> For the complete documentation index, see [llms.txt](https://docs.tjuav.org/tjuav/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tjuav.org/tjuav/rc-guide/aerodynamics/forces-of-flight.md).

# Forces of Flight

There are four main forces of flight: Thrust, drag, lift, and weight.

![Four forces of flight](https://lh4.googleusercontent.com/NTzldfEpGT_lUDEm8WOZlyMEGOscxn8o1uq4b-VG-mDiNabuX9NMU8jJUCbMm5_Z8th0-6WkR4LjHLqjbBAl4RVtv0T42cYdzItaRHGtHCz9WCrV1B1Ew-x1EvHzQTlIj1Kkp-Wl)

In RC aircraft, thrust comes from our motors and propellers. Drag acts opposite of thrust and comes from the friction/interaction between the plane and the air. Weight is the earth’s gravity acting on the plane, and lift is an upwards force created by the plane’s wings.

### Lift

Lift is a complex topic not easily explained in a few sentences. [This video (10 mins)](https://www.youtube.com/watch?v=PF22LM8AbII\&ab_channel=SixtySymbols) gives an in-depth explanation of lift if you’re interested. If not, a simplified explanation states that planes generate lift by redirecting the airflow over their wings towards the ground, creating an "equal and opposite" force upward on the plane.

### Drag