Turning Engine off at Altitude to stop contrailing to conceal a dive?

[Haza]

Gents,

 

It would appear that some players are now turning their engine(s) off at high altitude to stop contrailing to conceal their dive onto fighters below, as it happened to me today on WOL.  Thankfully I realised what this player was doing, although he did get hits, I got away

However, the main thrust of this post is that I would be interested to know firstly what real world effects doing this would have on both the aircraft and the engine or whether an engine start would be as simple as pressing E or whether an in-flight engine start is even correctly modeled or is just the same as a ground start.  In addition, was this something done in RL as a tactic to stop contrailing, or is it just an arcade way of getting an advantage, although in my Oxford Dictionary gaining an unfair advantage means something else.  It has been years since I did propulsion theory and propellers (flight fine pitch stops and all that stuff at Halton) and looking at how a prop can cause braking effects with over speed or incorrect pitch angels, so is any of this modeled?

 

Thoughts?

 

 

Regards

Edited October 11, 2017 by Haza

[Willy__]

LUL WHAT ?!?

 

Never heard about it. Guess I should try that next time I fly on mp. 

 

 

People gonna game the game if they have the chance... nothing new here.... 

[Haza]

LUL WHAT ?!?

 

Never heard about it. Guess I should try that next time I fly on mp. 

 

 

People gonna game the game if they have the chance... nothing new here.... 

 

 

I agree players are going to game the game, but it would be nice to know what happened in RL if anything at all and whether an inflight engine start up (if not modeled)  might be implemented in future.

Edited October 11, 2017 by Haza

[Y29.Layin_Scunion]

Oh boy.

In all reality, I don't see how this could be very efficient.  How absolutely silly.  I would as well like to know the real life aspect of such things.

[AndyJWest]

Arcade nonsense. No sane pilot is going to turn off his engine when there are enemy aircraft below.

[US63_SpadLivesMatter]

This sounds like the sort of absolute [edited] I'd expect from us 1G fighter pilots.

[busdriver]

This sounds like the sort of absolute wank I'd expect from us 1G fighter pilots.

 

Respectfully, my legal department informs me (so I'm merely the messenger...don't shoot me) "when using the capital letter G, one must include reference to a comfy chair. The use of the lower case g does not require this reference."

 

A counterexample was a RL tactic used by F-15 guys where they formed a "wall of Eagles" (line abreast) above the contrail level. At a certain distance from the merge they would simultaneously descend through the contrail level, perhaps with the idea of intimidating their adversary (OMG here they come...run away...run away). As an F-16 guy, we loved it...tally 4. They generally had a tougher time getting a tally on 2 or 4 Vipers, the guys I flew with liked to use altitude splits.

 

To the OP...this is a 1G comfy chair fighter pilot tactic. 

[=SIM=Ruttley]

Arcade nonsense . No sane pilot is going to turn off his engine when there are enemy aircraft infantry below at night.

Enter; the PO-2

Edited October 11, 2017 by =SIM=Ruttley

[Venturi]

Gents,

 

It would appear that some players are now turning their engine(s) off at high altitude to stop contrailing to conceal their dive onto fighters below, as it happened to me today on WOL.  Thankfully I realised what this player was doing, although he did get hits, I got away

However, the main thrust of this post is that I would be interested to know firstly what real world effects doing this would have on both the aircraft and the engine or whether an engine start would be as simple as pressing E or whether an in-flight engine start is even correctly modeled or is just the same as a ground start.  In addition, was this something done in RL as a tactic to stop contrailing, or is it just an arcade way of getting an advantage, although in my Oxford Dictionary gaining an unfair advantage means something else.  It has been years since I did propulsion theory and propellers (flight fine pitch stops and all that stuff at Halton) and looking at how a prop can cause braking effects with over speed or incorrect pitch angels, so is any of this modeled?

 

Thoughts?

 

 

Regards

Simmers will always be simmers, gamers will always be gamers.

