Problems in a commercial flight

EridanMan writes:

The problem is that you do not know what you do not know ...

A greater problem is that a lot of pilots here don't know, either, although
many think that they know it all once they have a license (and that,
conversely, anyone without one knows nothing). The truth is considerably less
extreme.

... and lack of
practical experience has left your knowledge with a great number of
holes that you refuse to acknowledge.

The "holes" pointed out to me consist almost exclusively of physical
sensations of flying. The mistake made by pilots here is to think that these
sensations are 99% of flying, when in fact their importance varies with the
type of flying under consideration.

This is a consequence of many pilots here being tin-can, seat-of-the-pants
pilots, with little or no experience or knowledge of other types of aircraft.
They see everything from the cockpit of a Cessna, and they think that's all
there is.

That is a GROSS generalization.

It's also a very accurate one. It's painfully obvious that many of the pilots
here are low-time, small-aircraft pilots. Everything they say reflects this
viewpoint.

Yes, some pilot's only care about the planes that they fly... I would
say that is actually the exception rather than the rule, however.

Most of them only _know_ about the plane(s) they fly. They don't know about
other planes, so they don't care about them.

They think that knowing the fine details of control pressures in a Cessna is
vitally important, but when I point out that many large aircraft don't work
this way at all, they dismiss that as unimportant. But it's not unimportant
to an Airbus pilot.

The rest of us have just as much a passion for aviation as yourself
AND we fly.

Some people have resources, and others don't.

When we're not spending our spare time in a cockpit, we
spend it learning about aircraft and aircraft systems... Aircraft
design (A particular favorite topic of mine) and other aviation
related topics... and hell, even flying sims...

Some do, some don't. Some stop half-way and then pretend about the rest.

Your explanation of the cause of the roll oscillations was utterly
wrong ...

Provide the correct explanation, then.

... and your desire to attribute ultimate aircraft stability to
autopilot design is also largly incorrect (Except in a few isolated
(almost always military) cases of relaxed stability aircraft.

See above.

This might be a low blow but...

Isn't that the fundamental definition of Simulation?

Not really. Pretending depends on imagination alone. Simulation removes part
of the need for imagination, so simulation is much less pretending than
non-simulation.

One of the aggravations I have had, however - is you do not seem to
respond to anything BUT the personal attacks ...

Many posts contain nothing else, and in fact I let most personal attacks drop,
as they are unrelated to the discussion at hand. It's hard to get people to
discuss the topic, rather than me.

This post is a case in point. You say I was wrong, but you provide no further
information and no corrections, which I find odd. You spend the rest of the
post talking about me, rather than the topic at hand.

I have seen MANY knowledgeable, polite corrections and responses to
your assertions go un-heeded while you chose only to argue with those
who attacked you.

The fact that I do not reply to a post doesn't mean that I haven't read it or
understood it. It usually just means that I have no quarrel with it and no
further questions about it.

Those who engage in personal attacks also tend to be those who give wrong
answers or incomplete answers or no answers, and so I press them for answers.
People who are aggressive in this way are often being defensive because they
know that their opinions were adopted wholesale from someone else and are
fundamentally baseless. I press them for answers in order to compel them to
look at their opinions and decide whether they are really worth clinging to
when they cannot be substantiated. I consider this a public service.

It gives the impression that you seek the negative attention over
actual helpfulness.

I'm not worried about the impression I create. I've found that people have an
enormous tendency to believe what they want to believe, and it's an exercise
in futility to try to make them think more critically. But I try to err on
the side of optimism and so I still do the above.

I still wish you'd take some time to get your information from sources
OTHER than public forums however ...

Most of my information comes from other sources, since it is hard to find
people here who actually know what they are talking about. USENET is just one
of many sources.

So many of your questions could be
answered so much easier and faster via a quick Google search.

I do Google searches regularly, although I don't have as much faith in them as
you might.

And It would also be nice if you added an occasional "my understanding
is" disclaimer to some of your more authoritative-toned posts...

Why? To spare the overinflated egos of a minority? Why would I say something
that is _not_ my understanding? How could anything I say (or anything anyone
else says) be anything _other_ than an understanding?

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

A rarity! My killfile must have bitten the dust with last reformat. Alas.

Mxsmanic wrote:
The mistake made by pilots here is to think that these
sensations are 99% of flying, when in fact their importance varies with the
type of flying under consideration.

The counter-example being, of course, that even high-time regular
heavy-iron pilots find the loss of feeling in the control column in
modern fly-by-wire aircraft so disruptive and unnerving that the
engineers had to design systems to emulate them, leading someone more
prone to contemplation to perhaps consider kinesthetics more important
than not.

They see everything from the cockpit of a Cessna...

Whereas, one points out, you have not even seen that.


It's painfully obvious that many of the pilots
here are low-time, small-aircraft pilots. Everything they say reflects this
viewpoint.

Why say that? Provide some examples, lest you fall into your own trap of
incompleteness in objective.

Most of them only _know_ about the plane(s) they fly. They don't know about
other planes, so they don't care about them.

Perhaps, again, that other pilots in the group actually do know little
of the specific aircraft, and choose to refrain from making
pronouncements and edicts of procedure and performance, based on the
knowledge of their ignorance, instead of barging into threads where they
would only succeed in mucking things up with incorrect information and
speculation.

They think that knowing the fine details of control pressures in a Cessna is
vitally important, but when I point out that many large aircraft don't work
this way at all, they dismiss that as unimportant. But it's not unimportant
to an Airbus pilot.

See the first above.

Some people have resources, and others don't.

Some understand how to live within their means while enjoying their
passion, and others simply look in from the outside and stir the pot in
the hopes of becoming a part of the community.

Some do, some don't. Some stop half-way and then pretend about the rest.

And yet others pretend about it all.

Provide the correct explanation, then.

Provided by other posters, which that hypothetical contemplatieur would
note you have not chosen to respond to, and that is: positive stability
brought on by wing dihedral (which, one also notes, is a feature of BOTH
Boeing and Airbus wings: why make an active system to compensate for
what can be designed out with passive engineering?).

Simulation removes part
of the need for imagination, so simulation is much less pretending than
non-simulation.

Simulation allows for the so-called "suspension of disbelief", which
necessarily denotes that the participant recognizes and properly
attributes the qualities and failings of such "simulation" in the first
place.

---

Here we part with the third person (which, noted, you enjoy referring to
yourself with).

I have seen MANY knowledgeable, polite corrections and responses to
your assertions go un-heeded while you chose only to argue with those
who attacked you.

The fact that I do not reply to a post doesn't mean that I haven't read it or
understood it. It usually just means that I have no quarrel with it and no
further questions about it.

Netiquette demands at least a thank-you or acknowledgment of receipt.


Those who engage in personal attacks also tend to be those who give wrong
answers or incomplete answers or no answers, and so I press them for answers.
I press them for answers in order to compel them to
look at their opinions and decide whether they are really worth clinging to
when they cannot be substantiated. I consider this a public service.

Translation: I assault posters with incessant questions, even about
objective, immutable topics, in order to frustrate further conversation
or to provide some tangible ethical or moral response to which I can
cling and make incorrect, hurtful, baseless assertions. I consider
myself superior over all others, even those with a clearly higher
understand or better experience.

I've found that people have an
enormous tendency to believe what they want to believe, and it's an exercise
in futility to try to make them think more critically.

Found a mirror again?

Most of my information comes from other sources...

Of which you refuse to enumerate when issued questions or inquiry (which
inevitably leads to doubt of veracity).

Why? To spare the overinflated egos of a minority? Why would I say something
that is _not_ my understanding? How could anything I say (or anything anyone
else says) be anything _other_ than an understanding?

No, to spare the uninitiated of misplaced trust.

You fail to understand the difference between understanding and
knowledge (used in this vernacular). There is a fundamental dichotomy
between third-party repetition of information, and a statement of fact.
Even you must recognize that much of your writing comes off as though
you have real, first-party knowledge of a topic, when in truth you are
either re-stating another's or your own interpretation of subjective fact.

Thus, again casting doubt on your actual capability, which is not
assisted by your utter rigidity (or, colloquially, Ferrous Cranus).

http://redwing.hutman.net/~mreed/war...rouscranus.htm

TheSmokingGnu

TheSmokingGnu writes:

The counter-example being, of course, that even high-time regular
heavy-iron pilots find the loss of feeling in the control column in
modern fly-by-wire aircraft so disruptive and unnerving that the
engineers had to design systems to emulate them, leading someone more
prone to contemplation to perhaps consider kinesthetics more important
than not.

