"Urgent Wind Chill Advisory"

Jackal24 wrote:
"Jay Honeck" wrote in
oups.com:

About a month ago here, the high temp was -25F, with wind chills
around - 50F. Now that is an "extreme wind chill".

Good God, man. Where do you live?

I'm working in Bethel, AK.

Fascinating - the magnetic deviation from true north at the Bethel airport
appears to be large enough that runways 18 and 36 have a considerable slant
in the Google Earth satellite image, which is normally drawn squared with
true north:

http://www.google.com/maps?q=Bethel,...70124&t=k&om=1

So what's the deal with runway 29??

Jim Logajan wrote in
:


Fascinating - the magnetic deviation from true north at the Bethel
airport appears to be large enough that runways 18 and 36 have a
considerable slant in the Google Earth satellite image, which is
normally drawn squared with true north:

http://www.google.com/maps?q=Bethel,...60.780179,-161.
840158&spn=0.019106,0.070124&t=k&om=1

So what's the deal with runway 29??


11/29 is mostly gravel with a short paved stretch. It comes in handy when
the wind is blowing out of the east at 30 kts.

Also, not shown on that image is the fact that they are currently working
on building a parallel runway to 18/36.

Tyson

My desktop weather (courtesy of the Weather
Channel) is now blinking red, warning me (and millions of others) to
dress warmly, and to not go outside.

It's not the nanny state you are seeing. It's far more insidious.

It is extremely difficult to get an answer about how something works
these days. However, it's very easy to find out how to work it. People
want to be told what button to push. They don't want to know what
happens when they push it. I don't know what came first, but I find
very few people who even see a problem.

Jose
--
Humans are pack animals. Above all things, they have a deep need to
follow something, be it a leader, a creed, or a mob. Whosoever fully
understands this holds the world in his hands.
for Email, make the obvious change in the address.

What? You couldn't handle the Michigan weather so you moved south for
your health?

There's a joke that goes something like:
When it's 50 degrees, Floridians put on their coats... Wisconsoners go
swimming. When it's 30, Floridians stay inside, Wisconsoners put on a
t-shirt... when it's 10 below, Wisconsoners put on a sweater...

Different states, different temperatures, but I can't seem to find it.
Anyone know the way it goes?

Jose
--
Humans are pack animals. Above all things, they have a deep need to
follow something, be it a leader, a creed, or a mob. Whosoever fully
understands this holds the world in his hands.
for Email, make the obvious change in the address.

Jose writes:

It is extremely difficult to get an answer about how something works
these days. However, it's very easy to find out how to work it. People
want to be told what button to push. They don't want to know what
happens when they push it. I don't know what came first, but I find
very few people who even see a problem.

In a technologically advanced state, inevitably the percentage of the
population that knows how technologies work will shrink, whereas the
percentage of the population that uses those technologies regularly will
increase. Thus, the more advanced the state, the more people you have who
regularly use technologies they don't understand.

When people lived in caves, it's likely that everyone understood all the
technologies he had to use, or nearly so. Today, almost nobody understands
even a fraction of the technology that he uses each day, and indeed we all
depend on technologies the workings of which we don't fully understand.

The problem, then, arises whenever someone must step outside the very small
envelope of interactions with a technology for which he is competent. We all
know how to push buttons on a telephone to make a telephone call (the standard
envelope), but how many of us know what to do if the buttons don't work as
expected.

Aviation is just one of many high-tech domains in which there are many who
understand the standard envelope while not mastering the extended envelope;
and I'm talking pilots here, not passengers.

I notice this in discussions on this group. Most pilots (like most people in
general) learn by rote, because this allows people to make use of technologies
that they wouldn't be able to easily understand if they had to study the
fundamental theory. This is why, for example, pilots here will insist that
trim is used to relieve control pressures, and reject any other explanation of
trim, even when the other explanations are precisely equivalent to their own.
They learned the control-pressure explanation by rote, and they don't actually
understand the theory behind trim, so they reject any explanation that doesn't
correspond to what they were taught. Only someone who learned the actual
theory will recognize multiple explanations as being mutually equivalent, and
such people are rare. Training programs for complex activities typically
emphasize rote learning, in order to keep those activities accessible to
people with a wide range of intelligence levels. Forcing everyone to learn
theory would exclude a significant chunk of trainees who might have trouble
grasping abstract theory as opposed to a cookbook, rote approach to tasks.

--
Transpose mxsmanic and gmail to reach me by e-mail.