[MrNoice]

it would be nice to add a feature to realistic servers... ( engine start only on the ground)

[AndyJWest]

To be clear about this, it is possible to restart an engine in the air - see this A-20 engine being stopped and restarted (from 14:30 onwards):

https://www.youtube.com/watch?v=_sRoer4gMVc

 

That is a twin-engined aircraft though, and a training exercise where a failure to restart should be recoverable.

[=SqSq=Sulaco]

it would be nice to add a feature to realistic servers... ( engine start only on the ground)

 

Doubt it will be a big enough deal or issue to warrant that but I get where you're going with it.

[Flitgun]

??

 

Simply reducing the throttle to zero will stop a contrail contrailing in this game. No need to switch off the whole engine (!)

 

And if one is diving, one might chop the throttle in order to prevent your wings snapping off. A bonus, I suppose, if your contrail stops, rather than a cheeky WoL cheat lol .

 

I've never enquired if this would happen in real life (contrail stop), but my guess is that it does - or at least greatly reduced contrails with the huge reduction of hot exhaust gases.

[Haza]

To be clear about this, it is possible to restart an engine in the air - see this A-20 engine being stopped and restarted (from 14:30 onwards):

https://www.youtube.com/watch?v=_sRoer4gMVc

 

That is a twin-engined aircraft though, and a training exercise where a failure to restart should be recoverable.

 

To be clear, I have no issue with an engine starting in the air, the question is what would the procedure have been back then and more importantly what if any impact would it have on say the pilots ability to start the aircraft while diving in for an attack.  Surely you just do not turn the Mags off and click back on again?!

I guess in game you could press letter E to stop the engine then start your dive, then press letter E again, and hey presto the engine starts after 10-015 seconds so during your dive no contrail!

All I was hoping for was for the game to simulate perhaps this as well, rather than it becoming another exploit.  However, now players are aware of it, they might not always trust the contrail to be the aircraft's current location!

??

 

Simply reducing the throttle to zero will stop a contrail contrailing in this game. No need to switch off the whole engine (!)

 

And if one is diving, one might chop the throttle in order to prevent your wings snapping off. A bonus, I suppose, if your contrail stops, rather than a cheeky WoL cheat lol .

 

I've never enquired if this would happen in real life (contrail stop), but my guess is that it does - or at least greatly reduced contrails with the huge reduction of hot exhaust gases.

 

OK, say perhaps the player did just throttle back instead of cutting the engine, however, as you have pointed out, would the contrail stop, or just reduce in size, but still be visible!?

Might have a test later!!

Edited October 11, 2017 by Haza

[busdriver]

Simply reducing the throttle to zero will stop a contrail contrailing in this game. No need to switch off the whole engine (!)

 

 

I've never enquired if this would happen in real life (contrail stop), but my guess is that it does - or at least greatly reduced contrails with the huge reduction of hot exhaust gases.

 

My RL experience suggests to me marking/conning (contrails) should continue even if at idle power. The exhaust gas temp is reduced, but it's still pretty warm.

[Flitgun]

My RL experience suggests to me marking/conning (contrails) should continue even if at idle power. The exhaust gas temp is reduced, but it's still pretty warm.

 

Interesting. (I don't mean that in a way that means I disagree.) I'd imagined it was more about the volume of hot air passing through the engine that was responsible for making the contrail in it's fullest form. I imagined with a tiny weeny bit of exhaust (zero throttle) you'd see almost nothing.

 

But, like I said, I'm guessing.

[US63_SpadLivesMatter]

Respectfully, my legal department informs me (so I'm merely the messenger...don't shoot me) "when using the capital letter G, one must include reference to a comfy chair. The use of the lower case g does not require this reference."

 

 

I forgot all about the comfy chair, my apologies!

 

Must be because I have to sit on the floor when I play.

[busdriver]

Interesting. (I don't mean that in a way that means I disagree.) I'd imagined it was more about the volume of hot air passing through the engine that was responsible for making the contrail in it's fullest form. I imagined with a tiny weeny bit of exhaust (zero throttle) you'd see almost nothing.

 

 

I can't argue with your intuition, lower the volume of hot air, decrease the size of a contrail. But it's still very hot air compared to the ambient air temp.

