Originally Posted by Honkozzie
At altitude our TAS is very high, therefore it behoves all of us to ensure timely weather avoidance. Transport aeroplanes will come apart inside these Cb walls at 8 miles a minute!
The certification regulations don't quite agree with you here. It is not your TAS which counts here, it's the dynamic pressure. At high altitude, at cruise airspeeds, the dynamic pressure is not as high as at medium altitudes. The gust limits which the aircraft structure must adequately resist (plus a safety factor) actually decrease for higher flight levels. Here is the current CS 25.341 (a) 5:
Originally Posted by CS 25.34 (a) 5
(i) VC: Positive and negative gusts with reference gust velocities of 17.07 m/s (56·0 ft/s) EAS must be considered at sea level. The reference gust velocity may be reduced linearly from 17.07 m/s (56·0 ft/s) EAS at sea level to 13.41 m/s (44·0 ft/s) EAS at 4572 m (15 000 fet). The reference gust velocity may be further reduced linearly from 13.41m/s (44·0 ft/s) EAS at 4572 m (15 000 fet) to 7.92 m/sec (26·0 ft/sc) EAS at 15240m (50 000 ft).
(ii) At the aeroplane design speed VD: The reference gust velocity must be 0·5 times the value obtained under CS 25.341(a)(5)(i).
PBL