VGs' are not certainly the solution in this case, there is a fair bit of CFD needed to sort out the underlying issue, and then a whole bunch of playing with the subsequent control forces to ascertain the real extent and solution of the problem, if, and only if it is considered that having a stab that cannot be controlled due to excessive airloads in manual mode is a bad thing
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What concerns me is that the initial CFD modelling showed at 0.6 degrees would be enough to mitigate the issues. On flight test, that was found not to be sufficient, and somewhere, the 0.6 turned in 2.5 degrees.
That is an exponential difference, and I would really like to see the modelling and assumptions that supported either numbers...
There is also the NYT report where the test pilot stated MCAS orginally used G force, and that was dropped somehwere along the line...now what was that used for? It seems that the high G manuevers the pilot was talking about such as wake turbulence or avoidance (that caused stall?)
Again, the CFD assumptions that required MCAS or where mitigated by MCAS would be very, very interesting to look at.
Vortex tabs to prove laminar flow over the wings should not required at this point in design evolution. I was really surprised when they showed up on the 787....will see on the 777-W