Overview
This lecture covers how to calculate load factor (measured in G-forces) and its relationship with bank angle, total load, and stall speed, as commonly tested on the FAA written exam.
Load Factor Basics
- Load factor is measured in G-forces, representing the ratio of total load supported to the airplane's weight.
- It is calculated as the aircraft's weight multiplied by the load factor from a chart.
Bank Angle and Load Factor
- Bank angle increases load factor; charts are used to determine the exact load factor for a given angle.
- At 30° bank, the load factor is about 1.2 G.
- At 45° bank, the load factor is about 1.5 G.
- At 60° bank, the load factor is about 2 G.
Calculating Total Load
- To find total load, multiply the airplane’s weight by the load factor.
- Example: 1,475 lbs at 45° bank (1.5 G) = 2,212.5 lbs total load.
- Example: 3,800 lbs at 60° bank (2 G) = 7,600 lbs total load.
Bank Angle and Stall Speed Increase
- Higher bank angles also increase stall speed due to higher load factor.
- At 60° bank, stall speed increases by about 42%.
- Example: Original stall speed 40 knots × 1.42 = new stall speed 56.8 knots.
Key Terms & Definitions
- Load Factor (G-force) — The ratio of total aerodynamic force to the weight of the airplane.
- Bank Angle — The tilt of the aircraft’s wings relative to the horizon during a turn, measured in degrees.
- Stall Speed — The minimum speed at which an aircraft can maintain level flight.
- Total Load — The combined force acting on the aircraft structure, equal to weight × load factor.
Action Items / Next Steps
- Review and practice using load factor and stall speed charts from the Pilot's Handbook of Aeronautical Knowledge.
- Obtain a free digital or affordable paperback copy of the handbook from the FAA's website.