Well I think Bernoulli’s theory must hold some water, even if it is only a small percentage, it does provide some lift, however small, the first link is indeed excellent and uses Newton’s theories very well, I think the thing with Bernoulli is the theory is relatively simple and easy to explain, probably why it is inherant within the training structure especially at PPL level, Ian you fly the 340 for Virgin so maybe you can clarify, generally aircraft have their CP aft of the CofG, which creates stability, and this stability causes a nose down pitching moment, this is why the tailplane has a downward force & negative angle of incidence which forces the nose up and level again, but the Airbus has it the opposite way? i.e. the CP is forward of the CofG, which means that the tailplane must cause an upward force to cause a nose down pitching moment to counteract the nose up tendancy (our ATPL instructor told us Airbus manufacture in this way), but one thing I have noticed with the Bus is that the tailplane appears to have the same angle of incidence as Boeings etc, if this is the case what causes the pitch up moment? surely the downwash theory must hold true for the tailplane as well? because if the first link I gave is to be believed, Bernoulli’s theory would suggest that there would not be enough lift provided by the tailplane airfoil?
(of course if my instructor was talking out of his proverbial disregard the above 🙂 )
If the downwash theory was conclusive, I wonder why member states (particularly JAR & the FAA) have not embraced it and use it in ATPL theory, or do you think it is a case of saying “ahh, the lift theory we have been using all these years is wrong, we need to use this now” ?, does this point to the fact that the downwash theory is not conclusive enough? or does it point to the fact that member states have been teaching the wrong theory all these years?
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