# How much is an airliner's drag coefficient?

How much is an airliner's Cd, using the frontal area as reference point. I want to compare values with cars and others objects, tear drops, cube etc.

Is Cd measured at zero lift AoA or when the plane is flying in a straight line?

Is Cd measured at zero lift AoA or when the plane is flying in a straight line?

Both.

$$C_D$$ is a function, not a number.

The "numbers" are the partial derivatives: $$C_{D_\alpha}$$ measures how $$C_D$$ changes w.r.t. the angle of attack $$\alpha$$, for example.

• How much is an airliner's Cd, using the frontal area as reference point?
– user52248
Dec 22 '20 at 7:24
• @Aeolus it depends on the speed, the AoA, the sideslip, the rates, the configuration
– Federico
Dec 22 '20 at 8:01