Hi idg
Thanks for your explanation though I am aware of what vortex generators are and what they do as well as MDLC or ACS.
But those vortex generators are only found on RAF L1011s. No civil TriStars being -500 with ACS or standard lenght version have them. So I was searching for a specific reason related with their tanker role, if it exists.
I mean, ok they have vortex generators to prevent bondary layer separation on that zone, but why? Do RAF L1011's usually fly at a higher speed near from Mmo causing compressibility problems? Or is there another reason?
http://www.airliners.net/open.file/233612/L/
Best regards,