 

There is a concept known as "shock cooling" an engine that folks that tow gliders or haul skydivers are familiar with. The gist being a pilot risks damage to his engine if after heavy usage (high engine internal temps...cylinder head temp, oil temp) the pilot reduces power too quickly or reduces it too much (long enough to cause "shock cooling"). It was a greater concern decades ago with engines that were not manufactured to the higher standards of today (think materials and tolerances). As an example, our club's 160 HP Super Cub can obtain CHTs (cylinder head temp) around 425C whilst towing at maximum power to 3000' AGL, once off tow we reduce power slightly to allow the CHTs to get below 385C (takes a couple minutes) before pulling the power to idle. I admit this is NOT analogous to a WWII fighter trying an idle descent through a contrail level, but perhaps you see a similarity. But I digress.

[SCG_Fenris_Wolf]

My RL experience suggests to me marking/conning (contrails) should continue even if at idle power. The exhaust gas temp is reduced, but it's still pretty warm.

But your experience is as the rocket man, not a prop rider.

Just reread on wiki (good sources provided), that contrails typically appear at ambient temp below -35℃. That would mean that the contrails in-game are way overdone anyway, on anything but winter maps they ought to appear above 8000m because only then the crystals form...

 

 

Maybe I'm wrong ? But, we aren't flying jets after all..

Edited October 11, 2017 by 2./JG51_Fenris_Wolf

[Flitgun]

I can't argue with your intuition, lower the volume of hot air, decrease the size of a contrail. But it's still very hot air compared to the ambient air temp.

 

There is a concept known as "shock cooling" an engine that folks that tow gliders or haul skydivers are familiar with. The gist being a pilot risks damage to his engine if after heavy usage (high engine internal temps...cylinder head temp, oil temp) the pilot reduces power too quickly or reduces it too much (long enough to cause "shock cooling"). It was a greater concern decades ago with engines that were not manufactured to the higher standards of today (think materials and tolerances). As an example, our club's 160 HP Super Cub can obtain CHTs (cylinder head temp) around 425C whilst towing at maximum power to 3000' AGL, once off tow we reduce power slightly to allow the CHTs to get below 385C (takes a couple minutes) before pulling the power to idle. I admit this is NOT analogous to a WWII fighter trying an idle descent through a contrail level, but perhaps you see a similarity. But I digress.

 

Shock cooling - I've heard of it. It's certainly not limited to such a small aeronautical niche. It's a basic engineering factor - relevant even to a farm tractor. I don't have any impressive figures for the farm tractor though. The best I can do is something like: 1st gear foot to floor + 5 minutes + drive into icy river = shock cooling = cracked cylinder head.

 

 

 

So, are you saying the contrail appears the same whatever the throttle setting in RL?

[Haza]

But your experience is as the rocket man, not a prop rider.

Just reread on wiki (good sources provided), that contrails typically appear at ambient temp below -35℃. That would mean that the contrails in-game are way overdone anyway, on anything but winter maps they ought to appear above 8000m because only then the crystals form...

 

 

Maybe I'm wrong ? But, we aren't flying jets after all..

 

Rocket Man?   Does that leader play this sim as well?

[Boaty-McBoatface]

This sounds like the sort of absolute [edited] I'd expect from us 1G fighter pilots.

This was in fact the [edited] that was seen from the ITAF boys today. Engine off, diving without contrails. Edited

Edited October 11, 2017 by SYN_Haashashin

[56RAF_Roblex]

Interesting. (I don't mean that in a way that means I disagree.) I'd imagined it was more about the volume of hot air passing through the engine that was responsible for making the contrail in it's fullest form. I imagined with a tiny weeny bit of exhaust (zero throttle) you'd see almost nothing.

 

But, like I said, I'm guessing.

 

Perhaps with zero throttle but the props still spinning the engine is putting out dirtier exhaust that act as seed particles and still give a contrail effect?

Edited October 11, 2017 by 56RAF_Roblex

[xvii-Dietrich]

My RL experience suggests to me marking/conning (contrails) should continue even if at idle power. The exhaust gas temp is reduced, but it's still pretty warm.

