P Of F Gurus, please help!

[InTgreen]

Quick question which may well lead to some debate about who is right! During the basic description of Inflow Roll, why does the Inflow Tilt axis retreat towards the lower side of the disc leaving Flapback as the major effect of 'fast' forward flight? It must have something to do with as the disc is progressivly tilted the Induced Flow at the 12 o'clok position is increased. I've been sad and am now getting square eyes on the reason for this.... Anyone help with a big writing and picture version of why??

[SASless]

Sounds like more absolutely critical information a working pilot really must know to be able to do his job......and please tell me this is not one of the questions on one of the dozens of exams one must take for a pilot's license!:{

[Foggy Bottom]

This is actually one of the simpler questions. For the definitive answer, refer to the curriculum under the chapter title PFM.

[InTgreen]

As it happens, I don't require the knowlege for the ATPL exams - more is the pity. Not got time to start those yet! I am just trying to get some of the more puzzling theory elements behind me. I know that some things happen - says so in my revision notes, but I would like to know WHY. It helps me remember stuff! For the definitive answer, refer to the curriculum under the chapter title PFM. Erm, Foggy, for the dumb Brit, please elaborate!

[[email protected]]

InTgreen - flapback is the major feature because the speed differences between the advancing and retreating sides of the disc are so great, remember we are talking V squared here so the effect is marked throughout the flight envelope.

The inflow angle changes are far less but most noticeable during the transition to forward flight - it is the difference between the inflow angles at the front and rear of the disc that is important and what causes the roll towards the advancing side. Inflow roll is present throughout the flight envelope - different designers have different ways to compensate for it.

I am sure there is a very complicated mathematical proof of what happens but I stick to the simple P of F answer which is an acceptable explanation for something we know happens:)

[InTgreen]

Cheers Crab, simple works for me really and just to hear someone else come up with V squared having the most influence in this case is good enough - cheers!

T green

[Trans Lift]

please tell me this is not one of the questions on one of the dozens of exams one must take for a pilot's license!http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/boohoo.gif Today 04:57


Is that not what the question banks are for? So that people can memorise questions without actually knowing the way these phenomenons work??:ok: