FAA Question Chapter 6, Section A

6-1 AMG003

When computing weight and balance, an airplane is considered to be in balance when

A— the average moment arm of the loaded airplane falls within its CG range.

B— all moment arms of the plane fall within CG range.

C— the movement of the passengers will not cause the moment arms to fall outside the CG range.

6-1. Answer A. JSGT 6A, FGH

The CG can be thought of as the average moment arm for the aircraft. This value must fall within an allowable range to be considered safe for flight.

6-2 AMG003

What tasks are completed prior to weighing an aircraft to determine its empty weight?

A— Remove all items except those on the aircraft equipment list; drain fuel and hydraulic fluid.

B— Remove all items on the aircraft equipment list; drain fuel, compute oil and hydraulic fluid weight.

C— Remove all items except those on the aircraft equipment list; drain fuel and fill hydraulic reservoir.

6-2. Answer C. JSGT 6A, FGH

According to FAR Part 23, the empty weight of an aircraft includes all items on the aircraft’s minimum equipment list, permanent ballast, unusable fuel, full hydraulics, and full oil (aircraft certified prior to March 1, 1978, are weighed with only the undrainable oil)

6-3 AMG003

The useful load of an aircraft consists of the

A— crew, usable fuel, passengers, and cargo.

B— crew, usable fuel, oil, and fixed equipment.

C— crew, passengers, usable fuel, oil, cargo, and fixed equipment.

6-3. Answer A. JSGT 6A, FGH

The useful load of an aircraft is the difference between the maximum gross weight and the empty weight. It includes items such as passengers and crew, usable fuel, and cargo.

6-4 AMG003

Which of the following can provide the empty weight of an aircraft if the aircraft’s weight and balance records become lost, destroyed, or otherwise inaccurate?

A— Reweighing the aircraft.

B— The applicable Aircraft Specification or Type Certificate Data Sheet.

C— The applicable flight manual or pilot’s operating handbook.

6-4. Answer A. JSGT 6A, FGH
If an aircraft’s weight and balance records become lost or destroyed, the aircraft’s weight can only be established by reweighing the aircraft. The Aircraft Specification or Type Certificate Data Sheet is wrong because an aircraft’s type certificate data sheet only lists maximum weight and not an empty weight; and the flight manual or pilot’s operating handbook is wrong because an aircraft’s flight manual contains an average empty weight for that model aircraft.

6-5 AMG003

In the theory of weight and balance, what is the name of the distance from the fulcrum to an object?

A— Lever arm.

B— Balance arm.

C— Fulcrum arm.

6-5. Answer A. JSGT 6A, FGH

In the theory of weight and balance, the name given to the distance from the fulcrum to any object is the lever arm. The lever arm is multiplied by the weight of the object to find the moment. In actual aircraft weight and balance problems, an arm is the distance from the datum to an item.

6-6 AMG089

1. Private aircraft are required by regulations to be weighed periodically.

2. Private aircraft are required to be weighed after making any alteration.

Regarding the above statements,

A— neither No. 1 nor No. 2 is true.

B— only No. 1 is true.

C— only No. 2 is true.

6-6. Answer A. JSGT 6A, FGH

Both of these statements are false. There is no regulation that requires private aircraft to be reweighed. Generally, after alterations, the weight changes are calculated and recorded in the aircraft’s records. However, it is good operating practice to reweigh an aircraft whenever alterations may substantially affect an aircraft’s weight and balance.

6-7 AMG003

To obtain useful weight data for purposes of determining the CG, it is necessary that an aircraft be weighed

A— in level flight attitude.

B— with all items of useful load installed.

C— with at least minimum fuel (1/12-gallon per METO horsepower) in the fuel tanks.

6-7. Answer A. JSGT 6A, FGH

When an aircraft is weighed, it must be in a level flight attitude for the scale readings to be accurate. Weigh points, level points, and procedures for reweighing are usually contained in the Type Certificate Data Sheets and are provided by the manufacturer’s maintenance manual.

6-8 AMG003

What type of measurement is used to designate arm in weight and balance computation?

A— Distance.

B— Weight.

C— Weight/distance.

6-8. Answer A. JSGT 6A, FGH

Arm is the horizontal distance in inches or feet from the reference datum to an item of equipment.

6-9 AMG003

What determines whether the value of a moment is preceded by a plus (+) or a minus (–) sign in aircraft weight and balance?

A— The location of the weight in reference to the datum.

B— The result of a weight being added or removed and its location relative to the datum.

C— The location of the datum in reference to the aircraft CG.

6-9. Answer A. JSGT 6A, FGH

The location of items in an aircraft are given as positive or negative values according to their location relative to the reference datum. Items forward of the datum have a negative arm and items aft of the datum have a positive arm.

6-10 AMG003

What should be clearly indicated on the aircraft weighing form?

A— Minimum allowable gross weight.

B— Weight of unusable fuel.

C— Weighing points.

6-10. Answer C. JSGT 6A, FGH

The weighing points should be clearly indicated on the aircraft weighing forms because the arm values used for the scale readings are based on these locations.

6-11 AMG003

If the reference datum line is placed at the nose of an airplane rather than at the firewall or some other location aft of the nose,

A— all measurement arms will be in negative numbers.

B— all measurement arms will be in positive numbers.

C— measurement arms will be in both positive and negative numbers.

6-11. Answer B. JSGT 6A, FGH

All measurement arms aft of the datum carry a positive (+) value and arms in front of the datum carry a negative (–) value. When the datum is located in front of the aircraft, all measurement arms are positive.

6-12 AMG003

Zero fuel weight is the

A— dry weight plus the weight of full crew, passengers, and cargo.

B— basic operating weight without crew, fuel, and cargo.

C— maximum permissible weight of a loaded aircraft (passengers, crew, and cargo) without fuel.

6-12. Answer C. JSGT 6A, FGH

Zero fuel weight is the maximum permissible weight of a loaded aircraft, including the payload (passengers, crew, and cargo), but excluding the fuel load.

6-13 AMG003

The empty weight of an airplane is determined by

A— adding the net weight of each weighing point and multiplying the measured distance to the datum.

B— subtracting the tare weight from the scale reading and adding the weight of each weighing point.

C— multiplying the measured distance from each weighing point to the datum times the sum of scale reading less the tare weight.

6-13. Answer B. JSGT 6A, FGH

The empty weight includes the weight of extra items on the weighing scale that are not part of the aircraft. To determine the empty weight of an aircraft being weighed, add the weight of each scale reading and subtract out the tare weight.

6-14 AMG003

When dealing with weight and balance of an aircraft, the term “maximum weight” is interpreted to mean the maximum

A— weight of the empty aircraft.

B— weight of the useful load.

C— authorized weight of the aircraft and its contents.

6-14. Answer C. JSGT 6A, FGH

Maximum weight is the maximum authorized weight of the aircraft and its contents. This value may be found in the Aircraft Specifications or Type Certificate Data Sheet.

6-15 AMG003

If most modern aircraft are designed so that if all seats are occupied, full baggage weight is carried, and all fuel tanks are full, what will the weight condition of the aircraft be?

A— It will be in excess of maximum takeoff weight.

B— It will be at maximum basic operating weight (BOW).

C— It will be at maximum taxi or ramp weight.

6-15. Answer A. WBH

If all seats are occupied, all baggage allowed, and all fuel tanks full, most modern aircraft will be grossly overloaded. Excessive weight reduces the efficiency of an aircraft and the safety margin available if an emergency condition should arise.

6-16 AMG003

The major source of weight change for most aircraft as they age is caused by

A— accumulation of grime and debris in hard-to-reach areas of the structure, and moisture absorption in cabin insulation.

B— repairs and alterations.

C— installation of hardware and safety wire, and added layers of primer and paint on the structure.

6-16. Answer B. WBH

Repairs and alterations are the major sources of weight changes. The growth due to trash and dirt in hard-to-reach places is normally small.

6-17 AMG003

Use of which of the following generally yields the highest degree of aircraft leveling accuracy?

