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Mig 3 - First Impressions

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Right now MiG3 is best red side aircraft in terms of max dive speed. That totally contradicts to the original il2 experience. well done, development team!

Was that supposed to be sarcastic? Why wouldn't the MiG be the best dive performer?

Edited by Finkeren

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A pilot of a Cessna, or a Sukhoi 26, neither are experts in the behavior of the planes represented here.

 

Most aircraft represented in BoS saw mathematics, wind tunnel tests, and were designed by aeronautical engineers that weren't all pilots.

 

Just being a pilot doesn't equate to being knowledgeable in how plane's fly. Being able to drive a small sea craft doesn't make someone capable of captaining an ocean liner, just the same as everyone that drives day to day cars could never hope to drive a race car of any type on any track, and I don't mean to the limit, I mean no one would succeed above 80mph on a track by themselves not to mention with other drivers. The "not a pilot" retort is not acceptable. Pilots don't design the planes, and sometimes they don't even know how they operate... Take for example the jet plane taking off from a treadmill when the treadmill matches the plane's speed. Many a pilot has claimed it can't take off because the treadmill matches the plane's speed. The treadmill only causes more speed on the wheels, it doesn't have any impact on the aircraft's air speed. And yet, pilots have claimed otherwise.

[Edited]

Edited by Bearcat

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My printed words come from 2 books made by Soviet engineers in december 1940 and April 1941 respectivly. Where are yours coming from?

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So, what was the point of your pedantic rambling ? You by your own admission are not an expert at any of what is being discussed . You appear to be like most in this thread-simple  enjoy your the sight of your own printed words.

 

 

So you are an aeronautical engineer?  A simple pilot is as much an expert in such things as a corporal is in high strategy.

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I think it's likely the numbers are true - the few elite regiments that went up with the P-40 got

good results, which always eventually warranted replacement with the P-39 or La-5 once the time came. 126 IAP, 19 GIAP, 2

GSAP...

I doubt it. Everyone overclaimed but Soviet records are extremely unreliable in this

aspect.

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Well, obviously if you go high enough, air density becomes so low that the convection of the air becomes virtually insignificant and cooling is only achieved through radiation. A vacuum is the ideal insulator.

 

But is there a point, where the lower temperature at altitude overcomes the lower air pressure to provide optimal cooling? I don't know.

This also depends on the temperature of the object you want to cool. Generally, with normal liquid cooled operating parameters of around 100°C, reduced density and reduced ambient temperature pretty much cancel each other out, if the indicated air speed is not considerably slower. It's different with air cooled engines, with cylinder temperature limits of around 200°C. There the increased temperature difference does not compensate the reduced density.

 

Since heat convection is roughly equivalent to (air flow mass) * (temperature difference), short numbers example.

For a 110°C water cooler in standard atmosphere, you'd need to go 500km/h at sea level or 656km/h at 6000m for the same cooling effect - to achieve this, high up you'd need like 7% less power than down low, not far off for the average WW2 aero engine.

A 220°C cylinder head in standard atmosphere, going the same speeds and being at 220°C at sea level, would increase temperature to 265°C at 6km.

 

In standard atmosphere, temperature only decrease up to 10km, after which only density drops, so if there's a point where the balance no longer works, it's there.

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This also depends on the temperature of the object you want to cool. Generally, with normal liquid cooled operating parameters of around 100°C, reduced density and reduced ambient temperature pretty much cancel each other out, if the indicated air speed is not considerably slower. It's different with air cooled engines, with cylinder temperature limits of around 200°C. There the increased temperature difference does not compensate the reduced density.

 

Since heat convection is roughly equivalent to (air flow mass) * (temperature difference), short numbers example.

For a 110°C water cooler in standard atmosphere, you'd need to go 500km/h at sea level or 656km/h at 6000m for the same cooling effect - to achieve this, high up you'd need like 7% less power than down low, not far off for the average WW2 aero engine.

A 220°C cylinder head in standard atmosphere, going the same speeds and being at 220°C at sea level, would increase temperature to 265°C at 6km.

 

In standard atmosphere, temperature only decrease up to 10km, after which only density drops, so if there's a point where the balance no longer works, it's there.

 

Thanks,this is very informative. I had the intuition than, roughly, these two effects are compensating each other. I searched some thermodynamic parameters to support this, but haven't found them, except that air heat capacity is going down with T°, which let cooling less efficient at low temperature.

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MiGs with a starter tooth did exist, but they're rare in wartime photos (which is propably an indicator that they were rare in real life as well)

 

A couple of examples:

rubtzov.jpgwhite12fr.jpgMiG-3%20engine%20starter.jpg

 

For some reason they appear much more often in artwork, scale models and computer games. I think it's just become a way of indicating a late production MiG, even though it's not really representative of that either.

