Driver to drive?

[MK]

"Jon Slaughter" <Jon_Slaughter@Hotmail.com> wrote in message
news:almyk.79$YU2.18@nlpi066.nbdc.sbc.com...

"mpm" <mpmillard@aol.com> wrote in message
news:a4268f94-c499-4486-ae05-5df3a338c9e6@l43g2000hsh.googlegroups.com...
On Sep 11, 7:12?pm, Jim Thompson <To-Email-Use-The-Envelope-I...@My-
Web-Site.com

Just like all leftist weenies you miss that Obama purposefully dredged
that up to slam Sarah... trying to negate the "pit bull" amusement.

Honestly, (I probably shouldn't admit this...?)

I think Obama said it (it's a common expression everyone uses), AND
THEN IMMEDIATELY realized how it might be interpreted vis-a-vis Palin,
and tried to cover it with another analogy about wrapping old fish in
a newspaper called "change".
========

I don't know what his intentions were and I don't remember what first
popped in my mind when I heard it but I thought about it both ways.

BUT, obviously if he's such an intelligent guy he would have known better
and not used. So we can only gather he is not as intelligent as people
want to make him out to be.

I mean... it doesn't take much to see the commonality between "lipstick on
a pitbull" and "lipstick on a pig" specially when it was such a big
punchline and still in peoples minds.

So it's not so much if he intended it or not(and by the crowed laughing
they all got what he most likely was intending) but that he should have
known better. We'll never know what he was intending but we do know how it
was percieved... even by his own "people".

But since he said he didn't intend for it to be that way I think we would
have to take it as face value.... of course if it continues to do such
things over and over then he should be held accountable.

Don't you feel that your (probably correct imo) analysis is a little too
relaxed and rational for this NG ?

Michael Kellett

 

i have new blog right now anyone can help me to tell me about all
topic to purplish i have a lot of info and i need to publish it .
http://electronic-day.blogspot.com/

Specific topics:
* 2000-5000 Watt INVERTER (1)
* Automatic 12V Lead Acid Battery Charger (1)
* DC-to-AC inverter (1)
* Doorbell for the Deaf (1)
* Laser Communication System (1)
* Power Supply12 Volt 30 Amp (1)
* Ultrasonic Dog Whistle (1)

No rocket science..

 

In sci.physics Joe Chisolm <nospam@nospam.org> wrote:

There are stick-and-rudder folks that want to fly the airplane and there
are others that view the airplane as a transportation vehicle. The latter
crowd would want the airplane to fly a nice glide slope to touch down, no
slips allowed. The VLJs are not hand flown. Look at the Citation SP, you
have to have a working autopilot for single pilot operation. I had
the opportunity to fly jump seat on a 737 a few years back. From the
time the gear came up until on short final their hands did not touch
the yoke (nor feet the pedals). In fact, the only thing they touched
(other than their reading material) where the autopilot and radio knobs.

Yeah, it is possible and has been for a long time; so what's your point?

You obviously don't know why slips are performed.

There are two types, and without a lot of detail one is used to lose
altitude quickly without gaining airspeed and the other is used to
keep the airplane aligned with the runway in crosswinds.

Not following the glide slope tends to result in a bad landing or a
request to call the tower after landing or both.

Can you do something similar for GA, feet on the floor, hands on a simple
joy stick? I dont know. Could be. As long as you dont kill yourself
or anyone else and dont go broke, it's worth a try (actually the FAA will
gladly let you turn yourself into a smoking hole in the ground).

In calm air in a properly trimmed airplane it is not necessary to touch
any control.

Most of the time my feet are just resting on the rudder pedals and I
have two fingers on the yoke to null out minor bumps.

The big problem is, can you do this at the cost and level of safety
required. It would make for a very bad day if your computer system
decided up was now down while traveling along at 200+Kts.

It doesn't take a computer system or an autopilot.

All it takes is trimming out the airplane.

