Got a request from an avid aviation fan with a doozy of a question. Can anyone help him? I think he is getting confused on the yellow speed tape portion. The actual stall speed is near the bottom. You have to pass through Vls and alpha prot...
Heck, as an airline pilot I am paid to stay out of the red tape and the yellow tape (see below). If I do enter this envelope then I get really apprehensive, it sends mesaages to MCC (Maintenance Control Centre) and I have to answer for everything.
So all you Airbus experts out there....bring it on for this guy!
NOTE: PFD should read as PRIMARY Flight Display...late night for me. :))) Oopsie
I've got a question about the Coffin Corner. I read a post on your blog and have heard different explanations from different sources, I am trying to get it straight in my head. The intent of this question is not to prove you right or wrong, I'm just confused.
In your post you describe it as the altitude where Vs increases and your Vne decreases ( i know the terms in the airbus are a bit different) to create a small margin for error.
Your indicated stall speed would stay the same with an increase in altitude would it not? The True stall speed would increase, but all things being equal indicated stall speed stays the same. On the PFD pic of Coffin Corner on your blog, it shows your Vs at around 250 KIAS, but if the previous fact is true that indicated stays the same with altitude, then that means that your Vs in clean configuration is 250 KIAS at Sea Level. Is that true? That speed seems high to me (I dont fly a jet so I could be very wrong or missing a huge piece of the puzzle)
Where I get confused is I have also read it is the altitude where the low speed buffet and high speed buffet meet.
The other explanation I have heard is that low speed buffet is an angle of attack where the air over the wing is accelerated above the magic speed where you get a shockwave which separates the laminar flow with a decrease in lift and increase in drag (very similar to a stall). And the high speed buffet is where your actual speed is that magical speed where the shockwave separates the flow causing you to lose lift.
Can you enlighten me?