Mercure LNAV Mode?

[Lima]

Hi HJG Dassault Mercure Support Team,

I just wanted to know if there is an LNAV Mode that can be engaged in the Mercure, because I fly this wonderful airplane online (IVAO) and it flies pretty darn good except that I need fly the plane on course to the destination on HDG Mode, I have been reading the documentation but cannot seem to solve my issue, anyway will appreciate your help.



Regards,

Lima

[aerofoto - HJG Admin]

It's all represented there .... both V anf L NAV .... and both are fully functional.

Refer to section "2.01: MAIN PANEL - AP MODE CONTROL PANEL" of our following linked forum based online manual for the MERCURE ....


tonymadgehjg.proboards.com/thread/8797/amd-mercure-installation-handling-notes


The entirety of "SECTION 4" .... and in particular the following 2 sections ....

- 4.03: CLIMB TO CRUISING ALTITUDE - AP MANUAL MODE

- 4.03-A: CLIMB TO CRUISING ALTITUDE - ALTERNATIVE PROCEDURE - AP IAS/MACH MODE


.... should explain everything more than adequately too .... especially if studied in conjunction with the above mentioned "SECTION 2.01"

Mark C
AKL/NZ

[Lima]

Thank you Mark for your response I will be checking that out on my next flight from Toulouse To Marseille   

[mariopilot - HJG Guest]

Hello,

Sorry for not popping around here more often... been busy...!

The real thing was never equipped with a FMS, therefore it can fly either on HDG (PSH) or VOR LOC mode. At the moment, the way the autopilot is programmed prevents any external program from controlling the HDG variable. Perhaps such a functionality could be implemented for a future release...

[bjoern]

VOR/LOC mode should be just fine when coupled with a GPS and the default NAV/GPS functionality set to "GPS".

[Dale Moore]

Mario
Thanks for the efforts you've put into such a realistic model. I've tried hard to force the hdg setting by an external FMC but to no avail. Your post explains the reason. Like Lima suggests, the use of FMC entered waypoints makes flying online much simpler Be really good if a future upgrade could support external heading control
Best regards
Dale

[Lima]

Oops been busy this week and unable to see updates on my posts here, Spot on Dale, I have been doing the same thing but it would not budge perhaps I should try using CIVA anyway, I having been trying to fly the plane using the VOR/LOC mode of the auto pilot as mentioned in the manual, it works but sometimes the plane locks on to it, diverts away from it and sometimes it simply does not detect the VOR, perhaps it could be the distance from the VOR also setting up the course helps it but not for long, even flicking the NAV to GPS on the GPS panel does not force the plane to fly to the VOR or waypoints sadly. My flight's departure airport is Nice LFMN Airport, France and the destination is Montpellier Airport LFMT,France , The VORs I fly to are:

AZR (109.65) (It locks on to this VOR but by the time I lift off I have to switch to the next VOR)
ADC (109.25) (This VOR is not registered in my FS9 Nav Database so I fly to the next VOR)
NIM (111.60) (It did not detect this VOR)
FJR (114.45) (Not even this one I think)

So if some of you could fly this route in FS9 let me if know if you get the type of result,
Regards,
Lima

[Lima]

Edit: It does detect the VOR but It only gives a DME reading and no direction

[paracetamol]

Lima: NIM is a DME-only station so you'll get distance reading but no directional information.

Cheers,
Salvador

[aerofoto - HJG Admin]

NIM is a DME-only station so you'll get distance reading but no directional information

Another thing to bear in mind also is .... "IN FS" the major VOR stations only have a DME range of up to "194 miles" at the very most .... and some (like TISX in the Caribbean) have far less DME range than this


ANYWAY .... AND IF I AM UNDERSTANDING THIS THREAD CORRECTLY ....


I've just performed another MERCURE test flight this morning .... with the simulation having been set up in accordance with its "READY TO GO" scenario.

I flew an overland VOR to VOR route from KSEA to KLMT (around 300-400 miles .... using the simulations AP HDG and AP VOR/LOC modes throughout the entire route .... and here is what I can report ....

