Viper low speed handling

[Glide]

1 hour ago, Katj said:

 

Yes. It is also the same in pitch.

Go test it for yourself if you own the module.

Cool!  I will check this out.  With AAR, it's all about holding a steady airspeed for me.  It's either walking forward too fast or falling back immediately after connect.  And then a short push to bring it back in sync with the tanker usually breaks the connect.  I don't think it's about deadzone on my hotas.  If the flight path marker drifts from the steering que by even a pixel the viper follows.

[Glide]

I added a deadzone of 2 to my axis, and confirmed the roll rate is slower (Cat 1 fastest, Cat III slower, Landing Gains slowest) with the AAR door open.  Got shot down by an Su-25, so no landing test. Got to connect with the tanker no problem, but could not keep it there.

[Glide]

This is a learning experience as with all things DCS.  Deadzones and axis curves make the Viper seem more "boaty" to me.  The only reason I had them in the first place was because I read it in a pdf.  So I took out the pitch and roll deadzones and made the curves all zero.  Now the Viper feels more responsive and less slushy, but my muscle memory is all screwed up.    I've added a small deadzone to the throttle to smooth it out.  I'll fly this for a week and see how it goes.

[_SteelFalcon_]

I suggest keeping control inputs linear and fly like that for some hours. The viper feels amazing that way. Maybe a deadzone to the rudder for ease of taxi/takeoff with NWS on

[Rhinozherous]

I hope the F16 is getting as much love as the Hornet got the last months. Would be nice to have a complete Flightmodel and Antiskid. 

[normanleto]

OP here   Thanks for all information above. After several days of training and trying various curves with AA refueling mission, I start to get more decent results. The [Ctrl + Enter] input viewer is very useful in solving curves problems. It seems I am at the stage where curves aren't perfect, but at least I can fly under tanker and get connection for a moment. The problem stays with throttle (too slow or too fast) but I guess it is now a question of practice.

 

Do you have any advices about throttle movements during air refuel? Do you move it back-forward in some certain rhytm? 2-3 times per second or some rare corrections when needed?

In the hornet, rhytmic and quite frequent throttle micro-corrections are the best to keep onspeed. Viper seems to be more woobly with speed. Too fast or too slow.

I will write something after month from now and we will see if it was a practice problem or a result of bad setup.

 

 

[Theodore42]

1 hour ago, normanleto said:

Do you have any advices about throttle movements during air refuel? Do you move it back-forward in some certain rhytm? 2-3 times per second or some rare corrections when needed?

Always be moving it. If you get SUPER good at DCS you can get it to stick without moving it for maybe 10 or 15 seconds at a time but irl this is impossible.

You should always be adjusting the throttle by as tiny an amount as you can perceive the thrust being outputted.... if that makes sense.. lol

[_SteelFalcon_]

This helped me a lot for learning how to AAR

[Xavven]

I'm using a TM Warthog HOTAS and the Viper feels responsive and smooth. I am able to get about 5000 lbs of fuel in AAR with 0-2 disconnects. Nothing worth bragging about, just trying to give more data points to the guys with x52s and not having a good time.

 

I will say, though, that the roll rate of the Viper seems really low compared to the Hornet. It really feels like a boat even with maximum stick deflection, and yes I'm in a clean jet with the switch in Cat I.

[Theodore42]

2 hours ago, Xavven said:

I will say, though, that the roll rate of the Viper seems really low compared to the Hornet. It really feels like a boat even with maximum stick deflection, and yes I'm in a clean jet with the switch in Cat I.

 

Whaaa?? You must just be deflecting too slowly.

Try setting your saturation to 10% and see how that feels.

[LJQCN101]

On 3/17/2021 at 6:04 PM, Katj said:

I think the most likely the reason is that I started out ever so slightly banked to the left, and the jet just continued to roll. The roll to the left isn't the issue, though.

What I'm trying to illustrate is that the right stick input does nothing. You guys should be able to reproduce it.

 

It could be that your input is within the DFLCS software breakout (deadzone), which is -/+ 1.75 lbs for pitch and -/+ 1 lbs for roll, so that DFLCS disregards your input.

 

 

[Terzi]

In Hornet while you fly around the carrier with flaps down, you are supposed to adjust the vertical velocity by using the throttle. This is very useful doing carrier ops. The physical shape along with the flight computer software was designed to do so. You trim the airplane for AoA and you don't need to use the stick at all for pitching up/down.

