Airbus Gust-Load Alleviation systems

From:         m.fiddler@staffs.ac.uk (Martin)
Organization: Staffs University, UK
Date:         29 Jul 96 02:29:35 
Followups:    1 2
Next article
View raw article
  or MIME structure

Hi
I remember attending a lecture on the A320 wing, and we were told that
it, and the A330/A340 wing, incorporated gust-load alleviation systems.
Assuming I remember/understood correctly: a g-force sensor senses that
excessive turbulence is causing too much stress on the wing.  The high
loading is at the bottom of the drop, when the wings have to take the
inertial load of containing the downward momentum of the fuselage when it
stopps dropping and re-starts normal flying.  The GLA works by immediatly
opening the wing spoilers/(lift dumpers?), reducing the sudden load on
the wing and bringing the maximum bending moment on the wing down to a
lower level. The guy said it works well (in reducing max bending moment)
but the passengers percieve that the turbulence is worse than it is, due
to the wing's reduction in lift during the downwards phase.

So, is there such a system as I have described?  Does it work like I
described it? Is it's complexity worthwhile - considering the highly
optimised airbus wing that may well need protecting from high bending
moment, and the availability of the SEC computers it may be a good system?
Martin

--
m.fiddler@staffs.ac.uk
Phone: 0976 382655
http://www.staffs.ac.uk/sands/engs/staff/mf/mfiddler.htm