A— Electronic load cell(s)

B— Spirit level(s)

C— Plumb bob and chalk line

6-16. Answer B. WBH

The most accurate method of leveling an aircraft is a plumb bob and grid plate and not a plumb bob and chalk line. Of the choices given, spirit levels are the most accurate method of leveling an aircraft.

6-18 AMG003

In the process of weighing an airplane to determine the CG, the arms from the Weighing Points always extend

A— parallel to the centerline of the airplane.

B— straight forward from each of the landing gear.

C— directly from each weighing point to the others.

6-16. Answer B. WBH

An airplane’s CG is determined from the distribution of weight along the centerline. Lateral distribution is not considered in determining an airplanes CG.

6-19 AMG003

The useful load of an aircraft is the difference between

A— the maximum takeoff weight and basic empty weight.

B— maximum ramp or takeoff weight as applicable, and zero fuel weight.

C— (1) the weight of an aircraft with all seats filled, full                              baggage/cargo, and full fuel, and

        (2) aircraft weight with all seats empty, no baggage/cargo, and          minimum operating fuel.

6-19. Answer A. JSGT 6A, FGH

The useful load of an aircraft is the difference between the maximum gross weight (maximum takeoff weight) and the empty weight. It includes items such as passengers and crew, usable fuel, and cargo.

6-20 AMG003

When determining the empty weight of an aircraft, certificated under current airworthiness standards (FAR Part 23), the oil contained in the supply tank is considered

A— a part of the empty weight.

B— a part of the useful load.

C— the same as the fluid contained in the water injection reservoir.

6-20. Answer A. JSGT 6A, FGH

Under current airworthiness standards (FAR Part 23), full oil is considered part of the empty weight of an aircraft. Until March 1, 1978, empty weight included only undrainable oil.

6-21 AMG003

The maximum weight as used in weight and balance control of a given aircraft can normally be found

A— by adding the weight of full fuel, pilot, passengers, and maximum allowable baggage to the empty weight.

B— in the Aircraft Specification or Type Certificate Data Sheet.

C— by adding the empty weight and payload.

Answer B. JSGT 6A, FGH

The maximum weight of a particular model of aircraft is found in the Aircraft Specification or Type Certificate Data Sheet. Empty weights and useful loads vary with the equipment installed on a particular aircraft. These values must be located in the permanent records for that aircraft.

6-22 AMG003

The amount of fuel used for computing empty weight and corresponding CG is

A— empty fuel tanks.

B— unusable fuel.

C— the amount of fuel necessary for ½ hour of operation.

6-22. Answer B. JSGT 6A, FGH

The empty weight of an aircraft includes only the weight of that fuel which remains in the sumps and plumbing of the aircraft and is termed unusable fuel.

6-23 AMG003

As weighed, the total empty weight of an aircraft is 5,862 pounds with a moment of 885,957. However, when the aircraft was weighed, 20 pounds of potable water were on board at +84 and 23 pounds of hydraulic fluid were in a tank located at +101. What is the empty weight CG of the aircraft?

A— 150.700

B— 151.700

C— 151.365

6-23. Answer C. JSGT 6A, FGH

The hydraulic fluid is part of the empty weight and may be ignored. Alcohol for alcohol/water injection is not part of the aircraft’s empty weight and, therefore, must be subtracted out to determine the empty weight. It is typically easier to solve this type of problem if you enter the information into a table.

Item	Weight	Arm	Moment
Aircraft	5,862		885,957
Alcohol	-20	84	-1,680
Total	5,842		884,277

With the weight and moment of the alcohol subtracted out, divide the total moment by the total weight.

The aircraft’s empty weight CG is 151.365 inches (884,277 ÷ 5,852 = 151.365).

6-24 AMG002

Two boxes which weigh 10 pounds and 5 pounds are placed in an airplane so that their distance aft from the CG are 4 feet and 2 feet respectively. How far forward of the CG should a third box, weighing 20 pounds, be placed so that the CG will not be changed?

