Weight & Balance

Question 1

What performance characteristics would an overweight aircraft experience?

Answer 1

• High takeoff speed
• Longer takeoff roll
• Lower max altitude
• Shorter range
• Reduced speed
• Poor maneuverability
• Higher Stalling speed
• High approach and landing speed
• Longer landing roll
• Excessive weight on nose wheel ore tail wheel

Question 2

What are the characteristics of a Forward CG

Answer 2

1. More longitudinally stable due to CG being farther from CL
2. Good Stall recovery
3. Less fuel effecient, slower cruise speed: More induced drag (more elevator and trim needed for level flight) due to high tail downforce needed to keep the nose up
4. Higher Stall speed (higher AOA)

Question 3

Characteristics of an aft CG

Answer 3

1. Less Stable: CG and CL are close together
2. Poor stall recovery
3. More effecient: Less tail downforce needed to keep the nose in level flight
4. Lower stalling speed (lower AOA)

Question 4

What is Arm?

Answer 4

The distance of a mass from the standard datum plane from which all items are measured

Question 5

What is CG?

Answer 5

The theoretical point at which the entire mass of the aircraft is concentrated

Question 6

What is Basic Empty Weight?

Answer 6

Standard Weight (aircraft, all fixed items, unusable fuel, oil) + Any optional equipment

Question 7

What is Useful Load?

Answer 7

Weight of persons, baggage, usable fuel.

Question 8

Why is the CG usually located slightly forward of the CL?

Answer 8

Because it causes a nose down tendency, which is desirable for stall recovery

Question 9

What is Moment?

Answer 9

In the simplest terms, a ‘moment’ measures how a force causes something to rotate around an axis.

1. The greater the moment, the greater the rotational force
2. The further the force from the center of gravity, the greater the moment and the greater the effect from a defined force

Remember: Weight X Arm = Moment

Question 10

What is the purpose of Zero Fuel Weight?

Answer 10

The purpose of Zero Fuel Weight is to ensure the wings are not overstressed in flight by excessive weight

Question 11

Define Zero Fuel weight

Answer 11

The total weight of an aircraft and its contents, excluding fuel.
* It includes the weight of the aircraft’s structure, crew, passengers, baggage, cargo, and any other non-fuel items on board.

The purpose of Zero Fuel Weight is to ensure the wings are not overstressed in flight by excessive weight

Question 12

Which loading scenario is worse, a more Forward CG, or an Aft CG?

Answer 12

An Aft CG is preferable because:
- Much more fuel efficient
- Lower stall speed