 

Interesting. (I don't mean that in a way that means I disagree.) I'd imagined it was more about the volume of hot air passing through the engine that was responsible for making the contrail in it's fullest form. I imagined with a tiny weeny bit of exhaust (zero throttle) you'd see almost nothing.

 

I can't argue with your intuition, lower the volume of hot air, decrease the size of a contrail. But it's still very hot air compared to the ambient air temp.

 

 

 

Contrails are water droplets. The water comes from the reaction of the fuel (a hydrocarbon) and oxygen.

 

C_xH_y + O₂ --> H₂O + CO₂

 

(atomically, this is not balanced, but the principle is the same). The water produced in this reaction is in gaseous form (i.e. water vapor, which is an invisible gas).

 

These exhaust gases (incl. the water, H₂O) are superheated from the combustion, typically several hundred degrees celsius. At those temperatures, a gas can "hold" a large amount of water vapor. (In a way, you can think of this as the water vapor being dissolved in the gas.)

 

As the gas cools (due to it expanding and mixing with the surrounding air), it will cool to below the condensation point, in which case if forms a trail of condensation (contrail). That condensation point depends on several factors, such as:

 

1. How much water is being produced. The bigger the engine and the more fuel being burned, the more water is being produced and hence the greater tendency to produce a trail. This is related to the amount of air in the mix from compressors, etc. (relevant to turbofan engines, for instance).
2. The exhaust gas temperature (and pressure). The hotter this is, the longer it will take for it to cool to ambient. This gives the water vapor more time to diffuse and thus not to condense. This is why a car engine that has just been turned on on a cold day will produce condensation, whereas the same engine that has been running for a while will not.
3. The ambient air temperature. The colder the surrounding air, the less water vapor it is capable of holding. Therefore, it is more likely that new water vapor injected into it will condense.
4. The ambient air relative humidity. This is closely related to the previous point. It is the amount of water already in the air. If the air is particularly dry, then it can take in more water, thus making the contrail less likely.
5. The diffusion rate. If the exhaust gas mixes quickly, it can drop in temperature quickly and thus condense. However, if the mixture expands over a larger volume, then there is more ambient air involved. The cooling is greater, but in certain air conditions, the diffusion is great enough that the local air can cope.
6. Particulates. The condensation needs a condensation point. It is possible to super-saturate the air with water vapor. Without a particulate (e.g. engine soot) or local condensation point (e.g. micro-ice-crystals) there might well be no contrail, when one would otherwise be expected. A sooty engine (e.g. due to over-rich mixture setting) can still produce smoke, but without condensation due to the ambient temperature and humidity being able to diffuse the water vaopr without condensation.

Ultimately, the production of a condensation trail is a complex process related to the chemistry and physics of the engine, engine environment and ambient conditions. Given a set of conditions it is moderately straightforward to work them through and estimate what might be expected. However, there are a LOT of input parameters for this, so there is no simple hot-air-equals-contrail type of answer.

 

 

 

Summary

 

An engine which is running is producing water. Whether that water turns into a condensation trail or not depends on the volume of water produced, the diffusion of that water vapor into the atmosphere, the local air temperature and humidity.

 

 

 

 

References

 

• http://www.engineeringtoolbox.com/water-vapor-saturation-pressure-air-d_689.html
• https://en.wikipedia.org/wiki/Water_vapor

[SCG_Fenris_Wolf]

Rocket Man? Does that leader play this sim as well?

:D I would not know, for I am no North Korean agent

[ITAF_Cymao]

Ok I confess, I was diving who with the engine off.
But the reality is different, I wanted to write "reds in ..." in chat while I was starting to dive but I didn't press enter well and when I typed e I turned off the engine ...
I often turn off the engine thinking of writing in chat.

What I can say is that once I happened the same thing in H111 but when I turned on the engines they got damaged...

 

S!

[Jade_Monkey]

it would be nice to add a feature to realistic servers... ( engine start only on the ground)

Jesus Christ

[Lensman]

If you're diving from altitude then you will accelerate and that's not always desirable. I often zero my throttle when diving and hadn't considered any external implications. You might be observing a symptom and presuming it to be a cause.

[busdriver]

But your experience is as the rocket man, not a prop rider.

