Questions (Carburetor, mixture, attitude indicator)

[Barth 9]

Hello! 

First of all, I am very happy to fly another great vintage airplane like the Boeing 314!! Many, many thanks and respect to the development team and their hard work!! She's a pleasure to discover and fly! 

I fly the B314 on P3D(v4) since a few week and am still very unexperienced. Perhaps I missed some infos in the manuals, or my general understanding is bad... Still, 5 questions went through my mind:

What are exactly the "carburetor selectors" (off-1-2 off-3-4)? And does the engines have carb heating?? On my last flight they regularily iced (MAP fell down in clouds & rain with low exterior temp + pitot icing) so I had to fly quite low under clouds.. 

I have a throttle quadrant (CH Products), but I set the mixtures individually with the levers in the VC. On the A2A Constellation this "overrides" my controller and stay the way I put them. However, on the B314, the levers will stay as I put them, but the mixture (in the code of the plane, in the sim, showed on the Fuel flow gauges) will be set on whatever the position of my physical controller is..  So the VC-levers don't appear to work?

I'm not familiar with the inverted attitude indicator (artificial horizon). Whenever I turn in one direction, the gauge shows a turn the "wrong" way. It gets me very confused in bad weather. This is probably intended so?! I'm curious of the reason why, though... 

Another thing... Why are the mooring lights only on when the engines run, and at dusk/night?  I thought that's the point of having mooring light (as any water-ship) when 'parked'. 

And the final question : cylinder temps cool really, really fast when I turn the engines down. Is it normal? (it doesn't bother me) 

Thank you, again, for this wonderful plane! I assume it was a long process to gather all the infos to recreate one for the sim, and i truly admire your dedication! 

 

Barth

Edited December 12, 2021 by Barth

[dragonflightdesign 98]

Hello Barth

1. The 'carb selectors' display the air temperature in the carb venturi.

2. For carb icing info, see the manual (Part 1), 'Contemporary Technical Information | The Chandler-Groves Floatless carburettor'. However, the fuel pressure provided by the sim indicates that it is modelling a Stromberg-type carb which according to the Curtis-Wright Cyclone 14 manual, '(...) the Stromberg Injection Type carburetors are inherently non-icing [except under very specific circumstances]'. So the sim pretty much has that wrong too. As I'm still working on the B314-A, I think a way around this problem is to turn on carb heat whenever prop de-icing or wing de-icing is turned on and not to turn carb heat off again until both prop and wing deicing are also turned off.

3. I'm pretty sure we've fixed the mixture lever problem. I can't check here as I don't have a throttle quadrant but the beta tester does and he's very, very exacting in his testing.

4. Which attitude indicator are you refering to? They all seem to be working correctly here, but then it is entirely possible that I have fixed that problem and forgotten about it.

5. Mooring lights... yes; they should be shifted to the battery/shore power. I'll do that. [EDIT]. They're already on battery power. It's a bug - now fixed.

6. Cylinder head temps are read from the sim and modified to provide a cylinder base temperature reading too. I agree the cool down period appears to be way too short but that is what is being given by the sim.

-Dai

Edited December 13, 2021 by dragonflightdesign

[Barth 9]

Hello,

Okay, thank you for the "in depth" answers! 

With the attitude indicator I mean the artificial horizon. It shows a right run, when in fact the plane is turning left : but as I said, it's perhaps just me who is not used to it!

For the mixtures : yet the problem is here. The individual levers doesn't seem to set the mixture as they should, as this seems to rather "follow" the master lever (the lever on my controller which I don't move). I'll get back at it the next days, to be sure of what I say (I'll let you know). 

Thanks again for providing the flight sim world with such a well done plane! 

 

Barth

Edited December 14, 2021 by Barth

[dragonflightdesign 98]

You are right about the t-scan artificial horizon. I can only apologise for missing that. Fixed. The gyropilot AH is okay.

-Dai

[Barth 9]

Hello!
So, I looked deeper into the mixture. I interpreted this the wrong way : there is NO issue at all.
As for the carburetor heat, in the B314 Manual an automatic feature is described (with a thermostat controlled valve for "hot air"), one can override with a manual control on the backside of the engines in the wings.
So like you said, it seems that in real life carb. icing couldn't really occure.

[dragonflightdesign 98]

I've now attached the engine anti-ice to both the de-icing boots and the prop de-ice. Either one will turn the engine anti-ice on and it will only turn off when both props and boots are turned off. The downside is that you will get a drop of a few RPM when engine anti-ice comes on. Because the sim does not allow for individual prop de-ice, I have linked the port and starboard switches to operate together.

 

Additionally I have moved the mooring lights, navigation lights and passenger compartment lights onto the battery bus.

Edited December 20, 2021 by dragonflightdesign

[Barth 9]

Thank you! 

I see you have (and already had) to trick the sim a lot to get it realistic. 

Here I come with another question : when i want to regulate the prop. pitch individually, with the switches, they always get back to their original position within a few seconds. Is it normal? 

Yesterday I reached Nouméa (new-caledonia) form Wellington (NZ) for my first long-range flight aboard the B314, all with time estimation, wind correction and 2 NDBs along the way, it was a really enjoyable experience! 

Thank you for keeping the hard work on this floating beast! 

Barth

[dragonflightdesign 98]

The prop-pitch switches are momentary (biased to centre-off), so the behaviour you are seeing is correct. Again, this was forced on me by the sim because if you hold down the prop-pitch event, it has a key accelerator on it which causes the pitch angle to overshoot very rapidly. I would have liked to have had right-click to start the pitch change and left-click to stop it, but it isn't possible because of that key accelerator.

[Barth 9]

Hey,
Oh, I meant the prop RPM "always get back to their original positions(RPM) within a few sec.". I understood that with the switches, no problem at all.

But the RPM are getting back to their original state a few seconds after i (successfully) regulated it with the switches :  if for exemple Engine 2 has a few more RPM than 1, I click a couple times on the switch to lower the RPM; then the needle moves back to the original unsynchronized RPM.

[dragonflightdesign 98]

If this is during the engine warm-up period then that is correct behaviour: rpm increases as the oil temperature increases and the resistance gets less. I don't see this in flight...?

[Barth 9]

Hello Dai,
First of all, I wish you nice holidays!
I was talking about setting individual RPM while in flight. I tested it a bit more, and it works most of the time. But sometimes I can't set it, or it would quickly "reset" itself. I made a little video of it:

As you can see, I'm not able to set the RPM via the switches (on the same flight in the same "savegame" it was already possible).
Also, I could'nt bring the engines to feather while testing it in flight and on the ground.
The RPM drops when activating the pump, but never feathers. In flight, with a stopped engine, this also was'nt possible and the RPM rised again as soon as I let the pump go.
Thanks for your help!

Barth

Edited December 29, 2021 by Barth

[dragonflightdesign 98]

Found the feathering problem - it's a fight between what my code says should happen and what the sim thinks should happen. I've re-written it so that the props feather a lot faster. It's not as accurate as I would like it, but it stops that 'fight' from occurring.