Mechanics of Elevator Trim. In Detail.

On Thu, 19 Jun 2008 13:15:54 -0500, "Allen"
wrote in :

all. "This is a very novel
concept, and if it's successful, it will be revolutionary," said Subrata
Roy, the ship's inventor, who applied for a patent on it last week. "If
successful, we will have an aircraft, a saucer and a helicopter all in one
embodiment." The saucer is propelled by a force called magnetohydrodynamics,
which is created when a current or a magnetic field is passed through a
fluid. By interacting with the atmosphere, the for


Towering Obstacles? One wonders what the maximum magnitude of the
magnetohydrodynamic force created when the "plasma pushes around the
surrounding air" might be. :-)

http://news.ufl.edu/2008/06/11/flying-saucer/
Fittingly, Roy said his flying saucer one day could soar through
atmospheres other than Earth’s own. For example, the aircraft
would be an ideal vehicle for the exploration of Titan, Saturn’s
sixth moon, which has high air density and low gravity, Roy said.

The U.S. Air Force and NASA have expressed interest in the
aircraft, and the university is seeking to license the design, he
said.

“This is a very novel concept, and if it’s successful, it will be
revolutionary,” Roy said.

The vehicle will be powered by a phenomenon called
magnetohydrodynamics, or the force created when a current or a
magnetic field is passed through a conducting fluid. In the case
of Roy’s aircraft, the conducting fluid will be created by
electrodes that cover each of the vehicle’s surfaces and ionize
the surrounding air into plasma.

The force created by passing an electrical current through this
plasma pushes around the surrounding air, and that swirling air
creates lift and momentum and provides stability against wind
gusts. In order to maximize the area of contact between air and
vehicle, Roy’s design is partially hollow and continuously curved,
like an electromagnetic flying bundt pan.

One of the most revolutionary aspects of Roy’s use of
magnetohydrodynamics is that the vehicle will have no moving
parts. The lack of traditional mechanical aircraft parts, such as
propellers or jet engines, should provide tremendous reliability,
Roy said. Such a design also will allow the WEAV to hover and take
off vertically.

Though the design is promising on paper, towering obstacles stand
between the blueprint and liftoff.

No plasma-propelled aircraft has successfully taken flight on
Earth. Such designs have found some success in space, where
gravity and drag are minimal, but a vehicle hoping to fly within
Earth’s atmosphere will need at least an order of magnitude more
thrust, Roy said.

Also, the power source needs to be extremely lightweight yet still
produce enough power to generate the necessary plasma. Not to
mention the fact that the very same plasma that will allow the
aircraft to fly also will interfere with electromagnetic waves
necessary for communication with the vehicle.

But Roy is confident that the unique nature of his design will
allow it to clear the technological hurdles and take to the skies,
and he’s not deterred by the risk of failure.

“Of course the risk is huge, but so is the payoff,” he said. “If
successful, we will have an aircraft, a saucer and a helicopter
all in one embodiment.”

The propulsion system for Roy’s saucer sprouts from his extensive
U.S. Air Force-funded plasma actuator research, the results of
which have appeared in more than 15 scholarly journals.

The production of the aircraft will be a joint project of UF’s
mechanical and aerospace engineering department and its electrical
and computer engineering department.

wrote in message
...
On Jun 19, 12:15 pm, "Allen" wrote:
An engineer at the University of Florida has unveiled a design for a
"flying
saucer" that can take off vertically, hover, and fly, and it has no wings
or
propeller -- it doesn't have any moving parts at all. "This is a very
novel
concept, and if it's successful, it will be revolutionary," said Subrata
Roy, the ship's inventor, who applied for a patent on it last week. "If
successful, we will have an aircraft, a saucer and a helicopter all in
one
embodiment." The saucer is propelled by a force called
magnetohydrodynamics,
which is created when a current or a magnetic field is passed through a
fluid. By interacting with the atmosphere, the force is able to create
lift
and momentum and provides stability against wind gusts. The ship's
surface
is partially hollow and continuously curved, like an electromagnetic
flying
bundt pan. Unfortunately, it seems the technique is likely to work better
in
space, where pesky things like gravity and drag are minimized.

