Aerodynamic Coefficients – Canadian Flight Trainers

Aerodynamic coefficients are dimensionless numbers that standardize the aerodynamic forces and moments acting on an aircraft, allowing comparison across different aircraft sizes, speeds, and air densities. The most commonly used are the lift coefficient (C_L) and drag coefficient (C_D).

Common Aerodynamic Coefficients

C_L (Lift Coefficient): Relates lift force to dynamic pressure and wing area; increases with angle of attack up to the critical angle
C_D (Drag Coefficient): Relates total drag to dynamic pressure and wing area
C_M (Pitching Moment Coefficient): Describes the aircraft’s tendency to pitch nose up or down
L/D (Lift-to-Drag Ratio): The aerodynamic efficiency at a given angle of attack; maximum L/D gives best glide speed

On the TC Written Exam

For PPL and CPL exams: C_L increases with angle of attack up to the critical (stall) angle; the angle of attack for maximum L/D gives best glide speed; aerodynamic coefficients allow the same physics to apply regardless of aircraft size.