Just reread on wiki (good sources provided), that contrails typically appear at ambient temp below -35℃. That would mean that the contrails in-game are way overdone anyway, on anything but winter maps they ought to appear above 8000m because only then the crystals form...

 

 

Maybe I'm wrong ? But, we aren't flying jets after all..

 

You are correct that my RL experience producing contrails is in jets. My RL flying is currently limited to small two-place airplanes of the general aviation variety.

 

The rationale for my remark which I clearly failed to explain, is simply that engines produce noise, heat, and hot exhaust as by product of converting fossil fuels to energy. A high performance (think WWII fighter) engine produces a lot of hot exhaust. Simply reducing power to idle does not eliminate the hot exhaust. I've observed this in low powered, taildraggers that I currently fly. I fly in the winter as well, occasionally but rarely below -20C.  This natural phenomena is NOT specific to jet engines.

 

Regarding the -35C as a ballpark ambient temp for conditions favoring contrails...sounds reasonable. In aviation science, a Standard day is a condition of sea level and a temp of 15C. I was taught an adiabatic lapse rate (temp decrease as the altitude increases) of 2C per 1000 feet. But that is an approximate lapse rate. So to go from 15C to -35C would require approximately 25,000 feet or about 8000 meters. 

 

And just so there is no confusion this time...none of the science or my observations and opinions were based upon having flown jets.

 

Dietrich provided a much more comprehensive thumb nail sketch of the variables.

Edited October 11, 2017 by busdriver

[216th_Lucas_From_Hell]

Thanks for the explanation, Dietrich

 

On the dynamics of restarting an engine while diving, from my limited understanding so long as the propeller or turbine are producing enough rotations while assisted by the wind the engine has a good chance of starting properly. The catch is that there is only so much altitude for you to get it running

[Guest deleted@30725]

I don't think a real plane you can press the 'E' button to start your engine.

[1PL-Husar-1Esk]

I don't think a real plane you can press the 'E' button to start your engine.

But when I press e button automat is doing all "necessary" steps to start the engine, you can't skip that - it take time.

[Venturi]

I can't argue with your intuition, lower the volume of hot air, decrease the size of a contrail. But it's still very hot air compared to the ambient air temp.

 

There is a concept known as "shock cooling" an engine that folks that tow gliders or haul skydivers are familiar with. The gist being a pilot risks damage to his engine if after heavy usage (high engine internal temps...cylinder head temp, oil temp) the pilot reduces power too quickly or reduces it too much (long enough to cause "shock cooling"). It was a greater concern decades ago with engines that were not manufactured to the higher standards of today (think materials and tolerances). As an example, our club's 160 HP Super Cub can obtain CHTs (cylinder head temp) around 425C whilst towing at maximum power to 3000' AGL, once off tow we reduce power slightly to allow the CHTs to get below 385C (takes a couple minutes) before pulling the power to idle. I admit this is NOT analogous to a WWII fighter trying an idle descent through a contrail level, but perhaps you see a similarity. But I digress.

 

Air cooled work differently than water cooled.

 

In water/glycol cooled aircraft, the engine temperatures are moderated by the insanely high specific heat of water - in effect, temperature fluctuations are severely curtailed.

 

In air cooled aircraft, the engine temperatures fluctuate wildly depending on many factors, but primarily this effect is due to the low specific heat of the metal comprising the engine itself. (All metals have low specific heats when compared to water.) This greater fluctuation in temperature is why air-cooled engines must be manufactured to more stringent metallurgical and parts-clearance requirements (the clearances are always greater but more tightly controlled in manufacturing for a air-cooled engine).

 

Shock cooling is a thing for the turbochargers powering engines as well, regardless of the engine's actual cooling method (air or water/glycol) because of the extremely high heat that the turbine itself deal with, but the general principle is the same as that for the air-cooled engine, above.

[Venturi]

As for volume of air, this is the issue:

 

Not only is every revolution of the engine producing an exhaust volume, but the TOTAL exhaust volume the engine produces varies greatly depending on the manifold pressure. The maximum manifold pressure of an engine in turn depends on the supercharger impeller speed and the air density. A higher impeller speed, given by a higher engine RPM, will therefore increase manifold pressure and thereby total exhaust volume.