A lot of student pilots develop a death grip on the yoke and the cure
for that is to have them trim the airplane and fold their arms.

GA airplanes are required by law to be stable.


--
Jim Pennino

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In sci.physics Le Chaud Lapin <jaibuduvin@gmail.com> wrote:

On Sep 12, 1:25?am, j...@specsol.spam.sux.com wrote:
In sci.physics Le Chaud Lapin <jaibudu...@gmail.com> wrote:
A software defined radio would be much more complex and have more parts
than today's simple, LSI based aviation radios, which in itself will
add cost.

I designed my first analog radio when I was 20,

I designed my first radio when I was 9 or 10.

"In the long term, software-defined radio is expected by its
proponents to become the dominant technology in radio communications"

For certain applications, it probably will.

It is especially attractive in HAM circles where things are always
changing, but, one more time, aviation radio is cast in international
treaty concrete and is NOT going to change.

Also, I noticed that you keep writing "LSI".

Since you don't seem to know what much of anything means, I was
dumbing it down for you.

I'm well aware of what is in a modern radio.

Not true. There are radios, fully assembled, for less than $7 at local
supermarket. In any case, I have completed the actual application for
certain bands/classes from FCC. As I recall, the costs are not that
great. In some cases, it is not more than few thousand dollars. A
transceiver that I designed in mid 1990's would have cost < $10,000US.

The independant testing lab will charge way more than that.

http://www.ask-wi.com/certification.html

That is for Part 15 toys.

Aviation is covered by Part 87.

My god you are ignorant.

You can NOT get around FCC acceptance for any other radio service.

I never said I would.

No, you implied that you were going to.

OK, now, what technology are you going to use to build this pressurized
airframe and it's aerodynamic surfaces?

Proprietary.

Babbling idiot; it can't be proprietary since all you would have to do
is look at it and you would know what the TECHNOLOGY is.

The TECHNIQUE used can be proprietary, but the TECHNOLOGY can't.

So which is it, aluminum, composite, or hybrid aluminum/composite?

There aren't any other choices for a pressurized airframe.

What is is that your home build fly-by-wire airplane will be able to
do that any modern GA aircraft such as a Cirrus SR22 can't do?

If you encounter significant turbulence, what is the first thing you
do and why?


--
Jim Pennino

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In sci.physics Jeff Liebermann <jeffl@cruzio.com> wrote:

On Fri, 12 Sep 2008 06:35:04 GMT, jimp@specsol.spam.sux.com wrote:

Irrelevant; RPV's don't have passengers that would write nasty letters
or try to sue for hard landings. The are also expendable.

I wasn't thinking so much about takeoff and landing as maneuvering
(flying donuts) and possibly aerobatics. The RPV's I tinkered with
has gyro stabilized platforms to stabilize the cameras. I have no
idea how well they would do aerobatics. I suspect fairly badly as
feedback to the yoke and pedals is fairly important.

Maneuvering flight is easy and pretty trivial.

Landing where you are moving at high speed and are close to the ground
is a bit more critical of precision control of the airplane.

And I fly real airplanes. Have you any idea what goes on when making
a short field landing in gusty crosswinds?

Is this is quiz or credibility check? In a cross wind, I have to crab
(side slip) the aircraft on landing. I had to do that anyway on a
Cessna 150 because the engines torque center is not on the aircrafts
center line. For a short field landing, I would do a power off
landing. I've never tried it with both a short field and a crosswind.

A little of both.

Actually, the torque is centered and would cause the airplane to spin
around the axis of the propeller shaft, but all the aerodynamic forces
result in a turning moment, generally to the left.

A short field landing is done with power at just above minimum
controllable airspeed.

Do you know how to trim an airplane?

Sure. With the trim tabs and the trim wheel. Keep the nose up and
all that.

What you do is set up the airplane then use the trim wheels to eliminate
any control force.

