Originally Posted by OK465
Is VLS redisplayed?
VLS is based on Vs1g, which depends on weight, flap/slat position and alphamax. Alphamax varies with Mach, similar to the stall warning threshold. IMO it would be logical that the system uses the same logic for alpha max as it does for alphaSW, i.e. the highest of the valid Mach values is used to determine alphamax. The display of VLS on a PFD reqires that the speed displayed (ADR1, 2 or 3) is not 'invalid' (SPD flag displayed), and that VLS is within the range of displayed speeds.
Vs1g (aka Valphamax) is only displayed in normal law. In alternate law Vs1g is replaced by Vsw. IMO a logical consequence of the loss of protections: at the high speed end of the envelope, alternate law reduces Mmo to 0.82.