 

So RPM and manifold pressure are tied together at low air densities.

 

Additionally, increased combustion pressures increase the exhaust gas heat. High exhaust volumes also increase the heat of the exhaust gasses, as thermal soak sets in to all the parts that gas touches.

 

Bottom line, RPM and manifold pressures both influence contrails. Even at idle, exhaust gasses are hot compared to surrounding air, but the volume of exhaust would be far less by an order of magnitude, due to the processes I described above.

 

Also, no one would purposefully shut off their engine in a dive in a real combat scenario, ever.

[GridiroN]

I fought a bunch of FW190s on WoL trying to do this against me, and I didn't find it overly hard to track where they were going. If you didn't know someone was diving on you, saw a contrail, and then saw it end, the player on the other end will get a few cheap kills, but generally, you were dead anyway. 

 

The amount of times you'd see a contrail, not find the plane it belongs to, reaquire the plan half way into a dive, and have enough time not to get hit are very low. 

 

Now don't get me mistaken; I think it's cheesy, but lots of things in sim are cheesy. That wouldn't bother me nearly as much as people chasing around dead planes in hopes of kill steals. 

Edited October 12, 2017 by GridiroN

[Haza]

I fought a bunch of FW190s on WoL trying to do this against me, and I didn't find it overly hard to track where they were going. If you didn't know someone was diving on you, saw a contrail, and then saw it end, the player on the other end will get a few cheap kills, but generally, you were dead anyway. 

 

The amount of times you'd see a contrail, not find the plane it belongs to, reaquire the plan half way into a dive, and have enough time not to get hit are very low. 

 

Now don't get me mistaken; I think it's cheesy, but lots of things in sim are cheesy. That wouldn't bother me nearly as much as people chasing around dead planes in hopes of kill steals. 

 

Gridiron,

 

The thrust of the post wasn't to agree whether it was or wasn't cheesy, but to merely discuss what would actually happen regarding contrails and engine restart procedures etc at high alt in RL. 

 

However, regarding my encounter, when you are at contrail height and you see a higher contrail with the aircraft in front directly above you and the contrail abruptly stops, it is very difficult to see an aircraft that is diving without the give away tail-tale contrail against the blue of the bright blue sky.  In this case, I put 2 and 2 together and realised what was about to happen and although I got hit I had managed to break away in time without seeing him but knew what he was going to do. 

 

I'm more interested the the RL aspects of this situation.  Perhaps the contrail effects may not be able to be altered as the physics etc required are to difficult, but perhaps a different start-up cycle of an engine in flight perhaps could be looked at, although the time and effort required to do this perhaps is not worth the effort for a once in a blue moon occurrence, but I still would be interested to know the procedures as I'm sure each aircraft would be different depending on alt, time etc etc.

 

However, a mass formation of B-17s turning off their engines perhaps would not have concealed their presence over an enemy target (Tongue and cheek).

 

Regards

Edited October 12, 2017 by Haza

[GridiroN]

Gridiron,

 

The thrust of the post wasn't to agree whether it was or wasn't cheesy, but to merely discuss what would actually happen regarding contrails and engine restart procedures etc at high alt in RL. 

 

However, regarding my encounter, when you are at contrail height and you see a higher contrail with the aircraft in front directly above you and the contrail abruptly stops, it is very difficult to see an aircraft that is diving without the give away tail-tale contrail against the blue of the bright blue sky.  In this case, I put 2 and 2 together and realised what was about to happen and although I got hit I had managed to break away in time without seeing him but knew what he was going to do. 

 

I'm more interested the the RL aspects of this situation.  Perhaps the contrail effects may not be able to be altered as the physics etc required are to difficult, but perhaps a different start-up cycle of an engine in flight perhaps could be looked at, although the time and effort required to do this perhaps is not worth the effort for a once in a blue moon occurrence, but I still would be interested to know the procedures as I'm sure each aircraft would be different depending on alt, time etc etc.

 

However, a mass formation of B-17s turning off their engines perhaps would not have concealed their presence over an enemy target (Tongue and cheek).

