[jhb_airlines] Re: Autopilot APPR HOLD problem

  • From: Gerry Winskill <gwinsk@xxxxxxx>
  • To: jhb_airlines@xxxxxxxxxxxxx
  • Date: Sun, 16 Oct 2005 19:58:32 +0100

I can't find any reference to Vspeeds in the Reference file. They must be in somewhere, 'cos the panel I'm using has Vnumber calls.
I've just increased Elevator Trim Limit, and inserted an effectiveness line. There was no entry for Flap Drag, so I've inserted that, starting at 1.5, since it's difficult to get down to 115, on the ILS, without using the Airbrakes, too.
Not tested yet.




Gerry Winskill

Bones wrote:

I've had a longer look at the .air file and have made quite a few changes to
this (and to the aircraft.cfg file). Yet to test these to see what
difference they make but it was obvious that old FS98 and FS2002 values
still lingered on in it.

I can't give you the V speeds as the aircraft is a different variant to
N324JC. I use this model because no-one has come up with a decent CJ1
version yet. Do you need more values than in the CII_ref.htm file?

bones

-----Original Message-----
From: jhb_airlines-bounce@xxxxxxxxxxxxx
[mailto:jhb_airlines-bounce@xxxxxxxxxxxxx] On Behalf Of Gerry Winskill
Sent: 16 October 2005 17:41
To: jhb_airlines@xxxxxxxxxxxxx
Subject: [jhb_airlines] Re: Autopilot APPR HOLD problem


The data supplied with the aircraft is sparse. Do you have any V numbers, from your trips?

Gerry Winskill


Bones wrote:



Initial check of the .air file shows nothing odd about it but I need to
look at it more closely in AirEd.

bones

-----Original Message-----
From: jhb_airlines-bounce@xxxxxxxxxxxxx
[mailto:jhb_airlines-bounce@xxxxxxxxxxxxx] On Behalf Of Gerry Winskill
Sent: 15 October 2005 21:55
To: jhb_airlines@xxxxxxxxxxxxx
Subject: [jhb_airlines] Re: Autopilot APPR HOLD problem


Thanks, just had a look. The panel I've been using seems the closest but is the least legible. Must start modifying one of the others. 'Ere we go again. I may be gone for some time.

Gerry Winskill


Bones wrote:





Yep - all the pictures are on the Photography page.

bones

-----Original Message-----
From: jhb_airlines-bounce@xxxxxxxxxxxxx
[mailto:jhb_airlines-bounce@xxxxxxxxxxxxx] On Behalf Of Gerry Winskill
Sent: 15 October 2005 19:35
To: jhb_airlines@xxxxxxxxxxxxx
Subject: [jhb_airlines] Re: Autopilot APPR HOLD problem


Is there a shot on your website, of the 550 in which you had a couple of jaunts? Grinds teeth loudly.

Gerry Winskill

Bones wrote:







It sounds almost as if you are talking about a totally different
aircraft to the one I fly! The C550 flown manually is a real softy
and I can fly visual circuits in it without any problem. As mentioned
on the web page I did increase aileron authority a bit because roll
rate was awful but I have otherwise made no tweaks.

The other comments you make seem more related to the autopilot
functions but I will test my version again to make sure. I've not had
any problems so far capturing speed or the glidepath.

I might just delve into the .air file because I agree that rolling
left seems faster than rolling right. This may be due to incorrect
values for the aileron ratios.

bones

-----Original Message-----
From: jhb_airlines-bounce@xxxxxxxxxxxxx
[mailto:jhb_airlines-bounce@xxxxxxxxxxxxx] On Behalf Of Gerry
Winskill
Sent: 15 October 2005 17:52
To: jhb_airlines@xxxxxxxxxxxxx
Subject: [jhb_airlines] Re: Autopilot APPR HOLD problem


I've downloaded tis aircraft, used the FS Panel Studio panel ant tried a flight. Only two comments. I think it may be a bit overpowered, since AutoThrottle couldn't reduce sufficiently quickly to stop it exceeding 240 kias, in the initial climb. Approaching IOM, it captured the Localiser very efficiently, usin APPR. From then on it was downhill. When it caught the Localiser, still below the Glideslope, and with Alt Hold still selected, it started to descend, rapidly, from the setting of 2500'. It's not the only a/c to do this. No idea why. Things then got worse. I tried to fly the ILS manually. Maintaining GS was no problem. The Localiser was a different matter, since at what I thought was a high finals speed of 120 kias, any turn to the right needed full right ailerond AND full right rudder pedal. Once the speed was taken to about 130, full aileron authority returned though, unlike the real aircraft, it still needed full deflection to initiate turns.

Gerry Winskill

gwinsk@xxxxxxx



Bones wrote:









Give me the name of this panel and I'll download it and have a hunt
around. If the autopilot is an XML file I should be able to track
down why the APPR button isn't working. OTOH if it's and old GAU
file then that's beyond my abilities as I have no C++ skills.

I've built an autopilot for the Aztec and the code is very simple.
An APPR button isn't very hard to do so I could probably add this to
the Citation if the original is faulty.

bones

-----Original Message-----
From: jhb_airlines-bounce@xxxxxxxxxxxxx
[mailto:jhb_airlines-bounce@xxxxxxxxxxxxx] On Behalf Of Mike Lucas
Sent: 15 October 2005 12:48
To: jhb_airlines@xxxxxxxxxxxxx
Subject: [jhb_airlines] Re: Autopilot APPR HOLD problem


bones

Thanks for this info, and your other reply on gauge design.  I have
no desire to enter a minefield ....

I may try a different panel with the Citation and see if I can get
APPR_HOLD to work.

