Coordinated turns without rudder, and autopilots

Snowbird writes:

MSFS has for a long time been known to have a rather inaccurate flight
model. MS tends to focus on the eye candy aspects of simulation.

Which aspects are inaccurate?

In my own experience, the stall/spin entry behavior is an easily explored
area which quite clearly reveals the inadequacies of MSFS' flight modeling
as compared to the real world. And it reflects of course as well in other
areas of the flight envelope.

A coordinated turn is neither a stall nor a spin.

Years ago I flew extensively with a popular WWII networked combat airplane
simulator (Warbirds). One of its claims to fame was that its flight dynamics
model was based on actual real-time calculation of the motional differential
equations that govern the flight dynamics of an aircraft. This in contrast
to the "simplistic table-driven flight dynamics model of the mainstream PC
simulators" probably referring to MSFS.

Table-driven models are often more accurate. They don't have to calculate
anything; they just look up the data taken from the real aircraft. They don't
work in exceptional regimes of flight because the data for those in the tables
are either absent or incorrect (as the real aircraft may have never been flown
in those regimes to gather the data). But they work better than physics
calculations in normal regimes of flight because they are guaranteed to match
the real aircraft--after all, they are just reproducing what the real aircraft
did in those cases.

Physics models are better at handling all regimes of flight, since they
calculate behavior on the fly. However, they rarely match the real aircraft
precisely, because inaccuracies in the model are extremely difficult to
correct completely enough to reproduce real-world behavior in flight,
especially in real time. It's much easier to just measure the real aircraft
and put that in a table. Additionally, if you want to certify a simulation,
table-driven simulation is a lot easier to certify because it's very easy to
make the simulation match a specific real-world aircraft.

Marketing talk aside, I found that simulator MUCH more realistic in the
flight dynamics modeling than MSFS. Especially at the edges of the flight
envelope, where the differences between different airplanes were very
significant.

See above. I don't fly at the edges of the envelope--on that path lies
danger.

"Mxsmanic" wrote in message
...


See above. I don't fly at the edges of the envelope--on that path lies
danger.

Did you fall out of your desk chair again?

"Mxsmanic" wrote ...

Which aspects are inaccurate?

All, to a lesser or higher degree. I already pointed out one of the most
glaringly inaccurate areas. Read what I wrote.

A coordinated turn is neither a stall nor a spin.

It is an area within the flight envelope. Read what I wrote.

Table-driven models are often more accurate.

Show me scientific proof.

I don't fly at the edges of the envelope--on that path lies
danger.

That's why pilots train stalls. Accurately knowing the signs of approaching
the danger zone gives safety.

Snowbird writes:

All, to a lesser or higher degree.

Then it is also inevitably true that all aspects are accurate, to a greater or
lesser degree. Of course, neither statement communicates much of real
utility.

Show me scientific proof.

How does one provide scientific proof of the self-evident?

A perfect measurement of a real-world random contour will always be perfect.
A mathematical recreation will always be an approximation.

Mxsmanic wrote in
:

Snowbird writes:

All, to a lesser or higher degree.

Then it is also inevitably true that all aspects are accurate, to a
greater or lesser degree. Of course, neither statement communicates
much of real utility.

Show me scientific proof.

How does one provide scientific proof of the self-evident?

Whoosh.


Do you even hear it as it whistles over your head, fjukktard?


bertie

"Mxsmanic" wrote ...
Table-driven models are often more accurate.

On May 31, 2:30 pm, Mxsmanic wrote:
Snowbird writes:
Show me scientific proof.

How does one provide scientific proof of the self-evident?

A perfect measurement of a real-world random contour will always be perfect.
A mathematical recreation will always be an approximation.

Table driven models are only "perfect" at the (often very few) points
in the table (and even there depends upon the accuracy of the
measurements). Elsewhere they too are only approximations, the
accuracy of which depends upon how well the real world contour matches
the interpolation method chosen.

Please remember that "mathematical recreation" is a synonym for
"simulation".

And what you see in your simulator MSFS is only an approximation of
reality. A model/simulation is always a process of give & take
between the accuracy in representing various processes & effects in
different regimes, and while MSFS allows you some control over some of
those choices most of them are hidden and have been made for you.
Without real world experience it would be very difficult for you to
realize many of these tradeoffs, those with real world experience can
spot them quite easily. The advice of those who have actually
experienced what you wish to simulate can be very informative - but
comes at the cost of learning what you are missing (possibly
diminishing your enjoyment of your simulator).

The alternative, of course is,"Ignorance is bliss".

Bob Crawford wrote in
oups.com:

"Mxsmanic" wrote ...
Table-driven models are often more accurate.

On May 31, 2:30 pm, Mxsmanic wrote:
Snowbird writes:
Show me scientific proof.

How does one provide scientific proof of the self-evident?

A perfect measurement of a real-world random contour will always be
perfect. A mathematical recreation will always be an approximation.

Table driven models are only "perfect" at the (often very few) points
in the table (and even there depends upon the accuracy of the
measurements). Elsewhere they too are only approximations, the
accuracy of which depends upon how well the real world contour matches
the interpolation method chosen.

Please remember that "mathematical recreation" is a synonym for
"simulation".

And what you see in your simulator MSFS is only an approximation of
reality. A model/simulation is always a process of give & take
between the accuracy in representing various processes & effects in
different regimes, and while MSFS allows you some control over some of
those choices most of them are hidden and have been made for you.
Without real world experience it would be very difficult for you to
realize many of these tradeoffs, those with real world experience can
spot them quite easily. The advice of those who have actually
experienced what you wish to simulate can be very informative - but
comes at the cost of learning what you are missing (possibly
diminishing your enjoyment of your simulator).

The alternative, of course is,"Ignorance is bliss".


He must be experiencing Nirvana.



Bertie

Bob Crawford writes:

Table driven models are only "perfect" at the (often very few) points
in the table (and even there depends upon the accuracy of the
measurements). Elsewhere they too are only approximations, the
accuracy of which depends upon how well the real world contour matches
the interpolation method chosen.

They can be made much more accurate than theoretical models, and they are
provably accurate with respect to the real aircraft at demonstrable points,
which is useful for certification.

"Mxsmanic" wrote ...
Snowbird writes:

All, to a lesser or higher degree.

Then it is also inevitably true that all aspects are accurate, to a
greater or
lesser degree.

What a brilliant deduction. I suppose next you will then postulate that the
simulator has a more accurate flight dynamics model than the real airplane.
Yeah, black is actually white, sure.

Of course, neither statement communicates much of real
utility.

Except that you once again clipped out my reference to the example that
illustrated my statement. I'm sorry, but in aviation you can't just pick the
bits that happen to fit your personal agenda. That is in fact an extremely
dangerous attitude.


Show me scientific proof.

How does one provide scientific proof of the self-evident?

So now you resort to declaring the issue self-evident, in order to avoid
producing proof.
(Wikipedia: "a self-evident proposition is one that is known to be true by
understanding its meaning without proof").
Then tell me why it's self-evident that a table-driven flight dynamics model
would always be better than a real-time differential equation-driven.


A perfect measurement of a real-world random contour will always be
perfect.
A mathematical recreation will always be an approximation.

Was that your "proof" of the above issue? What makes you believe the MSFS
flight model is based on "perfect" measurements? Show me proof that the
"perfect real-world measurements" always have less measurement errors than
the errors in the mathemathical approximations.

Snowbird writes:

What a brilliant deduction.

Thank you.

I suppose next you will then postulate that the
simulator has a more accurate flight dynamics model than the real airplane.

The real airplane is not a model, so this statement has no meaning.

Then tell me why it's self-evident that a table-driven flight dynamics model
would always be better than a real-time differential equation-driven.

Not always, but usually, especially cost-wise. The idea of a simulator is to
simulate a real aircraft, not real flight. It's more important that the
behavior of the sim match the real aircraft being simulated than it is for the
sim to approximate real flight in all regimes.

Full-motion ATP sims handle spins and other unusual attitudes poorly, but
since they are not used to simulate those unusual attitudes, it doesn't
matter, especially since they simulate normal flight with extraordinary
accuracy.