Instrument Only Flying in Su33

Hi all, as I'm getting more hours flying the Su33 I've been paying close attention to the coordination of instruments in following the waypoints. Specifically I'm watching the syncing of the Attitude Direction Indicator, Horizontal Situation Indicator and the HUD Navigation Mark. Sometimes it seems the HUD Navigation Mark doesn't point me in the same direction as the other 2 when I'm flying waypoints, so they seem out of sync. If I only fly to the HUD Nav Mark I don't remain nearly on course. Also, it looks like the ILS bars on the Horizontal Situation Indicator don't move as the manual says they should.

I'm wondering if this is because the Su33 module is still a beta release or am I misunderstanding the instruments, which is entirely possible :helpsmilie:

Hi all, as I'm getting more hours flying the Su33 I've been paying close attention to the coordination of instruments in following the waypoints. Specifically I'm watching the syncing of the Attitude Direction Indicator, Horizontal Situation Indicator and the HUD Navigation Mark. Sometimes it seems the HUD Navigation Mark doesn't point me in the same direction as the other 2 when I'm flying waypoints, so they seem out of sync. If I only fly to the HUD Nav Mark I don't remain nearly on course. Also, it looks like the ILS bars on the Horizontal Situation Indicator don't move as the manual says they should.

 

I'm wondering if this is because the Su33 module is still a beta release or am I misunderstanding the instruments, which is entirely possible :helpsmilie:

Just took a quick run through a number of WPs both with and without wind as well as a landing at Mozdok. Everything seems OK. The ADI, flight director circle (HUD Nav Mark?), HUD heading mark, HSI, and lateral cross-check error mark on the HDD all seemed to work in synch. So I'm not sure of what you're seeing. Can you provide an example?

The HSI ILS bars work as advertised. But they only work on runways that support PRMG landings which is part of the navigation system the Su-27/33 use. Both runways at Mozdok do and a few other runways elsewhere as well. They're the ones whose ILS information are in blue font rather than white on the mission map. Also be aware that they do not become active until you are 7.5 km from the threshold. For all other runways you'll need to rely on the flight director circle.

EDIT: I think I know what you're referring to in regards to the HSI glideslope indicators, if you're referring to its use in carrier landings. Yes, there comes a point close to the carrier where you can no longer trust it (or there used to be at least-haven't tested recently). I've never tested it further but I think it has to do with the landing offset and/or how fast the carrier is moving. I'm not convinced it's a bug. Landing on a PRGM runway, however, there are no issues.

Does the 33 need time for the HSI to stabilize before moving the plane?

Does the 33 need time for the HSI to stabilize before moving the plane?

Not that I've ever noticed.

Specifically I'm watching the syncing of the Attitude Direction Indicator, Horizontal Situation Indicator and the HUD Navigation Mark. Sometimes it seems the HUD Navigation Mark doesn't point me in the same direction as the other 2 when I'm flying waypoints, so they seem out of sync. If I only fly to the HUD Nav Mark I don't remain nearly on course. Also, it looks like the ILS bars on the Horizontal Situation Indicator don't move as the manual says they should.

When you say 'HUD Nav Mark' I'll take it you're referring to the director circle (and not the heading tick on the compass at the top).

In ENROUTE mode the director circle (and the yellow needles on the ADI) tell you which way to fly to get back on the desired track - not to the actual waypoint itself.

If you look at this MFD picture...

....you can see Waypoint 1 is a just a couple of degrees off dead ahead.

But looking at the ADI and HUD director circle....

....we see them telling us to veer off to the right.

What's happening is the aircraft is directing us to intercept the track that connects the waypoints, not the actual waypoint - and depending on the aircraft's location the interception angle can be pretty extreme :)

Also note how the angle of HSI course needle corresponds with the track line on the MFD.

A possible bug I did find is that the flight director on the 33 and the 25T are out of alignment by about 20m altitude.

Here's the 25T at 20m below the track altitude and still asking us to go lower....

Here's the 33 at the exact track altitude asking us to go lower...

Interesting discussion!

What's happening is the aircraft is directing us to intercept the track that connects the waypoints, not the actual waypoint - and depending on the aircraft's location the interception angle can be pretty extreme :)

 

That's the biggest problem, as the autopilot tries to fly to the track as well, rather than the desired heading towards the waypoint. This is especially bad when having the autopilot fly the transition from the RET leg to the LDG leg.

I believe in the real 27/33 - just like the DCS Ka-50 does - you can tell the autopilot to fly either desired heading or desired track. Would be nice if this could be added to the 27/33 as well.

I believe in the real 27/33 - just like the DCS Ka-50 does - you can tell the autopilot to fly either desired heading or desired track. Would be nice if this could be added to the 27/33 as well.

We can dream!

...In ENROUTE mode the director circle (and the yellow needles on the ADI) tell you which way to fly to get back on the desired track - not to the actual waypoint itself...

Good catch. For some reason, that being the issue never occurred to me.

...

 

I believe in the real 27/33 - just like the DCS Ka-50 does - you can tell the autopilot to fly either desired heading or desired track. Would be nice if this could be added to the 27/33 as well.

The Su-27 can, so I imagine the Su-33 can as well. Wouldn't it be nice!

Just took a quick run through a number of WPs both with and without wind as well as a landing at Mozdok. Everything seems OK. The ADI, flight director circle (HUD Nav Mark?), HUD heading mark, HSI, and lateral cross-check error mark on the HDD all seemed to work in synch. So I'm not sure of what you're seeing. Can you provide an example?

 

The HSI ILS bars work as advertised. But they only work on runways that support PRMG landings which is part of the navigation system the Su-27/33 use.

