From: mechalas@gn.ecn.purdue.edu (John P. Mechalas)
Subject: Re: FS: ATP Blue Box vs. Red Box
Organization: Purdue University Engineering Computer Network
Distribution: na
Date: Mon, 14 Dec 92 22:12:04 GMT

In article <exunmk.45.0@exu.ericsson.se> exunmk@exu.ericsson.se (Noel Kerns) writes:
>In article <1992Dec12.010419.14018@gn.ecn.purdue.edu> mechalas@gn.ecn.purdue.edu (John P. Mechalas) writes:
>>Are you serious???  ATP's flight model is *much* more realistic than FS4's.
>>For one, altitude effects are more accurately modeled...the most notable
>>of all the differences.  Not to mention the instrument panel is more realistic
>>as well...the most important difference here being IAS instead of TAS...
>
>Actually, I am serious. The feel of flight (such as it can be simulated on a 
>PC) in the OLD ATP was nowhere near FS4. (ballooning when flaps are applied, 
>realistic rudder response, etc.) I've only got a Private/ASEL license so I'
>ve never flown the "big iron", but I'm fairly certain that they don't fly 
>like ATP.  The single biggest problem was the tendency for the plane to 
>simply stay locked into what ever attitude you put it, no realistic 
>aerodynamic reactions whatsoever, such as even the most basic tendency to 
>seek wing level! In this sense it felt just the terrible program "F-16 

Hmm...This can be debateable.  I don't know what the restoring moments are
offhand for large aircraft, but a slow return to wings level at a high
bank angle may not be that unrealistic.  Remember, your small planes are
going to have a quicker response rate and a faster restoration moment.
As to how slow...I can't answer that, either.  But either way, the point
is actually irrelevant, because you are referring to the flight
characteristics of the plane, whereas I am referring to the flight *models*
of the entire simulation.  If you want a faster wings-level response, you 
can adjust the damping of the airplane.  You don't have to re-write the
flight model.  To make FS4 more realistic, however, the whole model has
to be changed.
   But there is more to simulation than just roll rate.  Two things that
I noticed in FS4.0:  1) Altitude affects are simplistic.  It's bad enough
only being given TAS instead of IAS, but the aircraft seem to buffet at the
same airspeed, no matter what altitude one is at.  Also, engine performance
should change with altitude.  In ATP, the computer autmatically leans your
fuel flow for you, but at least it is modeled.  In FS4, you should be able to
cut your fuel consumption rate at higher altitudes for more efficient flight,
but I have failed to notice any appreciable differences.  2)  FS4 does not
model the "phugoid" (long period) motion of aircraft very well.  If you are
in level flight, and you drop your airspeed, you end up in a dive as you
should...but you should also begin to pull up once speed is increased and
then climb until that energy bleeds off, as you are probably aware.  But the
period of that motion is too long in FS4.  In ATP, you get a much shorter
period...and if you compare to the two 747's, you'd see that ATP's responds
more realistically than FS4's (at least, according to my last Controls
class...I will admit, however, that it has been a year since then, so my
memory could be failing me here).
   The basic result is this:  FS4.0 uses a much simpler flight model.  ATP
uses a seperate set of equations for each aircraft, so that each plane is
more unique in it's flight characteristics.
   This does not mean that FS4 is a bad program...quite the contrary.  It
is fantastic for those of us who can't afford to fly for real.  But it
still has a simple flight model.

>Combat Pilot", a regrettable Electronic Arts release.  Also, the frame rate 
>was considerably slower than FS4.  I was running it on a 386/33 and was 
>understandably surprised by this.  I now have a 486/33 so I'd like to see 
>what the new product looks like on it.

Yes, it is slower.  ATP makes more calculations than FS4.0 for two reasons:
The flight model is more complicated...it takes more environmental factors
into account.  It also has a more complex scenery base than the default
FS4.0 scenery, and also displays all scenery at longer ranges (in FS4, flying
at 30,000 feet meant you could barely see anything because it only displayed
scenery that was within a certain range.  ATP looks farther "ahead").

>However, as I said in my original post, I was curious about the NEW atp 
>product. You did not state which one you were referring to.  I suspect, 
>though, you were talking about the new one, as I can't imagine any serious 
>Flight Sim afficianado being that taken with the old version...

Actually, as far as I know, both flight models are identicle...  The new
version has the talking ATC, and all known bugs were fixed.  That's pretty
much it.  And again, I disagree with you.  The old and new ATP programs
are excellent products, and good simulations.  Particularly the ATC, which
gives you a feel for what it's really like under the pressure of an 
instrument approach.

-- 
John Mechalas                                          "I'm not an actor, but
mechalas@gn.ecn.purdue.edu                                 I play one on TV."
Aero Engineering, Purdue University                     #include disclaimer.h
Newsgroups: rec.aviation.simulators