I experienced no difficulty intercepting any pre-selected VOR radial .... HOWEVER .... I did observe a constant, but, "v-e-r-y v-e-r-y s-l-o-w" tendency for the simulation to drift left and right over the intercepted/captured VOR radial (by up to 3-4 degrees or so either side) throughout most of the flight .... but .... it did "always" recross the previously intercepted/captured VOR radial during each cycle of this drift and which would be of approximately 10 minutes duration either side.

Although the simulation would not settle/stabilize upon the intercepted VOR radial .... I considered the observed drift to be "minor" (it was experienced during testing, but, didn't seem, to me, to be much and it therefore didn't bother me) .... since it is probably not completely out of order in regard to the replication of any late 1960'/early 1970's era navigation system .... otherwise I would have mentioned it within the "KNOWN ISSUES" section of the manual (which I may yet do as an update/NOTAM later on).

During these minor drift cycles .... if AP VOR/LOC mode was cancelled .... and AP HDG mode then engaged .... the desired course could "e-a-s-i-l-y" be adjusted (using HDG SEL) so as to re-align the simulation with, and maintain, the indicated VOR radial .... and it would then maintain the displayed course very well and with only v-e-r-y m-i-n-o-r adjustments to track being necessary in order to stay on the indicated VOR radial.

However .... and much further down the VOR track (more than 100 DME from the point of departure) .... and by this time still using the AP HDG mode .... "IF" the AP VOR/LOC mode was then re-engaged (as a means of trying to recapture and maintain the indicated VOR radial) .... then the simulation would intercept the VOR radial, but, the "v-e-r-y v-e-r-y s-l-o-w" drift cycle/s would recommence once again, but, this could by this stage result in drift of up to 10 degrees left and right of the intercepted VOR radial .... and which I acknowledge "IS" a little more disconcerting, but still, not a problem "IF" one is alert as to what's going on (and knows how to navigate manually by estimating and compensating for drift) .... and then manually adjusts the course as required.

This should be far less of any issue given the maximum 194 DME range of most FS VOR's .... and which should see one well within range of the next VOR navigation aid within a very short period.

There "probably is" a m-i-n-o-r gauge, or AP NAV FDE issue (or a combination of both) to be reconciled .... if Mario cares to revisit this .... "when he can"

In the meantime my recommended course of action is as follows :-


1. Use AP HDG mode to navigate to, and intercept, any desired VOR radial .... as normal.

2. Upon intercepting the selected VOR radial .... cancel AP HDG mode .... and engage AP VOR/LOC mode .... as normal.

3. "IF" drift becomes "a problem" (it shouldn't though) .... then cancel AP VOR/LOC mode .... re-engage AP HDG mode .... and then manually adjust heading to align the simulation with the indicated VOR radial and be prepred to make further very minor adjustments to stay on track..

4. Stay within VOR1 and VOR2 range along any route.


This will be necessary "until a permanent fix is devised".

Again .... the perceived issue shouldn't be any major problem "IF" one knows what they're doing/how to navigate, stays alert, adjusts/compensates for the drift, and stays within the range of 2 VOR aids.

There are no problems, at all, with either VOR1 and VOR2 indications .... but ... bear in mind some of these have different ranges and not all are DME featured.

Remember also .... the MERURE is "a short to medium range aircraft" suitable for trans-European overland sectors. It is not an over water/trans-oceanic aircraft (it simply doesn't have the range) .... so .... route planning in order to stay within continental VOR range is essential.

These are my recommendations .... "for the moment" .... and how I (personally) fly this simulation.

Incidentally .... I never use the FS GPS auto-navigation system (too easy and boring for me I'm afraid) .... and I understand it is not represented within this MERCURE simulation anyway.

Mark C
AKL/NZ

[Lima]

Salvador: Oh thanks for info didn't realize that no wonder why.

Thanks Mark for the explanation, I know know the Mercure does not have any major problems it's just my problem navigating it around however will keep practicing though.

[bjoern]

I can confirm the oscillation around the station signal for the FSX version of the Mercure.


With a bit of background knowledge, trial&error and patience, one may modify the autopilot behavior in NAV mode in the aircraft.cfg. The relevant parameters are:

nav_proportional_control = 15 //21
nav_integrator_control = 0.7 /1.1
nav_derivative_control = 0.01 //0.01
nav_integrator_boundary = 0.5 //0.5
nav_derivative_boundary = 0.35 //0.35

An explanation of the parameters can be found here: msdn.microsoft.com/en-us/library/cc526949.aspx#mozTocId942782 (scroll down)

For a bit of information about PID controllers: en.wikipedia.org/wiki/PID_controller

[Lima]

Thanks Bjoern will be checking those links out not sure if I can do the editing cause I am not so patient , but will definitely read up about it

[aerofoto - HJG Admin]

Just be careful posting CFG edits.

"WE" (meaning Mario and myself .... plus HJG's other primary testers too) need to check these .... then sign off on them "OUSELVES" .... otherwise if everyone starts pasting untested/unproven data to their CFG's then they're possibly at risk of making things worse for themselves ..... and others too .... and we don't want to destroy the integrity of a good simulation of course

The minor AP VOR/LOC drift issue (described with my report above) could well be resolved per CFG editing .... BUT .... not if there is any issue within the HSI gauge itself that needs fine tuning .... and which is something we have seen here recently, and fixed, with another yet to be released simulation.

I'll have a chat with Mario ....as son as I have time to do so .... and we'll take it from there.

Bear with us please .... and don't expect a prompt resolution for the moment .... we will get back to you though ASAP

ALSO .... earlier within this thread someone mentioned the possibility of installing the CIVA INS NAV system. That's fine .... and may work .... if people wish to do that .... BUT .... if people do this then kindly understand the CIVA INS "is not" an HJG offering so we "do not/cannot" provide technical support for it

Mark C
AKL/NZ

[bjoern]

Jan 19, 2018 19:23:42 GMT aerofoto - HJG Admin said:

Just be careful posting CFG edits.

"WE" (meaning Mario and myself .... plus HJG's other primary testers too) need to check these .... then sign off on them "OUSELVES" .... otherwise if everyone starts pasting untested/unproven data to their CFG's then they're possibly at risk of making things worse for themselves ..... and others too .... and we don't want to destroy the integrety of a good simulation of course

The minor AP VOR/LOC drift issue (described with my report above) could well be resolved per CFG editing .... BUT .... not if there is any issue within the HSI gauge itself that needs fine tuning .... and which is something we have seen here recently, and fixed, with another yet to be released simulation.

I'll have a chat with Mario ....as son as I have time to do so .... and we'll take it from there.

Bear with us please .... and don't expect a prompt resolution for the moment .... we will get back to you though ASAP

Mark C
AKL/NZ

I feel a bit offended now.
First, the value were straight from Mario's Aircraft.cfg.
Second, anyone can configure aircraft to their liking and posting the data is always done under the assumption of personal preference. Nobody is forced to use anything.
Third, why do you assume that people outside of the HJG team don't know what they are doing or can't come up with improvements themselves?



On that matter, here are my personal improvements to the Mercure:
- Pitch and roll stability increased (personal preference, also helps autopilot stability)
- More robust autopilot vertical modes (IAS hold now uses pure pitch trim instead of AP pitch hold, Mach hold above FL290, ALT Hold, ALT Sel)
- More robust fallback to AP pitch/HDG hold
- "F/S" indicator on ADI now used for target speed deviation or longitudinal acceleration if not on autothrottle (helps holding forward velocity)
- Panel load/save now done per livery via LOGGER (FSX/P3D only)
- No more absolute paths for the cockpit sounds (the aircraft may be installed in any folder now)
- Fuel system code revised (accounting for center tank pumps with a higher operational pressure)
- More robust engine starter code (no more flip-flopping starter when starting in flight)
- Running the APU now uses actual fuel (majority from the left wing tank, minority from the center or center and right tank, when using crossfeed; FSX only)
- Keyboard controls for the spoilers

These will be run by Mario, of course, but in case some of these won't make it into an update, the world will be regardlessly graced by their presence as what they are - optional enhancements.