Just like there’s a Va/Maneuvering Speed at which an aircraft will stall before the structure is damaged by excessive loads (https://www.faasafety.gov/files/notices/2015/Nov/V_Speed_Review.pdf), might there theoretically also be a–I’ll call it “Vmr”, e.g. V-maximum-rudder–a speed below which no combination of maximum rudder deflections would damage the vertical stabilizer?
Looking at the far ends of the speed spectrum, certainly jamming the rudder back and forth at 0 kias won’t cause vertical stabilizer damage. Doing so at 120 kias would probably be structurally sound but produce some terribly dangerous yaw and stall condition. Jamming it back and forth at 350 kias likely would do damage to the vertical stabilizer. Raf references AA587; what would it’s approximate airspeed have been about 1m:30s after departing the runway? 180kias? That airspeed would obviously be beyond my theoretical “Vmr,” for a loaded A300 at least, given the outcome. So… maybe around 150-170 kias for my theoretical “Vmr”?