The Japanese built a ship in the '80s using that propulsion
technology. No moving parts in the water; just a tunnel with some big
electrodes. I have heard no more about it; I thing the efficiency
losses are too big. Current flowing through seawater electrolyzes and
heats it, and there goes wasted energy. How does this guy get current
to flow through air?
Another lab built a small flying model using electrostatic
lift back in the 60s. It couldn't lift anything but itself and a few
feet of wire that led to the power source on the floor. It had pointed
electrodes on little posts mounted on but insulated from a screen
below; the posts were negatively charged and the screen positive, and
tiny amounts of current travelled via charged air particles from the
posts to the screen. The charges were not enough to cause sparks, like
lightning. The very light air movement generated lifted the device.
Again, far too inefficient to be useful.
When I was a kid magazines like Popular Mechanics and Popular
Science and Mechanix Illustrated had articles every month on
"Revolutionary" aircraft designs and wings and engines for cars and
airplanes and boats and so forth. They're still printing articles like
that. As kid I read all of this for years and when I grew up I still
saw the same old piston engines, four-wheeled cars, airplanes using
those old piston engines and the same old airfoils we've used for 75
years, and ships with propellers and either piston engines or steam
turbines. All old technology that refuses to go away. Even the modern
car is still using the same piston-connecting rod-crankshaft-camshaft-
valves arrangement that Henry Ford used, just with computer-controlled
spark and fuel controls that break down and cost a fortune to fix.
Nothing really revolutionary, 40 years after all those magazine
articles trumpeting the new stuff just around the corner. Kinda makes
a person more than a little skeptical when Le Chaud claims to have
better ideas, see? He has no idea how many of his ideas were already
invented before he was born.
I think there's more chance of antigravity technology being
developed. A lab has achieved a 4% reduction in gravitational force
above a rapidly spinning superconducting disk. Five or six yeras ago
already. Part of the problem is that no one really understands
gravity, and no one has been able to conclusively link it with
electromagnetism and the two nuclear forces, so until we figure it out
it'll be hard to create something that defeats it. And that's
annoying, seeing that even the weakest magnet can pick up something
against the feeble force of gravity.
The fuel pump in the tank of my car has now quit, and a new one
is $400 or so. The little car gets 42 mpg. The 1962 VW Beetle that was
my first car, got 45 mpg. The 1951 International pickup I restored,
and in which I put a Ford 300 six-banger, gets just under 25 mpg, much
better than most brand-new pickups are getting these days. It has a
$25 mechanical fuel pump and a carburetor with a manual choke. The
ignition uses points and a condenser, and when they get worn they'll
tell you that they're worn but they'll keep going until you get home
and won't stop dead in the middle of the freeway. Just what did all
this electronic stuff get us?

Dan

Remove and replace mechanics that can't troubleshoot unless the car is
hooked up to a diagnostic machine (oops, that's another $80 charge).

--

*H. Allen Smith*
WACO - We are all here, because we are not all there.

On Jun 19, 4:35*pm, "Allen" wrote:
wrote in message
* * * The fuel pump in the tank of my car has now quit, and a new one
is $400 or so. The little car gets 42 mpg. The 1962 VW Beetle that was
my first car, got 45 mpg. The 1951 International pickup I restored,
and in which I put a Ford 300 six-banger, gets just under 25 mpg, much
better than most brand-new pickups are getting these days. It has a
$25 mechanical fuel pump and a carburetor with a manual choke. The
ignition uses points and a condenser, and when they get worn they'll
tell you that they're worn but they'll keep going until you get home
and won't stop dead in the middle of the freeway. Just what did all
this electronic stuff get us?

* * * *Dan

Remove and replace mechanics that can't troubleshoot unless the car is
hooked up to a diagnostic machine (oops, that's another $80 charge).

Part of that is good-ole-fashion predation, and part of that is
reselling pig intestines and pasta for $100/serving.

It is known by the manufacturer of the device that the mechanic will
pass on exhorbitant costs of using the device to the consumer, so the
manufacturer inflates the price also. This behavior continues up the
food chain.