If you try to do it without the force feedback from the controls 9 times
out of 10 you will wind up oscillating around for a while before getting
it trimmed out.

To save you the effort of a cross examination, I do not have a pilots
licence. I took a few lessons in about 1968 where the idiot
instructor had me land in a cross wind with about 10 hours of time in
the log book. I noticed the windsock was all wrong, but didn't say
anything. When I hit the runway, the Cessna 150 bounced. The
crosswind got under the wing and tried to flip the plane over. Both
the instructor and I instinctively over compensated, grinding the
opposite wingtip into the runway. If I had hit the grass, we would
have cart wheeled. After that mess, I gave up flight skool. Most of
my subsequent flying was with friends. I've been invested in an
avionics shop for about 20 years.

Sorry to hear that. Where's the shop?

I went through 5 instructors; one got a better job so that one doesn't
really count, but the other 3 were probably good buddies with the one
you had. The one I finished with I still go to for flight reviews.

Anything you walk away from is considered a good landing.

Yeah, if there are no passengers to bitch about the landing and you
don't have to pay for the extra maintenance due to hard landings.

Ok. You're right. They won't kiss the ground after landing.

One of my former bosses worked on the ill fated Microwave Landing
System:
http://en.wikipedia.org/wiki/Microwave_landing_system
I learned quite a bit about it listening to his stories. I recall
that he mentioned that they successfully tested hands off landings
using it. However, I don't believe that the subsequent WAAS/LAAS GPS
landing systems were ever as good at landing as MLS. There were
plenty of reasons not to do this on a regular basis, but it is
possible to do a smooth hands off landing.

Yeah, I remember MLS.

I think the two big factors that killed it were the cost of the ground
equipment required and international politics.

Do the terms "short field landing" or "soft field landing" mean anything
to you?

Another credibility check (which incidentally has nothing to do with
my previous comments)? Yes, the terms mean landing on a short runway,
a grass field, or a muddy dirt road. I've never done any of these.

Thin skin because I've dealt with far too many naifs that have read
a couple of web articles on aviation and think they know everything
there is to be known about flying.

What does your question have to do with force feeback in airplane
controls? Sure, it's more difficult to land on these limited runways,
where hands off landings are probably a bad idea. However, I'm not so
sure that force feedback is going to be the determining factor for a
sucessful landing. Methinks much depends on the abilities of the
pilot. If they are experienced in zero feedback landings, methinks
they can do it well enough.

Again, just because something CAN be done doesn't mean it SHOULD
be done.

Having force feedback makes flying an airplane easier and ultimately
safer.

Hmmm... no force feedback on most (not all) of these simulators:
http://www.projectmagenta.com
http://www.projectmagenta.com/references/private.html> (examples)
http://www.wideview.it
This one uses pneumatic dampers and an air compressor for force
feedback:
http://www.schiratti.com/cockpit.html

You don't have to rebuild the firewall on a simulator when you slam
the nose wheel on the runway and bend the firewall/nose wheel attach
area.


--
Jim Pennino

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In sci.physics Richard Herring <junk@[127.0.0.1]> wrote:

In message
34a01ca5-57a7-4d6a-9883-af5038b5a5a2@f63g2000hsf.googlegroups.com>, Le
Chaud Lapin <jaibuduvin@gmail.com> writes
On Sep 10, 10:45?am, Richard Herring <junk@[127.0.0.1]> wrote:
In message
a00eefa0-8523-4a3a-a671-e054a9a5e...@d77g2000hsb.googlegroups.com>, Le
Chaud Lapin <jaibudu...@gmail.com> writes

Someone is going to figure out a way to build a safe, efficient,
electric-powered single-seat, ultra-long range aircraft to elminate
all this hassle. In such an aircraft, I would probably make one stop
along the way in Nova Scotia, then fly directly to Montpellier, mostly
on hands-off auto-pilot,

Sure. Now design the infrastructure needed to maintain separation
between you and all the swarms of other people doing the same in zero
visibility. Done much instrument flying yet?

