PPRuNe Forums - View Single Post - AF 447 Search to resume
View Single Post
Old 24th June 2010 | 03:11
  #1589 (permalink)  
Machinbird
15 Anniversary
 
Joined: Jul 2009
: ATP+Mil
Posts: 1,587
Likes: 185
From: Not far from a big Lake
I'd like a little assistance in ACARS reporting criteria. A while back I mentioned an old post regarding the normal law protection mode having the potential to cause a pitch up into a stall upon bogus sensing an approaching violation of the Vmo/Mmo limit airspeeds. If at time ~0208-0209Z before the primary string of ACARS events, the aircraft simultaneously filled all 3 pitot tubes with water or ice from one of the Cb cells it encountered thus plugging all bleed ports in the pitot tubes and then flew into colder ice that plugged the pitot inlets, it would then be possible to pressurize all 3 pitot systems in a fairly synchronous manner from water vapor pressure in the presence of pitot heat.

Would such an event (an apparently valid overspeed indication) show on the ACARS reporting? The original post by PILOTAYDIN indicated that there were no ECAM messages in the simulator session he participated in. I believe CONFiture earlier indicated that such a pitch up would require ace level systems knowledge to halt before it caused a stall.

If ACARS would tattle on activation of the Vmo/Mmo protections then we can pretty well eliminate a Vmo/Mmo protection induced pitchup prior to the current known ACARS events.

It would be useful to conclusively eliminate such a scenario since otherwise AF447 could be already on its way down in a deep stall at LKP and this would change the search strategy.
Machinbird is offline