New Boeing 737-800

[KL-666]

Hi It0uchpods,

As you know i tried the Soitanen version, of which you say it is old. So i suppose it should be very "bouncy". But i flew the plane, and it was not bouncy at all. In fact the flight model is very much in the direction of realistic.

What often goes wrong with sim pilots is that they watch their speed and vertical speed. In heavy metal this way of flying makes you run behind the facts all the time, causing overreactions and a sense of bounciness.

Heavy metal should be flown by pitch and power. Pilots know these settings by heart for their plane, and fly by it. They scan their horizon more than speed and vertical speed, because these parameters are always correct following pitch and power.

I remember only a few most used pitch and power settings for landing.

Level flight clean near 250 kts: 5 degrees and 60% power
Start of glide slope, flaps 5: 2 degrees and 45% power
Full flaps: 1 degree and 60% power again (flap drag)

There are tables published for this, like this one:

http://www.b737mrg.net/downloads/b737mrg_powersettings_737-NG.pdf

So the fdm of Soitanan is fine, but the pilot is flying bouncy. If you take out of the fdm what you experience as bouncy, you turn a near realistic fdm into an easy to fly game fdm. Do not do that. In fact in my first remark about the plane in my previous post (about inertia), i think that the plane should be even more "bouncy" as you call it.

About the reversers, maybe i can just set both properties under the same button. It can not harm if one of the two is unused by the plane i suppose. What should i add to the joystick xml?

@Jwocky
When i fly/test a plane, i shall produce lists of things that i notice, just in case the developers forgot about something. The developers can do with it as they like, do something about it or not. If you do not appreciate that, that's your business.

Kind regards, Vincent

[SHM]

Vincent,

Do you've an autopilot on/disconnect button on the joystick?

If yes, send the xml when you get time

And the t16000m is wonderful, thanks for the suggestion. Really wonderful to hand fly with the precision it offers.

SHM

[KL-666]

Do you've an autopilot on/disconnect button on the joystick?

I am sorry, i use the big pull-down switch on the AP panel.

Yes, the stick is really fine, at least for me. After 5-7 years some things deteriorated a bit. The hat is not as good as it was, so i put that on the keyboard arrows, and i had to put in a wee bit of null zone on the twist. But all other axes are as perfect as ever. Great compared to the 1 year lifetime of my previous sticks.

Btw, my buttons are:

On top:
Hand side: ptt
Other side and bottom: trim
Trigger: brake

At the base i use only the side i can reach with my other hand. From the stick side to the outside:
Top: toggle gear
Bottom: toggle reversers
Top: Spoilers in
Bottom: Spoilers full out (i actually barely use this)
Top: Flaps a notch up
Bottom: Flaps a notch down

With this, i do not think i ever use the keyboard while flying manually.

Alright, i am getting too much off topic. If more needs to be said about this, we better create a new topic.

Kind regards, Vincent

[Octal450]

No, that's not what I'm talking about @KL-666.

Please try the YV3399 version. I increased the inertia from Soitanen version ages ago.

Kind Regards,
Josh

[jwocky]

Okay, you can set the reverser-angle directly from a menu/key-binding as well. The reason, I implelmented it this way is, the Ruslan has two alternative engine sets, the Ivchenkos and the Alliance ones. So, that was part of a programming technique for planes which come with different engine-options. But for just two engines and no options, just set the property direct with property-assign if that bothers you so badly.

[Octal450]

I'm aware. But Vincent then has to change his joystick bindings, which is what I am saying to avoid.

[KL-666]

No, i changed my mind, i think i'll just put both yasim and jsbsim property settings under the same button. Then either fdm gets what it needs, and the other property is not used anyway by either fdm. I just do not know what property to set for the jsbsim variant. Tried to look it up in the keyboard xml, but could not find a del-key binding to see what is done there. The ways of Flightgear are mysterious

Kind regards, Vincent

[Octal450]

There is no standard way to do it. JWOCKY planes do it different than it0uchpods planes, and they do it different from others planes, and there are a few others which are different.

