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Landing Russian Birds with AoA


Steinsch

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Hi pilots,

 

I've been become quite proficient at landing the A-10A & C, the F-15 and the Mirage 2000. My approaches are based on respective ideal AoA for landing.

 

I've been recently playing with the Su-25T and Su-27 and manage to land them thanks to their version of ILS. However, it's rarely pretty, and I'd like to know the proper procedure for landing these birds that relies on AoA, not speeds (which varies according to weight). The absence of the FPM is also disturbing. Is there a way to overcome that obstacle?

 

Thanks!

Steinsch

Flying Virtual F-15s since 1989

YouTube channel: http://www.youtube.com/c/CommanderSteinsch

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I can't speak for the Su-25T as it's been months since I flew the thing.

 

As far as the Su-27 is concerned, it's not about the AOA, it's about the glide slope and sink rate. Obviously AOA, speed, sink rate and the glide slope angle are all synergistic, but the designated 3-degree glide slope (i.e. nose angle of +3 degrees) should give you the desired sink rate of 5 m/s at the correct speed and distance from the runway threshold. On finals your speed will be in the region of 270 - 310 Km/h depending on conditions and your landing weight.

 

In pure aerodynamic terms the AOA doesn't really matter as you'll never run up against the AOA limiter (if you do so whilst landing, you have bigger concerns) but practically you do need to keep the aircraft at a maximum of 14 degrees AOA otherwise you'll scrape the tail on landing.

 

The manual says that the maximum permitted landing weight is 21-23,000 Kg. You can go quite a bit above this but you have to flare rather aggressively and be very careful about your sink rate.

 

Attached is an example landing. I was fairly consistently too high and a bit fast but both are easily correctable. Not bad considering that was the first time I've flown in a couple of weeks :D

 

Edited to add: not having a flight path marker won't bother you... eventually. It's disconcerting at first but eventually you'll get a feel for what the aircraft is actually doing and you won't need a FPM to tell where the plane is actually going.


Edited by DarkFire

System Spec: Cooler Master Cosmos C700P Black Edition case. | AMD 5950X CPU | MSI RTX-3090 GPU | 32GB HyperX Predator PC4000 RAM | | TM Warthog stick & throttle | TrackIR 5 | Samsung 980 Pro NVMe 4 SSD 1TB (boot) | Samsung 870 QVO SSD 4TB (games) | Windows 10 Pro 64-bit.

 

Personal wish list: DCS: Su-27SM & DCS: Avro Vulcan.

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If by FPM you mean decent rate in feet per minute, well the Flanker is organized in metric so it gives readout in m/s both on the vertical velocity indicator and the ascent/decent rate display on the right side of the HUD.

 

If that's a typo for PFM (professional flight model), then be aware that the Su-27, Su-25, and Su-25T have fully developed aerodynamic models, while the Mig-29 and Su-33 do not.

Callsign "Auger". It could mean to predict the future or a tool for boring large holes.

 

I combine the two by predictably boring large holes in the ground with my plane.

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Hi pilots,

 

I've been become quite proficient at landing the A-10A & C, the F-15 and the Mirage 2000. My approaches are based on respective ideal AoA for landing.

 

I've been recently playing with the Su-25T and Su-27 and manage to land them thanks to their version of ILS. However, it's rarely pretty, and I'd like to know the proper procedure for landing these birds that relies on AoA, not speeds (which varies according to weight). The absence of the FPM is also disturbing. Is there a way to overcome that obstacle?

 

Thanks!

 

It may sound dumb and "cliche", but practice is all you need to get used to flying without the Flight Path Marker (FPM) and find visual cues that work for you. Like other mention, on Russian FC3 aircraft, you have to pay a bit more attention to weight, speed and vertical velocity while western aircraft, normally you can use the AOA with FPM. In Russian aircraft in DCS, the AOA is present on the gauge only but not on the HUD. On the HUD you will commonly see Pitch angle, vertical velocity, etc. (page 47 to 50 on the SU-27 manual for example). There is a plethora of videos online that might help as well.

 

I think is funny when you write;

The absence of the FPM is also disturbing.

Reading article like "Semper Viper", it seem most pilots in RL did not like the FPM idea when first came out and distrust it in aircraft like the A-7 and F-16. But how many pilots have flown how many aircraft without it? :joystick::D You will do find without FPM.

