Atmospheric stability and lapse rate

Andrew Sarangan wrote:
What you described is exactly the point many people (including
myself)
have been confused about. The 2C/1000' is the average environmental
lapse rate. Adiabatic lapse rate is never 2C/1000'. It is 1C/1000' or

3C/1000'. Many FAA texts do not explain this point clearly. Since
most
pilots get their meterology knowledge from FAA texts, and are not
formally educated on the subject, it is not surprising this confusion

exists.

There is an excellent explanation of all this stuff (including how to
predict cloud bases, the presence of vertical air currents, and the
likelihood of T-storms) in Reichmann's "Streckensegelflug" (man I hope
I got that right) which is translated into English (the whole book -
you need not speak German) as "Cross Country Soaring." It includes the
use of the Stuve diagram to predict what the atmosphere is going to do.

I would bet you any money that if you took a survey of CFI's
most would not know this fact.

Sure, as long as you limit to power-only CFI's. I can't think of any
glider CFI's who have not read Reichmann, though of course anything is
possible.

Michael

"Michael" wrote in message
ups.com...
Andrew Sarangan wrote:
....
Many FAA texts do not explain this point clearly. Since most
pilots get their meterology knowledge from FAA texts, and are not
formally educated on the subject, it is not surprising this confusion
exists.
....snipped...
I would bet you any money that if you took a survey of CFI's
most would not know this fact.

Sure, as long as you limit to power-only CFI's. ...

I have no doubt that this is absolutely correct.

Not being a soarer, but I expect he/she not only knows the "conditions" that
give rise to good thermal lift, but also the meteorological situations to
look for which are conducive.

Power pilots as a group seem less interested in the meteorological
situation. Give them the ceiling and visibility numbers from the TAF and
METAR and they go on that. Nobody seems to ask WHY does the TAF lower the
ceiling after 2100Z... If the ceiling should lower two hours early at 1900Z
instead of 2100Z, many are totally lost and simply consider this a "bad
forecast".

Power pilots as a group seem less interested in the meteorological
situation. Give them the ceiling and visibility numbers from the TAF
and
METAR and they go on that. Nobody seems to ask WHY does the TAF
lower the
ceiling after 2100Z... If the ceiling should lower two hours early at
1900Z
instead of 2100Z, many are totally lost and simply consider this a
"bad
forecast".

I think it's less a matter of disinterest and more a matter of
ignorance. Knowledge of meteorology isn't something that can
effectively be tested using a government-issue multiple choice test,
and it's not particularly easy to test in an oral exam either. For
that matter, it's not easy to teach, and it sure isn't easy to learn
from a textbook. I would have to say that of all the important
aviation topics, meteorology is the most poorly taught and the most
poorly understood. Power pilots as a group are simply not qualified to
speculate WHY the TAF lowers the ceiling after 2100Z. Quite a few
don't even understand that they should be asking why.

One thing I've noticed is this - when an inexperienced pilot cancels a
trip based on a forecast, very rarely is it a matter of good judgment -
meaning the weather is likely to be beyond the pilot's capabilities for
the reasons he believes to be true. Usually it's a matter of poor
understanding - he cancels because he doesn't understand what the
weather is actually doing, and this state of ignorance (quite properly)
scares him. Even when the weather is beyond his capabilities, very
rarely is it for the reasons he thinks it is.

By the same token, the decision by an inexperienced pilot to make the
trip in something other than good weather forecast to stay that way is
rarely a matter of properly understanding that the weather, while not
really good, is within the pilot's capability - it's usually more a
matter of rolling the dice. Even when the weather is within his
capabilities, his logic for coming to that conclusion is generally very
flawed.

This isn't a good situation, but I have to say that in power flying
that's basically the way it is - and that goes double for instrument
flying. I find it amazing that anyone can believe he is making
intelligent decisions with regard to his safety margins against
encountering icing and T-storms in IMC in any but the most clearcut
cases without an understnading of what lapse rates mean, yet here we
have quite a few instrument pilots and instrument instructors still
hashing out the topic. And I'm going to be honest - had I not had my
glider rating long before my instrument rating, and my CFI-G long
before my CFII, I would likely have been just as ignorant.