 

The starter tooth apparently started to be added to some MiGs late in its service life. I don't think I've ever seen a good explanation as to why it was added, other than presumably some MiGs had trouble starting their engines without assistance? :unsure::unsure::unsure:

 

I have a personal idea, that might be the explanation though (WARNING: This is pure speculation on my part) I think the MIGs with starter tooth could be examples that were re-engined with AM-38s, based on the fact that photos of them are really rare and that virtually all IL-2s with AM-38 engines have a starter tooth.

 

In BoM I think they chose to include the starter tooth simply to have an easy way to visually identify an up-gunned MiG-3, even though it's not strictly speaking historically accurate. In real life there was virtually no way of telling, what cowling armament a MiG carried. Some have even suggested, that the central gun port (which weren't in use on UBS or ShVAK armed MiGs) might not even have been covered, like it is in the BoM model, making the up-gunned MiGs completely imposible to distiguish.

I think the thing with the starter tooth is it's just too big on the 3d model. I was comparing it to wartime photos and the Il-2 (also uses Mikulin engine) and I think the size should be reduced a bit. I edited a couple of screenshots for comparison in this thread. http://forum.il2sturmovik.com/topic/18289-mig-3

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Here are some comparison shots of the MiG-3 vs Il-2 spinner and starter tooth. 

 

post-30291-0-55842600-1452114230_thumb.jpg

post-30291-0-69952800-1452114689_thumb.jpg

 

Ok I have everything thats wrong with this plane noted and described here http://forum.il2sturmovik.com/topic/12255-graphics-models-and-maps/page-3?do=findComment&comment=322082so hopefully the devs can check it out and make some adjustments. I just find it very disappointing since this is my favorite plane of all time. I've been watching the development since 2013 and I've been waiting specifically for this plane to actually jump on.

Edited by Danziger

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And you can find similar limits in manuals for all Soviet fighters of 1941-42 (around 650km/h IAS) due to the fragile connections in the delta wood on the wings. Yet test data shows Soviet fighter designs diving at +700km/h without issue.

 

The MiG-3 has the best acceleration in a dive (as I believe it should have) but maneuverability suffers to a large degree above 600km/h, so in practical terms it really doesn't matter if the MiG can attain a slightly higher dive speed than the other Soviet fighters (excluding the P-40) Because it's still way behind the German fighters and can hardly pull out of a dive at all, if you get above 700km/h.

Edited by Finkeren

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I had a pretty good sortie yesterday on my server, alone in a Mig-3 against two humans flying the Mc202, another human flying the F-2, and two more players in Stukas. Added to it, there were also up to 3 AI bf110 flying around that I had to keep an eye on.

 

I took the two Italians by surprise. Damaged the first who ran away, and killed the second who apparently had lost contact on me.

The F-2 was a real challenge.

 

Initially higher, I was lucky that the pilot was aggressive at the wrong time. The Mig-3 easily got out of the way when it had less energy, and it regained energy very well. It wasn't long before we were co-E. I tried to fly away, and I could have probably managed it, but turned back towards my enemy. What could have been a mistake, as the F-2 got on my six, became his mistake, as he committed to a turn fight with me. My flaps were not set up for combat, and apparently I had no idea how to activate boost, which means he might have had a decent chance to win that one. The real mistake though was leaving the fight, and fleeing in a curve (probably to keep an eye on me on his six).

 

 

It wasn't hard to catch up, and from then on the F-2 did not have a chance. One snapshot triggered a coolant leak, and that allowed me to focus on the other planes around. An AI in a bf110 had taken an interest in me, and ignoring it could be a mistake. I also thought for a moment I was fighting a human. The bf110 AI is pretty good, as in "believable as a human". I also had to watch for the Stukas. Normally I wouldn't fear them, but I knew those had to be humans. Being the designer of the mission really helps in cases like these. None of these attackers turned out to be any threat to me, as the AIs went down, and the Stukas left. I could make a few more passes on the crippled F-2, who should have taken his chance to leave the scene, but tried (and almost succeeded) to get back at me while I was chasing AIs. I don't think I managed to put more shots into the F-2, but its engine gave up and the pilot did a belly landing.

 

My impressions were that the Mig-3 was a very good plane. Fast and energy-efficient, nimble at low speeds. The rudder however is surprisingly sensitive. I had to stay off it. The plane is said to be subject to nasty stalls, and I can see that happening, but I never had any problem. The audio feedback you get at high angle of attacks is very noticeable.

