[jhb_airlines] Re: Autopilot APPR HOLD problem

  • From: "Bones" <bones@xxxxxxx>
  • To: <jhb_airlines@xxxxxxxxxxxxx>
  • Date: Sat, 15 Oct 2005 20:43:30 +0100

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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