RVDT, that may also be true as the strake would act as a spoiler on the "wing" top surface. Not sure in practice whether there would be circulation induced by the main rotor, since the whirl velocity gradient would be small over the height of the boom. MD had to go to some extreme solutions to generate circulation the other way - better to fit an aerofoil trailing edge methinks.
I seem to recall Nick Lappos mentioned that strakes had been tried at Sikorsky, but with no benefit found. Another Sikorsky endeavor, the S-69 ABC, suffered some hover position instability which was cured by fitting ventral strakes to force flow seperation at a fixed position. This reduction in control variation seems to offer a reasonable explanation for any advantages found in the field for fitting strakes. The machine would feel more yaw stable in crosswinds.
Mart
Last edited by Graviman; 24th March 2007 at 14:45.
Reason: Typo only.