Starting Second Engine Shuts Down First Engine

[DaveVanB]

Tom,

Just got the V2 of the MU-2 and looking forward to flying.

After starting the right engine, moving the start switch to LH Gnd Start and pressing the Yellow Start button, the right engine immediately quits.

Same happens if I start the left engine first.

Probably doing something wrong, but I'm following the checklist and v2 Stream by Jon Fly.  

If I reload the aircraft from the Developer menu, it has both engines started.

Dave

[tkyler]

Thx Dave.  That's an odd one for sure....smells of hardware config at first sniff, but can't be sure just yet.   Sorry for the barrage of questions here:

1)  Are you using hardware?   one paddle or two?    throttles or condition levers....if so

2) What axis are you mapping them to...?  throttle / prop, etc.

3) Have you made any adjustments to the response curves for those axis?..especially the condition levers.

If you can repeat the process, perhaps take a screenshot of the quadrant just before you hit that second starter button.

Thx

-TomK

[DaveVanB]

Tom,

Thanks for the quick response.

I am using the HoneyComb Throttle Quadrant and the on-screen levers are moving correctly with the hardware levers, so I don't think it's a hardware issue.

Here's a screenshot right before I try to start the left engine with the right one running.  I did confirm that pressing the left Yellow start button shut down the right engine.

Thanks for your help,
Dave

[DaveVanB]

 

Tom,

Additional attempts yielded success.  I believe the difference is I had the beta range light illuminated when I was having the problem.

I then did the procedure to extinguish the Beta Range light on the first engine and the second engine started without killing the first one.

Dave

[tkyler]

Glad you had some success Dave, but this one troubles me just the same.  I have never seen this issue....but then again, its easy for me to get into the same habits when starting the engines 1000 times.   In no case should what you observed have happen.  I'm going to try to recreate this one (anybody else also?)  by trying differing lever positions during start.  I don't like this one at all because it makes no sense to me just yet. (most bugs don't anyhow)

 

Perhaps a quick test though if you have time??  try and repeat it, same way...right engine first.  but before starting the left engine (and seeing the problem), try moving the right condition lever foward...either half-way towards full RPM or all the way to full RPM, doesn't matter, just get the right condition lever away from the taxi position.....and see if the left engine starts without killing the right engine then.  

Edited July 16, 2022 by tkyler

[DaveVanB]

Good news is, I couldn't reproduce the problem.   The second engine started just fine...likely because the first engine was not in Beta mode.  I tried to get the first engine into beta mode while not in reverse thrust mode, but couldn't.  So starting went normally.  I even tried with reverse thrust/beta mode on the first engine, but still able to start.

I suspect I somehow got the engines into Beta mode without reverse thrust and that somehow caused the problem.

I do wonder if minimum power/forward thrust should cause the aircraft to taxi in excess of 35 kts.  Is there a setting I can tinker with to get less thrust at idle without going into reverse?  I have the condition levers at minimum.

Thanks,

Dave  

 

[tkyler]

22 minutes ago, DaveVanB said:

I do wonder if minimum power/forward thrust should cause the aircraft to taxi in excess of 35 kts.  Is there a setting I can tinker with to get less thrust at idle without going into reverse?  I have the condition levers at minimum.

We have to clarify terms Dave.  Have you read the docs on Engine and Prop Operation?  Unsure what you mean by 'minimum power', i.e. "where are the levers"?

There's really no such thing as "reverse" on the TPE-331 per se.  Its only "alpha" and "beta"  Reverse is just "beta mode with negative thrust due to the prop angle set via the power levers"

I present to you this video.  Note how fast he's taxiing and his power levers are at the very edge of reverse pitch and still the thing moves quick. When he moves the prop levers forward to increase RPM...he actually applies a bit more beta/revese input to keep from accelerating more...since BETA is essentially a 'fixed-pitch prop' condition and increasing the RPM in BETA will increase thrust.  So to answer your question, the setting you can tinker with to get less thrust is the power levers   Bring those suckers back into reverse and slow that guy down because putting them at ground idle..(which his levers are below in the video)...can really get you moving!

Now for those using a single paddle joystick with no detent and toggling between beta/alpha where you move the joystick paddle forward to get the animated lever to move backwards....its actually normal to taxi in this condition, i.e. move your joystick throttle forward to slow down (animated lever moves back) and vice versa, etc.

 

the 

Edited July 16, 2022 by tkyler

[DaveVanB]

Thanks for the explanation and video.

I did read the manual and it could be something with the way my throttle quadrant is set up.

I keep the Condition Lever at Taxi.

