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Old 11th Mar 2019, 11:33
  #315 (permalink)  
NAROBS
 
Join Date: Feb 2008
Location: London
Posts: 6
Just looking at a profile picture of the 737 - 8 Max, it strikes even the mildly interested, that those huge new engines are positioned almost completely foward and clear of the leading edge of the wing. That must shove the Centre of Gravity of the aircraft way in front of the leading edge of the wing. That's non-standard for a start in a passenger aircraft. Usually the C of G is positioned on or just foward of the centre of lift. Yet the chord of the wing and the rear horizontal stablisers are ultra slim (To minimise drag and fuel costs) and presumably, therefore do not provide the same level of damping to movements in pitch in normal flight. A further consequence of narrow chord is that a small change in the angle of attack produces a large movement in the centre of lift, proportional to the chord, is it not ? A recipe for porpoising ?

IMHO, a compare and contrast of this airframe with its predecessors indicates the designers may have possibly pushed the principle of inherent aerodynamic instability to far and knowing this, have pressed the MACAS anti-stall software into service in a role it wasn't initially designed for. A possible subject for regulation ?

N.
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