Need help understanding The HSI

[simo1000rr]

As the title implies it , i need some help understanding the HSI needles in the Mirage . I've been flying the F15 so i know very well how the HSI work in Navigation with the CDI deviation needle and i can manage getting to the way point on the planned track . Now the HSI in the Mirage is different , at least to me . I've been trying to figure it out to no avail so i will explain my scenario and i hope someone can help.

 

im flying on the NTTR map , i contact Creech ATC to inform inbound , I set the TACAN to (87x) and i set the ILS/VOR to ( 109.5 or 109.3 not sure since im at work now ) those are the given information to the RWY, I have the ILS navigation knob on NAV. I turn the HSI knob to TAC. the HSI wide needle show me the bearing to the airport . Now how do i use the narrow needle .

[TomCatMucDe]

i m not sure if it is correctly working now. In principle it is a standard Nato thing and is very similar if not identical to the american style. I m no expert though :)

[Azrayen]

Did you look at the manual?

 

Very nice table p.81 indicating what is displayed by needles depending on various factors.

Thin needle is VOR Bearing, unless TEL mode (not implemented IIRC).

 

In principle it is a standard Nato thing and is very similar if not identical to the american style.

Really? What source supports that?

[TomCatMucDe]

Did you look at the manual?

 

Very nice table p.81 indicating what is displayed by needles depending on various factors.

Thin needle is VOR Bearing, unless TEL mode (not implemented IIRC).

 

 

Really? What source supports that?

 

I have read that somewhere, it could be unreliable, I am not giving any hard facts,

Also from reading the manual manual and trying to remember the HSI on the A10C, i found them very similar. I could be totally wrong, you can tell me :)

[jojo]

As the title implies it , i need some help understanding the HSI needles in the Mirage . I've been flying the F15 so i know very well how the HSI work in Navigation with the CDI deviation needle and i can manage getting to the way point on the planned track . Now the HSI in the Mirage is different , at least to me . I've been trying to figure it out to no avail so i will explain my scenario and i hope someone can help.

 

im flying on the NTTR map , i contact Creech ATC to inform inbound , I set the TACAN to (87x) and i set the ILS/VOR to ( 109.5 or 109.3 not sure since im at work now ) those are the given information to the RWY, I have the ILS navigation knob on NAV. I turn the HSI knob to TAC. the HSI wide needle show me the bearing to the airport . Now how do i use the narrow needle .

 

narrow needle is VOR. However it seems it doesn't work with ILS for now.

 

For ILS you have deviation needle on ADI and box in HUD if you select APP on PCA.

[IvanK]

Where in the Mir 2000C ILS system does the aircraft get ILS Localiser course info from ?

[Azrayen]

Also from reading the manual manual and trying to remember the HSI on the A10C, i found them very similar. I could be totally wrong, you can tell me :)

Well:

[TABLE] | M-2000's IDN | A-10C's HSI

HDG knob | probably no (*)|yes

HDG bug | no | yes

AP HDG index | yes | no

Course knob | no | yes

Course deviation | no | yes

Needle 1/thin | VOR / required HDG (**) | ADF / TAC

Needle 2/double | INS WPT / TAC / Sec. WPT / TGT bearing (**) | Current STP (equiv. INS WPT)[/TABLE]

 

 

(*) subject to check, I know that the left knob moves the AP HDG index in DCS now, I'm just not sure it's correct vs IRL ;)

(**) depends on mode

 

Also A-10C HSI has 2 needles (+CDI). F-15C HSI has one needle (+CDI).

 

I guess standardization is not total ;)

[Azrayen]

Where in the Mir 2000C ILS system does the aircraft get ILS Localiser course info from ?

INS.

[simo1000rr]

Did you look at the manual?

 

Very nice table p.81 indicating what is displayed by needles depending on various factors.

Thin needle is VOR Bearing, unless TEL mode (not implemented IIRC).

 

 

Really? What source supports that?

 

 

 

Yes i read the manual 2 times and i know the page you are referring to my question is ( maybe i didnt put it correctly ) how i can use the HSI to know the deviation , Like in the F15 you have a CDI needle that show you your deviation from a given course , from the deviation i can tell if im right or left of the course .

Edited January 4, 2016 by simo1000rr

[jojo]

Yes i read the manual 2 times and i know the page you are referring to my question is ( maybe i didnt put it correctly ) how i can use the HSI to know the deviation , Like in the F15 you have a CDI needle that show you your deviation from a given course , from the deviation i can tell if im right or left of the course .

 

It's not shown on HSI, you have deviation needles on ADI and and box in the HUD.

[IvanK]

INS.

 

So Localiser QDM is not manually set by the pilot for each approach ?

[jaguara5]

If you have to fly an IFR route, how do you set / observe track deviation?

Edited January 4, 2016 by jaguara5

[Azrayen]

So Localiser QDM is not manually set by the pilot for each approach ?

Why not, if need be?

Just not on the HSI.

[jojo]

If you have to fly an IFR route, how do you set / observe track deviation?

 

PCN (INS) tells you distance from track.