To whom it may concern,

I am an idiot, unfortunately for the world, I have a internet connection and a fondness for beer....apologies for that.

Thank you for you patience.

 

 

Many people don't want the truth, they want constant reassurance that whatever misconception/fallacies they believe in are true..

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Thanks guys.

 

MVS, you're right, practice is key. It took me a while to master VFR landings with Western aircraft in DCS. I understand the FPM is just a visual aid, and should not replace our visual sense. I used to land an old Cessna Skyhawk just fine, but it's also because I knew the beast.

It's just that it feels strange flying a jet without an FPM now (been using it since the late 80's in earlier "sims").

I tried to watch YouTube videos about landing with the Su-25T, but a lot of them were half-baked unaligned landings with wide variations of sink rates punctuated by "Hooray, see, I didn't die so I'm good!". The video recommended by Kunz has been however helpful and I'll keep practicing my visual references and learning proper descent rates and speed.

 

Thanks again.

Steinsch

Flying Virtual F-15s since 1989

YouTube channel: http://www.youtube.com/c/CommanderSteinsch

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The trick is to keep the runway threshold in the lower third of the HUD allowing it to slowly drop to the middle of that lower third as you close with the runway controlling your speed and sink rate. Here's a track (which will hopefully play back correctly) using the Su-27 and, after intercepting the IAP, switching to the general pilotage HUD to reduce the HUD clutter. Shortly before touching down, I'm still a little high and you'll see me adjust slightly with pitch and airspeed. You'll see the changes in the view through the HUD.

YouTube Channel: https://www.youtube.com/channel/UCU1...CR6IZ7crfdZxDg

 

_____

Win 10 Pro x64, ASUS Z97 Pro MoBo, Intel i7-4790K, EVGA GTX 970 4GB, HyperX Savage 32GB, Samsung 850 EVO 250 GB SSD, 2x Seagate Hybrid Drive 2TB Raid 0.

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...I noticed the flare was a bit early. Maybe a bit more thrust to reduce the rate of descent would have landed you right on the threshold?...

:) That's how I fly first thing in the morning on too little coffee... There were a number of errors but nothing insurmountable. The biggest problem was that I was still a bit high too close to the runway and had to adjust. I should have noticed it sooner. Then everything would have worked like clockwork-more or less.

 

Not that it matters in the sim but you'd get written up, if this bird's main gear touched down at speeds in excess of 280 km/h. For the nose gear it's 270 km/h. The issue is excessive tire wear at higher landing speeds, of course, not that you'd instantly break the airplane.

YouTube Channel: https://www.youtube.com/channel/UCU1...CR6IZ7crfdZxDg

 

_____

Win 10 Pro x64, ASUS Z97 Pro MoBo, Intel i7-4790K, EVGA GTX 970 4GB, HyperX Savage 32GB, Samsung 850 EVO 250 GB SSD, 2x Seagate Hybrid Drive 2TB Raid 0.

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I think I'm starting to get the hang of it. What do you think?

I won't be able to view it until tomorrow morning. Looking forward to it. :)

 

But it's easy to tell how you're doing. If you can land softly making only small measured adjustments to speed and pitch (assuming no extreme weather to contend with) on the way down to the runway, you're doing it right.

YouTube Channel: https://www.youtube.com/channel/UCU1...CR6IZ7crfdZxDg

 

_____

Win 10 Pro x64, ASUS Z97 Pro MoBo, Intel i7-4790K, EVGA GTX 970 4GB, HyperX Savage 32GB, Samsung 850 EVO 250 GB SSD, 2x Seagate Hybrid Drive 2TB Raid 0.

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I think I'm starting to get the hang of it. What do you think?

 

Very nice landing. Speed, descent rate & altitude were all very good.

 

One thing you'll notice about the Su-27 is that if you're established on a good glide slope it's entirely possible to fly the final approach and touch down using only the trimmer, i.e. stick neutral.

System Spec: Cooler Master Cosmos C700P Black Edition case. | AMD 5950X CPU | MSI RTX-3090 GPU | 32GB HyperX Predator PC4000 RAM | | TM Warthog stick & throttle | TrackIR 5 | Samsung 980 Pro NVMe 4 SSD 1TB (boot) | Samsung 870 QVO SSD 4TB (games) | Windows 10 Pro 64-bit.