Except that this isn't true. Feel and feedback are not hugely important and
one can easily become used to their absence. Simulating them in a large
aircraft is mostly a matter of convenience for pilots--not necessity. Indeed,
since the "feel" varies greatly from one aircraft to another, irrespective of
whether or not it is real or simulated, the habituation to control feel isn't
very transferable.

Whereas, one points out, you have not even seen that.

It's only a tiny dot on the aviation landscape, and I don't consider it
important. Most pilots have never seen anything from most cockpits. That
isn't much of a handicap.

Why say that?

Because it's true.

Provide some examples, lest you fall into your own trap of
incompleteness in objective.

The obsessions with sensation and control feel, issues that are highly
specific to certain types of aviation (such as small aircraft). The
preoccupation with VFR and VMC over IFR and IMC. The cluelessness with
respect to complex avionics and navigation systems. The acceptance of engine
failures as an unavoidable fact of life (most airline pilots go through their
entire careers without ever seeing an engine failure). And so on.

Perhaps, again, that other pilots in the group actually do know little
of the specific aircraft, and choose to refrain from making
pronouncements and edicts of procedure and performance, based on the
knowledge of their ignorance, instead of barging into threads where they
would only succeed in mucking things up with incorrect information and
speculation.

Nothing prevents them from studying to reduce their ignorance.

See the first above.

See an Airbus.

Some understand how to live within their means while enjoying their
passion, and others simply look in from the outside and stir the pot in
the hopes of becoming a part of the community.

Some people have resources, and some don't. And enjoying a passion doesn't
necessarily have anything to do with joining a "community" (boys' club).

And yet others pretend about it all.

So I've noticed, but that is their prerogative.

Provided by other posters, which that hypothetical contemplatieur would
note you have not chosen to respond to, and that is: positive stability
brought on by wing dihedral (which, one also notes, is a feature of BOTH
Boeing and Airbus wings: why make an active system to compensate for
what can be designed out with passive engineering?).

The reason for using an active system is that it improves maneuverability.
The drawback is that the aircraft has a tendency to depart from controlled
flight if the computers fail. That's Airbus. It's not Boeing (as far as I
know, with respect to civilian aircraft).

Here we part with the third person (which, noted, you enjoy referring to
yourself with).

No, I was simply continuing the style of the posts to which I responded, to
reduce ambiguity.

Netiquette demands at least a thank-you or acknowledgment of receipt.

Netiquette is an illusion. And in any case, I'm not interested in courtesy
rituals. Those who require the ego boost of some expression of gratitude need
not reply. Sharing knowledge should be its own reward.

Translation: I assault posters with incessant questions, even about
objective, immutable topics, in order to frustrate further conversation
or to provide some tangible ethical or moral response to which I can
cling and make incorrect, hurtful, baseless assertions. I consider
myself superior over all others, even those with a clearly higher
understand or better experience.

No. That is the perception that some have of it, but they allow their
emotions to rule, which is a bad thing in itself. People who are slaves to
their emotions are highly vulnerable and easy to manipulate. It's not good to
have large segments of the population with this handicap.

Of which you refuse to enumerate when issued questions or inquiry (which
inevitably leads to doubt of veracity).

There is no need to enumerate them. Others can do their own research and
learn for themselves whether or not I'm right. It's surprising how rarely
they do this.

No, to spare the uninitiated of misplaced trust.

Why would anyone trust a name on a screen?

You fail to understand the difference between understanding and
knowledge (used in this vernacular).

Which vernacular?

There is a fundamental dichotomy between third-party repetition
of information, and a statement of fact.

No, they are independent.

Even you must recognize that much of your writing comes off as though
you have real, first-party knowledge of a topic, when in truth you are
either re-stating another's or your own interpretation of subjective fact.

I leave verification as an exercise for the reader. And if I seem to have
real, first-party knowledge of a topic, that may well be correlated with the
fact that I am often right.

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

Mxsmanic wrote:
Except that this isn't true.

Do deny that airliners are fitted with artificial feel systems?

Because it's true.

Why?

