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Mechanics of Elevator Trim. In Detail.



 
 
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  #131  
Old June 19th 08, 07:15 PM posted to rec.aviation.student,rec.aviation.piloting
Allen[_1_]
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Posts: 252
Default Mechanics of Elevator Trim. In Detail.

This guy might be beating you to the punch!

From the June 19 AvWebflash:

Florida Researcher Proposes Wingless Flight

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.



Roy, however, is hopeful that his creation can prove useful here on Earth.
He calls it a "wingless electromagnetic air vehicle," or WEAV, and plans to
build a six-inch-wide prototype powered by on-board batteries.

--

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

"Le Chaud Lapin" wrote in message
...
On Jun 19, 9:40 am, wrote:
On Jun 19, 7:26 am, wrote:

The notion of first principles, like some of the conservation laws,
seems to be lost on Le Chaud and others. He calls himself an engineer,
but seems not very familiar with Newton, or concepts like energy
density when talking about a prime mover, or. . . but why go on?
Austin has its village idiot.


Lots of guys like that. The idea that electronics can somehow
make an airplane lighter and faster and better, all at once, is just
an obsession with electronics and computers.


This same statement could be made about the application of every new
way of doing things versus the old.

How could one say whether electronics would result in overall design
improvement if one does not yet know how the electronics would be
applied?

-Le Chaud Lapin-


  #132  
Old June 19th 08, 07:29 PM posted to rec.aviation.student,rec.aviation.piloting
BDS[_2_]
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Posts: 149
Default Mechanics of Elevator Trim. In Detail.


"Le Chaud Lapin" wrote

[Servos are used in many applications, some of them borderline hostile
(certainly more hostile than Earth's atmosphere).]

Sure, but you won't find any of those in a GA aircraft - they probably cost
more than the entire aircraft does right now without them!

[If the failure rate of electro-mechanical components in aviation is
significantly higher than the failure rate in other industries, the
aviation designer is mostly likely doing s/she should not be doing.]

Everything you propose is likely possible, or may be possible some day - who
can say. Good luck to you though - I hope your design is a success.



  #133  
Old June 19th 08, 07:37 PM posted to rec.aviation.piloting
Larry Dighera
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Default Mechanics of Elevator Trim. In Detail.

On Thu, 19 Jun 2008 07:40:55 -0700 (PDT),
wrote in
:

The idea that electric power is green is another falsehood;


Electricity generated by photovoltaics seems pretty environmentally
friendly to me.

where does most electricity come from?


http://www.fossil.energy.gov/program...ems/cleancoal/
As the President said in presenting his National Energy Policy to
the American public on May 17, 2001, "More than half of the
electricity generated in America today comes from coal.

Hydroelectric dams (devastated valleys)


True. There is quite an environmental movement afoot to demolish dams
and restore the valleys they flood. Here's an example:

http://www.sierraclub.org/ca/hetchhetchy/
http://www.hetchhetchy.org/

coal (dirty),


Apparently there's hope that coal fired electrical generating plants
can be made more efficient and less polluting:

http://www.fossil.energy.gov/program...ems/cleancoal/
The Clean Coal Power Initiative is providing government
co-financing for new coal technologies that can help utilities
meet the President's Clear Skies Initiative to cut sulfur,
nitrogen and mercury pollutants from power plants by nearly 70
percent by the year 2018. Also, some of the early projects are
showing ways to reduce greenhouse emissions by boosting the
efficiency by which coal plants convert coal to electricity or
other energy forms.


natural gas (CO2 and an increasingly limited resource),


Virtually anything that burns atmospheric oxygen produces CO2. But
the vast reserves of methane hydrates seems to contradict your
assertion that natural gas resources are declining significantly:

http://marine.usgs.gov/fact-sheets/g...tes/title.html
Gas hydrates occur abundantly in nature, both in Arctic regions
and in marine sediments. Gas hydrate is a crystalline solid
consisting of gas molecules, usually methane, each surrounded by a
cage of water molecules. It looks very much like water ice.
Methane hydrate is stable in ocean floor sediments at water depths
greater than 300 meters, and where it occurs, it is known to
cement loose sediments in a surface layer several hundred meters
thick.

The worldwide amounts of carbon bound in gas hydrates is
conservatively estimated to total twice the amount of carbon to be
found in all known fossil fuels on Earth.
http://www.sciencedaily.com/releases...1107083255.htm

nuclear (dangerous and waste problems), and so on.


