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BornToBattle

A-20 and Prop Feathering in General

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Posted (edited)

Today decided to take the A-20 up and do some flight familiarization again on the Kuban map. So then I figured, let’s pretend I have an emergency and need to shut down the number 1 engine and see how she handles. So I pulled the pitch all the way back and put the mixture control for the engine all the way back to idle cutoff. Engine still ran like a top. I then tried engine feathering via command keys LCtrl + F (or whatever it is) and nothing. Then I tried it in conjunction with the prop and mixture control. Still nothing.

 

Feathering aside, if one shuts off the fuel supply to an engine my thought was no fuel equals no combustion to be had which means no powering of the engine in question. I tried searching for the .pdf manual for this but to no avail. Shutting down one engine for whatever reason via the fuel supply aka mixture should, I always thought, kill the engine. It’s how I shut down single props all the time.

 

Does the A-20 need several minutes to exhaust its fuel supply to the powerplant or what? I’m stumped here. I’m using CH Product’s Quadrant for inputs. The devs at 1C have these planes modeled down to every nut and bolt, so its got to be something procedural-wise I’m scewing the pooch on here despite moving the mixture to cutoff.

 

Thanks in advance.

Edited by BornToBattle

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You'd do better to switch off the mags (if the switches for them are modelled), I don't think the mixture switch/lever is the same as a fuel cock.

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O percent mixture is only modeled as idle cutoff in some planes I think.

 

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Posted (edited)

Select engine and turn it off with E command. Feather prop, works for me.

 

Used this method plenty of times with a shot up engine. 

Edited by Tyberan
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So do you switch the engine off before feathering?  Maybe that’s where I’m going wrong. 

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Select the engine, shut it down, feather prop. close cowlings for that engine.

 

Re-select the running engine and fly home on it.   I've done it many time when losing an engine to enemy fire.

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Posted (edited)

Ahh..k. I’ll give this info a try. Right now engine start/shut down is linked to one key command. So I just hit that key when doing a cold start and all engines in sequence start, so  I’ll have to link a key command to have the individual engine to the start/shut down comman. Interesting, thank you.

 

1 hour ago, RedKestrel said:

O percent mixture is only modeled as idle cutoff in some planes I think.

 

I guess it’s “safe” to say then that if this statement is indeed true,  the A-20 is one of them then? If so, I wonder why some would be modeled while others aren’t? 

 

 Like I said, so far I have yet to run across where chopping the mixture back to cutoff WON’T cause a single engined plane to cease firing. My routine is to go to idle cutoff which kills the engine,  then key command to switch the plane down entirely, which includes of course electrical systems. (Of ourse I could just my command to end the flight but sometimes I just like to go the entire route).

Edited by BornToBattle

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Posted (edited)
1 hour ago, BornToBattle said:

Ahh..k. I’ll give this info a try. Right now engine start/shut down is linked to one key command. So I just hit that key when doing a cold start and all engines in sequence start, so  I’ll have to link a key command to have the individual engine to the start/shut down comman. Interesting, thank you.

 

You can just keep your common engine start/stop key.

 

Map keys you can get to easy for:

-Switch common control of engines on/off

-Switch engine 1 control on/off

-Switch engine 2 control on/off

 

I find that to be the most useful, but it's a little confusing at first

 

Edited by Drawbar

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Posted (edited)

I’ve apparently re-opened a can of worms if you will, as I found out digging through the past years of threads. This was started back in 2014 and revived again in 2018 with interesting results;..

 

 

To muddy the waters (and I honestly don’t know when this key command was added) there is a default key command for feather prop (I believe it is LCtrl+F). From the replies here I don’t see it even being used. Or yes? It’s listed in Key Mappings then under Engine Controls.

 

So true prop “feathering” can only be done on multi-pitch props (obviously) as the idea behind it is to shut down an engine then reduce as much drag as possible by turning the prop blades to course setting thus providing the smallest amount of blade surface towards the airflow. Sounds like some planes have hydraulic prop pitch and some electrical prop pitch. To actually see the prop turn it’s pitch while off I would suspect if this was done with hydraulic pressure and it is indeed modeled th only way would be to observe the pitch before taking flight, then set it to course pitch during flight, kill the engine then observe the pitch afterwards when the blade come to a stop as there would be no way to adjust pitch IF indeed the aircraft accomplished this through hydraulic pitch as there would be no pressure afterwards to do so. Unless there is residual pressure within the lines even after shutdown.

 

This is where it astounds me in the amount of details each and every aircraft is modeled by these devs. The countless system and the coding that goes into the sim is mind bending. I’m surprised they get them done in the amount of time that they do much less have them modeled correct and accurately. And then there is the quest of even finding the data in order to translate such systems to the sim (the Japanese planes of the Pacific theatre are an example of this)! Thinking of the feathering and systems involved just in this one case is a good example. Unreal. Hats off to this team, really. I thank God they didn’t go the War Thunder route everyday I’m up there with my head in the clouds doing my engine management routines. Closest thing going next to real life - and a LOT cheaper. Sorry for digressing here.

