Windshear on T.O

[Hugh Johnson]

Just got back from 900EX recurrent at FSI TEB. The excape maneuver is leave flaps and gear where they are, firewall the throttles, pitch up and ride the stick shaker/stall warning system until you exit the windshear. Period, end of sentence.

 

[HS125]

Just got back from 900EX recurrent at FSI TEB. The excape maneuver is leave flaps and gear where they are, firewall the throttles, pitch up and ride the stick shaker/stall warning system until you exit the windshear. Period, end of sentence.

The 900EX has some operating differences from the 900A/B even though they are the same airframe. I can't figure out the French.

Not to change the topic of the thread but, does the 900EX have publised X-wind limits for wet and slippery runways?

 

[Hugh Johnson]

Supp 2 of the performance manual, operations on contaminated runways, has a limitation of 5KT on "icy" runway. It defines icy as "contaminated by ice", "A runway surface condition where braking action is expected to be very low, due to the presence of wet or dry ice."

 

[bigsky]

As I understand it the stick shaker is max L over D. This is based on Angle of attack so it is the most accurate.
One thing I have noted when studying windshear accidents is the last thing on the voice recorder is " watch your speed" (In all cases they were slow as one would expect in windshear) As is our habit when we see a slow airspeed we want to lower the nose to prevent a stall. This is where they all released back pressure - lowered the nose and the airplane crashed into the ground..... most experts seem to believe if they had maintained their attitude they would have flown out of it.

 

[flatspin7]

The ERJ has 2 windshear escape modes ---
Yellow (increasing performance) calls for immeadite go around and reconfigure (gear up, flaps 9) There is a WindShear flight guidance mode but in this case it only comes active with the TOGA buttons.


A RED windshear (decreasing performance) call for immediate go-around with out re configuring and that flight guidance is set up for max performance... it is not necessarily "riding the shaker" in an severe encounter in the sim it seems to be going on and off a lot.


Either way the best protection you have in a windshear situation is to get your self as far from the ground as quickly as possible... in a severe down draft lowering the nose to increase ground speed will get your self killed.

Thing a severe downdraft can be upwards of 4000 fpm (really bad case) you need to find 4000 fpm of climb just to stay level!

 

[millhouse21]

I'm going to have to go ahead and kind of disagree with you on that....yeah...Windshear Escape Guidance mode will come on automatically any time it detects decreasing performance. It will also come on when the TOGA buttons are pressed in the yellow windshear mode.