HUD range resetting after switching from NAV to BVR mode

[holimoli]

Everytime I switch back from NAV in BVR mode the HUD range resets to 50. PRF and expected range settings stay.

 

Is this intended?

[holimoli]

up... Does nobody have an answer to this ? Can this be changed in some files somwhere? :)

[Mamba]

As long as I can recall, it's been this way. So intended I suppose.

[Hydrox]

Yes it kinda annoying to change range back everytime you switch modes, like when you are navigating (in Su-27 level flight :P), and you basically need to switch between nav and BVR mode. That is if you wanna stay on course of course. Wobbly autopilot doesn't help much either, I rather keep it off as much as I can, getting sea sick.

Edited February 18, 2016 by Hydrox

[DarkFire]

Pretty sure it's been this way since "Flanker 2.0" some 15 years ago :)

[Ironhand]

Unless it's your intention to take a general romp through your WPs, why do you need to switch out of BVR and go back to NAV in the first place? The Lateral Cross Track Error marker at the top of the HDD always points to the current selected WP and shows how far you are deviating from it (along with the HSI which also give you that info along with distance to the WP) and it automatically points toward the next WP as you pass through each one while in BVR (as does the HSI).

[holimoli]

Unless it's your intention to take a general romp through your WPs, why do you need to switch out of BVR and go back to NAV in the first place? The Lateral Cross Track Error marker at the top of the HDD always points to the current selected WP and shows how far you are deviating from it (along with the HSI which also give you that info along with distance to the WP) and it automatically points toward the next WP as you pass through each one while in BVR (as does the HSI).

 

if you want to cycle through your NAV modes for example

[Ironhand]

if you want to cycle through your NAV modes for example

I've been looking through the various control panels, etc, and I can think of no reason why only the Range Scale would reset to default--though, to be honest, that's the one controller I can't find.

 

Each switch has its "default" setting--the setting to which it should be positioned at the end of each flight. My guess is that it's simply using that convention on that particular parameter and not the rest. So probably an oversight.

[holimoli]

I've been looking through the various control panels, etc, and I can think of no reason why only the Range Scale would reset to default--though, to be honest, that's the one controller I can't find.

 

Each switch has its "default" setting--the setting to which it should be positioned at the end of each flight. My guess is that it's simply using that convention on that particular parameter and not the rest. So probably an oversight.

 

Ah!. Thanks for the information. Really appreciated. I owe you twice now ;).

 

Yes..might be an oversight..It's not that big of a deal but still needs to be fixed sometime. :)

[Ironhand]

Ah!. Thanks for the information. Really appreciated. I owe you twice now ;).

 

Yes..might be an oversight..It's not that big of a deal but still needs to be fixed sometime. :)

:) I'd feel more comfortable, if I could identify the controller. If it's a switch or knob with distinct positions then, yes, it should remain at the setting and not revert. If, however, it's a thumb switch that simply "bumps", then it would be software driven and that suggests that it would reset to default.

 

One think I do know from looking at this and some other things, people are going to have to have a lot to learn (and unlearn), if we ever have a fully implemented cockpit.

Edited February 19, 2016 by Ironhand

[DarkFire]

:) I'd feel more comfortable, if I could identify the controller. If it's a switch or knob with distinct positions then, yes, it should remain at the setting and not revert. If, however, it's a thumb switch that simply "bumps", then it would be software driven and that suggests that it would reset to default.

 

One think I do know from looking at this and some other things, people are going to have to have a lot to learn (and unlearn), if we ever have a fully implemented cockpit.

 

Looks like the DCS Su-27 flight manual is silent on the issue, but I vaguely remember reading somewhere that the range scale selection control is a rotating knob-type switch. If only I could remember where I read it. I think it may have been this forum but I'm honestly not sure, and I could be totally wrong :huh:

 

Ah, what I'd give for a DCS: Su-27 module...