Ideally, the diagnostic machine could be nothing more than a PDA or
notebook compuer with a USB port. Then, all the excuses about why the
diagnoses or the machine itself are so expensive would be invalid.

That's what so wonderful about computers - untruths about "necessary
costs" and "unavoidable overhead" are quickly revealed to be such.

A CDROM drive is one of the most complex machines ever built if one
considers all what one needs to know to build it from basic
components, but it can easily be had for $25US.

That's the power of true commoditization.

Of course, if the vendor determines that you intend to mount the drive
in your Gulfstream, then adding a couple of 0's to the price would be
in order.

-Le Chaud Lapin-

On Jun 19, 4:30 pm, Le Chaud Lapin wrote:
A CDROM drive is one of the most complex machines ever built if one
considers all what one needs to know to build it from basic
components, but it can easily be had for $25US.

That's the power of true commoditization.

Of course, if the vendor determines that you intend to mount the drive
in your Gulfstream, then adding a couple of 0's to the price would be
in order.

Those extra zeros reflect the cost of certification and the cost
of liability insurance to protect the maker when the drive quits and
the pilot loses control in IMC and crashes and the widows of his
highly-paid passengers sue everyone that ever had anything to do with
that airplane. Tell me how commoditization is going to fix that.
Common, "commoditized" hardware can't be used on aircraft, for
two reasons: There's way too much counterfeit junk on the market, and
the cost of ordinary hardware is almost as bad as the cost of aircraft
hardware. In the former instance, we are now sold SAE/AISI Grade 5
nuts and bolts in the hardware stores that could come from the US or
from China. It all has the same head markings, but the counterfeit
stuff won't make the grade and if one uses such stuff in an airplane
it will come apart under stress. Grade 5 bolts are supposed to have a
tensile strength of 125ksi but the cheap stuff might have half that
and would shear or snap during high loads, or it might be brittle and
have no margin between yield and ultimate. It might have no
anticorrosion properties at all, and so it fails after pitting
somewhat. That's the reason the Government aviation regulators demand
that certified aircraft use only the parts listed in the
manufacturer's parts manual, and the manufacturer will specify AN or
NAS or MS hardware becauase it is made to a hard specification and is
traceable all the way back to the manufacturer, who also has records
as to where the metal came from and what its composition was and what
heat treatment it received. This takes paperwork which costs money,
but it minimizes the occasional unfortunate incidents where unapproved
parts get into an airplane and it comes apart in flight like that
Convair 580 did over Finland a few years ago when the fin came off
because some crook sold the overhaul facility a counterfeit fitting
that failed under load. The paperwork system was ignored somehow. The
people who had those 40 relatives die in that accident would never
agree with "commoditization" that could lead to an enormous increase
in inflight structural failures.
And as far as the cost of that hardware, the universal AN/MS/NAS
hardware is not at all expensive since there are numerous companies
making it. When my son was into building RC model airplanes I got him
small AN hardware for less money than for the cheap junk that the
hobby shops sell. A few bolts (like the landing gear bolts on the
Citabria) cost around $35 for a 1/2" x 3" or so NAS bolt, but that
bolt has a tensile strength of about 190ksi, something no industrial
hardware reaches. Even at that those bolts get changed out every 500
hours and can be reused after NDI. A lesser bolt would fail,
guaranteed, and someone would get hurt. Besides, aircraft hardware is
made of nickel steel and other fancy alloys, not the plain carbon
steel used in common hardware. Huge difference, and when I, a
mechanic, am out flying and think about some of that critical hardware
that's hold me up, I'm glad we paid more for it than we could have by
using common stuff.
Numerous homebuilders have designed airplanes intended to cost
much less by using non-aviation parts, but they ALWAYS end up heavy
and more than a little questionable.
And as far as automating flight goes, flying will always
require both skill and awareness unless we turn the whole thing over
to computers like we did the telephone system. And I sure wouldn't
want to trust such a system, especially with opportunistic terrorists
around.