 

Going to go flying today and try these suggestions and do some experimenting also, particularly with the feathering prop key command  as yesterday I had no luck with it. I’ll get back and thanks again everyone

12 hours ago, Drawbar said:

 

You can just keep your common engine start/stop key.

 

Map keys you can get to easy for:

-Switch common control of engines on/off

-Switch engine 1 control on/off

-Switch engine 2 control on/off

 

I find that to be the most useful, but it's a little confusing at first

 

Yes, this is what I currently DON’T have mapped is the individual commands for EACH engine on/off so I’ll be doing that today with the CH Quadrant. It still seems “inherently weird” to be able to pull the mixture all the way back to cutoff in the A-20 and still have the engine humming away with no fuel no longer going to it - nothing on the devs of course - perhaps the engine/fuel management dynamics are more complicated than I’m looking at them, at least for this aircraft. I’m also thinking ahead for when the B-25 is made flyable as well. But that’s another story and remains to be seen.

Edited by BornToBattle

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Posted (edited)

I see the blades turning to full coarse in the Ju88 (so assume it's visible in all planes that can be feathered). I have two switches mapped for turning off engine controls, so switch off engine #2, use the E button to turn off #1's mags, use my mapped button for feathering (LCtrl+F), then switch off #1 control and switch #2 control back on (so the throttles etc will work for it again but not for #1).
 

I've done a ground test in the A-20, it works exactly the same as for the Ju88 (apart from the controls being the opposite way around re left and right, no idea why.).

Edited by Uffz-Prien
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4 hours ago, BornToBattle said:

Yes, this is what I currently DON’T have mapped is the individual commands for EACH engine on/off so I’ll be doing that today with the CH Quadrant. It still seems “inherently weird” to be able to pull the mixture all the way back to cutoff in the A-20 and still have the engine humming away with no fuel no longer going to it - nothing on the devs of course - perhaps the engine/fuel management dynamics are more complicated than I’m looking at them, at least for this aircraft. I’m also thinking ahead for when the B-25 is made flyable as well. But that’s another story and remains to be seen.

 

Nah, If it's "humming away", it's just windmilling (note, the difference in engine tone is there allright, it's just not well audible with the other one making full noise). Just tested the A-20 and indeed, mixture to cutoff kills the engine for good, no need to hit start/stop key, BUT, you do need to use feather command to see the prop being animated accordingly and stop.

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50 minutes ago, Art-J said:

 

...no need to hit start/stop key, BUT, you do need to use feather command to see the prop being animated accordingly and stop.


Which means he does need to isolate the good engine from being controlled while he shuts down and feathers the bad one (assuming he's using a collective set of controls for both engines). :)

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Works fine for me :)

9AAF63F5-B3EC-4662-B87E-E2AD298BA967.jpeg

But yes in this instant I shit down engine and then feathered the prop

Anyone know if it’s a hydromatic constant speed type prop?

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Not tried it in the A-20, but in the 110-G2 it works appropriately. If anything it feathers rather slowly, so you can watch the blades turn. I discovered this when it really mattered, in the Nightfighters over the Kuban scripted campaign; a Pe-2 gunner took out my starboard engine, and with the port on full emergency power I could barely maintain altitude. With the starboard prop feathered however, I could climb (albeit slowly) on the one engine, trim out the uneven thrust (mostly) and make a decent controlled landing back at base.

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There's some question if the engine stops because it fails, if you can still feather after that, or if you have to shut down the engine before it fails to feather. 

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The A 26 had an auxiliary oil pump just to feather the prop if the engine failed, I'm guessing the A20 did too.

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A lot of aircraft had the whole hydraulic system running from one engine, and in plenty of cases there was a hand pump to build accumulator pressure for the hydraulic systems. If I recall correctly the P-47 had a hand pump you could use to force the gear down; the Corsair did not, and instead had a CO2 bottle you could use to blow it down with instead. Different strokes for different folks of course, but as BoX doesn't have secondary bindings like "emergency gear down" and similar in other sims, I suspect it simply uses the same binding to simulate you or your crew pumping by hand. 

 

 It's also equally possible you still have hydraulic pressure, because unless you're doing something to lose pressure in the accumulator it should, at least theoretically, remain available to you.

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9 hours ago, spartan85 said:

Anyone know if it’s a hydromatic constant speed type prop?

 

Looking at the "trademark" Hamilton shape of the cylinder dome, yes it is. How deeply is it modelled in the sim though, no idea. But the basic functionality is there as we can see.

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Posted (edited)

Bingo. Went ahead and shut left engine down on A-20 following;

 

1. Prop back to course pitch

2. Throttle back

3. Mixture back to idle cutoff

4. LCtrl + F for feather

 

Only the left engine at this point was feathered as spartan85 also shows in his pic.