No. Not any in fact [except for simulator].

I'm not talking about practising hand-eye coordination to keep yourself
the right way up in zero visibility, important though that is, but about
the procedural stuff. Did your "simulator" require you to fly SIDs and
STARs and airways, holds and missed approaches? Did the simulator keep
issuing new levels and headings?

This is a software issue, IMO, and not something that is technically
insurmountable.

Sure. And in your universe, everything's a SMOP and all problems can be
solved by adding another level of indirection. And in that universe,
emergent complexity and scalability issues simply don't exist.

The issue I was alluding to is maintaining separation under IFR in IMC,
or, more colloquially, "pushing tin". Consider what happens to the
infrastructure that manages this if every airliner is replaced by
several hundred "safe, efficient, electric-powered single-seat,
ultra-long range aircraft", all of which have to be prevented from
colliding.

It's probably been done already in some other
context.

There are regular stories in comp.risks about failures of computerised
ATC systems under current levels of loading, let alone the hundredfold
increase you're suggesting.

Exactly.

Add to that the common misconception that ATC is somehow and magically
actually controlling the movement of all those airplanes.

--
Jim Pennino

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[BobW]

"John B" <spamj_baraclough@blockerzetnet.co.uk> wrote in message
news:48ca9d7a$0$770$4c56ba96@master.news.zetnet.net...

On 12/09/2008 David L. Jones wrote:

http://www.hasthelhcdestroyedtheearth.com
Money well spent so far!

Dave.

Watch the webcams and see for yourself!

http://www.cyriak.co.uk/lhc/lhc-webcams.html

--
John B

That is hilarious!

Bob
--
== All google group posts are automatically deleted due to spam ==

 

In sci.physics Le Chaud Lapin <jaibuduvin@gmail.com> wrote:

On Sep 12, 12:15?pm, j...@specsol.spam.sux.com wrote:
In sci.physics Le Chaud Lapin <jaibudu...@gmail.com> wrote:
I designed my first analog radio when I was 20,

I designed my first radio when I was 9 or 10.

By design, I mean actually design, like employing the concepts of
semiconductor physics, electrodynamics, theory of complex variable,
etc. I did not mean putting together a kit, if that's what you mean.

No, that is not what I meant.

The only manufactured electronic part was the variable capacitor.

Babbling idiot; it can't be proprietary since all you would have to do
is look at it and you would know what the TECHNOLOGY is.

Are you 100% sure about that statement?

Well, since I had to post the definition of "proprietary" because you
didn't know what it means, yes.

What materials are you going to use to build your homebuilt's
airframe and aerodynamic surfaces?

What is it that your fly-by-wire home built will be able to do that
any modern aircraft such as a Cirrus SR22 can't do?

If you encounter significant turbulence, what is the first thing you
do and why?


--
Jim Pennino

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In sci.physics Don Bowey <dbowey@comcast.net> wrote:

Stall/spin (recovery) practice, at altitude, is good to do and will give a
pilot a much higher survival rate. The FAA used to require such training
for a Private rating, but instructors complained about the numbers of
students that terminated their training after the first power-on stall, so
the FAA eliminated the requirement. I opted to do them anyhow. It's
cool... You're in a spin before you recognize what happened.

Spin training at the private level was eliminated some years ago, but
stall training is still required.

The justification was that the numbers indicated more accidents from
spin training than accidents by private pilots who got into spins.

What is now taught is spin avoidance and spin recovery without actually
doing a spin.

Lacking that training and practice, a student will probably encounter their
first stall and spin entry while they are in the pattern for landing,
probably while turning onto final. Since the untrained reactions are
completely wrong (they will increase the stall), the plane will likely
crash.

True.

The emphasis now is stall and spin avoidance since usually if you do
stall during the landing phase there isn't enough altitude to recover
anyway.