[simo1000rr]

It's not shown on HSI, you have deviation needles on ADI and and box in the HUD.

 

Oh so you can spot your deviation by the ADI but i can barely see a thing on the ADI plus it needs a manual for itself to understand this strange mirage ADI

[IvanK]

Why not, if need be?

Just not on the HSI.

 

So lets say you need to perform an ILS that is not also in the INS as a landing Waypoint. You Tune the ILS where do you input the Localiser course ? Its not as if you selecting a runway from an FMC type navdatabase.

[jojo]

The current landing waypoint is a workaround waiting for full INS.

 

Otherwise you enter runway threshold lat/ long/ alt/ heading/ glide slope

You set altimeter to QFE.

 

This is to have synthetic runway.

 

You can skip some parameters and you'll just have the box.

[fjacobsen]

I really expect the HSI needle and course settings to be separate.

otherwise navigation would solely rely on the INS, which I really doubt.

 

What if the INS fails, then You cannot use the VOR course deviation and DME readouts as a backup.

 

Normally You would also use VOR/DME for updating the INS on longer flights.

 

 

FinnJ

[jojo]

What do you want me to say ?

 

There is no sign in available Mirage 2000 C RDM manual of VOR/ TACAN update.

 

This is not an airliner, and as wild guess I would say INS failure is RTB case. So it's no longer time to do perfect IFR flight plan following airways.

 

TACAN and VOR needle are enough for direct "go to".

What's the relation between DME and INS ?

 

INS update are performed by waypoint overfly or waypoint radar ranging through the HUD.

[PiedDroit]

Great info in this thread :thumbup:

I'll throw my 2 cents :D

 

The current landing waypoint is a workaround waiting for full INS.

 

Otherwise you enter runway threshold lat/ long/ alt/ heading/ glide slope

You set altimeter to QFE.

 

This is to have synthetic runway.

 

You can skip some parameters and you'll just have the box.

ILS glide slope is fixed and dependent on the runway equipment, so I doubt you can enter it manually. Also not needed to display a runway.

[IvanK]

However to Fly an ILS in just about any installation in any aircraft there needs to be a way to input the Localiser course. Traditionally this is via the CSEL switch on the HSI. I would have assumed the Course set switch (+ -) knob on the lower left corner of the HSI might have been the method to input this course in the Mirage 2000.

 

I understand that the INS providing the Synthetic rwy, however their still needs to be a method to fly a Raw ILS without any refrence to the ILS. That is ILS deviation bars on the ADI without the synthetic rwy in the HUD.

 

We are not talking about INS updating just the means to display ILS data for the pilot to fly. A part of this is the requirement that the Instrument system used to fly the ILS needs tio know the inbound ILS/Localiser course. This can be provided directly by the pilot or by means of Nav data base lookup.

Edited January 4, 2016 by IvanK

[jcbak]

What is the difference between the two NAVs....Cm, Cv......The chart in the manual indicates they basically provide the same information.

[Azrayen]

I really expect the HSI needle and course settings to be separate.

otherwise navigation would solely rely on the INS, which I really doubt.

 

What if the INS fails, then You cannot use the VOR course deviation and DME readouts as a backup.

 

Normally You would also use VOR/DME for updating the INS on longer flights.

 

 

FinnJ

 

Hi

 

I guess you're puzzled by a translation issue.

 

What we call, here in this topic, "the INS" is in fact the PCN (Poste de Commande Navigation - Nav control panel) / UNI (Unité de Navigation Inertielle / Inertial Navigation Unit).

 

Of course it manages the INS, but not only. If the inertial part of the system fails, the PCN still can be used for other features.

If you set the PCN to CP/PD you may vizualize/enter the "CP" (Cap Piste, Runway Heading) and "PD" (Pente Désirée / Desired Glideslope).

 

If the PCN (UNI) totally fails, you have no more Nav on the IDN (HSI).

 

What is the difference between the two NAVs....Cm, Cv......The chart in the manual indicates they basically provide the same information.

Cm = Cap magnétique / magnetic heading

Cv = Cap vrai / true heading.

 

++

Az'

[simo1000rr]

What is the difference between the two NAVs....Cm, Cv......The chart in the manual indicates they basically provide the same information.

 

as far as i know and someone can correct me that Cm is magnatic compass while the other one is the true compass i might be wrong though

[Dingo_Bob]

So far I've been using it as follows,

 

Set waypoints in ME

once setup and in the pit airbourne, select my WP on the INS/PCN, climb to altitude, turn to direction of waypoint, activate Autopilot / Altitude hold and use the Course set switch (+ -) to line up the arrow on the outer ring with the red divation arrow, AP will bank the aircraft and turn to set course and hold on the set direction until waypoint is reached, then adjust to next WP as needed, check out vid below

 

${1}

 

I've been tryng to follow VOR but the thin white neelde doesn't seem to want to point to the correct VOR direction to what is on the maps of NTTR

for example VOR 109.8 needle will fly you north east out from Nellis, unless I was doing something wrong

Edited January 4, 2016 by Dingo_Bob