 

I wasn’t following through at the END with prop feathering key command. The one time I performed the key command must have been out of sequence as both props stopped. I’m assuming the command for feathering recognizes the engine inputs and correctly feathers said engine only.

 

Thank you all for the information. In the process of this post also learned some other facts as well! Interesting reading.

Edited by BornToBattle

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Posted (edited)

BtoB, how do you find CH quadrant in this sim anyway? Putting feathering aside, Is it possible to manage twins without the whole selecting/deselecting individual engines thing? Don't remember if all individual assignments are available in controls menu and can't check it at the moment.

 

I've been thinking about purchasing such a unit to deal with upcoming Lightning and DCS Mosquito (some extra levers would come in handy in Thunderbolt as well) but I'm not sure how compatible it is with BoX and CloD.

Edited by Art-J

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Posted (edited)
13 minutes ago, Art-J said:

BtoB, how do you find CH quadrant in this sim anyway? Putting feathering aside, Is it possible to manage twins without the whole selecting/deselecting individual engines thing? Don't remember if all individual assignments are available in controls menu and can't check it at the moment.

 

I've been thinking about purchasing such a unit to deal with upcoming Lightning and DCS Mosquito (some extra levers would come in handy in Thunderbolt as well) but I'm not sure how compatible it is with BoX and CloD.


It works perfectly and yes, you can map the engines and all their controls individually. :)

Except feathering, you have to de-select the good motor in order to feather the dead one. No idea why they made feathering a common control.

Edited by Uffz-Prien

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Got it, thanks. Well, time do do some shopping then :).

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Posted (edited)
5 hours ago, Uffz-Prien said:


It works perfectly and yes, you can map the engines and all their controls individually. :)

Except feathering, you have to de-select the good motor in order to feather the dead one. No idea why they made feathering a common control.

Ditto.

 

I almost sent mine back because stupid me - I had forgotten I still had my throttle linked to the joystick as well and so while flying intermittently at times the throttle would all on its own cut back to idle because the sim was getting two different commands at the same time! Duh. It was a simple matter of just deleting all throttle, prop and  mixture assignments to the yoke and stick - problem solved. Easy to overlook though.

 

Also with the Ch Quadrant they give you interchangeable lever tops so you can swap out as needed, though they are really a snug fit. I have mine mapped from left to right two each for the typical throttle, mixture then prop as I also use it for flying twins in XPlane 11. They have a relatively short throw but unlike some other users I find them to be spot on when it comes to accuracy. Bought mine through Amazon due to their great return policy if I found it was defective.

 

There are six six switches located beneath the quadrant and I have these mapped (so far) for inlet cowls, outlet cowls, then oil radiator and water radiators from left to right. I still have two more left for assignment.

 

Really cool for planes such as the Fokker for the throttle as being a single engine I mapped the second throttle not previously used for the high altitude throttle. Hundreds of ways to map it of course to your own desire. Feels much more like the real deal when you grab a bunch of throttle (well okay, it’s only two but you get the idea. Hell, you could have it mapped for four independent throttles if you wanted for another sim). Especially useful for flying in VR due to the interchangeable tips.

 

I can also recommend it! Just plug and play!

Edited by BornToBattle

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UPDATE: While practicing on the A-20 I’ve come to notice that when I go through the sequence mentioned above for the left engine, all works great. Far CTrl +  F the prop animates to the stopped feathered position. But upon going through the routine for the right engine hitting the feathering command won’t elfect the right engine as it does with the left engine even though prop, throttle and mixture are all th way back as it was for the left. LCtrl + F for me will only feather the le engine. Looks like I need still to dive into the individual engine commands I guess. Hmmm...

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On 3/30/2019 at 10:14 AM, Uffz-Prien said:

I see the blades turning to full coarse in the Ju88 (so assume it's visible in all planes that can be feathered). I have two switches mapped for turning off engine controls, so switch off engine #2, use the E button to turn off #1's mags, use my mapped button for feathering (LCtrl+F), then switch off #1 control and switch #2 control back on (so the throttles etc will work for it again but not for #1).
 

I've done a ground test in the A-20, it works exactly the same as for the Ju88 (apart from the controls being the opposite way around re left and right, no idea why.).

Gonna try this.

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20 hours ago, BornToBattle said:

UPDATE: While practicing on the A-20 I’ve come to notice that when I go through the sequence mentioned above for the left engine, all works great. Far CTrl +  F the prop animates to the stopped feathered position. But upon going through the routine for the right engine hitting the feathering command won’t elfect the right engine as it does with the left engine even though prop, throttle and mixture are all th way back as it was for the left. LCtrl + F for me will only feather the le engine. Looks like I need still to dive into the individual engine commands I guess. Hmmm...

Ya I believe you need to select/unselect what ever engine you want to feather/un-feather...

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