Zapletal Writes Steelpillow you wrote 1 I do find the airship analogy dangerous perhaps spurious The situations are utterly different Just before making that analogy I wrote 5 TWO CASES TO THINK ABOUT please don t say Oh but that s different The first airship example was intended to make clear that a Lift force can be created in a fluid by pressure forces alone so dP dt is NOT absolutely essential The second wave example hinted at how dynamic effects can create such Lifting pressure zones o0o 2 Only part of the overall flow pattern supports the aerofoil in that part that actually supports the wing the air is being deflected downwards etc That whole paragraph is wrong or at the least very misleading All parts of the flow pattern depend on all other parts of the flow pattern That is why it is called Continuum Mechanics Any smallish volume of fluid near the aerofoil ie any fluid that might be said to actually support the wing necessarily has very small mass There is simply NO WAY that this small mass can cause ALL of the Lift via its dP dt Instead this small volume of fluid is responsible for a VERY SMALL part of the Lift via its downward dP dt The rest of the Lift comes from the PRESSURE FIELD surrounding this small volume That pressure field established when the aerofoil first started to move or accelerated is also related to the momentum changes of all the other parts of the fluid more than half of which are now UPWARD dP dts o0o 3 Thus in practice the application of dp dt is quite complex So the true debate here should be how do we give a simple introduction to the Newtonian model of dynamic lift introducing the basic principle to the relevant localised airflow What you are suggesting is that this article should teach a FALLACIOUS model of Lift for purely IDEALOGICAL reasons This shouting is just to make this point clear so I don t have to repeat it Specifically your qualitative Newtonian Model is incapable of giving any quantitative results To get any results at all you must first know the Lift then ARBITRARILY assume an amount of mass to do the Lifting ie your relevant localised airflow after which you get an average acceleration value but NO IDEA of what the actual flow field looks like This is an utterly useless approach to understanding FDL ie it is of zero help in designing aerofoils that is taken simply to support an idealogical viewpoint ie that Lift MUST be due to Downwash with that viewpoint being WRONG anyway ie as many others here now agree there is NO NET change of vertical momentum As I wrote earlier In short the editors of good encyclopedias filter out the nonsense If this does NOT happen then very soon we will have to believe that the world is flat voodoo is real and the star signs predict our future To which we might have to add and because Newton said so all FD Lift is due to Downwash And maybe after that ETT can make a comeback o0o 4 Besides seeking refutations of Clancy s position I emphasised the importance of relevant citations I had hoped for verifiable quotations clearly relevant to Newtonian flow deflection and explicitly countering Clancy s position yet the silence on this point is becoming deafening No relevant citations no progress Again your deafness seems decidedly idealogical in nature As already quoted and cited many times the major part of Lanchester s book is directed at refuting Newtonian flow deflection All of the Circulation Vortex Theory of Lift hugely successful for 100 years and which has countless citations from umpteen reliable sources refutes it If anyone is seriously interested in this Article then they should study this body of knowledge more deeply before trying to impose a false idealogy upon the next generation I will be away for the next week so not able to respond to any questions for a while End Zapletal