Warbird Information Exchange

http://www.airpowerexpo.com/

I'm taking a C-17 down there for a static display. If anybody comes out be sure and stop by and say howdy.

_________________
Brad

Brad, what is the reason for the little 'delta wings' on each side of the engines?

looks like it will be a good show. BUT i'm working saturday.

The small wings on each side of the C-17's engine nacelles are vortex generators. Most aircraft have them on the wings, but on the C-17 they are on the sides of the nacelles.

Walt

Walt has pretty much summed it up.

From the Hymnal (Structural Repair Manual): "The strakes help reduce turbulence at the wing leading edge during high angle-of-attack flight."

From the Bible (Flight Manual) "The nacelle strakes improve wing aerodynamic efficiency and the fuselage strakes reduce cruise drag. Cruise performance is therefore improved."

_________________
Brad

For those of you interested www.airshowtime.com will be webcasting the show live.

Thank you, RareBear and Brad.
Unusual (to me) to see them on engines.

The thrust line of the engines is higher up than on most nacelle equipped airliners (as well as being mounted closer to the wing) and consequently have a greater impact on the wing's aerodynamics at higher angles of attack. The 737-300 and later series of that aircraft have much the same issues and have vortex generators on their nacelles as well. Check out:

http://www.aerospaceweb.org/question/ae ... 0255.shtml

http://old.smartcockpit.com/operations/ ... rators.PDF

HTH! Mark

Good links Mark! I thought I knew about vortex generators, but was unaware they were in such widespread use on engines. Quite surprised and impressed at the amount of benefit they offer.

They are Nacelle Aerodynamic Strakes. Yes, they control the airflow at high angles of attack.