[jhb_airlines] Re: Apparent height

  • From: "Bones" <bones@xxxxxxx>
  • To: <jhb_airlines@xxxxxxxxxxxxx>
  • Date: Mon, 16 Aug 2004 20:21:54 +0100

> -----Original Message-----
> From: jhb_airlines-bounce@xxxxxxxxxxxxx 
> [mailto:jhb_airlines-bounce@xxxxxxxxxxxxx] On Behalf Of Mike Brook
> Sent: 16 August 2004 17:29
> To: jhb_airlines@xxxxxxxxxxxxx
> Subject: [jhb_airlines] Apparent height
> > I think I might have the answer to the floating aircraft problem.
> >
> > In the ATOCAircraftFile.INI file there is a height value
> > for all the
> > ATOC aircraft. For example their entry for the C172 shows
> >
> > Height=3.765
> >
> > Which is fine if you fly the C172 because this is the same 
> height as 
> > the value in the default C172 aircraft.cfg file -
> >
> > Static CG height=3.765
> >
> > Now, say you are flying the Dreamfleet PA28 Archer. You position and
> > height values are sent to the ATOC server and then on to other ATOC
> > users. The Archer isn't in the ATOC approved list of
> > aircraft and so it
> > is likely to default to the C172 for most users. However
> > the Archer has
> > a Static CG Height of 3.85 and a C172 placed at this
> > height is going to
> > float in the air a little bit.
> >
> > bones
> Mmmm.  So which one should I alter (if any)?  If I lower my 
> AusSim Warrior's static_cg_height (which is set at 4.475) to 
> match the ATOC 172 will I then sink below the tarmac on 
> landing/takeoff?  I could alter the ATOC 172's Height setting 
> on my machine to match my Warrior's setting but how would 
> anyone else see this?  Or should I just leave everything 
> alone and accept the discrepancies?
> Confused of Solihull (aka MikeB)

It is confusing isn't it? I think it works like this:

FPI is a fast system because they have decided to do away with
transmitting aircraft data across the servers. All that gets sent is
position and height, plus a code for the ATOC aircraft category. That
way the servers aren't cluttered up with loads of aircraft data and
operations stay nice and fast - one reason why aircraft don't dance
around the sky like in MP flight.

I don't know exactly what the content of the data packets are but I
would guess that the aircraft you select in the flight plan drop down
menu is then linked to the code in the ATOCAircraftList.ini file. 

Say you select the JHB repaint of the A321 in the flight plan. This is
linked to the following data in the aircraft list:

[ATOC 321 JHB]
Description=JHB Airlines, Airbus A321
Description2=Model by ARNZ - AIS AI, Textures by John Woodside

Probably what happens is that the title of [ATOC 321 JHB] is sent along
with the FS position data. Anyone else online will receive this packet
and the ATOC software will look for {ATOC 321 JHB] to load into FS as
the appropriate AI aircraft. If it doesn't find the JHB aircraft in the
receiving users list it defaults to the ATOC A321. Same aircraft but
with the FPI colours rather than JHB's. In other words it is the
receiving user's computer that does all the work.

What I don't know is what happens if Pilot A has all the FPI aircraft
kits on his system and chooses the MD81 for the flight plan and Pilot B
only has the default ATOC collection installed. Here the code [ATOC
MD81] is being sent but Pilot B will not have this listed. The data for
this aircraft is:

Description=FlightProject, McDonnell Douglas MD81
Description2=Model by FS Painter, Textures by FlightProject

So I am guessing that it may default to displaying the aircraft that
ATOC has coded 322. This may be the A321 but the TypeEx codes are not
all obvious - I see others as 111, 211, 212, 213, 221, 222, 242, 331,
341, 1000, 2000.

Now this is where it becomes tricky...

If you fly your Cherokee in ATOC but choose the C172 in the flight plan
then this won't be too bad - because everyone has the default C172 in
ATOC. However your PA28 height is slightly wrong and this will cause
them to see you as a C172 but at PA28 height. Options?

1. You can change your PA28 aircraft.cfg file to match the C172 height
but this isn't good for yourself as your flying height will be different
and you'll sink into the ground when you look at the aircraft in chase

2. You can't change the height in your ATOCAircraftList.ini file as this
only works for you receiving other aircraft data from FPI users. It
doesn't alter your own transmitted data packets.

3. Other users could alter the above file so that your PA28 sat on the
ground correctly - but this would only work for the AusSim PA28 now. If
they saw any other ATOC user flying the default C172 then these would
now be floating/sinking.

4. The same problem applies to any other none ATOC aircraft you choose
to fly in FS on FPI sessions. My Tiger Moth plays havoc with what you
see in FS - I guess it would be the C172 but stuck up in the air
pretending to be a taildragger.

For now I'd suggest leaving well alone and just accept that if Gerry
says he is flying a Katana and you are in the PA28 then both aircraft
will have height variations that result in the C172 on the receiving
display to float/sink. I suppose we could all stick with the default
aircraft but that would kill a lot of fun.

FPI are still developing this side of their software and I know they
intend to increase the ATOC aircraft kits quite a lot. In this process
they may come up with a better way of displaying aircraft. For example,
if you choose Aircraft X in FS they might be able to read the height
value from the aircraft.cfg file and use this instead of the default
aircraft static height. Just a guess but it would help.


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