--
Jim Pennino

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In sci.physics Jeff Liebermann <jeffl@cruzio.com> wrote:

I think that's called wheel-barrowing. With just the nose wheel on
the ground, the aircraft acts like a wheel barrow. I haven't flown
enough to have run into the problem. However, like all beginners, I
have managed to overcompensate several times. My first attempt at
simply maintaining altitude was an exercise in overcompensation until
I got the feel of the airplane.

If you are going down the runway on the nose wheel, it is called
wheel-barrowing.

If you are bouncing up and down, it is called porpoising.

Yep. So what's your opinion? Can a general aviation (production, not
experimental) airplane be built that flys using a joystick and limited
force feedback? Is force feedback optional, desirable, or mandatory?
Is PIO such a major technology killer that practice and training are
insufficient ineffective?

No, not for a normal category airplane as it would never meet the
stability and controlability requirements of Part 23.

As a home built experimental it would get the reputation of being
squirrelly and no more than 1 or 2 would ever be built.


--
Jim Pennino

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In sci.physics Le Chaud Lapin <jaibuduvin@gmail.com> wrote:

On Sep 12, 2:40?am, Mike Monett <N...@here.adr> wrote:
? The moral of the story is a pio happens so quickly ?and unexpectedly
? that most pilots will crash the plane.

Perhaps thats why, in the show about Blue Angels I mentioned, the
pilots were required to know calculus and basic theory of complex
variable, or at least that's how it appeared. I did see an H(s)
written on the whiteboard during the show, and several Blue Angels
pilots sitting watching the instructor.

I think once a pilot understands the basics of control theory, it is
hard to not trust the math after that.

The Blue Angels aren't flying GA aircraft, they are flying high
perfomance, aerobatic, jets with a huge thrust to weight ratio and
wearing G suits.

--
Jim Pennino

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In sci.physics Le Chaud Lapin <jaibuduvin@gmail.com> wrote:

> wrote:
The issue I was alluding to is maintaining separation under IFR in IMC,
or, more colloquially, "pushing tin". ?Consider what happens to the
infrastructure that manages this if every airliner is replaced by
several hundred "safe, efficient, electric-powered single-seat,
ultra-long range aircraft", all of which have to be prevented from
colliding.

There are regular stories in comp.risks about failures of computerised
ATC systems under current levels of loading, let alone the hundredfold
increase you're suggesting.

I would not use the ATC.

Then you would go to jail.

ATC is international in scope.


--
Jim Pennino

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[Skywalker]

Simply not true anymore when considering typical power station
efficiencies, transmission losses, battery charging losses, controller
losses and electric motor efficiency. Plus if you need to heat the
cabin, that uses electricity but with an ICE it makes use of 'free'
waste heat.

A diesel will easily equal it. 'Next generation' auto diesels are
targeting 40% efficiency. Very large marine diesels can already exceed
50% thermal efficiency.

You need to learn accounting.

Graham

Graham, it doen't matter about efficiencies in the short term.
Electrical energy can be improved in time to use cleaner sources
(possibly solar), current gasoline engines cannot.

I would much rather have a hydrogen fuel cell car, with a hydrogen
source from converted water using power from solar panels. You could
even store the hydrogen for days when solar energy is weak.

Luke

 

[Skywalker]

Jamie <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in
news:_vzwk.41295$Rs1.19874@newsfe08.iad:

Kris Krieger wrote:


When You find a panel that small that delivers that much energy, let
me know. I also would love to experiment with small area high output
cells.

I currently have 4 RV panels that does an impressive job even with
the
lack of light we have here compared to other locations.


http://webpages.charter.net/jamie_5"

I know of some panels like that


http://www.spectrolab.com/prd/space/cell-main.asp


A panel that produces average efficiencies of 26.5%,

Ultra Triple Junction that produces efficiencies of 28.3%

AND - XJT produces 29.9% efficiency

I believe you would get close to 8W with the Ultra Triple Junction. And
yes you can purchase from them.

Luke

 

In sci.physics Le Chaud Lapin <jaibuduvin@gmail.com> wrote:

On Sep 12, 1:15?pm, j...@specsol.spam.sux.com wrote:
In sci.physics Le Chaud Lapin <jaibudu...@gmail.com> wrote:
Perhaps thats why, in the show about Blue Angels I mentioned, the
pilots were required to know calculus and basic theory of complex
variable, or at least that's how it appeared. I did see an H(s)
written on the whiteboard during the show, and several Blue Angels
pilots sitting watching the instructor.

I think once a pilot understands the basics of control theory, it is
hard to not trust the math after that.

The Blue Angels aren't flying GA aircraft, they are flying high
perfomance, aerobatic, jets with a huge thrust to weight ratio and
wearing G suits.

I have often wondered what would happen if a would-be-Blue Angel could
not get past the math.

Well, since you have to be a carrier-qualified, active duty, Navy or
Marine tactical jet pilot with at least 1,350 hours, and before you
can become that you have to have, among other things, a 4 year degree,
I doubt by that point the math is much of a problem.


--
Jim Pennino

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[Kris Krieger]

mpm <mpmillard@aol.com> wrote in news:a4268f94-c499-4486-ae05-5df3a338c9e6
@l43g2000hsh.googlegroups.com:

On Sep 11, 7:12�pm, Jim Thompson <To-Email-Use-The-Envelope-I...@My-
Web-Site.com

Just like all leftist weenies you miss that Obama purposefully dredged
that up to slam Sarah... trying to negate the "pit bull" amusement.

Honestly, (I probably shouldn't admit this...?)

I think Obama said it (it's a common expression everyone uses), AND
THEN IMMEDIATELY realized how it might be interpreted vis-a-vis Palin,
and tried to cover it with another analogy about wrapping old fish in
a newspaper called "change".

Yeah, forgtt tha McCain used 5 times, IIRC, this year alone, a couple times
in refence to bills proposed by a female legislator.

I'm waitnig for some 'deep thinker' to claim that the "fish" word also
refers to her =>

Weak, but I give him kudos for trying. (And I don't think he had
Palin in mind.)

Eve if he did, if the repub.s can't stand up to that, they sure as hell
won't be able to deal with tthe un-PC world leaders that are out there.

Some Oklahoma congressmember was on Hardball last night saying the
"old fish" comment was referring to Mrs. McCain. (Unlike Fox, I am
not making this up!!)

Oh Good Grief.

IMO, if soemone is that hypersensitive and that deluded that anything
anyone says revolves around them, all I can say is Well, if the shoe
fits...

So I guess there's no end to what Republicans will conjure up, as long
as its not a substantive issue voters care about.

That's the most irritating thing.

I heard McCain last night, and you wouldn'tthink that he is actually
associated with the campaign, which leads on to think that (choose all that
apply) either:
(1) he is completely out of touch with
(2) the campagn (and/or its former 7 lobbyists) own him
(3) he has no clue as to what they're doing
or
(4) he knws exactly what they're doing and is cynically feigning immocence.


Frankly, I'm sick of *both* campaigns. I think all the dirt-slingers and
hypersensitve insult-finders, the insult mongers and self-proclaimed
pundits and illogical knee-jerkers, would *ALL* shut the f*** up, and just
let the candidates speak for themselves.

All of this bullshit is just that. I think *everyone*, Repub., Dem.,
Indie, and so on, should write to the candidates and tell them to
disassociate themselves *vigorously* from the childish shit-slingers and
stick to their promises of running issues-focused campaigns.

 

[Skywalker]

You clearly know NOTHING about either PV solar or the characteristics
and properties of hydrogen.

Let me explain. 'Hydrogen economy' ? There isn't going to be one.