Edited by coconut
  • Upvote 1

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Very nice writeup of what seems to have been an awesome fight coconut.

 

Yes, in skilled* hands the MiG is a pretty darned strong fighter, provided you stay aggressive.

 

The one thing I don't recognise is when you say, that the MiG-3 is very nimble at low speeds. I find that it has superior agility to the 109s in the 300-500kmh range, but below 300 I find it almost imposible to complete sharp maneuvers without having to abort to avoid an accelerated stall.

 

* My own hands unfortunately being only semi-skilled I still kinda suck in the MiG despite flying pretty much nothing else.

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Fun write-up indeed coconut :)

 

Finkeren, if you need a further unskilled pilot to provide an easier target for your pursuers let me know, I'm not on BoM yet so it's all Lavochkin to me but anyhow.

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Very nice writeup of what seems to have been an awesome fight coconut.

 

Yes, in skilled* hands the MiG is a pretty darned strong fighter, provided you stay aggressive.

 

The one thing I don't recognise is when you say, that the MiG-3 is very nimble at low speeds. I find that it has superior agility to the 109s in the 300-500kmh range, but below 300 I find it almost imposible to complete sharp maneuvers without having to abort to avoid an accelerated stall.

 

* My own hands unfortunately being only semi-skilled I still kinda suck in the MiG despite flying pretty much nothing else.

 

I've found the same. It takes a lot of coordination on the controls to make the MiG-3 work at lower speeds. The leading edge slats save me about half the time... If they weren't there then I'd be in the ground a lot more. :)

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The one thing I don't recognise is when you say, that the MiG-3 is very nimble at low speeds. I find that it has superior agility to the 109s in the 300-500kmh range, but below 300 I find it almost imposible to complete sharp maneuvers without having to abort to avoid an accelerated stall.

 

300 km/h - 500 km/h is what I meant by "low speed". OK, I can see how that might have been misleading  ;)

 

I think I only got below 300 during that right turn and on top of climbs. In these situations, the F-2 seemed to be struggling just as much, if not more.

But then, neither I nor my opponent used flaps, where a few percents might have helped.

 

Oh, and I just now noticed I have apparently flown the entire time on boost, since I was at full throttle and finest RPM. The engine did not seem to complain. Maybe because I kept all rads open all the time (engine management à la coconut  :unsure: ...)

Edited by coconut

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After 10 mins at full boost you run the risk of the engine suddenly dying on you without warning.

 

If you truly wanna get a feeling for what the MiG is capable of, try flying her on a winter map, where you will seldom have to open those radiators/air brakes more than 50%. The MiG is a race horse on the summer map but a god damn cheeta in winter.  

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And you can find similar limits in manuals for all Soviet fighters of 1941-42 (around 650km/h IAS) due to the fragile connections in the delta wood on the wings. Yet test data shows Soviet fighter designs diving at +700km/h without issue.

 

The MiG-3 has the best acceleration in a dive (as I believe it should have) but maneuverability suffers to a large degree above 600km/h, so in practical terms it really doesn't matter if the MiG can attain a slightly higher dive speed than the other Soviet fighters (excluding the P-40) Because it's still way behind the German fighters and can hardly pull out of a dive at all, if you get above 700km/h.

 

that doesn´t make any sense. Any chance you´ll show those other manuals and test data? Or explain why a vibration warning would be in the flightmanual if unnecessary or how that could be related to "fragile connections" in plywood? I mean, it´s fine that you like the mig 3 above anything else, it´s a fine aircraft.. but I don´t think soviet aircraft engineers are that different to any other aircraft engineer. If there is a warning in the flighthandbook, it has a reason... and if you have "excessive vibrations" in a dive you´re not fine or having "individual aircraft problems".. Comon sense aerodynamics would also suggest that a plane the shape of a 109 is much more likely to have a faster initial dive acceleration and if you don´t believe me, build models and throw them. The wingshape alone makes that clear, that the 109 is the diver of the two.. as well as fuselage diameter, wingloading etc... I haven´t looked it up, but I suspect there is hardly any historical evidence otherwise.

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that doesn´t make any sense. Any chance you´ll show those other manuals and test data? Or explain why a vibration warning would be in the flightmanual if unnecessary or how that could be related to "fragile connections" in plywood? I mean, it´s fine that you like the mig 3 above anything else, it´s a fine aircraft.. but I don´t think soviet aircraft engineers are that different to any other aircraft engineer. If there is a warning in the flighthandbook, it has a reason... and if you have "excessive vibrations" in a dive you´re not fine or having "individual aircraft problems".. Comon sense aerodynamics would also suggest that a plane the shape of a 109 is much more likely to have a faster initial dive acceleration and if you don´t believe me, build models and throw them. The wingshape alone makes that clear, that the 109 is the diver of the two.. as well as fuselage diameter, wingloading etc... I haven´t looked it up, but I suspect there is hardly any historical evidence otherwise.