Additionally, there is the issue of the limited life span of nuclear
generating facilities, generally about 25 years. After that the
entire facility must be sawed into blocks and moved to a storage site.
When the cost of clean up from inevitable radioactive discharges and
the resulting liability settlements, short life span, decommissioning
costs, and monitored storage of radioactive waste for centuries are
figured into the equations, nuclear energy isn't very cost effective,
not the mention it's potential long-term (tens of thousands of years)
impact on the environment.

Hydrogen fuel cells, even if they worked well and were affordable,
require hydrogen, which requires the electrolysis of water, which
needs vast amounts of electricity.


While it may not be very efficient (currently), solar energy can
nevertheless provide adequate power to electrolyze water. And solar
generated electricity can be harnessed where it is needed while it
provides shade to reduce air conditioning costs. Here's what Honda is
testing:

http://world.honda.com/news/2005/c051114.html
Further advancing its vision of a gasoline- and emissions-free
transportation future, Honda R&D Americas, Inc., in conjunction
with technology partner Plug Power Inc., introduced the Home
Energy Station, which provides heat and electricity for the home
as well as fuel for a hydrogen-powered fuel cell vehicle.



http://www.forbes.com/businesswire/f...7005373r1.html
Southern California Edison Launches Nation's Largest Solar Panel
Installation
03.27.08, 3:02 AM ET
Southern California Edison (SCE) today launched the nation's
largest solar cell installation, a project that will place 250
megawatts of advanced photovoltaic generating technology on 65
million square feet of roofs of Southern California commercial
buildings - enough power to serve approximately 162,000 homes.

"These are the kinds of big ideas we need to meet California's
long-term energy and climate change goals," said Governor
Schwarzenegger. "I urge others to follow in their footsteps. If
commercial buildings statewide partnered with utilities to put
this solar technology on their rooftops, it would set off a huge
wave of renewable energy growth."

"This project will turn two square miles of unused commercial
rooftops into advanced solar generating stations," said John E.
Bryson, Edison International chairman and CEO. "We hope to have
the first solar rooftops in service by August. The sunlight power
will be available to meet our largest challenge - peak load
demands on the hottest days."

SCE's renewable energy project was prompted by recent advances in
solar technology that reduce the cost of installed photovoltaic
gen...

The utility plans to begin installation work immediately on
commercial roofs in Southern California's Inland Empire, San
Bernardino and Riverside counties, the nation's fastest growing
urban region.

"These new solar stations, which we will be installing at a rate
of one megawatt a week, will provide a new source of clean energy,
directly in the fast-growing regions where we need it most," said
Bryson.

SCE sees numerous customer benefits from its new solar program,
among them locating the new generation in areas of growing
customer demand. And the clusters of solar modules SCE plans to
install will be connected directly to the nearest neighborhood
circuit, eliminating the need to build new transmission lines to
bring the power to customers. Additionally, solar units produce
the most power when customer usage is at its highest.
  #134  
Old June 19th 08, 08:01 PM posted to rec.aviation.student,rec.aviation.piloting
[email protected]
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Posts: 1,130
Default Mechanics of Elevator Trim. In Detail.

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

  #135  
Old June 19th 08, 08:19 PM posted to rec.aviation.student,rec.aviation.piloting
Le Chaud Lapin
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Posts: 291
Default Mechanics of Elevator Trim. In Detail.

On Jun 19, 1:11*pm, wrote:
* * * * * * Fly-by-wire makes sense in large airplanes or in agile
fighters. The lifting capacity of transports or fighters is an order
of magnitude higher than small airplanes because of much better power-
to-weight ratios, much higher airspeeds, and much more wing area. The
electronics to control those systems weigh every bit as much as the
electronics to control the systems in a small airplane; the only
difference is the size of the hydraulic actuators and pumps. In small
aircraft, where the *ratio between stall speed and cruise speed might
be 2:1, maybe 3:1 max, instead of the 4:1 or much more in FBW system
aircraft, the extra weight makes no sense whatever. Just think of the
hydraulic pumps and their actuators (or bigger alternators and primary
servos). Lots and lots of weight. In a small two-place airplane that
has no more than a 600 pound useful load, they are simply not
welcome.
* * * * The distance between the pilot and control surfaces also makes
a difference, and the need for some sort of boost anyway in larger
airplanes means that FBW becomes more of a minor change rather than
the addition of a whole system.
* * * * * * But someone will do it for light aircraft, and they'll try
to sell it. It will be expensive (so it won't sell well), heavy (so
the utility we be gone), and will remove the pilot from the feel of
the air (and there's goes much of the fun). Kind of like putting anti-
skid brakes and power steering and an automatic transmission on an
Indy race car; it's just plain dumb. Might sell a few to people who
don't really want to do the flying. Couch potato pilots.


