Weight and Balance Flashcards
Airplane Flight Manual AFM
An PAA approved document, prepared by the holder of a type certificate for an aircraft, that specifies the operating limitations and contains the required markings and placecards and other information applicable to the regulations under which the aircraft was certified.
Arm
The horizontal distance from the reference datum to the CG of an item.
Ballast
A weight installed or carried in an aircraft to move the center of gravity to a location within its allowable limits.
Basic Empty Weight
Standard empty weight plus optional equipment.
CG Center of Gravity
The point at which an airplane would balance if suspended. Its distance from the reference datum is determined by dividing the total moment by the total weight of the airplane
Center of Lift
The location along the chord line of an airfoil at which all the lift forces produced by the air foil are considered to be concentrated.
CG Arm
the arm obtained by adding the airplane’s individual moments and dividing the sum by the total weight.
CG Limits
The extreme CG locations within which the aircraft must be operated at a given weight.
CG Limit Envelope
An enclosed area on a graph of the airplane loaded weight and the CG location. If lines drawn from the weight and CG cross within this envelope, the airplane is properly loaded.
Datum
An imaginary vertical plane or line from which all measurements of arms are taken. The datum is established by the manufacturer. Once the datum has been selected, all moment arms and the location of CG range are measured from this point.
Empty Weight
The weight of the airframe, engines, all permanently installed equipment, and unusable fuel.
Load Factor
The ratio of the maximum load an aircraft can sustain to the total weight of the aircraft.
Maximum Zero Fuel Weight
The maximum authorized weight of an aircraft without fuel. This is the total weight for a particular flight minus the fuel. It includes the aircraft and everything that is carried on the flight except the wight of the fuel.
moment
the product of the weight of an item multiplied by its arm.
Pilot’s operating Handbook (POH)
An Faa-approved document published by the airframe manufacturer that lists the operating conditions for aa particular model of aircraft and its engine(s)
Ram Weight
The zero fuel weight plus all of the usable fuel on board
Station
A location along the airplane fuselage usually given in terms of distance from the refernece datum
Unusable Fuel
The fuel remaining after a test has been completed in accordance with governmental regulations
Usable Fuel
The fuel available for flight planning.
Useful Load
The difference between takeoff weight or ramp weight if applicable, and basic empty weight.
Zero Fuel Weight
The weight of an aircraft without fuel.
The weight and balance system commonly employed among aircraft consists of what 3 equally important elements?
The weighing of the aircraft
The maintaining of the weight and balance records.
and the proper loading of the aircraft. An inaccuracy in any of the above elements defeats the purpose of the system.
True/False The final loading calculations are meaningless if either the aircraft has been improperly weighed or the records contain an error.
True.
Effects of Overweight
Longer takeoff run. Reduced rate and angle of climb. Service ceiling lowered. Cruise speed reduced. Cruise range is shortened. Maneuverability is decreased. Longer landing roll. Excessive loads on structure and landing gear imposed.
Forward CG
Longer takeoff roll. Longer landing roll. Higher stall speed. Easier stall recovery. Decreased cruise speed.
Aft CG
Lower stall speed.
Reduced elevator authority.
Difficult stall recovery.
Faster Cruise speed.
Forward CG Why: Longer takeoff roll
Because the weight is concentrated forward in the aircraft, it will need to gain more airspeed before it is able to reach liftoff speed.
Forward CG Why: Longer Landing roll
The forward weight will create momentum in pulling the aircraft down the runway. Also, there won’t be as much weight over the main wheels so braking will be less effective.
Forward CG Why: Higher stall speed
The aircraft will stall at a higher airspeed due to “wing loading.” The wins will seem to be carrying more weight and will need to fly at a higher airspeed to produce enough lift to carry the additional feel of weight.
Forward CG Why: Easier Stall recovery
the forward cg will assist the aircraft in recovering from a stall
Forward CG Why: Decreased cruise speed
Because the cg is forward, the pilot will need to trim the aircraft “nose-up” to maintain altitude at cruise. The deflected trim tab will cause drag with the relative airflow.
Aft CG Why: Lower stall speed
with the cg aft the aircraft will have lower stall speed due to decreased wing loading.
Aft CG Why: Reduced elevator authority
The aft cg will cause the elevator and rudder to be less effective. This is because the arm from the cg to the elevator and rudder is shorter.
Aft CG Why: More difficult stall recovery
because the weight is concentrated aft in the aircraft, it will be more difficult to lower the angle of attach in order to recover from a stalled condition
Aft CG Why: Faster cruise speed.
The aft cg will not cause the trim tab on the elevator to be deflected as far. Creating less drag at cruise.
Weight x Arm =
Moment
CG=
Weight x Arm =Moment; Moment divided by weight.
Weight shift formula
Weight Shifted/Total weight = Change of CG/ Distance weight is shifted
100/8000 = Change of CG/120 Changeof CG = 1.5 inches.
What chapter of what book is the CG limit Envelope located?
Chapter 6 of the POH
Fuel weighs how much per gallon?
6lbs