I'm not saying the flight manual should be ignored, and I don't think the devs have done so.

 

If you dive the MiG to 650 you'll see she really does "vibrate excessively" (as do all Soviet produced aircraft in this sim) in addition to being damn near imposible to pull out of the dive at that speed. What I'm saying is, that the vibrations don't mean that the plane should automatically come apart once you reach 700.

 

As to which plane should have the best initial acceleration in a dive: I'm no aeronautics engineer, but I honestly don't see why the 109 has an obvious advantage over the MiG. Both are certainly very aerodynamically shaped aircraft, but both have their strengths and weaknesses. The 109 has the thinner wing profile, but the MiG has the shorter wingspan and slightly backswept wings. The MiG has the big, square intake on its belly, but the 109 has a flat, squared off windscreen compared to the bubble shape on the MiG. I'm not even sure the cross section of the fuselage is larger on the MiG. It might look more bulky, but keep in mind, that the overall dimensions of the MiG are tiny even compared to the 109. The MiG has one clear advantage in a dive though: It's 10-15% heavier, meaning that the 109 would need a significant aerodynamical advantage to beat it in a dive, which I just don't think it has.

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I'm not saying the flight manual should be ignored, and I don't think the devs have done so.

 

If you dive the MiG to 650 you'll see she really does "vibrate excessively" (as do all Soviet produced aircraft in this sim) in addition to being damn near imposible to pull out of the dive at that speed. What I'm saying is, that the vibrations don't mean that the plane should automatically come apart once you reach 700.

 

As to which plane should have the best initial acceleration in a dive: I'm no aeronautics engineer, but I honestly don't see why the 109 has an obvious advantage over the MiG. Both are certainly very aerodynamically shaped aircraft, but both have their strengths and weaknesses. The 109 has the thinner wing profile, but the MiG has the shorter wingspan and slightly backswept wings. The MiG has the big, square intake on its belly, but the 109 has a flat, squared off windscreen compared to the bubble shape on the MiG. I'm not even sure the cross section of the fuselage is larger on the MiG. It might look more bulky, but keep in mind, that the overall dimensions of the MiG are tiny even compared to the 109. The MiG has one clear advantage in a dive though: It's 10-15% heavier, meaning that the 109 would need a significant aerodynamical advantage to beat it in a dive, which I just don't think it has.

 

 

Physics are impartial... it doesn´t matter if a plane "nazi" or "commie" and if you get excessive vibration in any aircraft (in the designrange ww2 prop fighter with straight wings) in a dive at those speeds you are very likely starting to have compressibility issues and the plane will go out of control or break up shortly if you continue to dive and even if you try to recover, that is a dicey thing. Hard to say an "exact" limit of how much more it takes in terms of km/h for final demise, but 50 is probably on the realistic side. Same would apply if the reason was flutter (in which case the "vibration" maybe a just an imprecise wording or translation error or whatnot). Bottom line: if you are in a plane of that category and you have excessive vibration, then you reduce speed imiately or you won´t make it.

 

In Physics, heavier objects don´t fall faster (cue the famous dropping a penny and a feather in a vacum tube experiment).. in athmosphere "denser" and less dragier objects fall faster. In aerodramatics, one needs to measure to know, but some design features are giving an educated guess a direction: profile thickness, wing aspect ratio etc. The wingspan alone itself is not so relevant. And all those points point to a plane with the shape of a 109 being more likely to have a faster dive accerleration then the Mig 3 shaped one. Wings have more percentual influence then the fuselage to the drag, but in both aspects (wing shape, thickness and aspect ratio as well as fuselage diameter and cleanlyness) with a simple look one can expect the 109 to be the better diver.

 

don´t get me wrong, the mig is an awesome desgin.. and it is very cool engineering, but in the real world in a diving contest my money would be clearly on 109s f/g

Edited by Dr_Zeebra

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Problem is zebra that Russian planes have a Huge disparity in quality even between models of the same serie. No doubt a well made or a mig 3 prototype would break any manual regulation, whereas an average Frontline plane would dislocate passed 680 km/h.

 

I suspect developer used "high quality plane" tests to design Russian FM, this problem did not concerned LW until very end of the war, and quality and performance of planes were much more standard.

 

Inside a same serie of aircraft, VVS pilots observed up to 30-40km.h top speed difference between their planes....

