P-39? What gives?

[VvonAlmen]

I have about 300 hours in IL2. I've spent most of my time in German or American fighters, but have recently branched out to Russian planes too. The LA-5 is good fun. Pretty easy to handle, and very effective. I'm also a massive fan of the P40, even with its downsides. The P39, however, I just don't understand. I don't really play online, just against AI. I consider myself an alright pilot, and can generally hold my own against Ace or Veteran AI. But in the P-39, I have to fight for my life just to take out a single Average difficulty 109. It's such an interesting plane, but for some reason it seems like an impossible task to survive a fair dogfight. It feels like the energy just drains away no matter what you do. Is there something I'm missing? I feel like there has to be. This plane was supposed to be the favorite of Russki aces during the war. I've seen other threads about the Aircobra, but they felt a little inconclusive. Any advice? 

 

Thanks,

 

VV

 

[the_emperor]

2 hours ago, VvonAlmen said:

Is there something I'm missing?

 

yes, the game cant replicate soft factors, which made a big impact on real life experience.

e.g. working and reliable radios (or radios at all), reliable electrical and other secondary systems built to a high quality standard (overall a very high built quality compared to soviet aircraft), good plexiglass...

and not get slowly poisoned by exhaust fumes if you have your canopy closed 😁

Edited October 6, 2024 by the_emperor

[jollyjack]

Seems behaving just as an old Volkswagen Beetle or VW bus. Exhaust fumes when the aircooling heatingsytem started getting rusty.

And wasn't very fast also. Both fun to drive however, especially the van when it was windy; you really needed to keep pulling the steering wheel just to drive it straight on.

[MasterBaiter]

Well, contrary to popular belief the P-39 is one of the best turning planes in the game, unfortunately the way timers works make it quite difficult to master. I hope it can get the same engine mod as the P-40 at some point. Don't be afraid to push the engine to its limit, you will break some engines, but at some point you will have the timers just right in your head.

 

It's a lot of pain to get to the point where you master it, (I'm talking online, it should be easier offline) but when It comes to dogfight : P-39 is all about cutting your opponent's trajectories and using its instantaneous turn rate. (Go for the angle in front of the bandit.)

 

Having good situation awareness is also crucial as you are quite slow at "continuous" pace, so you need to pay attention to your surroundings and pick your fights. (Although the thing can turn into a speed demon for a brief moment.)

 

Good luck in your Airacobra journey, this plane is amazing and very rewarding once you get to know it. Definitely one of my favorites.

 

Edited October 6, 2024 by Winterz

[kraut1]

During spring / summer I created a US P39 campaign with 50 missions, enemies were mostly La5 - Zeros / Oscars.

I flew all missions.

At the beginning I had problems with engine, but with advices by others I learned, that most importent is that the cooling water temperature must not exceed ca. 115 "C.

In respect of combat vs AI planes I used frequently in  dogfights for turns the flaps (only ca. 10...20° together with military power ca.42 45 inch hg )

With this fighting against the La5s was possible.

In general I fly mostly german planes. When I tested last week Yak1, Lagg3 vs BF109G2(average AI) it seemed to me that the AI BFs are experts in hitting the cockpit and knocking out the pilots with few hits.

https://forum.il2sturmovik.com/topic/87791-p-39-airacobra-how-to-use-military-power-42inchhg-3000rpm-for-ca-15min-without-overheating/

 

Edited October 6, 2024 by kraut1

[Trooper117]

1 hour ago, Winterz said:

unfortunately the way timers works make it quite difficult to master. I hope it can get the same engine mod as the P-40 at some point. Don't be afraid to push the engine to its limit, you will break some engines, but at some point you will have the timers just right in your head.

 

Yes, timers again, my main peeve with GB... during WWII real pilots took their aircraft beyond 'official' limits, why? because their lives were at stake, but did their engines suddenly die because they exceeded that time limit?... they may have shortened the engines life span, they may have damaged performance and the aircraft's abilities for future combat, but pilots did push those aircraft beyond the makers specs to survive to fight another day, or to win the fight...

[Jaegermeister]

Keep in mind you guys are talking about one of the first 3 aircraft built in this sim over 20 years ago. It was the first one I flew in the demo release.

 

I would also like to see it get some upgrades, at the very least new engine specs like the P-40 and possibly the timer and aerodynamic revisions some others are getting. It would be fun if it was brought up to the same level as some of the more recent planes.

[jokerBR]

4 hours ago, kraut1 said:

During spring / summer I created a US P39 campaign with 50 missions, enemies were mostly La5 - Zeros / Oscars.

Interesting. Is this campaign available?

