On May 13, 4:44*pm, Douglas Eagleson
wrote:
On May 13, 4:29*pm, "JR Weiss"
wrote:





"Douglas Eagleson" wrote...
A predicate theory was used to deselect all fighters in general.

Actually, not. *You selected a generic "canard" fighter and a generic
"horizontal stabilizer" fighter. *You then provided specific claims for each of
them. *THEN you applied the claims to "canard vs horizontal stab" in general.

Canard stall recover was claimed by me to be intrinsically stable. *Stalling a
fighter inverted for the rear stabilizer aircraft was claimed to be ALWAYS
nonrecoverable. *This is the point of the debate, thanks for recognizing it.

The theory as a general theory is flawed. *"Canard stall recover" is
"intrinsically stable" (understood as "inherently achievable") ONLY because
current canard designs are such that the canard stalls before the main wing.
hence, the wing is still flying when the canard loses lift, and the nose will
drop and place the canard in a flying AOA again.

So if an experienced fighter pilot says I am wrong on this exact point, then
my ability is challenged. Inverted means real inverted g-forces. Meaning maybe
12g's.

You are wrong.

No current airplane is designed to withstand -12g. *No human pilot can function
under -12g!

I claim to know all stabiblity for the rear stabilzer appears bad under high
inverted gs. If I am wrong and you know so, then state my incorrectness as a
fact.
Is that hard?

No; it's easy.

An airplane with a rear horizontal stabilizer can easily be designed to function
under high + or -g. *It is a matter of specific design parameters, not inherent
physical or aerodynamic law.

An airplane that has a profile *symmetric about the lateral plane behaves the
same whether upright or inverted. *Today, such an airplane COULD be designed and
flown, with stability provided by computer-controlled surfaces. *It would not
"know" whether G was + or -, except for some artificial reference provided to
the computers. *Its stability and maneuverability would be exactly the same
under "+" or "-" g. *ONLY the pilot would be subject to the artificial
limitation of + or - g.

Also do not forget the difference between fighters and common aerobatic
aircraft. Aerobatic aircraft use propellor power against the rudder to
recover, jet fighters have no ability to do this.

Again, it is a SPECIFIC design problem, not an inherent design flaw. *Both prop
and jet airplanes are built in canard and horizontal stab configurations.. *All 4
permutations are viable. *All 4 come in a wide variety of specific designs. *All
4 have their advantages and disadvantages, proponents and detractors. *NONE of
them is inherently unsuitable for high-g maneuvering!

Now a days there is experimentation with thrust vectoring. *A problem with
always thinking is that somebody has to go out and test thrust vector stall
recovery. *And the answer is obvious. *Why does this fail to assist in stalls
for jet fighters? Maybe I am ignorent of modern thrust vector method, but it
seeems to me to make little help.

Post the citations for such failed tests, and maybe we'll be able to help you
figure out the problem -- which may be simply that you are again trying to posit
a general theory from a specific design fault!

Well, you avoided the issue, high g stalls.

Maybe I am wrong about actual stalls, but do not just allude to me
being wrong about stalls in canards.

If you can go to the edge of the envelope and stall safely you can
beat nonstallable aircraft. It is an exact stall issue, not flight,
but stall.- Hide quoted text -

- Show quoted text -

http://www.aoe.vt.edu/~mason/Mason_f...AlphaNotes.pdf



Here is a study that mentions a critical aspect of the issue of canard
flight. High angle of attack allows for very fast roll rates in
general. A wing designed for high angle of attack becomes a superior
wing in general.

A f-22 uses a special thrust vectoring to achieve high angles of
attack, it does not use a superior wing design. A major fact shown
was the roll rate as angle of attack is varied. Reliance on thrust
vectoring to compensate for a wing design reduces the roll rate.

Roll rate is a speed to turn in. And the degree of roll appear
amendable to only a f-16 challenge.

In dogfights it has a deficiency. In stealth it likely has
superiority. Maybe a tradeoff was accepted. As long as pilots know of
this limitation they may alter tactics to overcome lower performance
ability.

In decision making many factor appear and my guess is it is to be
termed a fourth generation dog fighter and a fifth generation stealth
fighter.

Roll rate is another envelope variable and the lack of speed to turn
appear to make another maneuver available to be considered. A basic
cork screw as a prelude to turn is either to be followed or not
followed by the attacker, say an F-22. A leading enemy can expect the
F-22 to not follow.

An F-22 cannot keep up.

As a result all acts to avoid the US fighter can be successful break
off maneuvers. If you do not match the cork screw, you also loose. A
whole class as a basic dogfight disappears.

It is a huge compromise design, the non-canard F-22.