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in athmosphere "denser" and less dragier objects fall faster

 

If we assume that drag is proportional to speed, and that the engine isn't contributing to the dive speed, we get that acceleration = g - (speed * drag factor / mass). Of two planes that have the same drag factor and have identical speeds in dive, the heavier one will accelerate more.

 

If we assume that drag factor = "how sleek the plane looks" * "size of the aircraft", and if we assume Finkeren's claim that sleekness are equal, and the Mig-3 is smaller, then the Mig-3 has a smaller drag factor. If it is also heavier, then that's another advantage.

 

Note that the assumption that the engine isn't contributing is just wrong, as we are not talking about gliders, but if we include engine effects the problem gets a bit harder to analyze.

 

 

 

In aerodramatics

 

Is that physics as discussed in these forums? Don't know if you coined that term on purpose, but I like it  ;)

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If we assume that drag is proportional to speed, and that the engine isn't contributing to the dive speed, we get that acceleration = g - (speed * drag factor / mass). Of two planes that have the same drag factor and have identical speeds in dive, the heavier one will accelerate more.

 

If we assume that drag factor = "how sleek the plane looks" * "size of the aircraft", and if we assume Finkeren's claim that sleekness are equal, and the Mig-3 is smaller, then the Mig-3 has a smaller drag factor. If it is also heavier, then that's another advantage.

 

Note that the assumption that the engine isn't contributing is just wrong, as we are not talking about gliders, but if we include engine effects the problem gets a bit harder to analyze.

 

 

 

 

Is that physics as discussed in these forums? Don't know if you coined that term on purpose, but I like it  ;)

 

Not my term, but the "aerodramatics" comes from within a certain airplane manufacturer in europe, where system engineers with a "slap-on" mentalities like to put things on an airframe have routinely to deal with "oooh, but this´ll cost XYZ in performance" outcries from another department. I just find it so extremely fittin for flightsim-fan discussions ;=)

 

like i said, absolute truth is only in measurement..  I just "guesstimate" out of certain design aspects, that the 109 would likely be a bit cleaner then the mig. In my eyes that would also match the historical anectdotes about the 109s dive efficency.. But yeah, I´m also mainly a glider guy and maybe the whole prop-disc and propwash currents and the like may make it more complicated then just a first glance.

 

Nonetheless, I think the Mig 3 just as design is a world class aircraft design for it´s time, and arguably simply the best medium-high altitude interceptor in it´s theater at it´s time. And by looking at the historical quotes and design features I´d say it´s repution is a bit "unfairly" affected by production and real-use circumstances (which are not a desingflaw). It´s designers where smart men who really understood that speed and altitude where of prime importance and put out a bit of a radical design that packs a lot into small dimensions. I think people often overlook that it has even a bit of "more" range compared to the other fighters in it´s class and the best speeds above 4000m. It seems a bit like a racehorse: designed to go fast and stay fast. 

 

I would guess (from the design features) that all the famously quoted things like low level flight dynamics, directional stability issues when aiming etc.. actually are because it was used different to what it was originally optimised for: keeping it fast and keeping it fast for prolonged periods of time at altitude. All those huge radiators are there for a reason, I´d guess.. together with a lot of "changing weight" (fuel,ammo,oil) beeing close to the CG, so that you would probably experience very little change in trim it all fits the profile of an interceptor that has the sustainable speed and range to counter air attack very efficently and even outrun the enemy fighters at it´s design altitude in level flight.

 

 

Trinkof,

I don´t think manufacturing issues as well as wear&tear (affecting all sides, off course) are good to bring into a game environment. It´s simply doesn´t really work as a game design element.. In a game, you have 1000s of iterations of everything more then in real life. If you have "random defects" people just spawn until the have the right plane.. having a random failure just when you´re doing good in a fight, may be interesting once.. but it get´s anoying and old if you have it a hundred of times. Games will always be games and 100% realism is neither optainable nor would it make sense, gamewise, if you could.

Edited by Dr_Zeebra

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Yes I think it's a shame that the MiG-3 often gets dismissed because of a reputation it gained from untrained pilots and misuse. People assume that they stopped production because it sucked so bad but it was actually Stalin himself who gave a final warning to stop MiG-3 production because the engines were needed more by Il-2. The MiG-3 was actually the most advanced Soviet fighter at the start of the war. Further along than Yakovlev or Lavochkin.

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And (as I learned here in fact) it was a Polikarpov design originally :) The man had a flair for designing aircraft that were the fastest in their field at their introduction dates. Once you keep that in mind you can see the signature traits of his designs - big engine, cockpit placed way back, manoeuvrable but unforgiving, and fast.

