Was MCAS needed?

[fdr]

LE stall strips generally act to give a reliable buffet signal to the driver from vortex impingement on the stabilizer, while that is nice to have, they generally don't act on altering the stall event. They can, but if you look where they are located, they are not used for that purpose.

Vortilons are great at stopping the spanwise flow, which has it's benefits but not to the issue of the nacelle Cm effect. The NG adopted them and they were great, along with the revised aileron design in stopping the 737's aileron vibration at high Mach (relatively...) Wing VGs are not going to do a whole lot to alter the Cm issue either, not if the flow is already happily attached, and the Cm non-linearity starts before there is separation on the outboard sections. The 737 aileron effectiveness in high AOA is not too bad, so long as the slats are rigged symmetrically. The suto-slat function could have avoided the MCAS, it is scheduled at an AOA however, so would have needed to have some reliability, I can't recall if it has dual sensing or not, its a few years since I last stalled a 737.

Have a look at where the stall strips are located and where that is relative to the outboard tips of the stab.(other than the early 737s which had a strip on the Krueger which was a curious thing to have) The neat thing about fluid flow is that almost everything you do will work to some extent. A B52's stunning cheese grater array, like the Gloster Javelin, The Lear's various forms except for John Raisbecks beautiful MK II wing... The Avanti's wing... lots of fluid getting pushed around there... the B707, B757, B767, the 737 tail area, a fence on the 727, hawker vortilon & VGs...... , the outboard wing on the classics, the mid-wing on the classic, and NG, the 787... the MD80 vortilon, the Hunter and F4s dog tooth, notches, MiG15, 17, 19, 21 fences, (not great help on the 15, good on the 21 though) etc and pretty much everything else out there. The EFA Typhoid drools a notch inboard.... a bit like a 330. The A-10 has some stuff going on out there, looks suspiciously like aileron effectiveness related. Gee whizzes have lots of cheese slicers on the wing outboard... which is aileron buzz related I guess. Of all of those, the P168 is curious, the cuff on a beautiful little rocket seems out of place, about like a Ferrari with a bull bar. I digress. Pretty clean wings came out on the 747, and on the A330-340-350-380. Boeing excelled with the 747, but Airbus really did well on their wing design (making up for the A300Bs wing/aileron... woof).