A— 3 feet

B— 2.5 feet

C— 8 feet

6-24. Answer B. JSGT 6A, FGH

For the center of gravity to remain the same, the moments forward and aft of the CG must be equal.

The two boxes added aft of the CG have moments of 40 foot/pounds (10 lbs × 4 ft = 40 ft/lbs) and 10 foot/pounds (5 lbs × 2 ft = 10 ft/lbs).

This is a total moment of 50 foot/pounds. The box loaded forward must also have a moment of 50 foot/pounds to maintain balance.

To determine the distance forward of the CG to maintain balance, divide 50 foot/pounds by 20 pounds.

This results in a distance of 2.5 feet (50 ft/lbs ÷ 20 lbs = 2.5 ft).

6-25 AMG003

If a 40-pound generator applies +1400 inch-pounds to a reference axis, the generator is located

A— -35 from the axis.

B— +35 from the axis.

C— +25 from the axis.

6-25. Answer B. JSGT 6A, FGH

This question requires the application of the formula, Moment = Weight × Arm. Substituting the values given, the arm is +35 inches from the axis (1,400 ÷ 40 = +35).

6-26 AMG003

In a balance computation of an aircraft from which an item located aft of the datum was removed, use

A— (-) weight × (+) arm = (-) moment.

B— (+) weight × (-) arm = (+) moment.

C— (+) weight × (-) arm = (-) moment.

6-26. Answer A. JSGT 6A, FGH

Anytime you remove something from an aircraft, the weight is subtracted (-), and anytime an item is aft of the datum, it has a positive (+) arm. Therefore, a (-) weight times a (+) arm yield a (-) moment.

6-27 AMG003

Datum is forward of the main gear center point 30.24 in.

• Actual distance between tail gear and main gear center points.....360.26 in

• Net weight at right main gear.....9,980 lb

• Net weight at left main gear.....9,770 lb

• Net weight at tail gear.....1,970 lb

These items were in the aircraft when weighed

1. Lavatory water tank full (34 pounds at +352)

2. Hydraulic fluid (22 pounds at +8)

3. Removable ballast (146 pounds at +380)

What is the empty weight CG of the aircraft described above?

A— 62.92 inches.

B— 60.31 inches.

C— 58.54 inches.

6-27. Answer B. JSGT 6A, FGH

It is typically easier to solve this type of problem if you enter the information into a table.

Item	Weight	Arm	Moment
Tail Wt.	1,970	380.90	749,265.0
L.M. Wt.	9,770	30.24	295,444.8
R.M. Wt.	9,980	30.24	301,795.2
Water	34	352.0	11,968.0
Ballast	146	380.0	55,480.0
Total	21,540		1,299,077.0

Lavatory water and removable ballast are not part of the aircraft empty weight and must be removed.

Therefore, you must subtract their weights and moments to determine the empty weight CG.

On the other hand, full hydraulic fluid is considered part of the aircraft empty weight and, therefore, is not used for this calculation.

To calculate the CG, divide the total moment by the total weight. The CG is 60.31 inches (1,299,077 ÷ 21,540 = 60.31).

6-28 AMG003

When an empty aircraft is weighed, the combined net weight of the main gears is 3,540 pounds with a arm of 195.5 inches. At the same time, the nosewheel net weight is 2,322 pounds with an arm of 83.5 inches. The datum line is forward of the nose of the aircraft. What is the empty CG of the aircraft?

A— 155.2

B— 151.4

C— 146.5

6-28. Answer A. JSGT 6A, FGH

It is typically easier to solve this type of problem if you enter the information into a table. The position of the datum has no bearing on this problem.

Item	Weight	Arm	Moment
Nose	1,322	83.5	110,387
Mains	3,540	195.5	691,417
Total	4,862		895,147

Calculate the CG by dividing the total moment by the total weight.

The empty weight CG is 151.4 inches (895,147 ÷ 5,862 = 151.4).

6-29 AMG003

Find the empty weight CG location for the following tricycle-gear aircraft. Each main wheel weighs 753 pounds, nosewheel weighs 22 pounds, distance between nosewheel and main wheels is 87.5 inches, nosewheel location is +9.875 inches from datum, with 1 gallon of hydraulic fluid at -21.0 inches included in the weight scale.

