Dive Speeds

[=EXPEND=13SchwarzeHand]

Hello,

 

I wanted to share a question that was asked on the Russian forum regarding dive (Thanks for the Link, Radick and Lepiak). Finn here, especially asks regarding the 190 dive acceleration and whether the Rudder adjustments which are coming soon will have an effect on the dive speeds (https://forum.il2sturmovik.ru/topic/5709-155-ya-chast-dnevnikov-razrabotchika/page-3). An Petrovich gives an interesting answer (goolge translate).

 

Finn, on 08 Apr 2017 - 05:05, said:

    At the same time look at the dynamics of acceleration on the dive.

The dynamics of acceleration in the dive - this already applies not to stability / controllability, but to trajectory movement.
In turn, the trajectory movement is based on polars.
Tronesh Polars - "go" everything: and the maximum speed in GP, ​​and the climb time, and bends ... etc. etc.
Therefore, "at the same time" will not work, it is a separate big topic, requiring verification of the LTH for all reference modes. And if it is something to "look" - then under this task it is necessary to allocate a separate time, which is not present now.
Those changes, which are now being introduced into aerodynamics, have a minimal effect on the Polars.
So ЛТХ will remain without any noticeable changes. Only the characteristics of stability and controllability will change.

 

So I have also have 2 questions to you guys.

 

Does anybody know what i meant by ЛТХ reference modes?

 

When I do a test dive with the 190 from 10.000m to 6000m I need around 35 sec. which is pretty much in line with this test here (data sheet in the link is somewhat misleading since the actual dive starts at sec 26)

 

http://www.wwiiaircraftperformance.org/fw190/Fw_190_Dive.pdf

 

However, something that I found interesting is that the report states that the engine was automatically set by the Komandogerät to 2300 rpm and stayed there. In the game the throttle has to be cut totally in order to not overrev the engine. What could be the cause of this discrepancy or am I missing something obviouse?

 

Thanks!

Edited April 25, 2017 by II/JG17_SchwarzeDreizehn

[Holtzauge]

Great chart so thanks for linking to it. I seem to recall seeing it before but I had forgotten about it and it is a good chart with lots of info so was nice to see again. Unfortunately however, looking at the dive angle it seems this varied quite a lot during the dive so it’s difficult to reproduce either in a C++ simulation or in-game. Anyway, I tried to interpret what the devs say in the link and to me it seems they are saying that the planned flight characteristics changes will not affect the in-game dive performance which makes sense since AFAIK they are planning to change the handling characteristics and it seems strange if that should impact the high speed drag characteristics. As to the meaning of the “LTH”, just guessing, but maybe this is some google translate result for L/D ratio? In addition, for dive performance compressibility effects are very pronounced and I don’t know to what extent BoX models that. That important component was missing in the old IL-2 series but IIRC then team Daidalos added that on later which was good. Another thing that is difficult to access is propeller efficiency in a high speed dive: This really takes a hit when you start going fast because a progressively larger part of the prop blade will be going supersonic which also needs to be accounted for. This is also something I don’t know to what extent is modeled in BoX…..

 

On a tangent: I have seen in this forum some posters that think that the Fw-190 should be much better than the Yak in the dive but I don’t think that is the case: I have done C++ simulations and while the Fw-190 will pull away, the difference between different fighters is in general not that large as some seem to think and if you start off from a low E and separation situation then diving is no silver bullet even if you are sitting in a P-47. In addition, the P-47 is actually a good example since even in a Thunderbolt a lighter aircraft (higher T/W ratio) will initially actually close the gap on you until T<D which can actually take some time even if you point the nose down……

[=EXPEND=13SchwarzeHand]

Thanks Holtzauge,

 

 

. As to the meaning of the “LTH”, just guessing, but maybe this is some google translate result for L/D ratio?

That is what I suspected, but I just wasn´t sure. It would make sense however. I think the original letters are ЛТХ so LT and the German ch sound and the sound that does not exist in English. Accordingly it was translated to LTH by googletranslate.

