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.

Maybe you already heard it as a verb, while driving a car, that somebody was “slipstreaming” a truck or another vehicle, so as to catch the short depression that follows an object moving through air and be “pulled” forward by it.

Well, ok, maybe not THAT close…

But then, we will look at the noun “slipstream”.

slipstream (n.)

UK / ˈslɪp.striːm / US / ˈslɪp.striːm /

The noun “slipstream” can mean either:

  • an area of reduced air pressure and forward suction immediately behind a rapidly moving vehicle, which is also the origin of the verb we were talking about earlier

OR

  • a stream of fluid (such as air or water) driven aft by a propeller

Now, this is the one that is most interesting for us. You probably know that when you follow a jet aircraft, the controller may warn you about the presence of “jet blast”, which is the strong stream of air that is used to propel the aircraft forward. Well, “slipstream” is quite similar to it, except that it is generated by a propeller, to keep it short.

It is the very same effect that, in your single-engine propeller aircraft, forces you to correct the induced yaw movement by applying rudder when using engine power. Yaw? Well, that is for next week!

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