Weight and Balance

Question 1

What is ‘Basic Empty Weight’ in helicopter weight and balance?

Answer 1

Basic Empty Weight is the weight of the helicopter, including unusable fuel, full oil, and system fluids.

It reflects the aircraft’s weight in a ready-to-fly state, minus occupants, baggage, and usable fuel.

Question 2

How is ‘Gross Weight’ defined in helicopter operations?

Answer 2

Gross Weight is the total weight of the helicopter plus occupants, fuel, and cargo have been accounted for.

It reflects the actual weight during flight.

Question 3

What is the difference between ‘Useful Load’ and ‘Payload’?

Answer 3

Useful Load includes the difference between max gross weight and basic empty weight covering all passengers, cargo, and fuel. More relevant in a training setting.

Payload excludes fuel and crew and only accounts for passengers, cargo, and baggage. More relevant in a commercial setting.

Question 4

What is a ‘Datum,’ and why is it important in weight and balance?

Answer 4

The Datum is a manufacturer-defined reference line from which all CG measurements are taken.

In the Robinson R22, the datum is 100 inches in front of the main rotor mast.

Question 5

Define ‘Arm’ in weight and balance terms.

Answer 5

Arm is the distance from the Datum to any object within the helicopter. Each component has its designated arm, which is used to calculate the balance effect of each weight.

Question 6

What is ‘Moment,’ and how is it calculated?

Answer 6

Moment is a measure of the turning force generated by a weight located at a certain distance from the datum.

It’s calculated by multiplying the WEIGHT x ARM

Question 7

How do you determine the ‘Center of Gravity’ (CG) of a helicopter?

Answer 7

TOTAL MOMENT / TOTAL WEIGHT = CG

Question 8

What is meant by ‘CG Range,’ and why must pilots stay within it?

Answer 8

The CG Range is the safe range within which the CG must stay to ensure stability. Exceeding these limits makes the helicopter harder and potentially unsafe to control.

Question 9

How does a ‘CG Envelope Graph’ assist pilots?

Answer 9

The CG Envelope Graph shows the safe limits for weight and CG. Pilots use this graph to check that both takeoff and landing CGs stay within limits.

Question 10

What is the ‘Weight Shift Formula,’ and how does it help with balance?

Answer 10

The Weight Shift Formula helps pilots calculate CG adjustments by moving weight within the helicopter for safe and stable flight.

weight shifted / total weight = CG / distance weight shifted

Question 11

How does fuel burn affect the CG during flight?

Answer 11

Fuel burn can cause the CG to shift forward because fuel tanks are often located behind the rotor mast.

Question 12

What are the risks of operating above the maximum gross weight?

Answer 12

Exceeding the maximum gross weight stresses structural components, reduces lift, increases takeoff / landing distance, and limits climb rate.

Question 13

What is ‘Lateral CG,’ and why is it significant in helicopters?

Answer 13

Lateral CG refers to the helicopter’s side-to-side balance, which is especially important for maintaining control during hover maneuvers.

Question 14

What issues arise from a forward CG that exceeds safe limits?

Answer 14

Minimizes cyclic range and
-makes hovering difficult
-make stopping / slowing down difficult
-impairs heli’s ability to flare in an autorotation

Question 15

How does an aft CG affect helicopter control?

Answer 15

Minimizes cyclic range and
-limits forward forward cyclic control, making it hard to reach higher speeds
-makes it more difficult to maintain control in turbulence

Question 16

What is the primary method for calculating weight and balance in R22 and R44 helicopters?

Answer 16

The Computational Method, which uses weight x arm values to calculate the moment and then total moment / total weight to find the CG

Question 17

How do the ‘Graph and Table Methods’ work for weight and balance?

Answer 17

These methods allow pilots to approximate moments based on pre-set weight values using a graph or table. However, the R22’s POH does not include these methods.

Question 18

Why is fuel calculation so critical according to the HFH?

Answer 18

Proper fuel calculation ensures that both takeoff and landing CGs remain within limits, even as fuel burns during flight.

Question 19

Explain how a helicopter’s balance is similar to a seesaw.

Answer 19

Like a seesaw, helicopters balance by adjusting weights based on their distance from the datum. Shifting weight impacts balance.

Question 20

What is the purpose of the R22’s right-seat-only requirement for solo flights?

Answer 20

The R22 requires solo flights from the right seat to maintain proper lateral balance, as the primary fuel tank is on the left side.

Question 21

What role does passenger comfort play in weight and balance?

Answer 21

An unbalanced helicopter can feel unsettling to passengers. Keeping the helicopter level improves safety and enhances passenger comfort.