The obsessions with sensation and control feel, issues that are highly
specific to certain types of aviation (such as small aircraft). The
preoccupation with VFR and VMC over IFR and IMC. The cluelessness with
respect to complex avionics and navigation systems. The acceptance of engine
failures as an unavoidable fact of life (most airline pilots go through their
entire careers without ever seeing an engine failure). And so on.

I still fail to see the specific examples I requested, but rather your
opinions and interpretations instead.

Also, do you feel that engine failures are such a rare occurrence that
they should be deprioritized in training and emergency procedure
(keeping in mind that vast number of reasons that an engine might fail)?

Nothing prevents them from studying to reduce their ignorance.

Ah, but even then they would have to say that they have merely studied
the surface issues, and still yet have no direct experience.

See an Airbus.

Seen, noted, observed wing dihedral, question remains unanswered.

So I've noticed, but that is their prerogative.

Ah, so you DO re-read your posts?

The reason for using an active system is that it improves maneuverability.
The drawback is that the aircraft has a tendency to depart from controlled
flight if the computers fail. That's Airbus. It's not Boeing (as far as I
know, with respect to civilian aircraft).

What maneuverability would be required? Certain posters here would have
us believe that civilian jets are hardly capable of the turns they make,
let alone any kind of extreme evasion; more to the point, why design
systems that fail catastrophically? Why not use a passive design that
cannot fail in any kind of practical sense, and which always returns to
center?

Sharing knowledge should be its own reward.

Can we list the antithesis, that suffering speculation is its own torture?

There is no need to enumerate them. Others can do their own research and
learn for themselves whether or not I'm right.

You could at least do the courtesy of leading them in the right
direction, since you consider this a service to the public. The listing
of sources is a time-honored tradition in any kind of academic or
educational capacity (to wit: theses, or indeed any kind of research
paper); I don't expect formal formatting, but even an informal list,
perhaps?

Why would anyone trust a name on a screen?

Why would anyone trust words on a page?

Which vernacular?

The one to which I was referring, within the present context, with
accompanying explanation and dissertation.

No, they are independent.

You /ARE/ familiar with the term "dichotomy", correct?

I leave verification as an exercise for the reader. And if I seem to have
real, first-party knowledge of a topic, that may well be correlated with the
fact that I am often right.

See the above sources. If you have practical first-hand experience,
by all means validate your evocations with a qualifier, so that people
(again, your deserving public) may more readily distinguish between
research and anecdote.

TheSmokingGnu

TheSmokingGnu writes:

Do deny that airliners are fitted with artificial feel systems?

Some are. But feel varies significantly from one aircraft to another.
Sometimes it is simulated just because pilots expect it.

Why?

I don't know why it's true.

Also, do you feel that engine failures are such a rare occurrence that
they should be deprioritized in training and emergency procedure
(keeping in mind that vast number of reasons that an engine might fail)?

I think they should be kept in perspective. Engine failures in certain phases
of flight are serious emergencies, and since they are so easy to practice in
simulation, there's not much reason not to do so. But at the same time, they
are extremely rare in large commercial airliners, so practicing them in excess
(to the detriment of practice in other, more likely emergency scnearios) is
probably not a good idea.

In small aircraft, the engines are so unreliable that engine failures must be
practiced. Ironically, there's no really good way to practice them, since
full-motion simulators for small aircraft are rare, and it's too dangerous to
practice true engine failures in a real aircraft (setting an engine to idle
doesn't count).

Ah, but even then they would have to say that they have merely studied
the surface issues, and still yet have no direct experience.

There isn't any specific limit to the depth of study one can undertake. Both
study and experience are legitimate ways to learn; both can lead one to attain
the same goals.

Seen, noted, observed wing dihedral, question remains unanswered.

Some Airbus aircraft are designed to be unstable, under the assumption that
computers will keep them flying straight and level.

What maneuverability would be required?

That's a good question. You'd have to ask Airbus. I can't think of any high
maneuverability requirements for airliners.

Certain posters here would have
us believe that civilian jets are hardly capable of the turns they make,
let alone any kind of extreme evasion ...

They are capable of much more than is usually requested of them. This being
so, going beyond that seems illogical. But I've never seen much logic in
Airbus--after all, it's a political organization.

... why design systems that fail catastrophically?

Systems fail catastrophically when they are _not_ designed. Catastrophic
failure modes are characteristic of unanticipated exceptions in digital
systems.