Graham

Actually on the contrary, I just put a research paper together about PV
solar. But I am not going to waste my time proving things.

Sounds like your ego is getting in the way of better judgment. But thats
to be expected with people who don't their research and take a strong
one sided opinion.

I read you other posts, and you just seem to like to argue. Have you
ever posted once where you didn't criticize?

Luke

 

[Skywalker]

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote in
news:48CABFD6.A66FA1AA@hotmail.com:

Skywalker wrote:

it doen't matter about efficiencies in the short term

On which planet ?

Graham

I like how you cut out part of my post to take it out of context.

You forgot this part:
"Electrical energy can be improved in time to use cleaner sources
(possibly solar), current gasoline engines cannot."

 

[Skywalker]

Designed for spacecraft. Have you any idea how much they cost ?

Yep, if you would have looked at the web page instead of just scanned it
over and make snap judgments like you do everything you would have
noticed.

Here in the FAQ



8. Q: For budgetary purposes, what is the price of the cells at large
volume?

A: Taking the CDO-100 cells as an example, at volumes of 10 MW per year,
we estimate the bare cells to be approximately $10 each and cells with
welded interconnects to be approximately $14 each. These prices will
continue to decrease with sales volume over the next few years.

A simpler question might be simply "have you any idea ?".

Simple answer "see above".

How shove off out of a group that's for professional design engineers
that know what they're talking about and take your fantasy ideas to
some obscure alt. group. There's alt.savetheworld or something -
should suit you nicely.

Graham

"How shove off out of a group" ? First of all, you need to learn how to
write.

And since this is for "professional design engineers" then this latest
technology knowledge should be something they should know about.

Let me guess, you got pissed when SMT came out.

Luke

 

[Mike Monett]

Jeff Liebermann <jeffl@cruzio.com> wrote:

On Fri, 12 Sep 2008 07:40:59 +0000, Mike Monett <None@here.adr
wrote:

I got into a PIO in 1957 while landing a Cessna 172. Most of my
flying up till then was in taildraggers, and I was not accustomed
to having a nosewheel. It hit the ground first and the aircraft
pitched up. I applied forward pressure to bring the nose back
down, and the nosewheel hit again. At that point, I was locked in
a cycle that was 180 degrees out of phase with what the a/c was
doing, and it was only the quick action of the instructor that
got us out of the oscillation. Otherwise, I would have crashed
the plane.

I think that's called wheel-barrowing. With just the nose wheel on
the ground, the aircraft acts like a wheel barrow. I haven't flown
enough to have run into the problem. However, like all beginners,
I have managed to overcompensate several times. My first attempt
at simply maintaining altitude was an exercise in overcompensation
until I got the feel of the airplane.

It's only wheel-barrowing for a fraction of a second. The nose wheel
touches the ground first while the a/c is still descending. The
contact is very brief, and the springs push the nose back up into
the air.

The pilot's first instinct is to push the nose back down, but he
overcontrols and the nosewheel hits again. Now the pilot is 180
degrees out of phase with the a/c, and the resulting pio usually
results in a crash.

http://www.dfrc.nasa.gov/Gallery/Movie/F-8DFBW/HTML/EM-0044-03.html

No mention of force feedback. That was filmed in 1978 on an
aircraft that was probably designed a few years earlier. My
guess(tm) is that since this was a research project, the initial
configuration would have been very Spartan and without any
feedback to the pilot to see what could be done with a minimal
configuration. Force feedback was probably added later. Dunno for
sure.

