Text 13599, 70 rader
Skriven 2014-04-01 11:39:54 av alexander koryagin (2:5020/2140.2)
  Kommentar till text 13556 av Roy Witt (1:387/22)
Ärende: Re: MH370 update on my March 17th message
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Hi, Roy Witt!
I read your message from 31.03.2014 16:12

  ak>> Yes, and this process maintains speed.

  RW> There is such a thing called 'glide ratio'... for instance a 747
  RW> has a glide ratio of 17:1. This means that for every 1 foot in
  RW> altitude, it can glide for 17 feet forward. If it were to lose all
  RW> engines at 35k feet, it will be able to glide over 110 miles, as
  RW> long as the pilot doesn't do something stupid like pulling the nose
  RW> up.

  RW> 1 foot = 30.48cm

    The question is -- was it possible to land the plane on the ocean
surface, in one piece, gliding down from a high altitude. The horizontal
distance doesn't matter.

<skipped>

  WD>>> In order to maintain the forward momentum and create lift, the
  WD>>> plane has to be in a constant nose-down attitude.

  ak>> But near the ground the plane can lift its nose and diminish its
  ak>> vertical speed.

  RW> Virtually any plane that can fly can glide. Of course the kinetic
  RW> energy to overcome drag and move forward has to come from somewhere
  RW> so without an engine it comes from the potential energy of
  RW> altitude. The ratio of altitude lost to distance flown. Of course a
<skipped>
  RW> To a certain extent this is the correct procedure on landing. The
  RW> rate of descent of a steady state glide may be too fast for a safe
  RW> landing so the pilot will lift the nose or flare to slow the rate
  RW> of descent and airspeed for a safe landing.

    We still argue with him could the plane (that ill fated Boing) be
controllable, like a glider, when its fuel ended. Could its hydraulic
system work? The following URL says that loosing both engines and APU is
not the end for the hydraulic system:

http://www.dailykos.com/story/2013/05/01/1205857/-How-Airliners-Work-Hydraulics
-----Beginning of the citation-----
OK smart guy, what if the APU doesn't work? Now what?

    We're not completely screwed just yet. We've got one last trick up
our sleeve.
    The RAT!
    RAT stands for Ram Air Turbine. It's a little propeller with a
hydraulic pump attached to it. If we lose both engines this little guy
is spring loaded to pop out and power the center hydraulic system. This
lets us steer (important) while we hopefully get an engine restarted or
find a place to land.
-----The end of the citation-----

    So even if fuel is run out the hydraulic system is still alive; as I
said hydraulic pumps do not demand much power.

  RW> On Ward's exalted throne, he is still seated on nothing but his big
  RW> arse.

    I think if a person indeed worked in this area he knows many special
details. But anyway, I am glad when I learn something new. In this case
our correspondence gains some sense. ;-)

Bye, Roy!
Alexander Koryagin
fido7.fidonews 2014
--- FIDOGATE 5.1.7ds
 * Origin: Pushkin's BBS (2:5020/2140.2)