Dan

On Jun 19, 1:44 pm, wrote:
On Jun 19, 2:32 pm, "Ken S. Tucker" wrote:

True actuator #1 can fail, then actuator #2
still works, then actuator #1 is replaced.
Asking the question about the F-16, "fly-by-
wire" fighter, dated 1972, do we have failures
due to the electonics and servos?
Ken

Don't ask me. Ask the USAF about the failure rate and resultant
bailouts and aircraft losses when they quit. Ask them how many
maintenance hours are spent on each airplane for each hour of flight.
And then compare that with the maintenance the average privately-owned
lightplane gets.
Dan

I'm a brat who did "points" on old ICE's, adjusted
carbs...then along comes electronic ignition and
fuel injection and my car starts easily at -20F.
So these advances are definitely reducing my
maintenance. Wife just bought a Gran Caravan
that's scary with electronics, (she loves it), but
I'm keeping a real close eye on all them gizmo's,
so far...excellent...after nearly 2 years.
Ken

Larry Dighera wrote:


Additionally, there is the issue of the limited life span of nuclear
generating facilities, generally about 25 years.

Larry, where the hell do you come up with this stuff?

Please take a look at this page.
http://www.entergy-nuclear.com/plant...ation/ano.aspx

Unit 1 went into service in 1974 and is licensed until 2034.
Unit 2 went into service in 1980 and is licensed until 2038.

On Fri, 20 Jun 2008 11:30:11 -0500, Gig 601Xl Builder
wrote in
:

Larry Dighera wrote:


Additionally, there is the issue of the limited life span of nuclear
generating facilities, generally about 25 years.

Larry, where the hell do you come up with this stuff?


I presume you have no quarrel with my contention that nuclear
generating facilities have a limited life span.

The 25 year figure was related to me by a worker at the San Onofre, CA
nuclear plant whom I chanced to meet on a ski lift some years ago. I
recall, that I was surprised to learn that nuclear plants were life
limited. So I was aware that the first nuclear reactor installed at
San Onofre, CA was shutdown after ~25 years, and presumed that was the
expected life span for all of them.


http://www.sce.com/PowerandEnvironme...SFactSheet.htm
Unit 1 was retired in 1992 after 25 years of service and is
currently being decommissioned.

Now I see that San Onofre Plant 1 was actually shutdown prematurely:

http://www.animatedsoftware.com/envi.../nukelist1.htm
Unit 1 was closed prematurely due to the costs of required seismic
retrofitting.


Indeed the other two reactors on the San Onofre site have longer life
spans:


http://www.eia.doe.gov/cneaf/nuclear...sanonofre.html
U.S. Nuclear Plants
On-line Date License Expiration Date

Unit 2 Sept. 7, 1982 Feb. 16, 2022

Unit 3: Sept. 16, 1983 Nov. 15, 2022

Which works out to about a 40 year useful life span, and the useful
live of the plant at Diablo Canyon is similar:


http://www.eia.doe.gov/cneaf/nuclear...rs/diablo.html

So, I thank you for calling my error to my attention. I'll try to
research my facts before stating them in the future.

Below is some information I found interesting as I researched this San
Onofre issue:


http://www.sce.com/PowerandEnvironme...missioning.htm
Q. What is Decommissioning?
A. Decommissioning consists of decontamination, dismantling,
shipment and final disposition of nuclear power plant components,
and site rehabilitation.

Decommissioning is a condition of the plant's operating license
from the federal Nuclear Regulatory Commission.

Q. When will decommissioning occur?
A. Decommissioning began in 1999 and the majority of the plant's
structures and facilities are expected to be decontaminated,
dismantled and removed from the site by 2008.

Q. How much will it cost to decommission Unit 1? How will it be
paid for?
A. The cost is estimated at $460 million. Sufficient money is
expected to be available to accomplish decommissioning now through
a trust fund financed through rates that was established when the
plant began operating.

Q. How many US nuclear plants have been decommissioned?
A. Four utility-size nuclear power plants have undergone complete
decommissioning, including Shippingport, Pennsylvania (72 MW),
completed 1989; Pathfinder, South Dakota (66MW), completed in
1992; Shoreham, New York (849 MW), completed in 1994; and Fort St.
Vrain, Colorado (330 MW); completed in 1996.