 

 

In addition, for dive performance compressibility effects are very pronounced and I don’t know to what extent BoX models that

I heard, that it is not modeled at all in BoX. At least I think it had been discussed before somewhere.

Edited April 26, 2017 by II/JG17_SchwarzeDreizehn

[Brano]

ЛТХ = летно технические характеристики = Letno Technicheskie Charakteristiky = in general, technical flight characteristics/specs of given airplane. (speed,climb,roll etc)

[Holtzauge]

You learn something new every day! Спасибо Brano!

 

Now how about aileron reversal speed info on the Yak and LaGG? You don't happen to have that in a drawer somewhere?

[BlitzPig_EL]

Is it possible that aileron reversal speeds for the Yaks could only occur at speeds that a Yak could not achieve?

 

Hence, no reason for it to be even thought about?

 

I was always under the impression the aileron reversal was something that was not encountered below transonic speeds, so not a worry for any prop driven aircraft,

[=EXPEND=13SchwarzeHand]

I have done C++ simulations and while the Fw-190 will pull away, the difference between different fighters is in general not that large as some seem to think and if you start off from a low E and separation situation then diving is no silver bullet even if you are sitting in a P-47.

 

 

That´s interestging. Do you have results from that simulation that you could share, In order to get an impression of what kind of difference is plausible?

Edited April 27, 2017 by II/JG17_SchwarzeDreizehn

[3./JG15_Kampf]

A little out of the post, but I have to comment. The other day, flying in Berloga, I plunged from FW 190 into a Yak. He was already diving, so our energies were similar. Then the yak pulled a turn at about 650km / h. I was about 150 meters behind him. I tried to curve with it, since we were at a speed where the elevators of fw190 should work better than the yak elevators. But to my surprise, the yak continued its even tighter turn, while my driver almost went black out and could not follow. By carelessness, I was not recording.

I do not know how Yak managed to keep turning. In this situation the limit is the pilot and not the plane anymore

[1PL-Husar-1Esk]

I think it will change with announced ruder fix patch - bigger elevator stuffiness during fast speed dives .

[Brano]

You learn something new every day! Спасибо Brano!

 

Now how about aileron reversal speed info on the Yak and LaGG? You don't happen to have that in a drawer somewhere?

  Unfortunately not in my drawer. There is a certain amount of different test and research documents circulating russian sites.To dig out this specific topic would be timeconsuming as hell. Maybe if I was unemployed I could spend the time searching.  

  But for sure there is more ,and of expected quality level, in Central Archive of Russian Ministry of Defense (TsAMO RF). From where devs are using NII VVS test reports as basis for FM development + TsAGI reports. I guess that what is readilly available,they allready have. What they do not have must be then searched in other archives (The one in Podolsk near Moscow is not the only one,part of the TsAMO is also in Saratov AFAIK) 

 Saratov was in fact hometown of Zavod 292 = mother plant of mass produced Yak-1.

And this might be overstretched by far,but main producer of LaGG-3s in 1943-44 was Zavod nr.31 in Tbilisi,todays Georgia (not the US one  ). 

 

Here is "How-to" for those interested in visiting and researching at TsAMO RF in Podolsk.It is 2005 edition so things might have changed since then.

If you are ready to overcome tons of bureaucracy and able to communicate in russian,it might be worth a visit.

http://genobooks.narod.ru/Arhiv_MO/arhiv_MO.htm

[Holtzauge]

Is it possible that aileron reversal speeds for the Yaks could only occur at speeds that a Yak could not achieve?

 

Hence, no reason for it to be even thought about?

 

I was always under the impression the aileron reversal was something that was not encountered below transonic speeds, so not a worry for any prop driven aircraft,

 

Well it’s true that the aileron speed is usually higher than the Vne but it still has an impact at lower speeds as I tried to visualize in the figure I posted here. So even if you never get close to the aileron reversal speed, you will roll much slower if this is closer to your Vne than if it is much higher, i.e. there is an impact even at speeds substantially lower than the actual aileron reversal speed.

 

That´s interestging. Do you have results from that simulation that you could share, In order to get an impression of what kind of difference is plausible?

 

I’ll put together a chart and post something this weekend.

 

  Unfortunately not in my drawer. There is a certain amount of different test and research documents circulating russian sites.To dig out this specific topic would be timeconsuming as hell. Maybe if I was unemployed I could spend the time searching.

  But for sure there is more ,and of expected quality level, in Central Archive of Russian Ministry of Defense (TsAMO RF). From where devs are using NII VVS test reports as basis for FM development + TsAGI reports. I guess that what is readilly available,they allready have. What they do not have must be then searched in other archives (The one in Podolsk near Moscow is not the only one,part of the TsAMO is also in Saratov AFAIK) 

 Saratov was in fact hometown of Zavod 292 = mother plant of mass produced Yak-1.

And this might be overstretched by far,but main producer of LaGG-3s in 1943-44 was Zavod nr.31 in Tbilisi,todays Georgia (not the US one  ). 

 

Here is "How-to" for those interested in visiting and researching at TsAMO RF in Podolsk.It is 2005 edition so things might have changed since then.

If you are ready to overcome tons of bureaucracy and able to communicate in russian,it might be worth a visit.

http://genobooks.narod.ru/Arhiv_MO/arhiv_MO.htm

 

Well unfortunately my Russian skills suck so I’m pretty much stuck but I’m thinking maybe to post some google translated question in the Russian section and see how that pans out. Maybe there are guys there that either have or can dig up that kind of info.

 

As to visiting TsAMO in Podolsk that would probably be an interesting experience but seeing I’ve exhausted my Russian vocabulary in my reply to you I think I better abstain.

[=EXPEND=13SchwarzeHand]

 

 

I’ll put together a chart and post something this weekend.

 

Sounds amazing!

[Holtzauge]

So here are two dive comparsions: One for the Yak 1 versus Fw-109A3 at 15 and 30 degrees dive angle at combat power and one for Fw-190A3 1.42 ata versus Spitfire Mk9 at +18 boost at a 45 degree dive angle.

 

The Fw-190A3 versus Yak-1 is pretty straightforward: The Fw pulls ahead from the beginning due to a slight advantage in T/W ratio. In addition, it keeps on building on that due to a better D/W ratio. However, the pace at which this happens is at a leisurely “jogging” speed so it takes time to gain separation meaning don’t expect to put your nose down and instantly get out of trouble: Diving is no “get out of jail free” card even if you are sitting in a Fw-190.

 

I included the Mk9 versus A3 because it is interesting from the perspective that it shows the importance of T/W ratio in the beginning of a dive. Initially, when I did the simulations I thought that I must have gotten something wrong because we all know that the Fw outdives the Spit right? But when I started looking deeper to figure out what was happening, it became clear that initially until the speed builds up past the max speed (for a particular power setting at a particular altitude) then the weight is actually a liability: It is only when the speed builds up past the max speed that the weight becomes an asset and this is why the Spitfire at +18 boost initially dives better than the Fw and it is not until about 20 s into the dive it pulls ahead. Even then, although it is now significantly faster, there is not much altitude left and the Fw only manages to pull ahead less than 100 m before it reaches 2 Km altitude.

 

Conclusion: A superiority in dive basically means you will not get caught: You still have to ensure that when you enter the dive, you need to do that with enough separation so you are not within effective guns range. In addition, the dive should be shallow: Diving at steep angle will not allow you to build up enough separation before you run out of altitude and in addition, if the pursuer is smart, he will stay at a more shallow dive angle and not burn as much E as the steeper diving plane meaning he will catch you when you level off.

 

So in conclusion: A diving Fw-190A3 or A5 can very well be caught by a Yak-1 unless you disengage with enough separation since it takes time to build sufficient separation from the dive alone. In addition diving steeply to get away is a recipe for disaster. AFAIK this is also what happens in-game here and as far as I can tell from the C++ simulations this is also how it should be…….

[JtD]

Thanks for these charts, it very well illustrates how small the margins in dives typically were.

[1PL-Husar-1Esk]

That corresponds with my empherical experiences. Thanks Holtzauge.

[L3Pl4K]

Hello Holtzauge, it is possible to make a simuation 109F4 vs 190A2/3. The test scenario could be extracted from this document:

http://kurfurst.org/Tactical_trials/109F4_Rechlin_vergleich_190A2/109F_Rvergleichsflg_190A2_de.html

b im Sturzflug

[BlitzPig_EL]

Thanks.

 

I wish there was a way to send those charts to every player in the sim.

 

Like you said, it's no get out of jail free card, but so many players think that it is.

 

This will also be very relevant in the Pacific when we get there as the US planes do dive better than the Japanese do, but it's still not an instant "save me" switch.

[ZachariasX]

Thanks for those Holtzauge! Very instructive indeed.

 

Makes me really guessing that much of the "real world dive capabilities" of the Fw190 come from two things: fast (initial) roll and the ability to be basically not slower than the competition once you disengage in a dive.

 

It means if you're just about in shooting range of an enemy aircraft at combat speed, being one second faster in rolling on your back and going vertical, you just added another 100 m of separation putting you out of shooting range. As a persuer you now have the choice of following him down to the deck where you will be most likely alone fighting him again (while you can't be sure that this would be his fate as well) or just disengage.

 

Making a dive after him just makes you an attractive prey for any scavenger as well. The calculations show that any other Fw can follow you as well, while you are leaving your friends.

 

Thus, I think much has to do with the roll rate. The 109 was great at diving because they could push the stick forward while rolling into a dive, also giving them the credit of an initial separation, usually beyond gun range, even though the Spit is in principle the fastest (highest Mach number) in a dive.

 

It also shows that if someone is coming towards you with a good excess in speed (that obviously requires less than one might think) you are dead when trying to dive away.

 

But really cool stuff Holtz!!

[JtD]

I also think that the roll rate helped a lot, but in addition to that I also see two things:

 

The Fw190 had to be flown or was capable of flying at higher combat speeds than most of the contemporary fighters. This always provides an advantage, and is particularly helpful if you want to start a high speed escape. Enemy pilots used to their own rides or used to be fighting the Bf109 would certainly notice a difference.

 

Also, when you enter a dive with an opponent on your six, the chased plane typically will initially dive steeper than the chasing plane, because the chaser will follow the chased. In the dive at some point they'll both be flying at the same angle and along the same path, with the chaser still behind, meaning higher. It will have converted less altitude into speed, meaning just from geometry alone, the chased plane will appear to have a better initial acceleration, with the high speed acceleration/capability being decisive about who's pulling away from whom.

[Holtzauge]

Thanks for the positive feedback guys! This inspired me to do another chart: I have read some posts and videos both here and in other forums where people are upset at being caught by a “slower” diving plane when disengaging.

 

However, in some cases I suspect this is simply due to not disengaging in time: For example, say you are in a Fw and have been BnZ:ing a Yak for a while and he has manged to evade so you have burned a lot of your E advantage in the process. You see the Yak turning around to across the circle and decide it’s time to get out of dodge and straighten out and put the nose over. Say you have been greedy and allowed yourself too much time in the horizontal and the Yak has slight speed advantage, what would happen? Now since you follow the golden rule to never go below 300-400 Km/h in the Fw you are safe right? Maybe not: Assume that the Yak has a slight speed advantage, say 5% which would be 20 km/h in this case.

 

Surprisingly, the simulation shows that initially the “poorer diving” Yak actually CLOSES on you and it takes an agonizing 35 s before you actually start to increase the distance between you. So even a slight misjudgement about your opponents initial E state can be fatal: In this case the bogey only has a 5% speed advantage going into the dive and it still takes more than half a minute before you start to pull away…….

 

I think in this type of situation it would be easy to start blaming the FM because judging your relative E state within 5% is tricky to say the least: “I was in a Fw and there was a Yak on my tail and when I dived he still gained on me! Something is wrong with the FM!!!!!”

 

[Holtzauge]

Hello Holtzauge, it is possible to make a simuation 109F4 vs 190A2/3. The test scenario could be extracted from this document:

http://kurfurst.org/Tactical_trials/109F4_Rechlin_vergleich_190A2/109F_Rvergleichsflg_190A2_de.html

b im Sturzflug

 

I could but its difficult to reproduce the situation: It just says that the Fw pulls ahead more than 100 m in a 2000 m dive. There is no mention if it is from 3 to to 1 km or 6 to 4 Km altitude and what was the initial speed? Was it from close to stall or close to max speed? All this would impact the results....

 

Is there any particular reason you want to  compare the Fw and Me? Does it have to do with their relative in-game performance in BoX?

[L3Pl4K]

Is there any particular reason you want to compare the Fw and Me? Does it have to do with their relative in-game performance in BoX?

I comapred the ingame 109 F/G with this:

http://www.wwiiaircraftperformance.org/me109/Me_109_Dive_Test.pdf

Ingame it is not possible to reproduce the test flights. The Engine died by over revolution and the plane gets to fast high divespeeds. It looks like the real plane need the thrust of the propeler, to get high speed. The ingame plane reach to high dive speeds with idle. The 190 also has over revolution problem with the engine. I make some test flights with comrades, different alt, dive angle and starting speed. It was not possible for 190 to gain some separation.

 

Edited April 30, 2017 by L3Pl4K

[Holtzauge]

I have not tried to make a detailed analysis of dives in BoX when it comes to compressibility effects so I don't know to what level it is modeled. However, if you get high speeds even with idle in BoX that could be an indication that compressibility it not completely taken into account. The "old" IL-2 did not capture this effect and planes dived far to well at high speed. I include a test on the P-51D from way back when another forum member helped me capture in-game data via devicelink and we compared that to the C++ simulation which does model compressibility effects (Me-109G2 Cdo(Mach) chart attached for comparison).

 

As you can see, the in the C++ simulation the P-51D hits the "Mach barrier", i.e. as speed builds up it "hits" the Mach barrier while in the vanilla IL-2 the Cdo was essentially flat AFAIK which meant that the speed could go up all the way to 970 Km/h which is way too high. In the C++ simulation OTOH, speed stabilizes at around 860 Km/h due to the compressibility effects.

[L3Pl4K]

Another question Holtzauge. I have made a "glide test" on stalingrad autum, Kalach,6k,33% fuel. I take Yak 1 B, 109F4 and 190 A3. Turn to the east at 300km ias and stop the engine. I closed radiator flaps if possible. I tried to maintain 300 km ias at the glide. I reached following distances, before i hit the ground:

190A3 app 67km

109F4 app. 58km

Yak1b app. 50km

It is possible to glide such long distances with such heavy airplanes?

 

[JtD]

Yes. The P-51 manual states a glide ratio of 14, meaning it can get 84km distance out of 6km altitude.

 

The biggest issue here is the propeller drag. What you need to do in order to achieve really good glide ratios ideally is to feather the prop (90° pitch). It is also the reason why in your test the Fw goes furthest. It has the most coarse pitch setting of the three, meaning lowest rpm and least drag. If you like, you can try fiddling with the prop pitch and see how much of a difference it makes.

[ZachariasX]

Another question Holtzauge. I have made a "glide test" on stalingrad autum, Kalach,6k,33% fuel. I take Yak 1 B, 109F4 and 190 A3. Turn to the east at 300km ias and stop the engine. I closed radiator flaps if possible. I tried to maintain 300 km ias at the glide. I reached following distances, before i hit the ground:

190A3 app 67km

109F4 app. 58km

Yak1b app. 50km

It is possible to glide such long distances with such heavy airplanes?

You should expect 1:10 as gliding angle (thumb rule) with these kind of aircrafts. Even airliners will give you that, modern ones possibly a bit more. These are plausible values. Weight has not much influence on the gliding angle. All extra weight makes is force you to glide at higher speed.

 

Thelling from that, the Yak would have probably glided farther if you were a tad slower with that one.

[L3Pl4K]

You should expect 1:10 as gliding angle (thumb rule) with these kind of aircrafts. Even airliners will give you that, modern ones possibly a bit more. These are plausible values. Weight has not much influence on the gliding angle. All extra weight makes is force you to glide at higher speed.

 

Thelling from that, the Yak would have probably glided farther if you were a tad slower with that one.

i made only 2 glide flights per plane. In the yak i make one with 0 percent rpm and one with 100 percent rpm. If i spend more time and make maybe 10 glide flights, it should be possible to generate some km more. Maybe BOX has some space for improvements in the aera of compressbility/ modelling of the german propeller/engine. It would be nice if AnPetrovich can tell us some about this topic.

[ZachariasX]

i made only 2 glide flights per plane. In the yak i make one with 0 percent rpm and one with 100 percent rpm. If i spend more time and make maybe 10 glide flights, it should be possible to generate some km more. Maybe BOX has some space for improvements in the aera of compressbility/ modelling of the german propeller/engine. It would be nice if AnPetrovich can tell us some about this topic.

In principle, the faster the prop is windmilling, the more drag you should expect. The prop can create A LOT of drag like that. 1:10 is gliding angle with a feathered prop. Not sure if BoX models that. Slightly out of scope but would be nice.

[ICDP]

Great charts Holtzauge.

 

I remember years back in IL-2 being banned from a server because I managed to shoot down the owner of the servers Wildcat in my A6M2.  He dove on me with what he thought was a good margin of speed advantage and I easily evaded his attack.  He bled what little speed advantage he had trying and failing to pull lead for a shot.  We weren't that high, maybe 3000m and he pointed the nose down thinking his Wildcat would out dive me easily because the Zero can't dive.  I simply slid in behind him at about 250m ripped him a new one.

 

The chat box was blue with cheat accusations and he permabanned me because "no way a Zeke outdives a Wildcat".  I tried pointing out that even a P-47 at co E with a Zero cannot simply point the nose down and be out of gun range instantly.  Didn't matter, he read the Wildcat always outdives a Zeke, so I must have cheated.

[6./ZG26_Klaus_Mann]

Didn't the P-40 Manual state a Glide Ratio of 1:4.5? 1 Mile of Altitude makes 4.5 on the Ground at 150mph

 

http://www.avialogs.com/index.php/en/aircraft/usa/curtiss/p-40warhawk/pilot-training-manual-for-the-p-40.html

Edited May 1, 2017 by 6./ZG26_Klaus_Mann

[ZachariasX]

Didn't the P-40 Manual state a Glide Ratio of 1:4.5? 1 Mile of Altitude makes 4.5 on the Ground at 150mph

 

http://www.avialogs.com/index.php/en/aircraft/usa/curtiss/p-40warhawk/pilot-training-manual-for-the-p-40.html

It is. But lets put this recommendation into perspective.

 

First of all, this is a training manual. Not a spec sheet. It is a recommendation on how to operate the aircraft to stay in good health (and the plane in good order). What would be your recommendation to a novice pilot where to gauge for landing if the engine quits? I have the impression that you fly glider planes. Say, you're in an ASW-28, 15 meter wings, and that gildes officially at 1:44. You're 1 km AGL. Would you assume you consider the next emergency landing field at say, 40 km distance, within safe limits? 4 km margin? What do you tell a student? If he halves the official glide angle and acts upon that, then you can safely assume that he makes the distance even with wet pants.

 

Second, let's say, it was 1:4.5. Taken from wiki, the gliding angle of the Space Shuttle is 1:1 hypersonic and 1:4 on approach. If the P-40 and the Space Shuttle had almost the same gliding angle, then I would think the devs gave us a very maneuverable P-40 in this sim...