I am beginning to think that much of the distaste for advanced
technology in GA has mostly to do with this last paragraph you wrote.

As someone who exceeds 100 mph at least once daily on average (for
various semi-legal reasons), I like my thrill to, but 'I' is not
'us'.

There seems to be a bit of hypocrisy in GA, at least with the pilots.

On the one hand, some complain that rate of increase in pilot
population is too low. On the other, things that would lead to more
pilots getting into the air are frowned upon (ultra-commoditized
components).

GA pilots are going to have to decide what is more important - the
seat-of-pants feeling that they get when yanking on their sticks, or
making flying accessible to a wider audience (which would decrease
overall cost of flying, etc.).

The FAA, NASA, and over government organizations, ironically, seem to
be pushing very hard for the latter, while pilots are holding out for
the former.

Maybe there is a middle ground, where pilots who prefer designs from
1970 can continue in those aircraft, while grandma and grandpa, who do
not care too much for carb icing, can opt for the latter.

-Le Chaud Lapin-
  #136  
Old June 19th 08, 09:13 PM posted to rec.aviation.student,rec.aviation.piloting
Jim Logajan
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Default Mechanics of Elevator Trim. In Detail.

Le Chaud Lapin wrote:
On Jun 19, 1:11*pm, wrote:
[Some stuff]

....
There seems to be a bit of hypocrisy in GA, at least with the pilots.


If you want to draw silly and offensive conclusions about an entire group
of people from a couple samples and ignore the results from all the other
samples, it is my humble opinion that you have problems both with reasoning
and social skills.
  #137  
Old June 19th 08, 09:32 PM posted to rec.aviation.student,rec.aviation.piloting
Ken S. Tucker
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Posts: 442
Default Mechanics of Elevator Trim. In Detail.

On Jun 19, 10:15 am, "BDS" wrote:
"Ken S. Tucker" wrote

Yup, electronics/electrical is the wave of the future,
and that's from a guy who prefers crank windows to
them thar fancy power windows in cars!
From satellite technology, to your hard-drive motors,
to auto focusing cameras...we're in the digital servo-
-age. May dinosaurs R.I.P.
Ken


It will be difficult to compete with mechanical actuation as far as
reliability vs. cost in a product meant for the consumer market, and in a
critical application such as movement of control surfaces.

Satellite technology won't be cheap enough for GA, and I've had enough
hard-drive, camera, and consumer electronics problems to know I don't want
that level of reliability in an aircraft. If your camera refuses to focus
properly, nobody dies.

Our aircraft uses servos in the autopilot system. In the last 16 years
we've had both the pitch and trim servos fail. Consider the consequences of
that if the servos were the primary means of control.


I studied your post carefully, and I agree.
The system, works like,
......actuators......
a--/\/\/---/\/\/---b
.......1........2..........

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
  #138  
Old June 19th 08, 09:41 PM posted to rec.aviation.student,rec.aviation.piloting
[email protected]
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Default Mechanics of Elevator Trim. In Detail.

On Jun 19, 1:19 pm, Le Chaud Lapin wrote:
On the one hand, some complain that rate of increase in pilot
population is too low. On the other, things that would lead to more
pilots getting into the air are frowned upon (ultra-commoditized
components).


We see new designs every year. More fancy electronic autopilots
and nav stuff, more engine FADEC stuff, more safety stuff like
parachutes. But fewer people still fly, because all of that fancy
stuff is so expensive. Most end up flying 35 or 50 year old airplanes
because that's what they can afford.
Airliners have had fly-by-wire for some time now but they're no
cheaper than they were to fly when they were mechanical. In fact, it
takes an army of highly-paid avionics techs to keep them safe and
flyable. It's deregulation of the industry in the 1970s that brought
air travel within the reach of the common man, not electronics, and
the resulting tiny margin of profit for airlines in a highly
competitive environment has resulted in many bankruptcies since then.

Dan
  #139  
Old June 19th 08, 09:44 PM posted to rec.aviation.student,rec.aviation.piloting
[email protected]
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Posts: 1,130
Default Mechanics of Elevator Trim. In Detail.

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
  #140  
Old June 19th 08, 10:01 PM posted to rec.aviation.student,rec.aviation.piloting
[email protected]
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Posts: 181
Default Mechanics of Elevator Trim. In Detail.

this Le Chaud kid doesn't even lie a good game. New prime mover, new
airform, loves to hear himself type.





On Jun 19, 4:44 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


 




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