Q. How long did SONGS 1 operate and how much electricity did it
generate?
A. The unit operated from Jan. 1, 1968 to Nov. 30, 1992. ...

It produced about 53.35 billion kilowatt-hours (enough to energize
1 million households for 9 years). Its generating capacity was 450
megawatts (enough to energize about 500,000 homes at a time). For
comparison, SONGS 2 and 3 generate 1,100 megawatts each.


http://www.sce.com/PowerandEnvironme...teDisposal.htm
Waste Disposal

Two distinct types of waste which require special handling and
disposal are produced at San Onofre, low-level and high-level
radioactive waste.

Low-level wastes typically contain small amounts of radioactivity
similar to those produced by medical procedures. Examples of such
waste materials include items such as towels, gloves and tools
used by workers, and water purification filtering materials.

High-level waste is the solid spent, or used, uranium fuel rods.
Disposal of used fuel requires long term, high-reliability
isolation from the environment.



Please take a look at this page.
http://www.entergy-nuclear.com/plant...ation/ano.aspx

Unit 1 went into service in 1974 and is licensed until 2034.
Unit 2 went into service in 1980 and is licensed until 2038.


Indeed:
Arkansas Nuclear One
Unit 1 Unit 2
Commercial Operation Date: December 1974 March 1980
License Expiration Date: 5/20/34 7/18/38



I'm pleased that you find no fault in the other points I raised
concerning nuclear power generation's radioactive waste.

Unfortunately, there are other objectionable environmental issues with
coastally sited generating facilities:


http://www.fox6.com/news/local/story...8-415c783dc82a
Artificial Reef is Built After San Onofre Nuclear Plant Damages
Kelp Beds

Last Update: 6/12 7:18 am

A $40 million, 150-acre artificial reef being built off San
Clemente is one of the most advanced anywhere, thanks to Southern
California Edison, which is bankrolling the work to replace kelp
beds damaged by the San Onofre nuclear plant, it was reported
Friday.

Crews have begun carefully dumping boulders into about 50 feet of
water to anchor what marine biologists hope will grow into a kelp
forest, which would shelter fish and other creatures just south of
the oceanfront nuclear-powered electricity generating station, the
Los Angeles Times reported. ...

Cloudy cooling water discharged from the plant, according to a
1989 study, drifts south and blocks the sunlight needed by a kelp
forest, of which about 180 acres have been damaged, The Times
reported.

Edison agreed to build the reef as part of a deal with the
California Coastal Commission. ...

The reef, more than a half-mile offshore, will be patches of rocks
that fit together like a puzzle and stretch about 2.5 miles,
roughly from San Clemente Pier to San Mateo Point, Craig Eaker of
Edison told The Times. ...

The power plant, which needs massive amounts of water to cool the
reactor, sucks in and kills about 600 tons of fish annually, even
though Edison has tried to remedy the problem.



http://articles.latimes.com/2008/jan...al/me-onofre15
The NRC “always claims there isn’t a high safety risk,” said Edwin
Lyman, a senior staff scientist at the Union of Concerned
Scientists. “But these fabrications went unnoticed by supervisors
and managers for 5 1/2 years. This says something about the
inadequacy of the NRC’s inspection process.”

Commission officials that a fire protection specialist on the
midnight shift from April 2001 to December 2006 falsified records
about hourly patrols around the plant to check for fires. ...

“A major fire at a nuclear reactor could release a thousand times
the long-lived radiation of the Hiroshima bomb,” Hirsch said.
“Fire protection data is the last thing one should tolerate being
fabricated at a nuclear power plant.” ...

Hirsch noted that the current violations were the latest of a
number of problems at San Onofre. Earlier this month, NRC
inspectors discovered the failure of an emergency generator during
three tests in late December. The diesel generator is one of two
that provide electricity to safety systems in the event of a power
outage.

Edison officials said the generator failed because of a faulty
speed sensor, which was replaced.

Dricks said the agency began investigating the fire patrol
fabrications in January 2007. NRC has uncovered the four other
violations. ...


http://articles.latimes.com/2008/jan...al/me-onofre16
January 16, 2008

Seven workers at the San Onofre nuclear power plant near San
Clemente have been disciplined or fired in connection with a rash
of safety and security problems uncovered by federal regulators
last year, Southern California Edison officials said Tuesday. ...