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Physics are impartial... it doesn´t matter if a plane "nazi" or "commie" and if you get excessive vibration in any aircraft (in the designrange ww2 prop fighter with straight wings) in a dive at those speeds you are very likely starting to have compressibility issues and the plane will go out of control or break up shortly if you continue to dive and even if you try to recover, that is a dicey thing. Hard to say an "exact" limit of how much more it takes in terms of km/h for final demise, but 50 is probably on the realistic side. Same would apply if the reason was flutter (in which case the "vibration" maybe a just an imprecise wording or translation error or whatnot). Bottom line: if you are in a plane of that category and you have excessive vibration, then you reduce speed imiately or you won´t make it.

 

I don't know if compressibility is accurately modelled in the sim, but I do know, that specifically with regards to the MiG, the effect is pretty much the same. As soon as you cross 500km/h IAS the elevator starts becoming heavy and at 700km/h it's so excessive that pulling out of a steep dive at that point is practically impossible. This means, that diving beyond 650 in the MiG actually does carry a significant risk, unlike for instance the Yak, which can pull out of a 750 km/h dive with little trouble.

 

Physics are impartial... it doesn´t matter if a plane "nazi" or "commie" and if you get excessive vibration in any aircraft (in the designrange ww2 prop fighter with straight wings) in a dive at those speeds you are very likely starting to have compressibility issues and the plane will go out of control or break up shortly if you continue to dive and even if you try to recover, that is a dicey thing. Hard to say an "exact" limit of how much more it takes in terms of km/h for final demise, but 50 is probably on the realistic side. Same would apply if the reason was flutter (in which case the "vibration" maybe a just an imprecise wording or translation error or whatnot). Bottom line: if you are in a plane of that category and you have excessive vibration, then you reduce speed imiately or you won´t make it.

 

In Physics, heavier objects don´t fall faster (cue the famous dropping a penny and a feather in a vacum tube experiment).. in athmosphere "denser" and less dragier objects fall faster. In aerodramatics, one needs to measure to know, but some design features are giving an educated guess a direction: profile thickness, wing aspect ratio etc. The wingspan alone itself is not so relevant. And all those points point to a plane with the shape of a 109 being more likely to have a faster dive accerleration then the Mig 3 shaped one. Wings have more percentual influence then the fuselage to the drag, but in both aspects (wing shape, thickness and aspect ratio as well as fuselage diameter and cleanlyness) with a simple look one can expect the 109 to be the better diver.

 

don´t get me wrong, the mig is an awesome desgin.. and it is very cool engineering, but in the real world in a diving contest my money would be clearly on 109s f/g

 

I don't really disagree with much of what you're saying, but I think you make a mistake by simply guessing from a quick glance, that the 109 must be a much more drag-efficient design than the MiG, I'm not at all sure, that's the case, and the numbers seem to bear that out as well.

 

Consider this:

 

The Bf 109 F2 (which I think is still the 109 we're talking about here) has a power/weight ratio with normal combat load of 0.42 hp/kg, slightly higher than the 0.40 hp/kg for the MiG. Yet the MiG reaches a maximum speed of 640km/h compared to the Bf 109F2's 615km/h. Form drag being by far the greatest factor limiting top speed in sub-sonic flight, this would indicate that the MiG is by far the more drag-efficient design. This discrepancy is ofc a bit misleading, because the MiG achieves its optimal power output and top speed at a higher altitude than the F2, so the difference is propably less noticable once that is accounted for. Still the overall picture is not that of the 109 being obviously less draggy than the MiG, when it can achieve a top speed some 35km/h higher with a lower p/w ratio.

 

A guesstimate from me would be, that the two designs are fairly close to one another when it comes to form drag with the 109s longer, narrower wings with less taper producing more lift induced drag than the stubbier tapering wings of the MiG, which is propably part of the reason why the MiG accelerates better at low speeds (induced drag becoming less important with increasing air speed)

 

In any case, the fact that a combat loaded MiG is some 20% heavier than a combat loaded Bf 109F2 while not being obviously more draggy would explain quite well the better acceleration in a dive of the MiG.

Edited by Finkeren

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The Bf 109 F2 has a power/weight ratio of 0.42 hp/kg, slightly higher than the 0.40 hp/kg for the MiG. Yet the MiG reaches a maximum speed of 640km/h compared to the Bf 109F2's 615km/h. Form drag being by far the greatest factor limiting top speed in sub-sonic flight, this would indicate that the MiG is by far the more drag-efficient design.

