speed
Less elevator control forces in T.O. landing
Faster cruise, (Lower angle of attack need less tail down force.)
Less overall stability, Less takeoff and landing distance

34. Lateral Balance
Lateral unbalance usually a result of unbalanced fuel load will cause additional lift and drag on heavy side

35. STANDARD WEIGHTS

36. Weights
Oil weighs 7.5 lbs. per gallon. Since oil is usually measured in quarts, each quart weights 1 7/8 pounds.
The average weight for passengers is approx. 170 lbs.
Aviation fuel (Avgas)weighs 6 lbs. Per gallon
2 gallons of fuel = 12 lbs.

37. Problem #1. Determine the CG of these three objects
Weight A=100 lbs Arm 50
Weight B=100 lbs Arm 90
Weight C=200 lbs Arm 150
What is the CG
=110

38. Problem #2 Basic Empty Weight = 1340 Arm=37
Front seats=140 lbs Pilot and 115 pound passenger, Moment=8,925
Rear seat =212 lbs passenger and 97 pound passenger. Arm 72
Useable Fuel=40 Gallons, Arm 48
Baggage 50 lbs. Moment 4,600
To stay in envelope CG limits=+35.6 to What is the CG? Is the aircraft in the envelope?

39. Problem #2 Answer CG=44.1 No the aircraft is not in the envelope.
Can we fly the aircraft?
No, not legal
One possible solution would be to trade places between the 212 pound rear-seat occupant and the 115 pound occupant. Using a weight shift equation we can see how far the CG will move.

40. Weight Shift Equation
By manipulating the formula we find that CG=(Weight shifted X Distance it is shifted)/Total Weight

41. Weight Shift Equation Weight to be shifted is equal to what?
(212lbs-115lbs)
Distance it is shifted is equal to what?
(72 inches-35inches)

42. Weight Shift Equation Total Weight = What? 2,194
( )X(72-35)/2,194=
97X37/2,194=
1.6 inches
This makes the new CG 42.5 within limits

43. B-19 PROBLEM BB2 PILOT 190 LBS ARM 109 FRONT PASSENGER 180 LBS ARM 108
BACK SEAT 15 LBS
FUEL 40 GALLONS
FLIGHT 1.5 HOURS
GPH 7.8
START RUNUP TAXI 1 GALLON