A— +97.375 inches.

B— +95.61 inches.

C— +96.11 inches.

6-29. Answer C. JSGT 6A, FGH

It is typically easier to solve this type of problem if you enter the information into a table. Remember, hydraulic fluid is part of the aircraft empty weight of the airplane, therefore should not be subtracted out.

Item	Weight	Arm	Moment
Nose	22	9.875	217.25
Mains	1,506	97.375	146,646.75
Total	1,528		146,864.00

To determine the location of the main gear, you must add the distance between the nosewheel and main gear to the location of the nosewheel.

The mains are located at 97.375 nosewheel. The empty weight CG is 96.11 inches (146,864 ÷ 1,528 = 96.11).

6-30 AMG003

The useful load of an aircraft is the difference between

A— the maximum takeoff weight and basic empty weight.

B— maximum ramp or takeoff weight as applicable, and zero fuel weight.

C— (1) the weight of an aircraft with all seats filled, full baggage/cargo, and full fuel, and (2) aircraft weight with all seats empty, no baggage/cargo, and minimum operating fuel.

6-30. Answer A. JSGT 6A, FGH
The useful load of an aircraft is the difference between the maximum gross weight (maximum takeoff weight) and the empty weight. It includes items such as passengers and crew, usable fuel, and cargo.

6-31 AMG003

If an aircraft CG is found to be at 24 percent of MAC, that 24 percent is an expression of the

A— distance from the TEMAC.

B— distance from the LEMAC.

C— average distance from the LEMAC to the wing center of lift.

6-31. Answer B. JSGT 6A, FGH

The mean aerodynamic chord (MAC) is determined from the leading edge to the trailing edge of the airfoil. The leading edge MAC (LEMAC) is the start, or 0 % MAC. The trailing edge MAC (TEMAC) is 100 % MAC. A CG that is 24 % MAC is 24 % of the distance from LEMAC to TEMAC.

6-32 AMG002

An aircraft’s LEMAC and TEMAC are defined in terms of distance

A— from the datum.

B— from each other.

C— ahead of and behind the wing center of lift, respectively.

6-32. Answer A. JSGT 6A, FGH

An aircraft’s leading edge mean aerodynamic chord (LEMAC) and trailing edge mean aerodynamic chord (TEMAC) are assigned fuselage or body station numbers representative of their distance from the datum. The actual MAC is the difference between the TEMAC and the LEMAC.

6-33 AMG003

When an aircraft is positioned for weighing on scales located under each landing gear wheel, which of the following may cause erroneous scale readings?

A— Gear downlocks installed

B— Parking brakes set

C— Parking brakes not set

6-33. Answer B. JSGT 6A, FGH

When an aircraft is weighed, chocks should be used to prevent the aircraft from rolling and the weight of the chocks subtracted from the scale weight readings as tare weight. Setting the brakes may cause adverse side load to be applied to the scale, causing inaccurate readings.

6-34 AMG003

When accomplishing loading computations for a small aircraft, necessary information obtained from the weight and balance records would include

A— unusable fuel weight and distance from datum.

B— weight and location of permanent ballast.

C— current empty weight and empty weight CG.

6-34. Answer C. JSGT 6A, FGH

When accomplishing loading computations on a small aircraft, it’s necessary to locate the current empty weight and empty weight center of gravity in the weight and balance records to have a starting point from which to calculate the effect of added weights of useful load items.

6-35 AMG003

If it is necessary to weigh an aircraft with full fuel tanks, all fuel weight must be subtracted from the scale readings

A— except minimum fuel.

B— including unusable fuel.

C— except unusable fuel.

6-35. Answer C. JSGT 6A, FGH

When weighing an aircraft, only unusable fuel should be considered part of the aircraft’s empty weight. If an aircraft is weighed with full fuel, all fuel weight must be subtracted from the scale weight readings except the unusable fuel, as specified in the aircraft’s type certificate data sheet or specifications.