Ironhand? Wow, I remember you from the old Flanker mailing list days in the '90's. I learned a lot over the years reading your posts...glad to see you're here :smilewink:

1) The Su-33 manual HUD section calls it both a "Navigation Mark" and "Director circle" so, yes we're both talking about the same circle.

2) Lixma provided the screen shots which are exactly the same thing's I'm seeing.

3) That explains my ILS bar question. I was flying a mission into Gelendzhik which doesn't have a beacon. I'll try flying into a fully equipped airfield. Thanks!

When you say 'HUD Nav Mark' I'll take it you're referring to the director circle (and not the heading tick on the compass at the top).

 

In ENROUTE mode the director circle (and the yellow needles on the ADI) tell you which way to fly to get back on the desired track - not to the actual waypoint itself.

Yes! Your screenshots are exactly what I'm seeing :thumbup:

I've been flying Flanker since the DOS days (though DCS only about a month.) With the super high cockpit resolution I now get, I wanted to see if I could complete a simple flight (hopping from one airfield to another) only looking down at my instrument panel - taking no visual clues from the front windscreen. Another tougher version of this mission would be flying at night with a malfunctioning HDD.

These instrument inconsistencies make me wonder if it's really possible to complete that type of mission? Is that something others have tried successfully?

Thanks :pilotfly:

I've been flying Flanker since the DOS days (though DCS only about a month.) With the super high cockpit resolution I now get, I wanted to see if I could complete a simple flight (hopping from one airfield to another) only looking down at my instrument panel - taking no visual clues from the front windscreen. Another tougher version of this mission would be flying at night with a malfunctioning HDD.

 

These instrument inconsistencies make me wonder if it's really possible to complete that type of mission? Is that something others have tried successfully?

 

Thanks :pilotfly:

In the past I've done loads of instrument only flying and landing in the Su-25T with my view zoomed in on just the ADI, altimeter, speedo, and VVI. It's very scary but the instruments, particularly the ADI are incredibly accurate - you just have to trust what they're telling you.

These days you may also need to take a peek at the flaps/airbrakes indicator as you can no longer hear them being deployed.

...

 

These instrument inconsistencies make me wonder if it's really possible to complete that type of mission? Is that something others have tried successfully?

 

Thanks :pilotfly:

It's a matter of understanding what they're telling you. You could do it completely from the HUD cues. Or keep your head down and use the gauges. It's just a matter of understanding what each instrument is telling you. They are either pointing directly toward the waypoint itself or toward the scheduled courseline. But each part does its job consistently. It's not doing one thing at first and then suddenly switching to the other. The director circle, for instance, is always steering you to the courseline.

EDIT: Lixma got there before me.

These days you may also need to take a peek at the flaps/airbrakes indicator as you can no longer hear them being deployed.

Yes, not to mention the inoperable lamp for the airbrake :( I have to pull back my view to the throttle to see if the switch is pushed forward or back...

The HSI ILS bars work as advertised. But they only work on runways that support PRMG landings which is part of the navigation system the Su-27/33 use. Both runways at Mozdok do and a few other runways elsewhere as well. They're the ones whose ILS information are in blue font rather than white on the mission map. Also be aware that they do not become active until you are 7.5 km from the threshold. For all other runways you'll need to rely on the flight director circle.

I've been trying landings at Mozdok and I'm not getting any movement on the ILS bars. I've gone through the ATC Tower/Mozdok/Inbound comms to request landing and have been successfully told to land, yet the ILS bars still don't move on final approach. Here's a couple screenshots showing me off course in NOC mode within 4.8 Km. Shouldn't the ILS bars be showing how far off I am?

Also I'm curious why the Su33 DCS NOC mode doesn't show the ILS bars on the HUD like the old LOMAC/FC NOC mode below? I'm guessing it's more in line with the actual way the Su33 operates?

The inverted L on the HUD indicates you are receiving ILS data so you're (just) within the beam but you are way off to the side so that's why the ILS bars on your HSI appear caged.

I've just tried Mozdok to check and the ILS bars seem OK...

The inverted L on the HUD indicates you are receiving ILS data so you're (just) within the beam but you are way off to the side so that's why the ILS bars on your HSI appear caged.

 

I've just tried Mozdok to check and the ILS bars seem OK...

 

Got it...I've just gotten the bars to work for Mozdok & Krymsk. Guess I was spoiled in LOMAC where the bars showed up on the HUD for every airfield & Kuznetsov :doh:

Thanks!

Additional: Very odd but no matter how I try I can't get the inverted L lock on and ILS bars for Krasnodar-Central & Maykop, only Mozdok & Krymsk :huh:

...

Additional: Very odd but no matter how I try I can't get the inverted L lock on and ILS bars for Krasnodar-Central & Maykop, only Mozdok & Krymsk :huh:

Here are the runways with the PRMG system and two good tutorials by DigitalEngine:

https://forums.eagle.ru/showpost.php?p=3189217&postcount=2

Thanks Ironhand. Watched both vids and d'loaded Chuck's L-39 guide which has an excellent and highly detailed section on "Navigation & ILS Landing" :thumbup:

Thanks Ironhand. Watched both vids and d'loaded Chuck's L-39 guide which has an excellent and highly detailed section on "Navigation & ILS Landing" :thumbup:

Excellent. You probably have a better handle on it now than I do.

ILS bars work on approaching Kuznetsov

Very happy to report that the ILS bars were activated and operating when landing on the Kuznetsov!!! At 14 Km out the inverted "L" appeared on the HUD and at 4Km the ILS bars activated. Of course I blew up on a deck strike anyway, but hey, practice makes perfect :thumbup:

Excellent. You probably have a better handle on it now than I do.

I'm not sure about that, but I know more today than I knew yesterday and that's always a good thing :book::smilewink: