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Hi all,

 

I've been back playing FC now that I've invested in an Oculus Rift S and using Pat's excellent campaign generator in a late-1917 Camel campaign.

 

Whilst I find the Camel a wonderful plane to fly and fight in (albeit only in SP), I am struggling with diving (and landing but that's another story), as I always seem to break the engine even if diving with the throttle at 0 or blipping regularly.

 

It means a height advantage is actually not that much of an advantage, because I have to nurse the Camel down from altitude.

 

Having recently read MvR's autobiography, "The Red Battle Flyer", there is also a chapter from Floyd Gibbons' 1927 biography about the Red Baron, and he quotes the following further to a post-war interview with Capt. Roy Brown regarding the Red Baron's final combat and death:

 

"The next second he (Brown), pushed forward on the stick and stood the Camel on her nose, and dove straight for the combat, his plane splitting the air with the combined speed of a full-out motor and the acceleration of gravity. Seven cherry-nosed Camels followed on the two-mile descent..."

 

Now, if I try that the engine will break within seconds and no way I am diving at full throttle for any time at all.

 

Any guidance on how to do this properly, or is the FM/DM a little suspect?

 

R

 

 

 

 

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Well, similar to the S.E.5a story recounted on page 2 in the WW1 scout dive performance comparison paper over at The Aerodrome forum, I remember reading (just not where for the moment!) an account of a Camel pilot diving after his leader with the needle against the stop in a close to vertical dive so this means that there is historical evidence that it should be possible to dive at least in excess of 180 mph IAS since that was where the scale ended.

 

Regarding the Camel engine handling in FC I have no idea but there should be some FC Camel jockey's out there (@ST_Catchov?) that could explain how that part can be managed. However, provided that you manage to avoid killing the engine, don't know what speeds you can attain in FC in the Camel before it breaks up?

 

Reference for Camel +180 mph dive: "Camel king of combat" book by Chaz Bowyer, page 77.

Edited by Holtzauge
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2 minutes ago, J5_Hellbender said:

Sideslip.

 

OK, but to what IAS speed can you safely go to in the Camel in-game?

 

Regarding the sideslip trick to keep speed down in-game that sounds interesting: Not sure it would have been such a good idea IRL though: For many WW2 fighters sideslipping at high speed was a big no-no since you could break off the whole tail section if you did. Not sure if the same applies to WW1 scouts although if it did, no one would have been around to talk about it would they? ;)

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20 minutes ago, Holtzauge said:

OK, but to what IAS speed can you safely go to in the Camel in-game?

 

Define "safely".

 

 

 

I'll have a look and see if this still works in FC.

 

Surely the wingless part won't be a problem.

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49 minutes ago, US213_Talbot said:

Supposedly, if you put your mixture full rich it won't over rev. Or something like that. I don't know for sure. I dont fly the thing but saw something posted in chat one time.

 

I've tried this and it worked for me. The rich mixture seems to gunk up the engine and stop it from over revving. That said, I don't think I've blown my engine from powering back except from over cooling it. 

 

Camel engine can indeed be a real dick. I've had it over rev once when I pulled out of the dive, started climbing and reapplied power.

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2 hours ago, Russkly said:

Whilst I find the Camel a wonderful plane to fly and fight in (albeit only in SP), I am struggling with diving (and landing but that's another story), as I always seem to break the engine even if diving with the throttle at 0 or blipping regularly. It means a height advantage is actually not that much of an advantage, because I have to nurse the Camel down from altitude.

 

In my experience that should be enough to prevent the engine breaking during dives.

 

I've heard about the full power full mixture trick but never tried it before as keep forgetting about it. So just gave a go doing three dives in the quick mission from ten thousand feet. From start point setting the engine and then nosing down into the dives (something around 70 degree dive would estimate, was diving on enemy flight that was set to be two and half thousand meters ahead at five hundred meters height). First one with full power normal mixture ended, quite soon, with dead engine which was not a surprise. Second doing my usual reduced throttle with blip switch (releasing now and then just enough to keep engine alive) which came rather close to sixteen hundred rpm (over that would go poof) but the engine survived. Then last the full power full mixture trick which lasted quite some time but near the bottom of the dive ended up breaking the engine for me also?

 

Is it during the dive that the engine becomes damaged or are you noticing afterwards on the pull out? As was often the case (sometimes still is) that I would power back up after the dive and then discover that my engine broke at some point. Seemed to be that was putting the power back on too soon. Though @kotori87 found when doing some tests that when the engine is overcooled (which does tend to occur on some dives with reduced throttle and blipping) the engines rpm limitations are reduced so when powering back on afterwards (and the blips during dive) your limits less than the norm.

 

Imagine that the full power full mixture trick its less likely that the engines going to overcool so prob one advantage to that.

 

Quote

Overcooling: If you overcool an engine, its maximum allowable RPM goes down. This makes it very easy to over-rev your engine in a long dive if you fail to shut your radiator, or if you're using a rotary engine. This doesn't appear to change what RPM you'll actually achieve at a given throttle setting, just what RPM the engine will fail at. I have blown my engine several times at lower RPMs than the usual failure point after I overcooled my engine.

 

EDIT: I see Gardimus just touched on that also.

 

Quote

Well, similar to the S.E.5a story recounted on page 2 in the WW1 scout dive performance comparison paper over at The Aerodrome forum, I remember reading (just not where for the moment!) an account of a Camel pilot diving after his leader with the needle against the stop in a close to vertical dive so this means that there is historical evidence that it should be possible to dive at least in excess of 180 mph IAS since that was where the scale ended.

Quote

OK, but to what IAS speed can you safely go to in the Camel in-game?

 

During the three dives that mentioned above (well on the latter two of them at least) I checked my airspeed and the needle was against the stop. There was quite some shaking going on but did not break the plane apart, damaged the engine on all but the one where I reduced the throttle and used the blip switch.

Edited by Oliver88
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1 hour ago, Holtzauge said:

OK, but to what IAS speed can you safely go to in the Camel in-game?

At 175 mph IAS it shakes hard, at 180 mph IAS is where the shedding starts, at 190 mph, wings are gone. You don't really want to go much beyond 170 mph.

 

1 hour ago, Gardimus said:

The rich mixture seems to gunk up the engine and stop it from over revving.

What is funny is that the "mixture trick" only works if you set full rich (or blip, same case!) BEFORE the engine reaches about 1100 rpm in the dive. Below that speed, windmilling will not crank up the prop. Having mixture set to a suitable level will always make the engine pick up excessive rpm in the dive. You will speed up to 175 mph where the engine is windmilled to 1600 rpm and it is destroyed. Thus, only cutting the engine with the blip (or cut-off lean) or 100% rich (that will decrease rpm below these 1100) BEFORE you dive will keep the engine alive all the way to 185 mph, from where wings really come apart.

 

Best I find for a dive or diving escape is strong side slip and at least 1000 rpm, you will not overcool the engine and you can go straight down safely with nasty Fokkers usually passing you if they stay in pursuit.

 

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3 hours ago, Oliver88 said:

During the three dives that mentioned above (well on the latter two of them at least) I checked my airspeed and the needle was against the stop. There was quite some shaking going on but did not break the plane apart, damaged the engine on all but the one where I reduced the throttle and used the blip switch.

 

2 hours ago, ZachariasX said:

At 175 mph IAS it shakes hard, at 180 mph IAS is where the shedding starts, at 190 mph, wings are gone. You don't really want to go much beyond 170 mph.

 

What is funny is that the "mixture trick" only works if you set full rich (or blip, same case!) BEFORE the engine reaches about 1100 rpm in the dive. Below that speed, windmilling will not crank up the prop. Having mixture set to a suitable level will always make the engine pick up excessive rpm in the dive. You will speed up to 175 mph where the engine is windmilled to 1600 rpm and it is destroyed. Thus, only cutting the engine with the blip (or cut-off lean) or 100% rich (that will decrease rpm below these 1100) BEFORE you dive will keep the engine alive all the way to 185 mph, from where wings really come apart.

 

Best I find for a dive or diving escape is strong side slip and at least 1000 rpm, you will not overcool the engine and you can go straight down safely with nasty Fokkers usually passing you if they stay in pursuit.

 

 

Some interesting information about engine management during a steep dive from Chaz Bowyer's book Camel King of combat where Capt. Ronald Sykes DFC had this to say about the Camel on page 77:

 

"We were soon going down vertically and the throttle and fine-adjustment levers needed closing slightly to keep the engine from the 'never-exceed' rpm."

 

"The ASI needle went all around the dial to its limit of 180 and the scream of the wind was alarming, but still my leader kept going straight down for thousands of feet"

 

Then at the end of the dive he comments on his leader: "Then his speed dropped slightly as he reduced engine power"

 

So according to this account mixture and throttle needed closing slightly to keep the engine from over-reving. No closing throttle completely, no blipping, no special tricks with mixture to prevent the engine from exploding. Simply closing throttle SLIGHTLY seems to have been enough......

 

Then this bit is nice: Going down vertically for thousands of feet AFTER the needle is against the stop at 180 mph. So if you are at 180 mph IAS, throttle only slightly reduced, and then keep on going down vertically for thousands of feet, how fast would you be going I wonder?

 

Returning to things in FC, I also did a few runs myself now from 5000 m in the Camel, not vertically, but steep enough to get a slightly increasing speed over time and I lost either an aileron or part of the wing at 290-300 Km/h IAS (180-186 mph) which seems low given Capt. Sykes testimony above.

 

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 I couldn't work out how to show the hud/thottle/mixture settings? but in this steep dive vid I leaned out the mixture fully (0% mixture) and shut the throttle which kept the revs at approx 1500 during much of the dive. Speed got up to approx 175mph before shaking started (eased off the steepness at that point,  then steepened again). The "cold engine" icon popped up at the end of the dive but disappeared as I flattened out and increased throttle and mixture with no apparent engine damage. This was just a test run as I don't usually BnZ in the camel. If I do, I stuff it up and end up doing the dogfight dance. I might experiment more. Anyway, for what it's worth ....

 

 

 

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3 hours ago, ST_Catchov said:

 I couldn't work out how to show the hud/thottle/mixture settings? but in this steep dive vid I leaned out the mixture fully (0% mixture) and shut the throttle which kept the revs at approx 1500 during much of the dive. Speed got up to approx 175mph before shaking started (eased off the steepness at that point,  then steepened again). The "cold engine" icon popped up at the end of the dive but disappeared as I flattened out and increased throttle and mixture with no apparent engine damage. This was just a test run as I don't usually BnZ in the camel. If I do, I stuff it up and end up doing the dogfight dance. I might experiment more. Anyway, for what it's worth ....

 

 

 

 

Very interesting, Catchov.

 

So, with throttle at 0 and mixture full lean you can do what looks to be a sustained 70-80 deg dive?

 

Not sure why leaning the mixture out would help with the throttle at 0, but it shows that a serious dive can be done in a Camel without breaking the engine.

 

I'll play around myself tonight but closing the throttle doesn't tally with real life accounts, where there seems to be clear evidence of (full) powered dives..

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Yes, interesting results and thanks for posting them. However, I see three problems: One is that the in-game max speed without damage seems to be too low just like for the S.E.5a and secondly that you need to throttle all the way back and thirdly so much fiddling with mixture, doing things in a special order (before entering dive) etc. is needed in-game while in the Cpt. Sykes testimony I posted above only a slight reduction in power was done and consequently that was a power dive as opposed to the idle power dive needed in-game.

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31 minutes ago, 1PL-Husar-1Esk said:

If I remember correctly you can dive Camel without worrying about overreving the engine by setting the mixture  full rich and zero throttle. 

 

That's the point, Husar.

 

One should apparently be able to power dive the Camel without fiddling with mixture.

 

We may have uncovered an in-game workaround, as you suggest, but IRL it seems that one could dive at full throttle without altering mixture or blipping breaking the engine.

 

I was wondering if I was doing something wrong in the dive compared to the combat testimonials that I and others have read, but it seems that the FM is modelled differently from real life.

 

That appears to be the takeaway from this thread.

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Posted (edited)

OK, done some testing this evening (sorry, I haven't learned how to do videos):

 

Starting at 15,000ft in level flight @IAS approx. 90mph with mixture optimised for the altitude (around 5).

 

1.0  70-80 deg dive at full throttle maintaining mixture

 

       Engine broke within seconds

 

2.0 70-80 deg dive at 0 throttle and full lean mixture (engaged prior to initiating dive)

 

      Lost ailerons and beginning to lose parts of both aerofoils/struts at 180mph

      Engine OK as RPM <1100 (forgot to check exactly what it was at airframe failure)

 

3.0  70-80 deg dive at full throttle and full rich mixture (also engaged prior to initiating dive)

 

       Dived without issue to ground level even though IAS at indicated limit (180mph)

       RPM remained at 1600

 

Bizarre!

 

R

 

Edited by Russkly
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Just tried it out in combat on a PWCG mission in late 1917 against the feared Halberstadts:

 

In essence, if you set mixture to full rich regardless of speed, dive angle or altitude, you can dive at full throttle to your heart's content.

 

Interesting.

 

R

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2 hours ago, Russkly said:

Just tried it out in combat on a PWCG mission in late 1917 against the feared Halberstadts:

 

In essence, if you set mixture to full rich regardless of speed, dive angle or altitude, you can dive at full throttle to your heart's content.

 

Interesting.

 

R

 

That was interesting indeed: I have blown my Camel engine in all my speed trials so far so that is a trick I for sure will try out next time.

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35 minutes ago, Holtzauge said:

 

That was interesting indeed: I have blown my Camel engine in all my speed trials so far so that is a trick I for sure will try out next time.

 

Please do and let me know - I'd be interested to have verification from other sources.

 

If it works, it's a bit of a 'gamey' workaround, but from what I've read and others have written in this thread, at least it seems to reflect reality in terms of the Camel's ability to dive with power on.

 

Pretty useful in combat...

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5 minutes ago, Russkly said:

If it works, it's a bit of a 'gamey' workaround, but from what I've read and others have written in this thread, at least it seems to reflect reality in terms of the Camel's ability to dive with power on.

 

Pretty useful in combat...

 

It's not gamey at all. A valid tactic;)  Anything to counter those flying armoured wagons.

 

I just tried the full rich/full throttle "tactic" again and it worked. The first time I tried it I blew the engine. I wonder if different altitudes/fuel levels make a difference?

 

Perhaps it's time to practice bnz a bit more .... 

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14 hours ago, ST_Catchov said:

 

It's not gamey at all. A valid tactic;)  Anything to counter those flying armoured wagons.

 

I just tried the full rich/full throttle "tactic" again and it worked. The first time I tried it I blew the engine. I wonder if different altitudes/fuel levels make a difference?

 

Perhaps it's time to practice bnz a bit more .... 

 

So, one time it didn't work?

 

Did you set full rich and full throttle before entering the dive?

 

I'll play around with it some more this PM, but it seems we may now have a BnZ option for Camel jockeys.

 

Good news, because gliding down gently onto lower-alt e/a just didn't seem very realistic and also pretty foolhardy against the Halberstadt gunners.

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9 hours ago, Russkly said:

 

Did you set full rich and full throttle before entering the dive?

 

Probably not. And that was my mistake! 

 

9 hours ago, Russkly said:

 

Good news, because gliding down gently onto lower-alt e/a just didn't seem very realistic and also pretty foolhardy against the Halberstadt gunners.

 

Indeed!

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11 hours ago, ST_Catchov said:

 

Probably not. And that was my mistake! 

 

 

Indeed!

 

Let me know, if it works for you, Catchov.

 

It means fiddling with the mixture before and after a dive, but this workaround has helped me a lot.

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On 1/7/2021 at 4:34 AM, Holtzauge said:

<snip>

 

Then this bit is nice: Going down vertically for thousands of feet AFTER the needle is against the stop at 180 mph. So if you are at 180 mph IAS, throttle only slightly reduced, and then keep on going down vertically for thousands of feet, how fast would you be going I wonder?

 

 

Just for comparison with the SE5a dive thread, I took a Camel, Kuban autumn map, 48% fuel, and dived from 20,000ft with the "realism" settings ticked for invulnerable and the other one (forgotten what it is called). Point is that this should give the terminal velocity of the Camel assuming the wings and engine do not break. The dive was maintained as close to zero G on the meter as I could get.

 

At 10,000 ft the IAS was 192 with engine completely turned off, 195mph at full throttle and full rich. There could probably be a little improvement with maximum revs for the altitude.

 

Conclusion - terminal velocity of a Camel much lower than an SE5a, perhaps 190-200mph range.

 

Makes sense qualitatively - it is quite a bit lighter but not much smaller, at least in frontal area.  Making the plane/engine more robust might be correct, but would in this case make not so much difference to the dive performance, since the limiting terminal velocity is low.

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On 1/7/2021 at 11:19 PM, Russkly said:

Please do and let me know - I'd be interested to have verification from other sources.

 

On 1/7/2021 at 11:35 PM, ST_Catchov said:

I just tried the full rich/full throttle "tactic" again and it worked. The first time I tried it I blew the engine. I wonder if different altitudes/fuel levels make a difference?

 

I tried diving with full rich now but what happens for me is that the propeller just acts like a big windmill and does not rev up at all thereby allowing steep dives. As a byproduct I get the engine overcooled icon as well. So full rich for me just seems to stop the engine from getting any high revs at all (even with full throttle!) which is a far cry from the IRL account stating that the throttle be reduced slightly to stop the engine overreving. Completely different techniques if you ask me but maybe I did something wrong in-game or is that the correct “full rich” in-game method for avoiding blowing up the engine?

 

1 hour ago, unreasonable said:

Just for comparison with the SE5a dive thread, I took a Camel, Kuban autumn map, 48% fuel, and dived from 20,000ft with the "realism" settings ticked for invulnerable and the other one (forgotten what it is called). Point is that this should give the terminal velocity of the Camel assuming the wings and engine do not break. The dive was maintained as close to zero G on the meter as I could get.

 

At 10,000 ft the IAS was 192 with engine completely turned off, 195mph at full throttle and full rich. There could probably be a little improvement with maximum revs for the altitude.

 

Conclusion - terminal velocity of a Camel much lower than an SE5a, perhaps 190-200mph range.

 

Makes sense qualitatively - it is quite a bit lighter but not much smaller, at least in frontal area.  Making the plane/engine more robust might be correct, but would in this case make not so much difference to the dive performance, since the limiting terminal velocity is low.

 

That speed (190-200 mph in-game) sounds low IMHO. If we assume that the RAE knew what they were doing when they estimated the terminal velocity at 265 mph IAS for the S.E.5a then if you go by the flat plate drag area to weight quotient as outlined in the dive performance estimate paper in The Aerodrome forum, then the Camel will have after terminal velocity faster than 195-200 mph. The rationale behind that is that if the S.E.5a is tuned in the C++ simulations to align with the RAE S.E.5a modeling, it's simply a matter of maths to estimate Camel terminal velocity based on this and using these numbers then the Camel’s terminal velocity would be more like 90% (240 mph) of the S.E.5a. Now mind you that is just based on force analysis and Newtonian motion and the Camel may well be less robust so it could be that that sets the limit instead.

 

Edited by Holtzauge
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Taking fuel out makes a bit of difference, since the Camel carries a lot.  ~10mph for 50% fuel at 10,000ft compared to full, using the drag equation and solving for A*Cd from the SE5a speed/weight case to get a base. But I agree the difference still looks large: so either my are tests not yet consistent or precise enough - very likely - or the game is modelling the Camel as draggier than the SE5a in some respect.  Perhaps the vibration, which causes significant g volatility in the dive, giving a braking effect (?), has more impact on the lighter plane.

 

I will do a set of tests for both planes, full fuel and empty, all engine off, to check the v at 10,000ft at some point soon.

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In Chad Bowyer's "Sopwith Camel - King of Combat" there is a section where he presents notes that Captain Ronald Sykes DFC, wrote about flying the Camel (150 HP BR1 engine). One is about diving, I join a screenshot of the excerpt. 

20210110_090853.jpg

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Just now, SYN_Ricky said:

In Chad Bowyer's "Sopwith Camel - King of Combat" there is a section where he presents notes that Captain Ronald Sykes DFC, wrote about flying the Camel (150 HP BR1 engine). One is about diving, I join a screenshot of the excerpt. 

20210110_090853.jpg

 

Excellent, Ricky. Many thanks for posting.

 

Very interesting and corroborates what we were saying above - you cannot do in Il2 FC what Bowyers says you can do in a Camel in real life ...unless you set mixture to full rich before initiating the dive, as others have discovered.

 

Looks like another WW1 aviation book I'm going to have to get. I thought I had pretty much all of them, but obviously not this one.

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42 minutes ago, Russkly said:

 

Excellent, Ricky. Many thanks for posting.

 

Very interesting and corroborates what we were saying above - you cannot do in Il2 FC what Bowyers says you can do in a Camel in real life ...unless you set mixture to full rich before initiating the dive, as others have discovered.

 

Looks like another WW1 aviation book I'm going to have to get. I thought I had pretty much all of them, but obviously not this one.

You're welcome, I've had this book for a few months in my "to read" pile and just started reading it last week. Sykes notes are a really interesting read.

 

As much as I manage to dive the Camel in game by reducing a bit power and blipping (but never knowing if overcooling will happen), I wouldn't dare to go vertical for several thousands feet....haven't tried yet the trick described above, but clearly Sykes states that they just needed reducing power and mixture a little bit.

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Yes, I find that story believable as well (which was why I posted the excerpts earlier) since it contains the very technical description about the effects of a rapid change in air pressure due to the dive and the need to hand pump up the pressure in the fuel tank to get the engine running so not just another bar room story to impress the audience.

 

Of course as a devil's advocate one could always argue that there could be a difference between the BR1, Le Rhone, Oberursel and Clerget engines in terms of how they behave in a dive but I seriously doubt that the BR1 could be run at close to the “never exceed rpm” in a dive while this was not possible for any of the other rotaries.

 

I have no idea why the type of "complex" engine behaviour and management we see in-game in FC was introduced in the first place but maybe it's a remnant from RoF and was ported over but IMHO both realism and game play would benefit if this was addressed in FC. In addition, I think such a change would probably help widen the appeal of FC to more users since some more casual players are probably quite put off by the engines going bang as soon as you try to dive a bit.......

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4 minutes ago, Holtzauge said:

Yes, I find that story believable as well (which was why I posted the excerpts earlier) since it contains the very technical description about the effects of a rapid change in air pressure due to the dive and the need to hand pump up the pressure in the fuel tank to get the engine running so not just another bar room story to impress the audience.

 

Of course as a devil's advocate one could always argue that there could be a difference between the BR1, Le Rhone, Oberursel and Clerget engines in terms of how they behave in a dive but I seriously doubt that the BR1 could be run at close to the “never exceed rpm” in a dive while this was not possible for any of the other rotaries.

 

I have no idea why the type of "complex" engine behaviour and management we see in-game in FC was introduced in the first place but maybe it's a remnant from RoF and was ported over but IMHO both realism and game play would benefit if this was addressed in FC. In addition, I think such a change would probably help widen the appeal of FC to more users since some more casual players are probably quite put off by the engines going bang as soon as you try to dive a bit.......

Oh sorry, totally missed the post where you quoted the exact same excerpt 😑

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4 minutes ago, SYN_Ricky said:

Oh sorry, totally missed the post where you quoted the exact same excerpt 😑

 

No apology needed: I think posting the whole story was a good move since you get the story in context. ;)

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34 minutes ago, Holtzauge said:

I have no idea why the type of "complex" engine behaviour and management we see in-game in FC was introduced in the first place but maybe it's a remnant from RoF and was ported over but IMHO both realism and game play would benefit if this was addressed in FC.

I think there are several issues to the mixture trick as we have it in FC. It is of note that blipping/cut-out-leaning/100%rich only works if the initial rpm is below a certain threshold. Above that, the prop windmills such that is always overrevs.

 

This shows two thing to me, either a strange prop efficiency (in windmilling configuration, but maybe this behavious also applies during traction) and/or a strange setting for internal friction of the engine.

 

It is my impression that the slip of the propeller in windmilling is not that different from normal flight (just in the other direction). As these blades are cambered, they show little slip in normal horizontal flight. But if you invert the profile, it is far less efficient, hence I would not expect the prop speeding up almost linearly vs rpm once it transitions into windmilling.

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1 hour ago, Holtzauge said:

Yes, I find that story believable as well (which was why I posted the excerpts earlier) since it contains the very technical description about the effects of a rapid change in air pressure due to the dive and the need to hand pump up the pressure in the fuel tank to get the engine running so not just another bar room story to impress the audience.

 

Of course as a devil's advocate one could always argue that there could be a difference between the BR1, Le Rhone, Oberursel and Clerget engines in terms of how they behave in a dive but I seriously doubt that the BR1 could be run at close to the “never exceed rpm” in a dive while this was not possible for any of the other rotaries.

 

I have no idea why the type of "complex" engine behaviour and management we see in-game in FC was introduced in the first place but maybe it's a remnant from RoF and was ported over but IMHO both realism and game play would benefit if this was addressed in FC. In addition, I think such a change would probably help widen the appeal of FC to more users since some more casual players are probably quite put off by the engines going bang as soon as you try to dive a bit.......

 

I would "think" that all rotaries would behave the same.  Engines can be "braked" by reducing the amount of air going in "evidently", so engines that are controlled directly by the pilot (as a human carburetor), mixing fuel and air, can reduce the air flow in, presumably causing a partial vacum, thereby controlling engine speed.  Obviously the fuel needs to be reduced also, otherwise an over rich or flooded/dead engine might ensue.  The problem with that technique is getting the fuel/air settings right.

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32 minutes ago, HagarTheHorrible said:

 

I would "think" that all rotaries would behave the same.  Engines can be "braked" by reducing the amount of air going in "evidently", so engines that are controlled directly by the pilot (as a human carburetor), mixing fuel and air, can reduce the air flow in, presumably causing a partial vacum, thereby controlling engine speed.  Obviously the fuel needs to be reduced also, otherwise an over rich or flooded/dead engine might ensue.  The problem with that technique is getting the fuel/air settings right.

 

I think so too. Would be much better to have an in-game behavior for all the rotaries, Le Rhone, Clerget etc. that all behaved more in line with the Capt. Sykes description for the BR1, i.e. a slight reduction of throttle needed in dives and no problems to go faster than 180 mph in dives. Probably difficult to judge how fast Sykes was going in that vertical dive but I would not be surprised if it was in the 220-240 mph range. However, since we don’t have any IRL numbers on Camel or Dr.1 dives maybe it’s difficult to make a case for that but what we do have a case for IMHO is that power on dives to +180 mph are possible.

 

1 hour ago, ZachariasX said:

I think there are several issues to the mixture trick as we have it in FC. It is of note that blipping/cut-out-leaning/100%rich only works if the initial rpm is below a certain threshold. Above that, the prop windmills such that is always overrevs.

 

This shows two thing to me, either a strange prop efficiency (in windmilling configuration, but maybe this behavious also applies during traction) and/or a strange setting for internal friction of the engine.

 

It is my impression that the slip of the propeller in windmilling is not that different from normal flight (just in the other direction). As these blades are cambered, they show little slip in normal horizontal flight. But if you invert the profile, it is far less efficient, hence I would not expect the prop speeding up almost linearly vs rpm once it transitions into windmilling.

 

Could well be that that is what is happening. OTOH I can’t understand why it’s been modeled so you need to use an exploit (yes, I’m calling a spade a spade!) like the “reduce speed sufficiently THEN apply full rich” to avoid damaging your engine and then you can dive steeply with the engine braking your decent in-game? To top it all you have to baby an overcooled engine on the end or blow it up for that reason instead.

 

Almost everyone in these forums is obsessed with realism (guilty as charged) and the way things are now really hampers BnZ style flying and is not very realistic. WW1 scouts were as it is even IRL very limited in terms of speed range and curtailing this even more in-game lowers the appeal both to the hard core simmers and a wider audience IMHO. Not saying people would flock by the thousands if we get a more realistic WW1 engine model and expand the speed range but for sure today some people may try out FC and do some dives, blow up the engine and then shelf the game which will hardly bring even more casual players into the game or lead to more positive reviews and buy recommendations.

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1 hour ago, Holtzauge said:

 

 the “reduce speed sufficiently THEN apply full rich” to avoid damaging your engine and then you can dive steeply with the engine braking your decent in-game?

 

Interesting you day that, Holtzauge - in my (albeit limited) testing, I initiated the bunt at full power after setting mixture to full rich, and I maintained the dive (70-80 deg.) to approx. 1,000ft at full power.

 

On levelling out, I simply adjusted the mixture slightly to optimum for the altitude (circa 9 given that I was at 1,000ft).

 

No throttle adjustment at all from bunt at 15,000ft to level flight at approx. 1,000ft.

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1 hour ago, Holtzauge said:

OTOH I can’t understand why it’s been modeled so you need to use an exploit

I think we are just kicking the enveloppe of the sim, the region where "c'mon, good enough for release" is. And I think too, so the following is more an excercise in curiosity than asking for things.

 

TL;DR: We have a correct propeller on the sim that perform near perfect efficiency, very much in line of what can reasonably be expected. However, as a windmill it performs excessively well and should maybe be toned down in that regard. It would mend a lot if all aircraft would get a second look in that department.