Here is a short segment of the 1992 crash of the prototype F-22
Raptor landing at Edwards Air Force Base in California. This
crash was linked to actuator rate limiting, causing the pilot,
Tom Morgenfeld, to over-compensate for pitch fluctuations. You
can see a bit of overcontrol starting while he is coming in over
the runway:

http://www.youtube.com/watch?v=faB5bIdksi8

Yeah, that would be a problem. If the actuators protect themselves
and are hard limited to some max rate at which they can move,
there's a real possibility of resonance or under-damping when
operating at the limits. That's a problem even in model airplanes,
where a slow moving servo and an overly aggressive pilot can
easily cause PIO (also known as porpoising). The trick, which is
quickly learned, is to intentionally shove the control well beyond
the desired position and quickly return it to normal, at just the
right moment. If you're too slow to recover, you get PIO. There's
no need for force feedback as this is really an exercise in
timing.

But thats exactly what pio is. However it starts, the pilot ends up
out of phase with what the a/c is doing.

It is very difficult to break out of that loop. The pilot in the F8
Crusader example above was extremely good. But he was also extremely
lucky since he was well above the stall speed of the plane. When he
got into the pio, he still had enough airspeed to be able to climb
and get out of it. That was an amazing piece of airmanship. But if
he was at or below the stall speed when the pio started, he would
have crashed.

The moral of the story is a pio happens so quickly and
unexpectedly that most pilots will crash the plane.

Yep. So what's your opinion? Can a general aviation (production,
not experimental) airplane be built that flys using a joystick and
limited force feedback? Is force feedback optional, desirable, or
mandatory?

Is PIO such a major technology killer that practice and training
are insufficient ineffective?

Personally, I think proportional force feedback is mandantory. There
are many other situations where the lack of feedback would cause the
pilot to overcontrol and pull the wings or tail from the a/c.

One example is recovering from a spin. The nose is pointed straight
down at the ground, and if you obey your instincts and try to pull
up too fast, you will likely lose the wings.

Another example is the crash of American Airlines flight 587 at JFK.

The lack of proportional force feedback on the rudder pedals led the
copilot into overcontrolling the plane. He ripped the rudder off,
followed by the engines. The result was the second worst crash in US
aviation history. This is described in a bit more detail here:

"Unknown to either the co-pilot or the airline's trainers, a change
in the way the plane's rudder mechanism worked seriously worsened
the problem. The change made the rudder control pedals far more
sensitive than any other plane's - including other Airbus models -
and the sensitivity increased dramatically with speed. This is
exactly the circumstance where excessive use of the rudder can cause
high stresses on it."

http://www.newscientist.com/article/dn6589-compounded-errors-caused-new-
york-crash.html

Another example is my second pio. This happened in Malibu N4360V,
which I bought new in 1984. You can see it coming over the threshold
while landing:

http://www.jetphotos.net/viewphoto.php?id=5874208&nseq=0

Notice the very wide stance of the main gear. This forms an almost
equilateral triangle with the nose gear. Normally this is considered
very good since it increases the stability whenever the wheels are
touching the ground. I flew this a/c cross-country from San Jose to
Boca Raton, Florida many times without incident.

But one time while landing in Palm Springs, everything was perfectly
normal until touchdown. The instant the wheels hit, the a/c went
into a very violent side-to-side oscillation that I could not
control. I quickly took my hands and feet off the controls to let
the plane stabilize, and luckily it ended up aligned with the runway
and I completed the rollout normally.

Would training have helped? Probably not. It started and was over in
fractions of a second.

Would force feedback help? No, in this case there was already normal
force feedback.

I think the problem with flying is things can go along normally for
a very long time, then suddenly something happens that is totally
unexpected. It happens so fast that the pilot ends up
overcontrolling the a/c, which usually results in a crash. The
problem is most of the time it is completely unpredictable.

In a perfect world, the a/c would be decoupled from the pilot, and
sufficient force feedback to make the pilot think he was in control.

But the software would not let the pilot get into the kind of
situations that would lead to loss of the a/c. It would eliminate
spins and stalls, flying into mountains or thunderstorms, running
out of gas, flying into known icing, high-speed stalls, and all the
other ways we can kill ourself in the air.

I don't think we are good enough to write that software. Close, yes.
But not perfect yet.

Best Regards,

Mike Monett