ORIGINAL: phlpsfrnk
ORIGINAL: onewasp
Quote "I rest my case. Quote
Not so fast______
"The effect begins to be noticeable when the aircraft's altitude is within 1-1.5 times the length of its own wingspan and, when the altitude is within about half a wingspan of the ground, the effect can increase lift by as much as 40%."
Yet another source, ______ yours is NOT conclusive____merely familiar to you.
There are MANY others and they do not all agree with one another.
You are perfectly correct. Mine is not conclusive. It is however the current knowledge required to obtain an airman certificate from the FAA. The 2nd edition asa source from the late 80's early 90's may no longer be correct. The asa dictionary of aeronautical terms is currently in its 4th edition and I'd be willing to bet that the definition has been updated. The quote "within about half a wingspan of the ground, the effect can increase lift by as much as 40%" is correct by all the sources I've read. All the sources I have read indicate one wingspan above the surface. Could you provide that source that clains 1.5?
BTW the asa news release for their New Forth Edition dated February 7, 2007 cites the same sources that I cited, as its sources. "All specific to the aviation industry, the terms have been gathered from the regulations, the Pilot/Controller Glossary from the AIM, and glossaries from government handbooks and manuals."
Your answer BEGS the QUESTION rather than answering it.
Why would you quote a full scale source as definitive for this discussion?!!?
Your profile states that you have been building/flying for 30 years. Surely then you are aware that model aerodynamics are NOT the same as full scale, in each and every case.
Reynolds numbers are a classic example of this as in full scale there is a raft of data to be referenced; while in model scale there is virtually none.
We KNOW the Reynolds numbers for our models are quite low but there it ends.
NO further data. That leaves us with assumptions and ???????????
Ever see a model Heli fly inverted??? How about full scale?
How about extended inverted flight (and maneuvers) with an undercambered airfoil??
Models yes. Full scale??????
SOME of the "rules" apply (perhaps even most) but a long, long way from all.
I consider your quotes as interesting but off topic. They apply to a SEGMENT of full scale flight. That's it.
Many of us on these sites are "ex-" about any level of any subject you care to mention, including military, civilian, commercial.
NOW, if you can quote Michael S. Selig I WOULD take notice as he is BOTH full scale and model experienced.