PHAK Chapter 10 Weight & Balance Quiz

Deficiencies of Overloaded Aircraft

• Overloaded aircraft experience increased takeoff speeds and extended takeoff runs.
• Climbing performance worsens with reduced rate and angle of climb, leading to lower maximum altitude achievements.
• Operational range diminishes, alongside reduced cruising speeds and maneuverability.
• Risks higher stalling speeds and increased approach and landing speeds, contributing to longer landing rolls.
• Overweight conditions can result in excessive load on either the nose wheel or tail wheel, affecting landing stability.

Weight of Fuel

• Fuel weighs approximately 6 pounds per gallon, influencing total aircraft weight calculations.

Center of Gravity (CG)

• CG refers to the specific location where an aircraft balances, crucial for stability during flight.

Nose Heavy Condition

• A nose-heavy configuration complicates control, particularly during takeoff and landing phases.

Tail Heavy Condition

• A tail-heavy aircraft significantly impacts longitudinal stability, hindering recovery from stalls and spins.
• This condition results in light control forces, increasing the risk of unintentional aircraft overstressing.

Negligible Weight Changes

• Negligible weight changes are defined as:
  • 1 lb or less for aircraft under 5,000 lbs empty weight.
  • 2 lbs or less for aircraft between 5,000 lbs and 50,000 lbs empty weight.
  • 5 lbs or less for aircraft over 50,000 lbs empty weight.

Negligible CG Change

• Any CG change less than 0.05% of Mean Aerodynamic Chord (MAC) for fixed-wing aircraft is considered negligible.

Arm Definition

• Arm represents the horizontal distance from the reference datum line to an item’s CG, measured in inches; it is positive (+) if aft of the datum and negative (-) if forward.

Basic Empty Weight

• Basic empty weight includes the standard empty weight along with weights of optional and special equipment installed in the aircraft.

Center of Gravity Limits

• CG limits are specified forward and aft positions that must be maintained during flight for safety and control.

CG Range

• The CG range represents the distance between the forward and aft CG limits essential for maintaining controllability.

Reference Datum

• An imaginary vertical plane or line that serves as a baseline for all measurements of an item's arm.

Delta Symbol

• Delta (Δ) is the Greek letter used to signify changes in values within calculations.

Floor Load Limit

• Refers to the maximum weight the floor of the aircraft can support per square foot/inch, essential for weight distribution safety.

Fuel Load

• The fuel load constitutes the expendable part of the aircraft's weight, considering only usable fuel.

Maximum Landing Weight

• The maximum landing weight is defined as the highest weight at which an aircraft is allowed to land safely.

Maximum Ramp Weight

• Maximum ramp weight includes the total weight of a loaded aircraft, accounting for all fuel and often exceeding takeoff weight due to fuel usage during taxi and run-up.

Maximum Takeoff Weight

• Identifies the maximum weight permitted for safe takeoff.

Maximum Weight

• Refers to the maximum authorized weight of the aircraft, including all equipment.

Maximum Zero Fuel Weight

• This weight excludes usable fuel, setting a limit for the aircraft’s weight without fuel.

Mean Aerodynamic Chord (MAC)

• MAC is the average distance from the leading to the trailing edge of the aircraft wing, vital in aerodynamic calculations.

Moment Calculation

• Moment is derived as the product of an item’s weight and its arm, measured in pounds-inches (in-lb).
• Total moment represents the aircraft's entire weight multiplied by the distance from the datum to its CG.

Moment Index

• Moment index is obtained by dividing the moment by a constant (100, 1,000, or 10,000), facilitating simpler weight and balance calculations.

Payload

• Payload encompasses the collective weight of occupants, cargo, and baggage within the aircraft.

Standard Empty Weight

• This weight comprises the aircraft’s structure, engines, and all permanently installed operating equipment, including necessary fluids and unusable fuel.

Station Definition

• A station is marked by a number indicating its specific distance in inches from the reference datum within the aircraft.

Useful Load

• Useful load refers to the combined weight of pilots, passengers, cargo, usable fuel, and drainable oil, critical for operational capacity.

Factors Reducing Maximum Gross Weight

• Specific practical aspects that may decrease the aircraft's maximum gross weight during operations must be considered for safety and performance.