Think I've got the AP autothrottle and IAS hold sussed now ... <g>

Mike L

Bones wrote:










You are walking into a minefield here Mike so it may be best to
leave well alone. I don't know anything about the panel you got for
the C550 but it would need a much closer look at the gauges
supplied to see what was included in the package and what was not.

The gauge line you quote doesn't mean a lot to me as I don't have a
fsd_generic.ap.appr.gau (it could be a CAB file too). It becomes
tricky because just because the line is in the panel.cfg file it
doesn't automatically mean the gauge itself is in your gauges
folder. Although likely I can't even say this is an APPR hold
function either. It's unusual if it is because ALL the autopilot
functions are normally contained in a single autopilot gauge.

The FS command AP_IAS_HOLD is a different beast to AP_AUTOTHROTTLE.
If you set a P8 button for the latter then (assuming the aircraft
is fitted with an AP and AT in the aircraft.cfg file) you have
access to speed control - it is, effectively, the Autothrottle Arm
function.

The AP_IAS_HOLD function is the same as the IAS button on the
autopilot panel on most aircraft. This is an engage/disengage
button but it has no effect if the Autothrottle isn't armed in the
first place. You don't need to allocate this button to a P8 switch
because it should already be programmed into the HOLD button below
the IAS/Mach rotary switch on your MCP. It's the same as the NAV
and HDG hold buttons alongside - press to engage or disengage.

So, what you should really have is the AP_IAS_HOLD command set to
the HOLD button below the IAS/Mach panel on the MCP. On the P8 you
allocate a button for the AP_AUTOTHROTTLE function. When flying the
aircraft you hit the P8 to arm the autothrottle, dial in a speed
you want and then press the HOLD button to engage.

You can mostly ignore the reference speeds in the aircraft.cfg as
they are only used in one of the FS menus - I think Weight and
Balance. They have absolutely no effect on the sim itself. The
speeds are actually the wrong way round but they are correct - the
Citation has a very low stall speed. It was intentionally designed
for slow flight as it gave the aircraft the ability to operate out
of very short strips - something no other jet is capable of. It was
an impressive feat by Cessna as the aircraft doesn't have any
complex wing devices at all, but there again it is quite a light
aircraft.

What is good about the Citation is that at 100kts the aircraft
still has excellent roll rate. It is a very nice aircraft indeed
for a pilot and doesn't really deserve its "toy jet" title from the
Lear/Falcon brigade.

bones


-----Original Message----- From: jhb_airlines-bounce@xxxxxxxxxxxxx [mailto:jhb_airlines-bounce@xxxxxxxxxxxxx] On Behalf Of Mike Lucas Sent: 14 October 2005 19:29 To: jhb_airlines@xxxxxxxxxxxxx Subject: [jhb_airlines] Re: Autopilot APPR HOLD problem


bones

I'm afraid I don't know what it is I'm looking for in the panel and
aircraft.cfg files ...

Panel.cfg contains the line -

gauge37=fsd_generic.ap.appr,  213,517,20,23

which suggests to me that there should be a working APPR_HOLD
function.

As regards the GoFlight autothrottle, I have disabled the "arm when
CMD is activated" option.  But I cannot get the IAS/Mach hold to
work








from a P8 button. The appropriate P8 light comes on but it doesn't








activate the IAS/Mach hold (yes, I have designated the correct
function in GF config).  I can only get IAS/Mach hold to work using
Ctrl+R.  Any ideas??

Going back to the Cessna Citation specifically, I found the
following in aircraft.cfg -

[Reference Speeds]
flaps_up_stall_speed=77.0      //Knots True (KTAS)
full_flaps_stall_speed=80.0    //Knots True (KTAS)
cruise_speed=262.0              //Knots True (KTAS)
max_indicated_speed=350.453125
max_mach=0.75

Surely flaps up stall speed should be higher than full flaps stall
speed?? - and I would have expected both to be 100+ kts.

Confused.

Mike L

Bones wrote:











First thing to suspect is the panel because it suggests the
autopilot gauge it uses may not be working properly. If it works
in other aircraft but not the C550 then it may be the interaction
between the panel and the aircraft.cfg file. In my copy both the
autopilot and autothrottle are flagged as available.

Check the MCP options in the GF Module. You should have two radio
buttons which enable/disable autothrottle with AP activation. I
don't actually use this myself as there are times when I want to
keep AT active when flying manually and so I have one of the T8
switches set for AT engage/disengage. This works perfectly well.
The command you want is called AP_AUTOTHROTTLE.

bones

-----Original Message-----
From: jhb_airlines-bounce@xxxxxxxxxxxxx
[mailto:jhb_airlines-bounce@xxxxxxxxxxxxx] On Behalf Of Mike Lucas
Sent: 14 October 2005 16:09
To: jhb_airlines@xxxxxxxxxxxxx
Subject: [jhb_airlines] Autopilot APPR HOLD problem


For one sector of my FPI session on Wed evening I flew the Cessna Citation by VENEAVIONES in JHB livery, with panel by Brian Williams. Unfortunately, I discovered that APPR HOLD didn't work (at EGTE). Can someone with more expertise than me in this area tell me if this is a problem somewhere in one of the config files (aircraft.cfg or panel.cfg?) that can be easily fixed?

Still coming to terms with the new GoFlight autopilot module, in
particular the apparent lack of an autothrottle arm switch.  Only
an IAS/Mach Hold and although I have configured one of my P8
buttons as A/Thr Arm it doesn't seem to activate and I have to
resort to Ctr+R
- which rather defeats the purpose of this all-singing,
all-dancing autopilot module (I can even get BBC2 on it .... <g>)

Mike L
















































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