Thinking about stalls
On Mar 14, 11:58*am, Bertie the Bunyip wrote:
wrote :
On Mar 14, 11:37*am, Bertie the Bunyip wrote:
TakeFlight wrote in
news:935d6394-8224-482e-9428-
:
Put me in the "not enough info" column.
Plane #2 could be in fact _in_ a stall (or spin), "descending fast
with 50% power" or _more_. *Think Delta Flight 191, for example.
That was something else entirely. That was a microburst. The rules
pretty much go out the window with one of those.
not to say the laws of physics are suspended, but it's a scenario
that is so different from what we learn as pilots that drastic
retraining was * introduced right across the board after it. Flight
guidance systems were modified to account for the new methods, so
it's not really relevant.
Just to give you some idea of what I mean, I'll give you a scenario.
You'v
e
just aken off and yoou're climibing away at best rate. Suddenly, your
airspeed increases by a fairly large lump. 15-20 knots, say. you
increase your pitcha bit to absorb it and your speed bleeds back a
tad. Still plent
y
in hand, though. all the sudden the pitch you have is dragging your
speed back and it's beginning to decrease as the wind that delivered
that extra speed vanishes. You're still OK and back to your orignal
pitch and have a couple of knots more than you had at the beginning.
All the sudden, the bottom falls out of your airplane. Your climb
stops and then a second late
r *
you begin to sink, and fast. another second or two and your speed
washes off even further and now you're sinkng and your stall warning
is starting to squeak.
you gotta do something and right now. you still have some altitude,
say 40
0
feet. what do you do?
Bertie
Alt-Ctl-Del
No, wait, change my underwear.
Yoke forward, nose down and max power?
That's what the Delta guys did. And that 727 in New Orleans. A different
approach was needed and what they came up with was full power. and in a
jet that means firewall and overboost to your little heart's contenet,
and nose up as much as you can. The stall warnign should be ringing off
the wall ( we have stick shakers, but same thing) and you keep this up
til you fly out the other side of the mess. It goes against everything
we've learned but that's what they tell us to do. There's generally some
guidance form the flight director as well. On some it's a set of yellow
"antlers" that give you best pitch and on others the pitch bar on the
flight director just gives you all the pitch info you need ( you just
put the airplane wings on a magenta bar, no brains required)
note this is for a sustained and powerful microburst and not for
recovery form a tiny bit of wind shear in a 20 knot wind.
Bertie
That's what I couldn't remember; I recalled the DFW incident (drove by
a couple of weeks after- messy) and remembered reading about the sim
duplication. Yep. Pull back would take some sim work I'd think to
ingrain something that seems so counter-intuitive.
So, pull back, firewall, recover, enjoy the shaking hands/knees,
change underwear. Gotcha. Oh, land, have beer.
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