Jet Provost 5x Aerodynamics

[SPD]

On the 'Wingtip-tankless' version of the JP5 (and possibly others) there is a roughened skim (concrete) on the outboard leading edge of each wing. Long ago as it is now since I flew the JP, I have generated some heated discussion amongst colleagues as to the REAL reason for this (presumably) aerodynamic tech-fix.

Does anybody remember the reason it is fitted or better still can they refer me to any RAF Doc that authenticates the reason?

Thanks

[212man]

Could it be in lieu of vortex generators to try and keep the flow attached longer? perhaps as a result of the loss of 'boundary fence' effect from the missing tip-tanks.

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Another day in paradise

[small4]

I tthink you will find that it was to generate more energy in the boundary layer for better aileron effectiveness. The JP3 with tip tanks always had a better more snappy rate of roll than the 5A. Never flew the 5B with the tanks. Anybody have comments on tthat particular variant?