 

"the 109s longer, narrower wings with less taper producing more lift induced drag than the stubbier tapering wings of the MiG"

 

i think you´re wrenching logic here. As a thought experiment: if the that logic was true, the speed of the mig would have to be even more faster down low, where there is more drag in a denser athmosphere. Obvious going from a general rated engine power per kg take-off weight is not going to give you a realistic performance comparision regarding to drag.

 

 

regarding your theory on aspect ratio: have you ever looked at the shape of drag optimised planes, let´s say gliders? How do you think their wings are.. short and stubby or long and slender? just sayin.

Bruno_Gantenbrink_Nimeta_D-KGYY.jpg

 

https://de.wikipedia.org/wiki/Eta_%28Flugzeug%29#/media/File:Nimeta.jpg

Edited by Dr_Zeebra

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If its engine gave a similar power output down low that would hold up, no? Let me see if I can find the test data for the MiGs with the AM-38 engine.

 

EDIT: Airpages has the ASL speed at 547km/h. Of course these were different engines, but the major benefit here was the low-altitude power output plus extra horsepower in general. How does the Friedrich hold up?

Edited by Lucas_From_Hell

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i think you´re wrenching logic here. As a thought experiment: if the that logic was true, the speed of the mig would have to be even more faster down low, where there is more drag in a denser athmosphere. Obvious going from a general rated engine power per kg take-off weight is not going to give you a realistic performance comparision regarding to drag.

 

 

regarding your theory on aspect ratio: have you ever looked at the shape of drag optimised planes, let´s say gliders? How do you think their wings are.. short and stubby or long and slender? just sayin.

Bruno_Gantenbrink_Nimeta_D-KGYY.jpg

 

https://de.wikipedia.org/wiki/Eta_%28Flugzeug%29#/media/File:Nimeta.jpg

 

Surely that is to do with their Lift/Drag ratio, not quite the same thing? If you want to reduce the drag of the fins of a rocket, would you not make them as small as possible?

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Rockets travel well faster than usual aircraft thus need less lift. There are however cruise missiles with rather long, thin wings.

 

EDIT: Airpages has the ASL speed at 547km/h. Of course these were different engines, but the major benefit here was the low-altitude power output plus extra horsepower in general. How does the Friedrich hold up?

Bf-109 F4 should be 525km/h from the top of my head (G-2 532 km/h).

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Thanks for the info, Stuka :) To be fair I have no place in this discussion, I'll let the wiser elaborate - I just thought the AM-38 MiG-3 was more suitable for a sea level comparison due to the AM-35 being optimised for high-altitude action (by no means a slouch down low, still).

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i think you´re wrenching logic here. As a thought experiment: if the that logic was true, the speed of the mig would have to be even more faster down low, where there is more drag in a denser athmosphere. Obvious going from a general rated engine power per kg take-off weight is not going to give you a realistic performance comparision regarding to drag.

 

The MiG would be a lot faster on the deck were it not for the fact, that the AM-35 engine had significantly lower power output at low altitude. That's kind of the drawback of the Mikunin Engine design, it really has to be optimised for maximum output at a certain altitude. That's why the prototype AM-38 powered MiGs were bloody race horses on the deck but had horrible performance at altitude, despite their engines being rated at over 1700hp: The AM-38 was optimised solely for low altitude performance, almost the exact opposite of the AM-35.

 

It think it's testament to the MiGs design, that it was even able to get close to 500km/h on the deck with the AM-35.

 

regarding your theory on aspect ratio: have you ever looked at the shape of drag optimised planes, let´s say gliders? How do you think their wings are.. short and stubby or long and slender? just sayin.

You are absolutely right. I had the rules for induced drag mixed up in my head. A long, slender wing will in fact produce low amounts of induced drag (but more form drag than a shorter wing) an eliptical wing is even better though, but the shape of the 109's wings from the F-model onwards is actually pretty good at lowering induced drag.

 

Regarding gliders however: You can say that they are "drag optimised", but only for the way that they fly, which is very, very slow (induced drag being much more significant at lower speeds) There is no such thing as a "drag optimised" shape that works under all conditions, else every single aircraft (and car) in the world would have that shape. Everything is always a tradeoff.

 

In the case of Bf 109 vs. MiG you have 2 radically different approaches to minimizing drag. Since the last DD, there has been a lot of talk about "fineness ratio" around here (I personally think it's a mistranslation in the context it was used)

In Polikarpovs designs culminating in the MiG we see a clear focus on using fineness ratio to combat drag. The reason the I-15, I-16 and MiG all have such extremely short fuselages is to bring them as close as posible to the optimal fineness ratio for sub-sonic speeds around 4.5. On the 109 you see quite the opposite: A long, slender fuselage with a very high fineness ratio that creates more drag, but which allows the 109 to have a very small tail section which reduces drag compared to the very large control surfaces necessary on the tails of Polikarpovs designs.