 

Anyway, as you guys know I am obsessed with propellers regarding the performance of fixed pitch aircraft. I know that the Clerget 130 Camel should have a 2.65 meter pitch prop, so I though i'd look what the sim does with that info.

 

This means, that in theory i get:

 

RPM / 60 * pitch[m] * 3.6 = TAS

 

This as an approximation, a best case for level flight.

 

If I plot RPM vs. theoretical TAS I get this:

grafik.png.6325f7ad672641deb1d15d43c3ea5745.png

 

Now, when I start the game and read IAS vs RPM on Mosow 1941, autumn @1300 meters and correct for TAS using a calculator I get:

grafik.png.ec2e9455547bf6aff252ad63b35654c0.png

 

Almost the same, In the game the performance is consistent, underperforming about 5-10%. It is of note that the proportional speed increase is more consistent than the absolute error.

 

Going up altitude a bit:

grafik.png.eacd90e8288bc3bd8436e2eba768593f.png

 

And I see basically the same picture. Maybe the prop is a tad less efficient, but this probably within the measuring error.

 

MAIN POINT: we absolutely do have a Clerget 130 with the standard 2.65 m pitch prop modelled in our game. That is verified and such can other aircraft be verified (talking to you, SE5a!).

 

Now, how does that look when diving under windmilling conditions?

 

For this I went up to 5000 m on the same map, acellerated to max speed at 100% throttle and optimal mixture (50% up there) and then cut throttle to idle while initiating a dive, reading IAS and altitude on the HUD and rpm on the gauge. Then I used the TAS calculator to get TAS from IAS at the respective altitude. What I got is this:

 

grafik.png.274a409d645fa06341e88e8b582aa530.png

 

How nice, the windmilling prop really has a different efficiency than the pulling prop. At idle, speed went up and rpm along with it until 1600 rpm where the engine is at once destroyed such that it doesn't turn anymore. Personally, from what I know I think it it is reasonable that at 1600 rpm there is little left of the Clerget that can rotate. It is of note that during the dive, the propeller has an easier time speeding up as it doesn't bleed energy from pulling the aircraft. And it is still much less efficient.

 

Conclusion: I like how propellers are modelled in this sim, especially the differences in efficiency. The fact that you CAN dive a Camel at idle up to ~350 km/h (TAS) without the engine over revving just shows that one should tune the windmilling prop efficiency of the FC aircraft. that way, most diving issues would go away. The slightly lower permissible dive speeds I do not consider making the difference between successful and unsuccessful attacks.

 

 

 

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Some more diving Camel results for terminal velocity ignoring break up - engine off at various weights.

 

Conditions:

 

1) QMB Kuban Autumn map, 12:00hrs, weather all off.

2) Plane mods - Aldis, gauge, light, wing cut out.

3) Unbreakable and Invulnerable in realism.

4) Full ammunition

5) Fuel settings: Full, 48%,12%

 

Plane dived five times for each fuel setting.

 

- Start 5,000m

- Engine off (E)

- As close to zero Gs on HUD as possible

- Feet off the rudder

- Note IAS in kph when passing 3,048m

 

There is very severe vibration and instability in pitch at these speeds, sometimes with up to +/- 2 Gs on the meter. So I took the best four out of five for the calculation of the mean result. (It would be a couple of mph slower otherwise).

 

Comparison to modelled results:

 

For the modelled results I took the RAF SE5a results in report 492 (in the SE5a thread) and solved for Cd*A

Taking the FC spec page wing area for the SE5a as A, solved for Cd

For the Camel, used the FC spec page wing area for A and assuming the same Cd as the SE5a (It would not surprise me if it was actually slightly lower in reality).

Then calculated the terminal velocities for the Camel at the test weights.  

 

RESULTS

 

1535633918_Cameltestresults.thumb.JPG.af5064de606e477b8fc252b9c9c1b185.JPG

 

Note that the Camel carries a lot of fuel - I expect the speeds players could achieve in practice would be at the lower end of the range - even when invulnerable - since your fuel state would be low either in typical MP fashion, or in SP after a long climb. In addition, these highest speeds would be completely useless in combat in the game, as the plane is so unstable: you certainly could not aim the guns. So I agree that having the Vne a little low makes little or no tactical difference unless the vibration is also much reduced.

 

Edited by unreasonable
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