Thus, the more advanced the state, the more people you have who
regularly use technologies they don't understand.

I'm not talking about not understanding, I'm talking about not =wanting=
to understand, and (on the flip side) refusing to explain.

This is why, for example, pilots here will insist that
trim is used to relieve control pressures

Trim =is= used to relieve control pressure (*). That is the "what
button to push" question. It is the "how do I use trim", not "what
happens when I use trim".

You seem to be asking (without successfully communicating the
distinction) "what, in detail, happens when trim is adjusted?", the
answer to which depends on the individual setup. You also got hung up
on a "neutral position", which either doesn't exist, or can be defined
arbitrarily (just like the w/b datum).

And yes, that's an example of being unsuccessful finding out "what
happens when I do this", which really is "what ELSE happens (that nobody
is telling me!) when I do this".

Jose

(*) ... in non-fly-by-wire aircraft anyway.
--
Humans are pack animals. Above all things, they have a deep need to
follow something, be it a leader, a creed, or a mob. Whosoever fully
understands this holds the world in his hands.
for Email, make the obvious change in the address.

Jose writes:

Trim =is= used to relieve control pressure (*).

That is only one of multiple possible uses for trim.

Adjusting trim holds control surfaces in fixed, non-neutral positions.
Relieving control pressure is not the only reason for doing that. The
autopilot doesn't use trim to relieve control pressure.

You seem to be asking (without successfully communicating the
distinction) "what, in detail, happens when trim is adjusted?", the
answer to which depends on the individual setup.

Trim pretty much causes the same thing to happen fundamentally on all
aircraft.

You also got hung up
on a "neutral position", which either doesn't exist, or can be defined
arbitrarily (just like the w/b datum).

A neutral position is easy enough to understand. Neutral trim produces the
same effect as the complete absence of trim tabs.

--
Transpose mxsmanic and gmail to reach me by e-mail.

I won't continue beyond the following statements:

Adjusting trim holds control surfaces in fixed, non-neutral positions.

No, it doesn't. Aerodynamic forces still work on the control surfaces,
and they are still free to move.

The autopilot doesn't use trim to relieve control pressure.

Yes, it does. It just doesn't sense pressure the same way a pilot does.

You seem to be asking (without successfully communicating the
distinction) "what, in detail, happens when trim is adjusted?", the
answer to which depends on the individual setup.

Trim pretty much causes the same thing to happen fundamentally on all
aircraft.

That statement is a perfect indication of the difference between "what
button do I push?" and "what happens when I push the button?". It may
"cause the same thing to happen", but it causes it in different ways.

A neutral position is easy enough to understand. Neutral trim produces the
same effect as the complete absence of trim tabs.

This is an acceptable but arbitrary definition which would work for
aircraft with trim tabs. This putative neutral position however has no
aviation significance (it doesn't correspond to any useful pilot input
or requirement), and is utterly meaningless for other trim methods, such
as bungee or jackscrew.

And that's all I have to say about that.

Jose
--
Humans are pack animals. Above all things, they have a deep need to
follow something, be it a leader, a creed, or a mob. Whosoever fully
understands this holds the world in his hands.
for Email, make the obvious change in the address.

--

NOTICE!!!!
Mxsmanic is NOT a pilot, has NEVER flown an aircraft and is NOT qualified to
issue competent information regarding any aspect of the operation of any
aircraft.

"Mxsmanic" wrote in message
...
Jose writes:

Trim =is= used to relieve control pressure (*).

That is only one of multiple possible uses for trim.

Adjusting trim holds control surfaces in fixed, non-neutral positions.
Relieving control pressure is not the only reason for doing that. The
autopilot doesn't use trim to relieve control pressure.

You seem to be asking (without successfully communicating the
distinction) "what, in detail, happens when trim is adjusted?", the
answer to which depends on the individual setup.

Trim pretty much causes the same thing to happen fundamentally on all
aircraft.

You also got hung up
on a "neutral position", which either doesn't exist, or can be defined
arbitrarily (just like the w/b datum).

A neutral position is easy enough to understand. Neutral trim produces
the
same effect as the complete absence of trim tabs.

--
Transpose mxsmanic and gmail to reach me by e-mail.

NOTICE!!!!
Mxsmanic is NOT a pilot

I know this.

Jose
--
Humans are pack animals. Above all things, they have a deep need to
follow something, be it a leader, a creed, or a mob. Whosoever fully
understands this holds the world in his hands.
for Email, make the obvious change in the address.