 

My point is, that one is not inherently better than the other, it's different approaches to the problem. If you only look at what makes the design work in the 109, and then look at the MiG and find something that looks different, you cannot automatically conclude, that the MiGs solution is inferior. It might just be different.

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 an eliptical wing is even better though

 

Regarding gliders however: You can say that they are "drag optimised", but only for the way that they fly, which is very, very slow (induced drag being much more significant at lower speeds)  There is no such thing as a "drag optimised" shape that works under all conditions, else every single aircraft (and car) in the world would have that shape. Everything is always a tradeoff.

 

 

No. Sorry, but you have not much of an idea. If we´re talking subsonic, high aspect ratio is where you pay less drag for your lift shopping... (and yes, unreasonable, that would make the L/D but you kinda need lift, else your aircraft doesn´t fly... ) And thats why you have long and slender wings on a 777 ER or other faster planes. I give up.. throw some models into a windtunnel, you will see the 109 is cleaner. It´s just the way things are.

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No. Sorry, but you have not much of an idea. If we´re talking subsonic, high aspect ratio is where you pay less drag for your lift shopping... (and yes, unreasonable, that would make the L/D but you kinda need lift, else your aircraft doesn´t fly... ) And thats why you have long and slender wings on a 777 ER or other faster planes. I give up.. throw some models into a windtunnel, you will see the 109 is cleaner. It´s just the way things are.

Where does this conflict with anything I said in the previous post? Yes, I admitted I had aspect ratio influence on lift induced drag mixed up. The 109 clearly has the better wing design in this regard, no question. The 109, incidently, also climbs far better, conserves energy better in maneuvers etc.

 

But weren't we talking specifically top speed in level flight and acceleration in a dive? These are two instances where I'd argue that lift induced drag plays a rather small role. Am I wrong about that?

 

And yes, I fully admit, that I brought lift induced drag and aspect ratio into the conversation. It was more of an afterthought and not really relevant for the discussion.

 

And at last, riddle me this ( because I genuinely do not know): If the Bf 109 F2 is obviously a much cleaner design across the board, why is it's top speed (TAS) at optimal altitude so much lower than the MiGs, when the 109 has a slight advantage in P/W ratio? Is that simply because the MiG reaches top speed at a higher altitude?

Edited by Finkeren

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Rockets travel well faster than usual aircraft thus need less lift. There are however cruise missiles with rather long, thin wings.

 

 

Yes I get that - I suppose long thin wings optimize endurance, good for gliders, cruise missiles and drones. 

 

In a dive however, you may not be generating any lift at all - in fact if you want to accelerate as fast as possible into a dive you set your AoA to zero and eliminate lift (and associated drag) altogether. Ie "unload" the aircraft.

 

You are then a ballistic object (once your drag exceeds engine thrust) in which case the best wings are the minimum required for control - ie lowest drag. 

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Trinkof,

I don´t think manufacturing issues as well as wear&tear (affecting all sides, off course) are good to bring into a game environment. It´s simply doesn´t really work as a game design element.. In a game, you have 1000s of iterations of everything more then in real life. If you have "random defects" people just spawn until the have the right plane.. having a random failure just when you´re doing good in a fight, may be interesting once.. but it get´s anoying and old if you have it a hundred of times. Games will always be games and 100% realism is neither optainable nor would it make sense, gamewise, if you could.

Fully agree with you here! I was just pointing that out as a possible explanation for the difference in dive speed we have in game versus official instruction.

 

I am by the way personally happy we have a "clean and perfect production" mig 3 in game regarding FM :)

 

S!

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Flew this thing all the way up to 10,000 km last night, fully pegged throttle and never leveling off. Rads/Oil fully open. Everything 100%, no overheating problems. This was for about an hour at max. Nothing ever happened until I ran out of gas (80%). My engine shutdown and I began a steep dive and then my engine finally broke probably from overspeeding. Seems fishy.

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Did you engage forsazh? Probably not.If you want to present your findings,please put your RPM and MP values.

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Flew this thing all the way up to 10,000 km last night, fully pegged throttle and never leveling off. Rads/Oil fully open. Everything 100%, no overheating problems. This was for about an hour at max. Nothing ever happened until I ran out of gas (80%). My engine shutdown and I began a steep dive and then my engine finally broke probably from overspeeding. Seems fishy.

 

Definitely fishy, since you didn't orbit.

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