Why not use a passive design that cannot fail in any kind of practical
sense, and which always returns to center?

That cannot be done with digital systems. They only fail safe in modes that
are anticipated in the design; in other modes, catastrophic failure is more
likely.

You could at least do the courtesy of leading them in the right
direction, since you consider this a service to the public.

That would not be verification.

The listing of sources is a time-honored tradition in any kind of academic or
educational capacity

Yes, and it is vastly overrated in consequence. Many incorrectly assume that
the mere presence of references somehow validates whatever uses them.

Why would anyone trust words on a page?

Exactly.

You /ARE/ familiar with the term "dichotomy", correct?

Yes. And I don't even need to look it up. Your use of the term puzzled me,
but it was part of a pattern I noticed in the entire post, so I let it slide.

See the above sources. If you have practical first-hand experience,
by all means validate your evocations with a qualifier, so that people
(again, your deserving public) may more readily distinguish between
research and anecdote.

They need to do their own research.

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

In small aircraft, the engines are so unreliable that engine failures must be
practiced. Ironically, there's no really good way to practice them, since
full-motion simulators for small aircraft are rare, and it's too dangerous to
practice true engine failures in a real aircraft (setting an engine to idle
doesn't count).

Loon mallet please....

Mxsmanic wrote:
Sometimes it is simulated just because pilots expect it.

So you admit that in expecting it, the pilots must necessarily feel it
(or rather, expect to feel it; want to feel it; know that they should
feel it; know that it should exist).

I don't know why it's true.

Then how can you say that it is not false?

But at the same time, they
are extremely rare in large commercial airliners, so practicing them in excess
(to the detriment of practice in other, more likely emergency scnearios) is
probably not a good idea.

In small aircraft, the engines are so unreliable that engine failures must be
practiced.

Surface analysis of the NTSB database would seem to mete this out; last
year there were just 2 incidents in jets, while general aviation racked
up 25. However, without a more detailed report of accidents per flight
or per mile (or per capita), I would be hesitant to make such claims
with authority.

Ironically, more of the GA accidents with fatalities occurred in large
turbine/heavy twin aircraft, while small "tin-cans" were generally
non-fatal if not merely incidental.


(setting an engine to idle
doesn't count).

Why not, if the purpose of the practice is to experience a loss of
meaningful power and to execute the proper diagnostics to the engine as
well as the correct emergency procedures? Idling the engine would seem
to be a perfect solution.

Some Airbus aircraft are designed to be unstable, under the assumption that
computers will keep them flying straight and level.

Which?

... why design systems that fail catastrophically?

Systems fail catastrophically when they are _not_ designed. Catastrophic
failure modes are characteristic of unanticipated exceptions in digital
systems.

Surely an engineer would anticipate the failure of a computer system.
Heck, that's why we have triple-redundancy hydraulic systems (with
backup electrics, no less).

That same engineer would also surely see that using an active control
system (with a failure potential) is inferior to using plain old physics
(which has already been demonstrated on many other designs; why try to
fix what isn't broken)?

That cannot be done with digital systems. They only fail safe in modes that
are anticipated in the design; in other modes, catastrophic failure is more
likely.

But the system in question here is not digital, nor is it controlled as
such by the fly-by-wire systems. Dihedral in a wing uses physics (and a
helping hand from Mr. Daniel Bernoulli) to roll an aircraft level (or
more towards level), sans control inputs. Why would an engineer ignore
this time-tested approach to wing design in favor of an active (and
potentially failure-prone) system?

That would not be verification.

But it would start the process.

Yes, and it is vastly overrated in consequence. Many incorrectly assume that
the mere presence of references somehow validates whatever uses them.

I think many assume that the presence of references provides a trail of
fact-checking and verification which is important when trying to assert
the validity of analysis and claims made in such academia.

Your use of the term puzzled me,

I'm not sure why; I used it to indicate two separate concepts, which you
promptly corrected me by saying that they were.... independent.

It would have seemed to the outside viewer that perhaps you had not
understood the usage.

They need to do their own research.

Hard to do without a platform to stand on from which to begin, eh? It
would hardly be fair if you wanted to verify my claims of why the sky
was blue, but you had to discover the atom first (and then molecules,
dipole bonding forces, light refraction, fusion, astronomy, and various
other sundry basal sciences), right?