“Where the acts were deliberate misconduct, employees were
discharged and contract workers were no longer permitted on the
property,” said Gil Alexander, an Edison spokesman. “Where the
conduct was determined to be less egregious, alternative
disciplinary actions were taken.” ...

The other violations involved a radiation worker who failed to
comply with a work permit; a failure by supervisors to oversee an
unqualified technician whose work led to the temporary shutdown of
a safety system; and two lapses in plant security. ...



http://www.animatedsoftware.com/envi.../nukelist1.htm
Nuclear power plants and other large nuclear facilities in the
United States Operating or closed.

Including their individual histories, locations, technical
details, official contact points, and local activist groups.

"Ken S. Tucker" wrote in
:

On Jun 12, 9:53 pm, Ron wrote:
On Thu, 12 Jun 2008 09:43:07 -0700 (PDT), "Ken S. Tucker"

wrote:
On Jun 12, 5:08 am, Tina wrote:
Yes, the time my son spent with canard aircraft brought out all
sorts of interesting information about canards and the history
of trying to scale up Rutan's original concept Beech Starship.
The smaller true canards like the Long-eze are pretty good
aircraft. However there is a reason why we don't see large (six
plus passenger) true canards. It's the relationship between CG,
fuel load, payload and range. Apparently in the scale up process
there is a point where it is no longer practical.
Ron Kelley

Hmm, how the XB-70 or this,
http://en.wikipedia.org/wiki/Boeing_Sonic_Cruiser

True, the XB-70 was a qualified success of a large canard type
aircraft. Most of it's problems were due to system failures and
trying to fly at Mach 3.0. The only control issues I know of were
related to overly sensitive pitch response to control inputs.
Ref:http://www.labiker.org/xb70.html

Thanks for that link.

As far as I know the Boeing Sonic Cruiser hasn't gone beyond the
artists concept stage. I guess it's no accident that all the current
crop of passenger jets look alike. That could be partially due to
the reluctance of any large airframe manufacturer to take a gamble on
trying to certify any new "radical" design. Who knows.

Personally, I am intrigued by the three surface aircraft like the
Piaggio. They seem to have done pretty good with their design. One
wonders if given enough time, money and talent, there is some room
for improvement there.

Yes! That Piaggio is one real impressive piece of
aerodynamics, and it sounds very pilot user-friendly.
Very remarkable how they utilized the canard.

I think the aircraft business is extremely conservative.
KISS applies, also canards are difficult for the average
pilot to understand, (Hey man, you got that thar tail on
the wrong end :-).

Would it not also be true that passive stability is not as
important in larger modern airplanes? I would guess (again, I
admit being ignorant of the realities) that adding a 10%
aerodynamically induced increased load on bigger aircraft would be
avoided for efficiency reasons? It might be better to have enough
fly by wire and computer induced stability instead. I don't know
enough about this stuff to even find the back of an envelope, let
alone do a calculation there.

Canards are NOT simple, I've designed quite a few,
and studied others, especially Rutan's.
I find they can be optimised for a given air speed
and are much better than the conventional lay-out.
The main problem is designing the stall.
Ken

Anyone who can design a successful canard aircraft has my respect. I
didn't learn a whole lot about the design aspects from my son (he was
in flight test, not design), but what we did learn was everything
interacted with everything else. The job was interesting, but didn't
last long.

Your son sounds like a cool dude.
The major PITA is designing aircraft to be efficient
at cruise, but safe all the way to stalling, and
recoverable. The difficulty is the movement of the
Center of Lift forward on the main wing as stall
begins.

Uh, no it isn't, fjukktard.



