Smoke over Airfoil with Slotted Flap

Smoke over an airfoil with a slotted flap.
1930s test conducted at NASA Langley Research Center's 6 by 19 inch Transonic Tunnel during its NACA era.

[@christianh8636]

That’s a really cool video, definitely going to show this to my students

[@Sanchoys914]

Nice, this gonna help me with my school project.

[@frieden6298]

less form drag