Public services usually aim to provide helpful and useful information,
as well as a stepping stone for learning more about the topic, not
commands from on-high from an individual who holds himself in higher
standing than his peers.

TheSmokingGnu

TheSmokingGnu writes:

So you admit that in expecting it, the pilots must necessarily feel it
(or rather, expect to feel it; want to feel it; know that they should
feel it; know that it should exist).

They want to feel it. They don't need it. It makes pilots comfortable,
especially those who dislike change. It makes them feel as if they are still
in control, even when they are not.

Then how can you say that it is not false?

I don't have to know why something is true just to know that it's true. I
know that some flowers are blue and others are red--it's definitely true--but
I don't know why.

Surface analysis of the NTSB database would seem to mete this out; last
year there were just 2 incidents in jets, while general aviation racked
up 25. However, without a more detailed report of accidents per flight
or per mile (or per capita), I would be hesitant to make such claims
with authority.

The NTSB database is pretty reliable.

Why not, if the purpose of the practice is to experience a loss of
meaningful power and to execute the proper diagnostics to the engine as
well as the correct emergency procedures?

Because an idle engine is not a stopped engine, as anyone who has experienced
an actual failure can attest.

Idling the engine would seem to be a perfect solution.

No, it just creates a false sense of security.

Which?

I've forgotten which models; presumably the more recent ones.

Surely an engineer would anticipate the failure of a computer system.

There are too many possible failure scenarios. Nobody, not even an engineer,
can anticpate them all. The ones that are not anticipated in the design will
generally produce catastrophic failures (in digital systems).

Heck, that's why we have triple-redundancy hydraulic systems (with
backup electrics, no less).

Mechanical systems are not digital. The catastrophic failures come from
software.

That same engineer would also surely see that using an active control
system (with a failure potential) is inferior to using plain old physics
(which has already been demonstrated on many other designs; why try to
fix what isn't broken)?

Sometimes engineers are seduced by the promise of better performance, to the
detriment of safety.

But the system in question here is not digital, nor is it controlled as
such by the fly-by-wire systems.

All modern fly-by-wire systems are digitally controlled, because they depend
on digital computers and software.

Dihedral in a wing uses physics (and a
helping hand from Mr. Daniel Bernoulli) to roll an aircraft level (or
more towards level), sans control inputs. Why would an engineer ignore
this time-tested approach to wing design in favor of an active (and
potentially failure-prone) system?

To improve performance. The usual reasoning is that prudent design for
default behavior is unnecessary because the computers can fix it all. This is
a very common error in engineering these days, and not just in aviation.

It's a bit like people who never learn to brake properly in wet conditions
because they expect the ABS to do it for them. The day the ABS fails comes as
a big surprise.

I think many assume that the presence of references provides a trail of
fact-checking and verification which is important when trying to assert
the validity of analysis and claims made in such academia.

That trail is useless if nobody follows it, and most people just assume that
the presence of references makes them valid, without checking. In reality,
there is no improvement in reliability just because there are references.

I'm not sure why; I used it to indicate two separate concepts ...

That's not what dichotomy means.

It would have seemed to the outside viewer that perhaps you had not
understood the usage.

That depends on the education of the outside viewer.

Hard to do without a platform to stand on from which to begin, eh?

Not at all. All research begins that way. That's why people do research.

It would hardly be fair if you wanted to verify my claims of why the sky
was blue, but you had to discover the atom first (and then molecules,
dipole bonding forces, light refraction, fusion, astronomy, and various
other sundry basal sciences), right?

Why does it have to be "fair"?

Public services usually aim to provide helpful and useful information,
as well as a stepping stone for learning more about the topic, not
commands from on-high from an individual who holds himself in higher
standing than his peers.

My public service is in forcing people to think, an activity that will benefit
them over the long term.

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

Mxsmanic wrote in
:

TheSmokingGnu writes:

Do deny that airliners are fitted with artificial feel systems?

Some are. But feel varies significantly from one aircraft to another.
Sometimes it is simulated just because pilots expect it.

God you're clueless.



Bertei

Mxsmanic wrote in
news
EridanMan writes:

The problem is that you do not know what you do not know ...

A greater problem is that a lot of pilots here don't know, either,

I do, and I know you are full of ****...



Bertie