Bertie

"Ken S. Tucker" wrote in
:

On Jun 13, 9:23 pm, Ron wrote:
On Fri, 13 Jun 2008 11:02:35 -0700 (PDT), "Ken S. Tucker"



wrote:
On Jun 12, 9:53 pm, Ron wrote:
On Thu, 12 Jun 2008 09:43:07 -0700 (PDT), "Ken S. Tucker"

wrote:
On Jun 12, 5:08 am, Tina wrote:
Yes, the time my son spent with canard aircraft brought out
all sorts of interesting information about canards and the
history of trying to scale up Rutan's original concept Beech
Starship. The smaller true canards like the Long-eze are
pretty good aircraft. However there is a reason why we don't
see large (six plus passenger) true canards. It's the
relationship between CG, fuel load, payload and range.
Apparently in the scale up process there is a point where it
is no longer practical.
Ron Kelley

Hmm, how the XB-70 or this,
http://en.wikipedia.org/wiki/Boeing_Sonic_Cruiser

True, the XB-70 was a qualified success of a large canard type
aircraft. Most of it's problems were due to system failures and
trying to fly at Mach 3.0. The only control issues I know of were
related to overly sensitive pitch response to control inputs.
Ref:http://www.labiker.org/xb70.html

Thanks for that link.

As far as I know the Boeing Sonic Cruiser hasn't gone beyond the
artists concept stage. I guess it's no accident that all the
current crop of passenger jets look alike. That could be
partially due to the reluctance of any large airframe manufacturer
to take a gamble on trying to certify any new "radical" design.
Who knows.

Personally, I am intrigued by the three surface aircraft like the
Piaggio. They seem to have done pretty good with their design.
One wonders if given enough time, money and talent, there is some
room for improvement there.

Yes! That Piaggio is one real impressive piece of
aerodynamics, and it sounds very pilot user-friendly.
Very remarkable how they utilized the canard.

I think the aircraft business is extremely conservative.
KISS applies, also canards are difficult for the average
pilot to understand, (Hey man, you got that thar tail on
the wrong end :-).

Would it not also be true that passive stability is not as
important in larger modern airplanes? I would guess (again, I
admit being ignorant of the realities) that adding a 10%
aerodynamically induced increased load on bigger aircraft would
be avoided for efficiency reasons? It might be better to have
enough fly by wire and computer induced stability instead. I
don't know enough about this stuff to even find the back of an
envelope, let alone do a calculation there.

Canards are NOT simple, I've designed quite a few,
and studied others, especially Rutan's.
I find they can be optimised for a given air speed
and are much better than the conventional lay-out.
The main problem is designing the stall.
Ken

Anyone who can design a successful canard aircraft has my respect.
I didn't learn a whole lot about the design aspects from my son
(he was in flight test, not design), but what we did learn was
everything interacted with everything else. The job was
interesting, but didn't last long.

Your son sounds like a cool dude.

Yeah, I kinda like him. ;-)

The major PITA is designing aircraft to be efficient
at cruise, but safe all the way to stalling, and
recoverable. The difficulty is the movement of the
Center of Lift forward on the main wing as stall
begins.

I seem to remember a problem they had with the fuel load and the
center of lift moving close to (ahead/behind?) the CG. They also had
a problem with getting enough fuel on board (this was a single engine
turboprop) and where to put it to get the range they wanted.

I guess one way to figure that out is to place weigh
scales under the tires and then fill in increments,
to give the exact CG in horizontal pitch, that can
be readily calculated by the ratios. Fuel movement
for various pitchs would affect the CG.
While on the subject of trim, any excessive trim
required *should* indicate a possible excursion
from the appropriate CG - CL relation.

Wow, you're obvioudsly san injunear.

I've misjudged you bigtime.

Ron Kelley

Regards
Ken
PS: I turned on a TV show "ECW" (no volume),
this is Friday PM here...near midnight, and two
busty chicks (a blonde and redhead) dressed up
in vinyl are beating each other up. It looks rough!


A scholar, of this there cna be no doubt.