While I admit it's possible in theory to learn enough about meteorology
from books and classes to make competent go/no-go decisions, I have to
say that I've never actually seen it happen in practice. In reality,
the only people I know who have actually learned to understand what the
weather is doing sufficiently to realistically asess the flight risks
are those who have flown in the weather. Unfortunately, every one of
these people has scared himself more than once by having misunderstood
or ignored some seemingly minor but actually very important factor.
And lest you think that it's somehow different for gliders, every one
of those glider pilots who has become pretty good at knowing what the
weather is doing has stories of guessing wrong and making an
off-airport landing or escaping one only by the skin of one's teeth.

Michael

"Michael" wrote in message
oups.com...
.... many relevant observations snipped....

This isn't a good situation, but I have to say that in power flying
that's basically the way it is - and that goes double for instrument
flying.
....more relevant observations snipped....
And lest you think that it's somehow different for gliders, every one
of those glider pilots who has become pretty good at knowing what the
weather is doing has stories of guessing wrong and making an
off-airport landing or escaping one only by the skin of one's teeth.

I had been around the periphery of aviation for many years, but have only
had my very first peeks "inside" since mid-2004.

What you have said mirrors that meager experience perfectly. It surprised
me a little...maybe more than a little.

Nicely done guys. This thread is the Usenet we all enjoy.

A Chinook is the classic demonstration of lapse rate in action. You can
even see it on the satellite feeds.

From a pilots perspective there are only three kinds of weather.
Getting better
Getting worse
Staying the same
All of our studying and experience are drawn on to make this judgment, and I
think it is true to say that you can't have too much weather knowledge.
Ultimately weather and running out of fuel seem to be the biggest cause of
aviation fatalities.

The internet is a wonderful resource for students of life as there is a huge
amount of very good material available for free and the access to aviation
weather maps and data lets us practice our skills by constantly watching the
sky and asking yourself, if you were flying today
is it getting better or worse?
and where is the hidden weather killer hiding?

I make it a point to check the aviation weather daily and find that my
forecasts are usually as good as the very good TV weather (CFCN) I also
find this practice useful for forecasting powder snow and use my knowledge
of lapse rates and winds aloft to estimate whether it is likely to be heavy
or light and its effect on the avalanche hazard or if the high chairlift
will be closed for wind..

Weather newsgroup sci.gen.meteorology Most of the guys on
this group know way more than me, but then that's true here too.

The following is a repost, my appologies to the usenet purists.

When the local FSS were closed NavCan recognized that the briefers in the
centers may lack the local knowledge that the local FSS had provided. A
project to gather this local knowledge for briefer training lead to the
production of weather manuals for each of the weather regions. These
manuals are available on their website. The general weather chapter seems
to be common to each manual and is as good as any of the pilot weather books
I have read, with the possible exception of the TC Air Command Weather
Manual CFACM 2-700 ( TC. TP9352E)

http://www.navcanada.ca/NavCanada.as...Definition Fi
les\Publications\LAK\default.xml

My favorite weather source is

http://www.flightplanning.navcanada....gue=anglais&No
Session=NS_Inconnu&Page=rb&TypeDoc=html

Blue skies to all





"Icebound" wrote in message
...

"Michael" wrote in message
oups.com...
... many relevant observations snipped....

This isn't a good situation, but I have to say that in power flying
that's basically the way it is - and that goes double for instrument
flying.
...more relevant observations snipped....
And lest you think that it's somehow different for gliders, every one
of those glider pilots who has become pretty good at knowing what the
weather is doing has stories of guessing wrong and making an
off-airport landing or escaping one only by the skin of one's teeth.

I had been around the periphery of aviation for many years, but have only
had my very first peeks "inside" since mid-2004.

What you have said mirrors that meager experience perfectly. It surprised
me a little...maybe more than a little.



and many previous posters