 

Also what they say in the manual ist that you have 1:4.5 at 150 mph. Looking at their advertised stall speed of 90 mph, this is a fast glide, meaning worse glide. Why so fast? You need 150 mph to be able to maneuver the plane reasonably well. Once you stall, you will require a lot of altitude to establish a good glide again. An altitude that you don't have as you, during a glide in such an aircraft, only do most manevering while you fly the pattern over your chosen landing strip/site/crater-to-be.

 

What they also say is that with power on glide, you can do that at 20'' Hg (less Hg will clog the sparks) at an airspeed of 110-115 mph. This would be about an airspeed that would be around best glide if stall is at 90 mph. In this configuration you have the prop acting as a huge airbrake, while being significantly slower than the safer 150 mph for dead stick glide. What you also have to assume is that if the engine quits, most pilots would not care to feather their prop and trim the plane for sail plane configuration, but that pilots should be able to act safely and quickly under circumstances that would be of great concern to their mothers.

 

In essence, they recommend that if your engine quits, look downward for an emergency landing field should you not feel like bailing out, and not look forward or to the sides.

 

What I find interesting is that to me the paragraph you mentined shows that in BoX, the brake effect from the prop doesn't seem to be modelled. A prop windmilling in idle is a very powerful brake that can well make you drop like a brick (or a shuttle) instead of gliding. But as said, I'd consider that omition not so important. (Altough trying to stay in a fight with engine dead clearly shows moral fiber )

 

I witnessed in our flying club once how strong this propeller brake can be. We had a Bravo tow plane, custom fitted with an Allison turbo prop. It was rather troublesome in the beginning, and once the prop got stuck in the beta (flat) position in flight, about 1 km AGL. Even with power cut immediately, the plane went down like almost it had Stuka dive barkes extended. The shocked pilot landed the plane in a soccer field about directly below where he was. Surprisingly, no harm was done. The airfield was no farther than 6 kilometers from where it happened, but reaching there was unthinkable. (They almost crashed the plane upon take off from the field, as, everyone nervous, they forgot to set the trim to take off from a position all the way back! The aircraft stalled out more then once right after take off. Good to have A LOT of power under the hood if you leave your diligence at home.)

[Holtzauge]

@ICDP: Yes, I think we all have preconceptions based on what we have read and I guess in many cases common knowledge is also true but then there are always exceptions to the rule and although I have not modeled it, I’m pretty sure that a Zero could outdive a Wildcat in the initial stages if the Wildcat was low on E. Also, based on your description of the attitude of the server owner you mentioned maybe it was not such a loss being banned?

 

@ ZachariasX: Nice story about the tow plane landing and taking off from a soccer field. Seems a bit tight taking off and I guess there were no high-risers at the end of that soccer field……

 

About the glide ratio: Lower than 1:10 is probably like you say with a windmilling propeller: I did a quick ballpark estimate of the best glide ratio on the Fw-190 from Bericht 6006 and it looks like it’s above 1:11 at least so the 1:4.5 for the P-40 is probably like you say a conservative rule of thumb for pilots based on that it can’t get any worse than that, i.e. prop generating the most drag possible.

[Hutzlipuh]

Interesting ... note especially the first sentences...

 

Me 109 G-2/G-6:
"The Russkies never followed to a dive. Their max dive speeds were too low, I suppose. It was the same in the Continuation War, their La-5's and Yak-9's turned quickly back up. "
- How heavy did the Me controls get at different speeds?
"It got heavy, but you could use the flettner. It was nothing special, but a big help.
- Did the roll capabilites change?
"Not so much. It got stiffer, but you still could bank."
- Were you still in full control at high speeds, like at 600-700 km/h?
"Yes. "
- Mauno Fräntilä, Finnish fighter ace. 5 1/2 victories. Source: Interview by Finnish Virtual Pilots Association: Chief Warrant Officer Mauno Fräntilä.

 

Yak speed limit in manual 650 kmh....(IAS ofcourse ,pilot has to have a reference on his speedometer)

Edited December 11, 2017 by Hutzlipuh

[Barnacles]

Dear all,

 

In the game, the 109's dive speed limit is listed as 850kmh.

 

https://forum.il2sturmovik.com/topic/25993-aircraft-flight-and-technical-specifications-and-operational/

 

In the flight manuals linked below, it is listed as 750kmh.

 

http://www.virtualpilots.fi/hist/pdf/bf109g6_english.pdf

 

http://www.virtualpilots.fi/hist/pdf/bf109g2_english.zip

 

I know that in BoX a plane doesn't start shedding parts exectly at the IAS stated in the manual (some historical sources for a Yak indicate a lower VNE too), but for example a spit's dive speed limit in the game matches the real life manual, whereas as far as I can see the 109 does not. Does anyone know why this is the case?

 

Edit: Also I've just checked the p40E operating instructions http://www.wwiiaircraftperformance.org/P-40/P-40E_Operation_Instructions.jpg which say maximum dive speed is 485mph (780kmh) yet in the game it's listed as 860kmh).

Edited December 11, 2017 by 71st_AH_Barnacles

[=EXPEND=13SchwarzeHand]

 

 

I know that in BoX a plane doesn't start shedding parts exectly at the IAS stated in the manual (some historical sources for a Yak indicate a lower VNE too), but for example a spit's dive speed limit in the game matches the real life manual, whereas as far as I can see the 109 does not. Does anyone know why this is the case?

 

Yes, all dive speeds were adapted due to actual test documents and not the manual. That´s why the Russian planes got higher max dive speeds than indicated in their manuals too. I don´t know about the Spit though. Maybe you need to come up with some documents indicating a higher dive speed than we have in game now, if you think that the current values are off.

 

S!

[sniperton]

- Did the roll capabilites change?

"Not so much. It got stiffer, but you still could bank."

- Were you still in full control at high speeds, like at 600-700 km/h?

"Yes. "

- Mauno Fräntilä, Finnish fighter ace. 5 1/2 victories.

 

Reading testimonies like this always reminds me of interviews with Kimi Raikkönen. The same experience would have been described in quite different terms by a Sebastian Vettel or a Lewis Hamilton, not to speak of a Fernando Alonso. Kimi would say "I could turn" and "in full control" where others would describe it as a struggle and something near-impossible to achieve.

[Barnacles]

Yes, all dive speeds were adapted due to actual test documents and not the manual. That´s why the Russian planes got higher max dive speeds than indicated in their manuals too. I don´t know about the Spit though. Maybe you need to come up with some documents indicating a higher dive speed than we have in game now, if you think that the current values are off.

 

S!

 

Thanks for that. Initially there seems to be lots of stuff about the mark IX achiving very high speeds in trials (over 900kmh undamaged) in dives but nothing about the V.

[=EXPEND=13SchwarzeHand]

Thanks for that. Initially there seems to be lots of stuff about the mark IX achiving very high speeds in trials (over 900kmh undamaged) in dives but nothing about the V.

If that is the case, I would try to figure out whether you can argue that the airframe of the mark IX is the same as in the V. I am not spitfire expert so I don´t know. Apart from that I think devs only take documents regarding the actual model to make any changes. Good look with your search!

Edited December 11, 2017 by II/JG17_SchwarzeDreizehn

[L3Pl4K]

 

 

whereas as far as I can see the 109 does not. Does anyone know why this is the case?

Maybe this could help:

http://www.wwiiaircraftperformance.org/me109/Me_109_Dive_Test.pdf

[E69_geramos109]

On the game now i have done a lot of tests and was imposible for me to outdive a yak 1 with the 109 at any angle.

I tested to reach both the max speed, both to 700, both to 600 and the yak just seem to take more speed with less angle so when the 109 comes to the ground the yak just have more altitude to still diving and finaly the yak overtakes the 109 quite easyly. I have not found any situation where to dive against a yak is a good option as much as you can win is some time but nothing more than that.

 

Is that correct? I have never heared a singel pilot talking about keeping the yaks on the dives with the german planes. They just talked about if they saw the german pilot to dive by by

Edited January 10, 2018 by E69_geramos109