I pull the throttle lever all the way back as depicted in the photo in the documentation, where it says it should be in reverse, but it still goes forward accelerating to above 35kts.  I can pull it over the detent and to the very bottom and it does go into reverse and the Beta Lights go on.  Moving back above the detent, the Beta lights go out.

So, maybe, what's going on, is I'm not getting into "Beta Mode" with the Power lever.  Is there a trick to get into Beta mode, besides just moving the Power levers back?

Also, in the video of the real aircraft, I noticed the pilot using 2 hands to change the Condition levers to Min-Cruise while taxiing.  He moves the Condition Levers with his left hand and did something with his right hand, but it's too dark to see what his right hand did.

Dave

[tkyler]

If the beta light comes on, then you're in BETA....how FAR into BETA you are is unknown so far.  That depends on your response curve mapping.  In the sample below for example, my joystick is set so that it goes into BETA at about 25% of the joystick lever travel...and then as I pull further back below oh...about 0.12 it looks like, it goes into reverse.  Note I do not use the "toggle_beta/reverse paddle" method in this example.  

When you have a response curve set up like this, then you will need to set your "Power lever detent ratio" to match the value on the vertical axis (about 0.34 shown below) so that quadrant animation stays in sync with your hardware lever.  What hardware are you using BTW?  and with detent?  

As far as the "two handed move" in the video, he's simply setting the "friction lock" for the condition levers.  Pilots will loosen the friction lock, move the condition levers and then retighten the friction lock right after.

 

[DaveVanB]

I thought it was the friction lock.  Glad I'm not going crazy.

I'm using the Honeycomb Bravo throttle quadrant.  It has a detent at about 25% of the motion range, but the throttle movement above the detent moves the levers in the SIM all the way back.

Thanks for the Response curve settings.  Tinkering with that might very well fix my issue.  I'll report back what I find.

Dave

[DaveVanB]

Checking the box "Has beta/reverse dentents" seems to allow me to get the Beta range correctly, even though the detent on the hardware throttle is not in play.

The only other change I made, which I don't believe was necessary, was to change to Cubic for the Interp Mode.  Probably any of them would work.

Thanks so much for your help Tom.

Dave

[tkyler]

Don't forget to set the "detent ratio" value to match your physical dent on your hardware.  I use that response curve window and then pull back my levers to the physical detent and then the number on the vertical axis...go put that into the "dentent ratio" field in the MU2 prefs. That setting gets your animation in sim to match your physical hardware for the ALPHA/BETA regions

[danhenri]

Hello,

I have the Honeycomb Bravo : I think it's not a good idea to apply these settings, because the Bravo has no detent (there is a simple button when pushing back the lever : so, it cannot be used to adjust the trhottle in beta range). I mapped the Toga button of the throtte lever to beta/toggle and it's worked very well (of course, as indicated in the documentation, when beta toggle is engaged, you have to physically push the lever forward, and not backward, as in the real thing).

Edited July 16, 2022 by danhenri

[Pils]

2 hours ago, DaveVanB said:

I'm using the Honeycomb Bravo throttle quadrant.  It has a detent at about 25% of the motion range, but the throttle movement above the detent moves the levers in the SIM all the way back.

There is no detent in the axis as far as X-Plane (joystick interface) is concerned. The position of the “detent” is the 0% point for the axis, below that is a simple on/off button.

[Matchstick]

20 hours ago, danhenri said:

Hello,

I have the Honeycomb Bravo : I think it's not a good idea to apply these settings, because the Bravo has no detent (there is a simple button when pushing back the lever : so, it cannot be used to adjust the trhottle in beta range). I mapped the Toga button of the throtte lever to beta/toggle and it's worked very well (of course, as indicated in the documentation, when beta toggle is engaged, you have to physically push the lever forward, and not backward, as in the real thing).

Personally I use the switch at the bottom of the left throttle axis as the beta toggle and finds that works take well for me, not least because I always know what the position is the physical throttle lever is when switching.

The reversed direction in beta mode is a little odd but didn't take much practice to get used to it.

Edited July 17, 2022 by Matchstick

[tkyler]

11 minutes ago, Matchstick said:

The reversed direction in beta mode is a little odd but didn't take much practice to get used to it.

Well we're working for the TBM style...which would probably work for you...you could bump that switch, its go into reverse and you could advance the lever to reduce the reverse if needed.....that's the goal.

[Matchstick]

14 hours ago, tkyler said:

Well we're working for the TBM style...which would probably work for you...you could bump that switch, its go into reverse and you could advance the lever to reduce the reverse if needed.....that's the goal.

Honestly I'm quite happy now with the way the throttle is at the moment

Edited July 18, 2022 by Matchstick