 

In Viper I noticed that similar thing happens, which is a wrong behavior. As you approach for landing with good AoA, adjusting the throttle controls how high or low the FPM (flight path marker) will go. This is incorrect for Viper and probably its because some part of the FLCS code might be copied from Hornet.

 

In Viper as you approach for landing, increasing the power should only let the jet go faster (not higher). The FLCS shall keep the FPM where it is, by pitching the nose down as necessary. The idea in Viper is that you place the FPM where you want to fly, and the FLCS will do its best to keep it there. Similarly when you set the power to idle during approach, the FPM will stay where it is, and flight computer will pitch the jet as necessary.

 

I hope when the flight model is done we get this behavior corrected.

[SCPanda]

4 minutes ago, Terzi said:

In Hornet while you fly around the carrier with flaps down, you are supposed to adjust the vertical velocity by using the throttle. This is very useful doing carrier ops. The physical shape along with the flight computer software was designed to do so. You trim the airplane for AoA and you don't need to use the stick at all for pitching up/down.

 

In Viper I noticed that similar thing happens, which is a wrong behavior. As you approach for landing with good AoA, adjusting the throttle controls how high or low the FPM (flight path marker) will go. This is incorrect for Viper and probably its because some part of the FLCS code might be copied from Hornet.

 

In Viper as you approach for landing, increasing the power should only let the jet go faster (not higher). The FLCS shall keep the FPM where it is, by pitching the nose down as necessary. The idea in Viper is that you place the FPM where you want to fly, and the FLCS will do its best to keep it there. Similarly when you set the power to idle during approach, the FPM will stay where it is, and flight computer will pitch the jet as necessary.

 

I hope when the flight model is done we get this behavior corrected.

Interesting. I didn't know that. I also noticed that changing power when landing moves the FPM in the Viper. Well, lets hope ED gets the FLCS right. 

[Theodore42]

Are you sure you're thinking about the F-16 and not... every other fighter?

Because the F-16 is famous for this behavior.

[LJQCN101]

1 hour ago, Terzi said:

In Hornet while you fly around the carrier with flaps down, you are supposed to adjust the vertical velocity by using the throttle. This is very useful doing carrier ops. The physical shape along with the flight computer software was designed to do so. You trim the airplane for AoA and you don't need to use the stick at all for pitching up/down.

 

In Viper I noticed that similar thing happens, which is a wrong behavior. As you approach for landing with good AoA, adjusting the throttle controls how high or low the FPM (flight path marker) will go. This is incorrect for Viper and probably its because some part of the FLCS code might be copied from Hornet.

 

In Viper as you approach for landing, increasing the power should only let the jet go faster (not higher). The FLCS shall keep the FPM where it is, by pitching the nose down as necessary. The idea in Viper is that you place the FPM where you want to fly, and the FLCS will do its best to keep it there. Similarly when you set the power to idle during approach, the FPM will stay where it is, and flight computer will pitch the jet as necessary.

 

I hope when the flight model is done we get this behavior corrected.

 

While the Hornet tends to hold a trimmed AOA with flaps down, the Viper on the other hand is designed to hold a zero pitch-rate in hands-off flight when FLCS is in Take-off & Landing Gains.

 

The Take-off & Landing Gains is a pitch-rate command system until 10 deg AOA, which means your stick is commanding pitch-rate, instead of G or AOA. A zero stick input will translate to a zero pitch-rate, regardless whether your aircraft is inverted, decelerating or accelerating.

 

When flying above 10 deg AOA, the Viper's FLCS starts to add nose-down command to your stick input, a negative pitch-rate command proportional to (AOA - 10). It's called a blended pitch-rate and AOA command system.

 

All of these behaviors are very different than in the Hornet.

 

 

There's one thing worth mentioning however. Let's say you manually trimmed to 13 deg AOA level and steady flight in the Viper. The pitch trim is added to the stick input, so you're essentially commanding a positive pitch-rate, while the FLCS is commanding negative pitch-rate proportional to (AOA - 10), since you're currently above 10 deg AOA. What's happening is that the aircraft will now tend to hold the trimmed AOA, and it flies like a Hornet with flaps down. Adjusting the throttle will now pitch the nose up and down.

 

Edited March 22, 2021 by LJQCN101

[normanleto]

6 hours ago, LJQCN101 said:

 

While the Hornet tends to hold a trimmed AOA with flaps down, the Viper on the other hand is designed to hold a zero pitch-rate in hands-off flight when FLCS is in Take-off & Landing Gains.

 

The Take-off & Landing Gains is a pitch-rate command system until 10 deg AOA, which means your stick is commanding pitch-rate, instead of G or AOA. A zero stick input will translate to a zero pitch-rate, regardless whether your aircraft is inverted, decelerating or accelerating.

 

When flying above 10 deg AOA, the Viper's FLCS starts to add nose-down command to your stick input, a negative pitch-rate command proportional to (AOA - 10). It's called a blended pitch-rate and AOA command system.

 

All of these behaviors are very different than in the Hornet.

 

 

There's one thing worth mentioning however. Let's say you manually trimmed to 13 deg AOA level and steady flight in the Viper. The pitch trim is added to the stick input, so you're essentially commanding a positive pitch-rate, while the FLCS is commanding negative pitch-rate proportional to (AOA - 10), since you're currently above 10 deg AOA. What's happening is that the aircraft will now tend to hold the trimmed AOA, and it flies like a Hornet with flaps down. Adjusting the throttle will now pitch the nose up and down.

 

 

I dont understand stuff you mentioned above, but I admire the level of insight.

[Katj]

 
It could be that your input is within the DFLCS software breakout (deadzone), which is -/+ 1.75 lbs for pitch and -/+ 1 lbs for roll, so that DFLCS disregards your input.
 
 

Yeah, I'm sure that's it. Again, I'm not saying it's wrong, it's just horrible with my stick. And as most don't have a force sensing stick, the default behaviour may not be optimal for them.

I wasn't trying to show a bug or anything, I was just showcasing the deadzone, the existence of which is denied by many.

[VampireNZ]

11 hours ago, Terzi said:

In Hornet while you fly around the carrier with flaps down, you are supposed to adjust the vertical velocity by using the throttle. This is very useful doing carrier ops. The physical shape along with the flight computer software was designed to do so. You trim the airplane for AoA and you don't need to use the stick at all for pitching up/down.

 

In Viper I noticed that similar thing happens, which is a wrong behavior. As you approach for landing with good AoA, adjusting the throttle controls how high or low the FPM (flight path marker) will go. This is incorrect for Viper and probably its because some part of the FLCS code might be copied from Hornet.

 

In Viper as you approach for landing, increasing the power should only let the jet go faster (not higher). The FLCS shall keep the FPM where it is, by pitching the nose down as necessary. The idea in Viper is that you place the FPM where you want to fly, and the FLCS will do its best to keep it there. Similarly when you set the power to idle during approach, the FPM will stay where it is, and flight computer will pitch the jet as necessary.

 

I hope when the flight model is done we get this behavior corrected.

 

Interesting behaviour you are getting on approach - I am not seeing that at all landing the Viper. I position the FPM on the threshold with the stick (once I get the glideslope line in HUD where I want it- usually at edge of runway), then I control the AOA staple position on the FPM using the throttle - so the FPM stays exactly where I put it previously, and the staple moves up and down with throttle movement, so I am adjusting power to keep staple positioned so top edge is on the FPM. Then at flare I pull back stick to move FPM to end of runway and reduce throttle to land, holding that 10deg flare to aerobrake to 90 knots.

So opposite of what you are seeing, and yes this is exactly the opposite of how I fly the Tomcat for example where you set AOA with trim & power then you just adjust glideslope with power without touching the stick aside from for line-up (I believe you actually get a wave-off if you are moving the nose too much on approach)

 

Not sure why you are seeing something different with landing the Viper? Perhaps it is because I am just slightly moving they throttle in the bounds of what I need to perform a normal landing - perhaps if I moved it way to much either way I would see the FPM movement you mention. But just landing the jet normally it all behaves at it should.

Edited March 22, 2021 by VampireNZ

[SmoglessPanic]

This issue sound to me like you have a problem with something centering. Set a deadzone on the little hat switch thumbstick thing on the throttle. I had some X-52's back in the day and the throttle thumbstick and the rotary dials get out of whack and need to be deadzoned. The one on the top of the throttle was one that constantly did it for me. If one of these buttons is not centered then it could throw off your stick movements.

 

I have no problems with the F-16 landing, AAR, dogfighting, etc. As someone mentioned it sounds almost like the autopilot is on. I use a T16000M stick, throttle, and rudders without any issues. 

 

Hope this help, I can elaborate more if needed, rushing out of work at the moment ... lol