Question raised 3 days ago by bubbers44:
Quote:
They were cruising at M .80 at FL350 so how much static pressure change with a climb would it take to go above mach limit with a blocked pitot tube?
Assuming a blocked pitot (business end + drain) and total pressure trapped inside the tube at FL350 / 275 KCAS / M 0.808 yelds:
FL375 / 302 KCAS / M 0.922
FL380 / 306 KCAS / M 0.944
NB: corrected from an erroneous previous post which I deleted.
Thanks DJ77. The only reason I brought this up is to explain why he pulled the nose up. Your data confirms that they had an overspeed warning due to the climb with frozen pitot tubes causing the overspeed warning when static pressure reduced to the lower pressure.
Doesn't this explain how this accident happened the way it did? The PF started a climb when the AP disconnected, got an overspeed and pulled up into a deep stall.