Weight and Balance Flashcards
What are the four main weight components that must be considered?
Basic empty aircraft, pilot/passengers, fuel, and baggage
Weight and balance calculations must account for four main components: the basic empty aircraft weight (which includes unusable fuel and oil), the weight of all occupants including pilot and passengers, the weight of usable fuel (6 pounds per gallon), and all baggage and equipment. Each component must be calculated separately and their impact on center of gravity considered.
How does aircraft weight affect performance?
Increased weight requires higher angles of attack or speeds for the same maneuver
When aircraft weight increases, more lift is required to maintain flight. This means either flying at a higher angle of attack (which increases drag) or maintaining a faster airspeed. The increased weight also affects various performance metrics including degraded climb performance, increased takeoff and landing distances, and generally reduced aircraft performance capabilities.
What is maneuvering speed (VA) and why does it change with weight?
Maximum speed for full control deflection - decreases with lower weight because the aircraft can be accelerated more easily
Maneuvering speed is the maximum speed at which full or abrupt control movements can be made without risking structural damage. It varies with weight because a lighter aircraft can be stressed by control inputs at lower speeds than a heavier one. For example, in a Cessna 172, VA decreases from 105 KIAS at 2550 lbs to 90 KIAS at 1900 lbs. This is crucial for safe operation, especially in turbulent conditions.
What’s the calculation for finding CG location?
Total moment ÷ total weight
The center of gravity location is found by adding all moments (weight × arm) and dividing by the total weight. This gives the average arm, which is the CG location in inches from the datum.
How do you correct an out-of-limits CG?
Redistribute weight, adjust fuel, or remove items
CG problems can be solved by moving passengers, redistributing baggage, adjusting fuel load, or removing items entirely. Always recalculate to verify the new CG is within limits.
What’s the relationship between weight and performance?
Higher weight = degraded performance
The Cessna 172 can be operated in either ____ category or ____ category
Normal or Utility
Each category has specific limitations and approved maneuvers.
Why must CG be calculated for both takeoff and landing?
Because fuel burn changes CG location
As fuel is burned during flight, both the total weight and CG location can change. Both conditions must be within limits for safe operation throughout the flight.
More difficult nose-up control and higher fuel burn is associated with a more forward or aft CG?
Forward
A forward CG makes it harder to raise the nose for landing and requires more up-trim, resulting in increased drag and fuel consumption
How is a moment calculated in weight and balance?
Weight times arm