[Ironhand]

...but I vaguely remember reading somewhere that the range scale selection control is a rotating knob-type switch. If only I could remember where I read it...

There's a target distance rotary on the throttle assembly. Is that what you're thinking of? Don't recall ever seeing anything in these forums concerning the range scale control. So far, haven't found reference to it in the Russian flight manual that's available online either.

 

Ah, what I'd give for a DCS: Su-27 module...

Be careful what you wish for... :)

[DarkFire]

There's a target distance rotary on the throttle assembly. Is that what you're thinking of? Don't recall ever seeing anything in these forums concerning the range scale control. So far, haven't found reference to it in the Russian flight manual that's available online either.

 

Be careful what you wish for... :)

 

Ah, that could be it, unfortunately I don't remember exactly :(

[Dudikoff]

There's a target distance rotary on the throttle assembly. Is that what you're thinking of? Don't recall ever seeing anything in these forums concerning the range scale control. So far, haven't found reference to it in the Russian flight manual that's available online either.

 

Maybe I remember it wrong, but I got the impression from the MiG-29 flight manual that these radar ranges were fixed to a specific value for each of the modes (e.g. frontal hemisphere, rear hemisphere, auto, SNP, etc.) and cannot be adjusted.

 

If that is indeed so, I'm not sure if the more advanced FCS on the Su-27 offers additional range options, but it might be the same story there (as I don't see any range options on the Su-27 HOTAS controls or the radar control panel).

Edited February 22, 2016 by Dudikoff

[karambiatos]

There's a rotary type thing on the su-27 it's used for setting the range and changing the gun funnel size.

[Bourrinopathe]

Tricky questions, and, imho, most probably a simplification as our Su-27 avionics are far from realistic compared to the real thing (as intended for a Flaming Cliffs aircraft).

 

Afaik, the scale display can (is?) controlled by the sensor mode (selected from the weapons panel (ОЛС/РЛС)).

 

 

5.1.7. Особенности работы СУВ при полном (ППО) и при неполном (НПО) приборном обеспечении.

 

СУВ обеспечивает применение УР и ВПУ в режимах:

− ППО, когда РЛПК и ОЭПС имеют полную информацию по параметрам, необходимым для решения боевых задач, при этом масштаб шкалы дальности принимает значения:

а) 150, 100, 50, 25, 10 и 5 км – при ведущем канале РЛПК;

б) 100,50,10 км – при ведущем канале ОЛС.

 

At least that's what suggests that description but I don't have the time to dig deeper.

 

The knob karambiatos is referring to is right below the "mechanical devices indicator" (gear/flaps/etc.). It's only for the target size (cannon).

 

I can't find any "scale" setting knob or rotary in the cockpit.

But if I remember correctly the expected target relative altitude is also reset to its default value if you change modes (?). That one is a knob and should not reset that easily ;)

 

 

Any reliable info about how it should work (even in the SK version) would be extremely welcome :thumbup:

Edited February 22, 2016 by Bourrinopathe

[Dudikoff]

There's a rotary type thing on the su-27 it's used for setting the range and changing the gun funnel size.

 

If I understand correctly, it's for setting the "expected target range" and definitely not for the radar range scale.

 

@Bourrinopathe: Thanks for the nice diagram posted here. Do you perhaps know what the triple position switches in the bottom row are for? The middle one is obviously for the target hemisphere modes (front, rear and auto), but I don't know what the other two do exactly? It was never discussed in that thread. The one on the right might perhaps be the search mode options, like default search, velocity search, etc.?

Edited February 22, 2016 by Dudikoff

[Ironhand]

...

Afaik, the scale display can (is?) controlled by the sensor mode (selected from the weapons panel (ОЛС/РЛС)...

According to that, the selectable ranges within the scale are determined by whether the Radar or EOS are given priority. After that, now that I'm looking at it closely, I think it's the thumb switch on the stick that controls which range within the scale is selected. I hadn't noticed until now that it appears to be self-centering. You bump it up or down and it recenters after each bump.

