Horizontal Stab vs Compressibility

[69th_chuter]

The 109F, on it's own, wouldn't come apart at it's full power terminal velocity of up to 906km/h   It needed the pilot trying to control the instability symptoms or dialing in too much nose up trim to exit the dive in too big of a hurry.  So the speed limit is there to keep the pilot from screwing up, not to keep the plane from self destructing.  It's been awhile since I've dived the BoS 109, but the rocking seemed to have been there though the yawing might have been missing.  The speed continued rising all the way to the ground instead of peaking at 4.5km as I remember and the trim simply pulled the nose up without the increasing nose up moment at lower altitude that could lead to wing failure.  The only way to keep a real 109F from pulling out of a throttle on dive was to have the stab set at +1.75 or more (nose down).  Rolling in nose up trim at speed was rather easy but jerky preventing precise adjustment and you wouldn't know you had too much until lower altitude.  Rolling in further nose down was impossible due to air load.