 

Personal wish list: DCS: Su-27SM & DCS: Avro Vulcan.

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Thanks.

 

Yes, the trim. That's actually what I'm trying to do with every plane. Pitch controlled with trim to achieve a certain AoA, and then descent rate controlled with throttles. It works great with the F-15 and the A-10, and it seems to work with the Flanker, but I still have trouble with the Su-25. Practice, practice, practice!

 

By the way, does anyone know if it's possible to reduce the sensitivity of trim?

Steinsch

Flying Virtual F-15s since 1989

YouTube channel: http://www.youtube.com/c/CommanderSteinsch

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Thanks.

 

Yes, the trim. That's actually what I'm trying to do with every plane. Pitch controlled with trim to achieve a certain AoA, and then descent rate controlled with throttles. It works great with the F-15 and the A-10, and it seems to work with the Flanker, but I still have trouble with the Su-25. Practice, practice, practice!

 

By the way, does anyone know if it's possible to reduce the sensitivity of trim?

 

I desperately wish it was possible to adjust the sensitivity of trim, because this is the one issue I still have with the Flanker, but apparently it's fixed :(

System Spec: Cooler Master Cosmos C700P Black Edition case. | AMD 5950X CPU | MSI RTX-3090 GPU | 32GB HyperX Predator PC4000 RAM | | TM Warthog stick & throttle | TrackIR 5 | Samsung 980 Pro NVMe 4 SSD 1TB (boot) | Samsung 870 QVO SSD 4TB (games) | Windows 10 Pro 64-bit.

 

Personal wish list: DCS: Su-27SM & DCS: Avro Vulcan.

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I think I'm starting to get the hang of it. What do you think?

 

Had a chance to view it this evening. I agree with DF...very nice landing. :)

 

As far as trim is concerned, it reacts to how long you "press". So a shot little bump yields less trim input. But even so, you usually find yourself having to take up a little of the slack with either a slight hand on the stick or a bit of throttle input.

YouTube Channel: https://www.youtube.com/channel/UCU1...CR6IZ7crfdZxDg

 

_____

Win 10 Pro x64, ASUS Z97 Pro MoBo, Intel i7-4790K, EVGA GTX 970 4GB, HyperX Savage 32GB, Samsung 850 EVO 250 GB SSD, 2x Seagate Hybrid Drive 2TB Raid 0.

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I tried to watch YouTube videos about landing with the Su-25T, but a lot of them were half-baked unaligned landings with wide variations of sink rates punctuated by "Hooray, see, I didn't die so I'm good!".

 

:D:smartass: Hey don't dismiss mediocre flying, it work for me 60% of the time all the time. Tracks from open beta.

To whom it may concern,

I am an idiot, unfortunately for the world, I have a internet connection and a fondness for beer....apologies for that.

Thank you for you patience.

 

 

Many people don't want the truth, they want constant reassurance that whatever misconception/fallacies they believe in are true..

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:D:smartass: Hey don't dismiss mediocre flying, it work for me 60% of the time all the time. Tracks from open beta.

 

Yeah I know. "Every landing you can get out of in one piece is a good landing". But I'm a perfectionist, and I'm always eager to learn how things are done right and understand why.

 

By the way, cool cross winds landing. I'm not there yet :pilotfly:

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Steinsch

Flying Virtual F-15s since 1989

YouTube channel: http://www.youtube.com/c/CommanderSteinsch

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There's a special section of hell assigned to mission designers who think that unless you have a 20 m/s crosswind then it isn't a real landing. :angry:

 

This was especially true of some of the official ED missions for the Flanker. The Ultimate Argument campaign for example: awesome missions and a great campaign, but every landing seemed to have me struggling desperately against gale force cross winds. So to all the mission designers out there who think that cross-wind landings are fun: No they're not! Stop it!!! :ranting:

 

/rant

System Spec: Cooler Master Cosmos C700P Black Edition case. | AMD 5950X CPU | MSI RTX-3090 GPU | 32GB HyperX Predator PC4000 RAM | | TM Warthog stick & throttle | TrackIR 5 | Samsung 980 Pro NVMe 4 SSD 1TB (boot) | Samsung 870 QVO SSD 4TB (games) | Windows 10 Pro 64-bit.

 

Personal wish list: DCS: Su-27SM & DCS: Avro Vulcan.

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