 

Regards

 

As far as I'm aware, in real life restarting your engine in flight typically requires restarting your fuel pumps and/or magnetos; not a major task, but would require attention. In WW2 fighters, if I'm not mistaken, many required achieving the right amount of pumps and achieve the right amount of pressure. Jetliners have a crank mode that allows the engines to use the wind to crank the turbine back up. Therefore, while it's entirely possible for a pilot to turn off and on their engine in flight, the time, distraction and potential loss of energy during combat would make it a bad idea.

 

In IL2, starting or shutting down your engine is just 1 button, so it's not significant disadvantage. 

Edited October 12, 2017 by GridiroN

[ZachariasX]

Depends what they mean with „turning off the engine“. All you had to do is cut the contacts with the magnetos. Once ignition stops, you stop producing a contrail.

 

This might be the way „they“ do it, but in real life you have some issues that might make you reconsider doing. As soon as you cut contact, fuel (plenty with such engines) will be pumped directly though the exhaust stacks spraying your aircraft. How much of it will vaporize, that you will find out once you engage magnetos again. As your prop is windmilling, you are pumping fuel. If you feather and stop your prop, good luck restarting your engine while approaching firing position. You should have a turning prop, else in most planes your guns wont‘t fire.

 

Alternatively, you could cut fuel, but as there would be some lag for the engine to stop, as well as it to start. Certainly an interesting moment in a hostile sky.

 

Both examples require the prop windmilling. But it is my impression that the brake effect of a windmilling prop in game is not modelled even close to RL. In my experience, in single prop planes if you have a windmilling prop, your plane goes straight down and certainly not behind anything remotely fast.

 

Doing the Ctrl E thing is the last you would do to stop is as that one should leave everything off, hydraulic pressure zero and prop set to fine. You would overspeed it right away, thinking of diving (instead of dropping, that is what you would do), you would quickly destroy your engine.

 

That people do it in game I consider to be owed to no proper drag modelled with a windmilling prop. Besides your frag coming cheaper than your life. Also, restarting engines of the era can be much more entertaining than in todays cars with the „Start“ button.

[1PL-Husar-1Esk]

Turing engine off results leaving propeller at high pitch (or setting it manually) and without tractor pulling down ,just G it could be used in dive as air break to avoid over speed/ over shot during dive attack. You can use nose cannon , if you don't turn engine on right before attack or not if no need for electricity to work. Just academic speculation.

Edited October 12, 2017 by 307_Tomcat

[ZachariasX]

When doing Crtl E to "turn off" the engine/airplane, the sequence should be that the airplane is shut down. You by all means must set prop at fine pitch then. Especially in the case of the russian planes, you will make it very, very hard to start the engine again when it is set all the way to coarse. It will be much harder to crank the engine. As you don't have pressure in your system you cannot set the prop to fine. Only once it is running. Leaving the prop to coarse when "shutting down" the aircraft would be dead wrong. Besides, shutting down the aircraft  includes releasing pressure form the hydraulics and also the pneumatic system. Not cool in flight. It should even engange controls lock. This would take care of the entire "Ctrl E argument" while in flight.

 

Turing engine off results leaving propeller at high pitch

What dou you mean by "turning engine off"? There is no such button. Master switch off (for airplanes that have such)? Iginition off? Fuel cock off? Circuit breakers off? Release hydraulic pressure (where applicable)? All of it off?

 

You can use nose cannon

If you have pneumatic pressure in your system. This requires the prop to at least windmill.

 

,just G it could be used in dive as air break to avoid over speed/ over shot during dive attack

There I can't follow you. How so? Besides the windmilling prop wil break you such that you can't catch anything but a Stuka with extended airbrakes (and maybe a Po-2, but only diving).

 

if you don't turn engine on right before attack or not if no need for electricity to work.

You honestly think you can start such an engine as fast and as easy as your car does with the start/stop function? What if the other guy sees you in the last moment and pulls away, and there you are enigine off, winmilling prop, dropping like a piano? What if the supposed victim has friends around?

Edited October 12, 2017 by ZachariasX