Here are the bindings for the 737-800:

Code: Select all

      <binding>
        <condition>
          <and>
            <property>/sim/input/selected/engine[0]</property>
            <less-than>
              <property>/autopilot/internal/servo-throttle[0]</property>
              <value>0.03</value>
            </less-than>
            <less-than>
              <property>/autopilot/internal/servo-throttle[1]</property>
              <value>0.03</value>
            </less-than>
            <or>
              <less-than>
                <property>/instrumentation/radar-altimeter[0]/radar-altitude-ft</property>
                <value>17.5</value>
              </less-than>
              <property>/b737/sensors/air-ground</property>
            </or>
            <equals>
              <property>/engines/engine[0]/reverser-pos-norm</property>
              <value>0</value>
            </equals>
          </and>
        </condition>
        <command>property-interpolate</command>
        <property>/engines/engine[0]/reverser-pos-norm</property>
        <value>1</value>
        <time>2</time>
      </binding>
      <binding>
        <condition>
          <and>
            <less-than>
              <property>/autopilot/internal/servo-throttle[0]</property>
              <value>0.03</value>
            </less-than>
            <less-than>
              <property>/autopilot/internal/servo-throttle[1]</property>
              <value>0.03</value>
            </less-than>
            <equals>
              <property>/engines/engine[0]/reverser-pos-norm</property>
              <value>1</value>
            </equals>
          </and>
        </condition>
        <command>property-interpolate</command>
        <property>/engines/engine[0]/reverser-pos-norm</property>
        <value>0</value>
        <time>3</time>
      </binding>
      <binding>
        <condition>
          <and>
            <property>/sim/input/selected/engine[1]</property>
            <less-than>
              <property>/autopilot/internal/servo-throttle[0]</property>
              <value>0.03</value>
            </less-than>
            <less-than>
              <property>/autopilot/internal/servo-throttle[1]</property>
              <value>0.03</value>
            </less-than>
            <or>
              <less-than>
                <property>/instrumentation/radar-altimeter[0]/radar-altitude-ft</property>
                <value>17.5</value>
              </less-than>
              <property>/b737/sensors/air-ground</property>
            </or>
            <equals>
              <property>/engines/engine[1]/reverser-pos-norm</property>
              <value>0</value>
            </equals>
          </and>
        </condition>
        <command>property-interpolate</command>
        <property>/engines/engine[1]/reverser-pos-norm</property>
        <value>1</value>
        <time>2</time>
      </binding>
      <binding>
        <condition>
          <and>
            <less-than>
              <property>/autopilot/internal/servo-throttle[0]</property>
              <value>0.03</value>
            </less-than>
            <less-than>
              <property>/autopilot/internal/servo-throttle[1]</property>
              <value>0.03</value>
            </less-than>
            <equals>
              <property>/engines/engine[1]/reverser-pos-norm</property>
              <value>1</value>
            </equals>
          </and>
        </condition>
        <command>property-interpolate</command>
        <property>/engines/engine[1]/reverser-pos-norm</property>
        <value>0</value>
        <time>3</time>
      </binding>


Yeah, soitanen went a little overboard on this, but this will only work on the 737-800 and maybe a few others. It can be done simpler. For example, it0uchpods JSB planes do it like this:

Code: Select all

            <binding>
               <command>nasal</command>
               <script>
               systems.toggleFastRevThrust();
               </script>
            </binding>


Kind Regards,
Josh

[jwocky]

The thing is, nothing of this is really a joystick problem. The main difference is, some, Soitanen's and some of mine, don't allow to set reversers while throttle is higher than a very low value.
So, the real problem we talk here is, which property to set. Yasim uses an internal listener, with JSB we have to set one up in Nasal. But then, we only touch here the peak of the iceberg to begin with. We use ONE lever/button because out joysticks usually have only one. Ore we defined only ONE key on the keyboard. Real planes (and some a bit more luxurious equipped flightsimmers) have a throttle lever per engine and a reverser switch per engine, right?
See, what we really would need is something like reversers-cmd. Not a digital state but a float 0-1. In Yasim, we just feed that in the original property, in JSB, we use it for a kinematic (to open the reversers slowly for example in model animations). JSB can something do, Yasim can't. JSB can change the reverser-angle and scale the thrust at the same time. I admit, I did not use that yet, so, like with Yasim, the whole thrust goes always on the reverersers from moment one, regardless whether those things are really already open. But we can make it a more dynamic thing here. Even better, since we can break it down into one value per engine, we can also make sure, failure systems can disable an engine clean without the nasty Yasim effect that with reversers the burning dead thing that was once engine 3 is suddenly well and alive as soon as I touch the reverser button.

[KL-666]

There is no standard way to do it

Ow, that is not really workable then, having hundreds of definitions under one stick button. Indeed it would be smarter to have the logic in a function, like you do, which all aircraft define with the same function name.

This brings me to another idea. All/most planes have their reverser logic under the del-key. Would it be possible to fire a key-event programmatically (in this case push del-key)? Then i put that in the stick button, and all planes are covered.

what we really would need is something like reversers-cmd. Not a digital state but a float 0-1

Yes, it can always be even more fancy In that case i would make it in a function with a parameter telling whether to use the float or simply the digital variant, so both physical thrust levers (float) and a keyboard button (digital) can use the same function.

Kind regards, Vincent