Weight and Balance Oral Flashcards
When should an aircraft be reweighed?
After an extensive repair or alteration that could change its weight or center of gravity.
Why is it necessary to consider the category under which an aircraft is licensed when computing its weight and balance?
Different categories of aircraft have different maximum gross weights and center of gravity ranges.
Where do you find the leveling means that are specified for a particular aircraft?
In the TCDS for the aircraft.
What is meant by tare weight?
The weight of any items used to hold the aircraft on the scales.
What must be done with tare weight when an aircraft is weighed?
It must be subtracted from the scale readings to find the weight of the aircraft.
Why are the distances of all the items installed in an aircraft measured from the datum when computing weight and balance?
This makes it possible to find the center of gravity.
Which has the more critical CG range, an airplane or a helicopter?
Helicopter
What is included in the empty weight of an aircraft?
The weight of the airframe, engines, and all items of operating equipment that has fixed locations and is permanently installed in the aircraft, optional and special equipment, fixed ballast, full reservoirs of hydraulic fluid and engine lubricating oil, and unusable fuel.
What equipment must be installed in an aircraft when it is weighed to find its empty weight center of gravity?
All of the equipment that is listed in the Aircraft Equipment List as “required equipment” or as equipment that is permanently installed
Where is the maximum allowable gross weight of an aircraft found?
TCDS
What is meant by permanent ballast for an aircraft?
Weight that is permanently installed in an aircraft to bring the empty weight center of gravity into allowable limits.
Is there a Federal Regulation requiring that all private aircraft be reweighed periodically?
Nope
What must be done with temporary ballast when weighing an aircraft?
It must be removed from the aircraft.
What must be done to find the empty weight of an aircraft if it has been weighed with fuel in its tanks?
The weight of the fuel and its moment must be subtracted from the weight and moment of the aircraft as it is weighed.
What is meant by minimum fuel as is used in the computation of aircraft weight and balance?
No more fuel than the quantity necessary for one-half hour of operation at rated maximum continuous power. It is the maximum amount of fuel used in weight and balance computations when low fuel may adversely affect the most critical balance conditions.
What is meant by the maximum zero weight of an aircraft?
The maximum permissible weight of a loaded aircraft (passengers, crew, cargo, etc.) minus its fuel.
What is meant by undrainable fuel?
The fuel that is left in the tank, lines, and components when the aircraft is placed in level flight position and the fuel drained at the main fuel strainer. This is also called residual fuel.
Describe the way you would find the empty weight and empty weight center of gravity of an airplane if there are no weight and balance records available.
The aircraft is weighed, and the empty weight center of gravity is computed. These values are recorded in new weight and balance records started for the aircraft.
How does the category of an aircraft affect it’s loaded weight?
Aircraft of different categories have different maximum gross weights and CG ranges
What are two reasons weight and balance control are important in an aircraft?
For safety of flight and for most efficient operation of the aircraft.
What is meant by the datum that is used for weight and balance computations?
A vertical line where all measurements of arm are taken from
Where is the center of gravity for most airplanes located in relation to the center of lift?
Ahead of the center of lift
What is meant by moment in the computation of weight and balance?
A force that tends to cause rotation. It is the product of the weight of an object in pounds and the distance of the object from the datum in inches. Weight x Arm.
How do you find the moment of an item installed in an aircraft?
Weight x Arm (distance from datum) = Moment
What is meant by the arm of an item installed in an aircraft?
The distance, in inches, between the center of gravity of the item and the datum.
Where do you find the arm of an item installed in an aircraft?
TCDS.
What is meant by a moment index?
A moment divided by a constant such as 10, 100, or 1,000
What is meant by the center of gravity range?
The distance in inches between the forward allowable center of gravity and the rearward allowable center of gravity.
What is the significance of the empty weight center of gravity range of an aircraft?
If the empty weight center of gravity falls within the EWCG range, the aircraft cannot be legally loaded in such a way that its loaded CG will fall outside of the allowable loaded CG range. Not all aircraft have an EWCG range.
Why is the empty weight center of gravity range not given in the Type Certificate Data sheets for some aircraft?
Center of gravity range is only given for aircraft that cannot be legally loaded in such a way that their loaded center of gravity will fall outside of the allowable limits
What is meant by the Mean Aerodynamic Chord (MAC)?
The chord of an imaginary airfoil that has the same aerodynamic characteristics as the actual airfoil.
What is a loading envelope?
The enclosed area on a graph of an airplane’s loaded weight and CG location. If lines drawn from the weight and CG cross within this envelope the airplane is properly loaded.
What is meant by permanent ballast for an aircraft?
Weight that is permanently installed in an aircraft to bring the EWCG into allowable limits.
Where must a record be kept of the current empty weight and the current center of gravity of an aircraft?
In the aircraft flight manual or weight and balance records required by 14 CFR §23.1583.
Describe the two most common ways of showing the C.G. location and /or the C.G. range?
It may be expressed in inches from the reference datum or in percent of MAC.
