Shock wave due to supersonic flow over an airfoil.

A visible shock wave due to supersonic local flow over the top of an A320 wing.

[SchmittVids]

The airplane is flying around Mach 0.80 (below the speed of sound) but the air accelerates over the upper surface of the wing due to the airfoil shape and reaches local speeds well above Mach 1.0. (Higher velocity over the wing = lower air pressure = LIFT!) The shock wave is the point where the local air velocity drops back below sonic speed. This type of shock doesn't produce a sonic boom like a supersonic airplane would generate.

[lucaas]

Great catch! Would you be okay with me featuring this in my series Weekly Dose of Aviation? Of course you will be credited both in the video and in the description. Thanks!

[pilot]

It is an interesting phenomenon to actually see. The first time I saw it I could hardly believe what I was seeing.

[pirobotbeta]

I first saw this on a trans-pacific flight...I knew what it was, but some primitive part of my brain was telling me I was in trouble.
Thanks goodness for drink-service...

[fireandcopper]

And to think my BB gun farts out a bb 3 times slower than the plane is traveling, which blows my mind. People are fine inside, eating, drinking soda and coffee, usimg the restroom, sleeping. Incredible

[lendavidhart]

Neat stuff, thank you for sharing your

[Planehype]

Insane Capture! can i use this as part of my series for a video? you will be credited in the description and video!

[DirtRyder]

Does the transonic airflow create a Sonic boom?

[thesolaraquarium]

interesting. never considered that before. the only thing I am skeptical about is if the top flow over the airfoil does go partially supersonic in places would that not create turbulent and not laminar flow? turbulent flow would seem undesirable and therefore would not travelling slower be preferable to avoid this?

[xres]

Just like Prof. Nagamatsu used to tell...

[yetkinkarabulut]

Turbulence does these movements. These commercial planes don't cruise at sound speed. Also when plane come close Mach 1, you need to see white colored air on the airfoils.

[sfsen]

My 2 braincells : "Sheeeesh, of course we know what we are looking at.
Nobody is looking at us now, right? Where's the shockwave?
We can't see 'cause probably we've already have our shockwave at the counter,
when we heard the ticket prices."

[vasiapetrov]

Видать, из-за этого они все время крыльями машут.

[knuckles]

Kids had a lot of imagination back then.

[fgm]

Sorry but that's not a shockwave. You can also observe this at the wingtips or flap edges during landing. Those are simply "transparent" air vortices.

[stephenskinner]

No. There is no supersonic airflow over this airliners wing. Not possible even at high cruise speed.

[patcism]

Commercial airplanes like this A320 do not travel faster than the speed of sound, so this is not supersonic.