Welcome back to our Word of the Week!

Every week, we look together at a word that is either interesting, funny or mysterious and that appeals to all of us in the aviation community.

If you think that this involves any sort of washing, or that your pilot uniform comes out clean after a downwash… well, read on.

Downwash: (n.) air that is deflected downwards by the aircraft wing or a rotor blade on a helicopter, usually when the aircraft is taking off.

It is far more noticeable with helicopters, given that they actually produce the downwash by mechanical force, but downwash is a phenomenon that happens even with fixed-wing aircraft.

Downwash is actually a secondary effect of the production of lift by the wing (be it fixed or rotary). The increased pressure below a wing, encountering no physical obstacle below, is relieved by creating a downward stream as a natural reaction to the physical force that creates lift.

The main effect of downwash created by fixed wing aircraft is very famous and is the dreaded wake turbulence. That will be the subject of another word of the week!

See you next week, and stay safe!

A beautiful rendering of downwash and wake turbulence