How to make shadow to be darker and less opacity?

In addition to what Mylenium said, your drone is too small. That kind of aircraft is a lot larger than you've got it set to in your scene.

See?

Also, and much more pedantically, that is a propeller-driven aircraft and not a jet. The prop is drive by a turbo-charged four cylinder engine - the Rotax 914 if Wikipedia is to be believed.

I mean, that might seem petty, but it makes a big difference when it comes to how it is animated.

E3D respects the shadow density setting of AE lights and has a global shadow intensity multiplier. you might also want to turn off ambient occlusion and/or tweak the materials. Shadows being too weak  means you have too much light in your scene and the diffuse values of your materials are too high.

Mylenium