Bertie

"Ken S. Tucker" wrote in
:

On Jun 14, 3:26 pm, Ron wrote:
On Sat, 14 Jun 2008 00:33:00 -0700 (PDT), "Ken S. Tucker"



wrote:
On Jun 13, 9:23 pm, Ron wrote:
On Fri, 13 Jun 2008 11:02:35 -0700 (PDT), "Ken S. Tucker"

wrote:
On Jun 12, 9:53 pm, Ron wrote:
On Thu, 12 Jun 2008 09:43:07 -0700 (PDT), "Ken S. Tucker"

wrote:
On Jun 12, 5:08 am, Tina wrote:
Yes, the time my son spent with canard aircraft brought
out all sorts of interesting information about canards and
the history of trying to scale up Rutan's original concept
Beech Starship. The smaller true canards like the
Long-eze are pretty good aircraft. However there is
a reason why we don't see large (six plus passenger) true
canards. It's the relationship between CG, fuel load,
payload and range. Apparently in the scale up process
there is a point where it is no longer practical.
Ron Kelley

Hmm, how the XB-70 or this,
http://en.wikipedia.org/wiki/Boeing_Sonic_Cruiser

True, the XB-70 was a qualified success of a large canard type
aircraft. Most of it's problems were due to system failures
and trying to fly at Mach 3.0. The only control issues I know
of were related to overly sensitive pitch response to control
inputs. Ref:http://www.labiker.org/xb70.html

Thanks for that link.

As far as I know the Boeing Sonic Cruiser hasn't gone beyond
the artists concept stage. I guess it's no accident that all
the current crop of passenger jets look alike. That could be
partially due to the reluctance of any large airframe
manufacturer to take a gamble on trying to certify any new
"radical" design. Who knows.

Personally, I am intrigued by the three surface aircraft like
the Piaggio. They seem to have done pretty good with their
design. One wonders if given enough time, money and talent,
there is some room for improvement there.

Yes! That Piaggio is one real impressive piece of
aerodynamics, and it sounds very pilot user-friendly.
Very remarkable how they utilized the canard.

I think the aircraft business is extremely conservative.
KISS applies, also canards are difficult for the average
pilot to understand, (Hey man, you got that thar tail on
the wrong end :-).

Would it not also be true that passive stability is not as
important in larger modern airplanes? I would guess (again,
I admit being ignorant of the realities) that adding a 10%
aerodynamically induced increased load on bigger aircraft
would be avoided for efficiency reasons? It might be better
to have enough fly by wire and computer induced stability
instead. I don't know enough about this stuff to
even find the back of an envelope, let alone do a
calculation there.

Canards are NOT simple, I've designed quite a few,
and studied others, especially Rutan's.
I find they can be optimised for a given air speed
and are much better than the conventional lay-out.
The main problem is designing the stall.
Ken

Anyone who can design a successful canard aircraft has my
respect. I didn't learn a whole lot about the design aspects
from my son (he was in flight test, not design), but what we
did learn was everything interacted with everything else. The
job was interesting, but didn't last long.

Your son sounds like a cool dude.

Yeah, I kinda like him. ;-)

The major PITA is designing aircraft to be efficient
at cruise, but safe all the way to stalling, and
recoverable. The difficulty is the movement of the
Center of Lift forward on the main wing as stall
begins.

I seem to remember a problem they had with the fuel load and the
center of lift moving close to (ahead/behind?) the CG. They also
had a problem with getting enough fuel on board (this was a single
engine turboprop) and where to put it to get the range they
wanted.

I guess one way to figure that out is to place weigh
scales under the tires and then fill in increments,
to give the exact CG in horizontal pitch, that can
be readily calculated by the ratios. Fuel movement
for various pitchs would affect the CG.
While on the subject of trim, any excessive trim
required *should* indicate a possible excursion
from the appropriate CG - CL relation.

Alas, we'll never know if they could have solved their problems. The
company went out of business. They made some smart moves and some
not-so-smart moves (based on investor funding and lack of funding)
and finally closed the doors.

Regards
Ken
PS: I turned on a TV show "ECW" (no volume),
this is Friday PM here...near midnight, and two
busty chicks (a blonde and redhead) dressed up
in vinyl are beating each other up. It looks rough!

Back on the "old days" we used to watch Roller Derby on TV. Man, you
wouldn't want to mess with those ladies if you didn't want your head
handed to you on a platter.

Wow, you're dating yourself. (I'm a 1953 boomer).
Yeah Roller Derby, Sat or Sun afternoon on TV,


Obviously where you learned both your physics and psychology.

Bertie