Flyinheavy CB scenario
--------------------------------------------------------------------------------
I am following this thread like the first A447 Thread from the very beginning. I am amazed how this speculation of entering a "monster CB" is beeing posted in a nearly constant frequence. Untill now there is no evidence for this.
I have seen other maps showing A447 as already outside the weather at 0214UTC. As far as I have seen no mention to entering a CB has been written in the BEA report.
With a difference of about 20 minutes LH507 did fly the same AWY and only diverted by 10NM, if I remember well. Many of you were claiming, that this 'monster CB' would have to be avoided by a lot more.
I do belive only the DFDR could tell us that part of the story.
What are you talking about? Who says it would have to be a "Monster CB" to cause a jet upset for a high and heavy aircraft? 35000' is barely chest-high on an
average CB, and moderate to severe turbulence can and does exist 5000' above a developing one, well in the clear of any visible cloud water vapor, and therefore even further above tops calculated by radar returns.
Every CB is a "monster" when it comes to potentially wreaking havoc with aerodynamics and air data. A 10-mile diversion is still a diversion. With developing CBs commonly having growth rates between 5'000 and 10,000 fpm (as measured by water droplets, which lag) a 20 minute difference in a convective, dynamic area can mean the difference betweeen safely transiting the area and having absolutely nowhere to go.
Furthermore, you don't have to be inside the contouring returns shown on airborne radar to experience localized areas of moderate to severe turbulence due to not only vertical, but also horizontal shearing in such a dynamic area, and anyone flying around them enough knows this. Developing cells, which often produce the worse updraft/turbulence, frequently offer little radar return at all compared to mature or dissipating cells nearby and have the fewest visual cues (like frequency of lightning) if its night or when the cells are obscured/imbedded.
The same goes for sudden and transitory temp increases aloft in these areas with such convective activity. Put the wrong combination of turbulence and temp together when you're high and heavy with narrow buffet margins/low performance/degraded maneuvering ability as limited by load factor, and the can of worms can quickly be well-opened.
Like someone else wrote..Occam's Razor. You can say there's "no evidence" for this yet jet upset is a very real thing with very real incidents and/or accidents, and the heightened potential for a high and heavy aircraft in an area of severe weather experiencing it is the 1,000 pound gorilla hanging over this event.
Otherwise, you accept that a sudden instrument or mechanical failure just happened to occur at that place and time (in the area of convective activity), was of a type that went around all engineering redundancies, and so sudden and catastrophic that the crew couldn't even transmit a Mayday. To believe that you have to ignore the 1,000 pound gorilla outside the window, and even though nobody makes mystery movies or CSI episodes about the obvious, it's still the high probablity reality compared to some obscure, one-in-a-zillion chance failure.