[Ironhand]

If I understand correctly, it's for setting the "expected target range" and definitely not for the radar range scale.

 

@Bourrinopathe: Thanks for the nice diagram posted here. Do you perhaps know what the triple position switches in the bottom row are for? The middle one is obviously for the target hemisphere modes (front, rear and auto), but I don't know what the other two do exactly? It was never discussed in that thread. The one on the right might perhaps be the search mode options, like default search, velocity search, etc.?

 

I think I have that info on my computer at work. If so, I'll pass it on, if no one has beat me to it.

[DarkFire]

Target hemisphere setting??? Is that in fact the PRF adjustment?

[Dudikoff]

Target hemisphere setting??? Is that in fact the PRF adjustment?

 

Pretty much, but I think in the real planes it also adjusts the scan bar pattern and radar range scale for the selected mode (as you cannot adjust these manually AFAIK).

Edited February 22, 2016 by Dudikoff

[Bourrinopathe]

Yes it's the PRF.

(ППС = (HPRF) high frequency (forward hemisphere (hot/closing target)) (стрельбе в переднюю полусферу))

(ЗПС = (MPRF) medium frequency (rear hemisphere (cold/receding target)) (стрельбу в заднюю полусферу))

 

@Dudikoff: I think the weapons panel switches are detailed in the Su-27SK manual. I can't remember if they're similar to what we have in the Su-27S but it should be in the chapter 5.1.5. (book 1).

I'll try to get my hand on the translation if I have the time, but I hope Ironhand will be faster than me ;)

[Ironhand]

Center switch (as already noted by others) sets the PRF

Left switch seems to have something to do with filtering out the effects of jamming.

Right hand switch is used to switch what target info is displayed on the HUD: azimuth-range or azimuth-speed

 

My problem is that my understanding of Russian is rudimentary and, then, there's the matter of interpreting the technical information. :)

Edited February 22, 2016 by Ironhand

[Bourrinopathe]

Thanks Ironhand!

 

As it's going a bit off-topic, I'll try to add these information in the "instruments" thread.

Also, remember ESAC_Mirmidon has been kind enough to share his impressive work on the Su-27SK manual translation with us.

It's in Spanish but much more comfortable than the transcripted russian version and with many notes and pictures/videos (still available >>> here <<<).

 

I think it's the thumb switch on the stick that controls which range within the scale is selected. I hadn't noticed until now that it appears to be self-centering. You bump it up or down and it recenters after each bump.

 

Are you thinking about the Б.Бой-Д.Бой switch?

(it seems to be a weapons selection switch but I found very little details about it - could it be integrated with the sensors and the range scale?)

 

Also, I don't understand that АЗ-Д-ОБН-АЗ-V switch. If I'm not mistaken the СЕИ-31 is the complete information display system (HUD and HDD mostly) and I'm wondering why there are two positions (azimuth-distance, azimuth speed) whereas we have all the information displayed simultaneously.

Well, I'm lost ^^

Edited February 22, 2016 by Bourrinopathe

[Ironhand]

...

 

Are you thinking about the Б.Бой-Д.Бой switch?

(it seems to be a weapons selection switch but I found very little details about it - could it be integrated with the sensors and the range scale?)...

That's the switch I'm referring to. So I'm most probably wrong on this.

 

Also, I don't understand that АЗ-Д-ОБН-АЗ-V switch. If I'm not mistaken the СЕИ-31 is the complete information display system (HUD and HDD mostly) and I'm wondering why there are two positions (azimuth-distance, azimuth speed) whereas we have all the information displayed simultaneously.

Well, I'm lost ^^

Well, in SCAN mode we get azimuth-range. So... But I'm coming at this piecemeal. I've begun working on this section of the manual trying to come up with a decent--none-Google/Bing type--translation.