General: Weight & Balance 🔊

Question 1

What is the datum and its purpose when making weight and balance computations?

Answer 1

It is an imaginary vertical line or plane from which all measurements are taken both forward and after to determine the relative location of items in the aircraft

Question 2

What items concerning weight and balance can be found in the type certificate data sheet?

Answer 2

Datum, CG limits, unusable fuel and oil, baggage capacity, seat locations, fuel capacity, leveling means, engine horsepower, weight maximum *DCUBS FLEW

Question 3

What is the purpose of weight and balance control?

Answer 3

Safety and efficiency in flight

Question 4

When computing weight and balance, what is the moment and how is it obtained?

Answer 4

Moment is a force which tends to rotate the aircraft about one of its axes. It’s obtained by multiplying the weight of an item in pounds by the distance of the item from the datum. It is expressed in inch pounds

Question 5

How would a negative moment be obtained forward of the datum?

Answer 5

By adding weight

Question 6

What is the arm of an item and how is it obtained?

Answer 6

It’s the distance in inches and item is located either forward or after the datum, it’s obtained by actually measuring or from weight and balance records

Question 7

What is tare weight and how is it handled when making weight and balance calculations?

Answer 7

Tare is the weight of extra equipment used for weighing aircraft such as chalks, jacks and chains. It must be subtracted from the scale readings in order to obtain the empty way of the aircraft.

Question 8

What is meant by minimum fuel and how is a calculated for weight and balance?

Answer 8

Amount of fuel needed for an extreme condition check to see if the center of gravity will be out of limits in that situation. For reciprocating engine airplanes, the calculation is maximum except takeoff horsepower divided by two. METO÷2

Question 9

What is meant by residual fuel?

Answer 9

Fuel remaining in the tanks, sumps, lines, and engine after fuel exhaustion also known as unusable. It is part of the aircraft empty weight

Question 10

What is meant by center of gravity range?

Answer 10

Distance in inches from the most forward acceptable center of gravity to the most rearward

Question 11

What is an aircraft loading graph?

Answer 11

A method for determining load distribution so the aircraft remains with an operating CG

Question 12

How would you determine the empty weight and empty weight CG of an aircraft if all weight and balance records are missing?

Answer 12

Re-weigh the aircraft and calculate new weight and balance records

Question 13

What is the difference between fixed wing and rotary wing aircraft CG ranges?

Answer 13

CG location and helicopters are much more critical than fixing aircraft, some helicopters CG range will be less than 3 inches

Question 14

When weighing an aircraft to determine the empty weight CG, what must you do regarding the fixed equipment which is normally carried in the aircraft?

Answer 14

All operational equipment must be included in the aircraft’s empty weight.

Question 15

Why do some manufacturers specify an empty CG even though the aircraft is not operated at this empty weight?

Answer 15

When the empty weight CG falls within the empty weight CG range, it’s unnecessary to perform a weight and balance check if standard loading and seating arrangements are used

Question 16

Why must the aircraft category be considered when computing weight and balance?

Answer 16

Some aircraft are certified in both normal and utility categories, meaning a different maximum allowable gross weight depending on which category the aircraft will be operating in that day

Question 17

Where is the center of gravity located in relation to the aerodynamic center of lift for most airplanes?

Answer 17

In front of the center of lift

Question 18

What are two common ways of representing the CG of an aircraft?

Answer 18

Inches from the datum or percent of mean aerodynamic chord (% of MAC)

Question 19

Is there a federal regulation that requires the regular re-weighing of private aircraft?

Answer 19

No

Question 20

Where must a record of the most recent empty weight and center of gravity be kept?

Answer 20

It should be maintained in the aircraft, flight manual or weight and balance records (FAR 23.1583)

Question 21

What should be done regarding aircraft fuel when performing a weight and balance when draining is not an option?

Answer 21

When weighing with full fuel tanks, the exact weight per gallon should be verified with a hydrometer. The weight of usable fuel must be mathematically subtracted in the weight and balance calculations.

Question 22

How should aircraft fuel be drained for weight and balance?

Answer 22

Level the aircraft per the TCDS then drain the fuel supply until empty, only leaving the unusable fuel in the system

Question 23

What is ballast?

Answer 23

It can be lead bars, metal plates, shot bags, sandbags, or other items of weight which are placed in the aircraft to attain a desired CG location.

Question 24

If the forward CG limit of an aircraft is exceeded after installing several items in the engine compartment, how could the limit be returned to limits without removing or changing any of the newly installed equipment?

Answer 24

By adding a ballast weight in the rear of the aircraft

Question 25

What are the placard requirements for ballast?

Answer 25

Ballast location must have a placard stating any limitations on contents that are necessary under the loading requirements

Question 26

What is recommended for marking a permanent ballast?

Answer 26

In red paint mark “permanent ballast do not remove”

Question 27

How should an aircraft be leveled for weighing during a weight and balance?

Answer 27

Leveled per the requirements of the aircraft specification or type certificate data sheet

Question 28

Name one common method of leveling an aircraft during weight and balance.

Answer 28

You may use a built-in leveling scale and a plum bob

Question 29

Describe a plumb bob and its use.

Answer 29

It’s a heavy object in the shape of a cone that is used to determine a spot directly below the point the tool is hanging from

Question 30

How can you determine if a part will affect the CG without weighing the aircraft?

Answer 30

By basic weight and balance computations if weight imbalance records are up to date.