[kraut1]

Just now, jokerBR said:

Interesting. Is this campaign available?

 

[GOA_Karaya_VR]

One of the best virtual pilots here with experience on P-39's is Krupinsky, he flies 39's very often online and does very well.

Maybe he can help you better that anyone with your questions.

 

Greetings.

[[CPT]Crunch]

The real P-39 was even worse, it couldn't be flown in any phase of flight inverted due to reversal in wing dihedral along with tail fin blanking.  That and flaps are ridiculously over modeled as documented here.

 

 

[MaxPower]

It looks like the lower the better for the P-39 vs. 109.  The P-39's flaps are able to extend to any arbitrary angle, and it stall speed and power to weight ratio are comparable to a 109 G-2... but I think the engine timers makes flying at this high power setting pretty risky.  I think you should be able to mix it up for a short time but then you need to get out of there and let your engine cool down.

[ZPA_Malan]

 I did a p39 career over kuban before switching to PWCG (way more fun, and the constantly unfolding combat is better suited to the p39s ambush strengths). Its frustrating because despite its quirks, on paper it should be The fastest soviet fighter low down before the La5FN arrives in numbers, so most of that campaign. But IMO it really needs to be flown as a BnZ fighter, its almost the exact opposite of a yak. Just because you can turn tightly doesn't mean you should.

 

Trim

Adjust aileron trim with RPM or else you bank left and lose speed. took me a sec to realize.  Rule of thumb:

nominal power (-15% aileron trim)

combat power (-20% aileron trim)

Takeoff/WEP (-25% aileron trim)

EDIT: There seems to have been a FM adjustment when the new engine mod was added, recently i haven't needed more than -5% aileron trim at full power, and mostly don't think about it now.

 

Nose should be trimmed down in combat something like 65% to keep it from wobbling, you can trim up outside of combat to climb.

 

Radiators

this plane can overheat easily! But flush radiators help a ton with speed/acceleration.

Best performance is 45% oil radiator and 60% water radiator - this is flush, there's no speed advantage from closing them further. Oil radiator shouldn't need adjustment unless you are damaged or something. However, you can't keep the water radiator there forever, and i find 75% to be a reasonable combat setting. Climb outside of combat with water radiator 100% open - no need to start a fight with a hot engine. In combat it's better to be at 75% with some temperature to spare so you can use that 60% flush setting for a chase when you really need it. Also get in the habit of opening the radiator whenever you dive, and if you find yourself out of immediate danger well away from enemies its helps to throttle back halfway and open the radiator - temps will be under control pretty quick and then you can climb before attacking again.

 

Weapons

IMO its essential to remove the wing guns, not only will this improve speed and roll rate, it brings the center of gravity forward, which this plane sorely needs.

The 37mm is a beast but has a terrible trajectory that doesn't match the 50s. So I bind the 50s to a separate trigger, and use only them for shots at long and medium ranges-nose guns are accurate. At very close range the trajectories are more similar so i fire both, which can sometimes take even bombers out with one hit.

 

Tactics

Climb, climb, climb before combat. There's no reason to fight fair, and this plane will punish you for trying. it handles really well in dives, and the sooner you are dropping 109s the less likely they turn the tables. Extend after the dive and don't climb again until you are sure no one is on your tail.  You will be outperformed above about 10k feet so i only go higher if i need the altitude to dive on them first. Try to turn gently and steadily, avoid turnfights like the plague since you will bleed speed much faster than opponents, and don't have the climb rate or time at full power to regain it. vertical maneuvers should always begin with a dive IMO, attempting a prop hang or loop etc from horizontal can often lead to you spinning in. Keep speeds above 250 mph (think about regaining speed soon) or 200 mph (stop what you are doing and regain speed) or the nose will wobble around and you'll be shot down, stall, or spin out. You have great armor from the front and the rear engine means you are safer than anyone else attacking head on or eating some hits from gunners, which is nice.

 

Edit: I should add that you can out-turn 190s even with relatively wide turns - either lose the tail or bring them down in the first 1-2 turns before you bleed too much speed, then extend. You can out-roll 109s but i wouldn't recommend scissors because again, bad acceleration. 1-2 well timed barrel rolls can keep decent speed while shaking them off.

 

Engine

There's no getting around the engine suffering a crazy amount from timers, its the worst. you have two minutes of max power - but thats not the most annoying part, since it'll overheat in that time with flush radiators anyway. the limits on the RPM and combat/takeoff power are the difference between sitting at around LAGG3 speeds in nominal because you are immediately out of timer, and being able to reliably hit 300mph level and climbing well enough to be competitive, even without using WEP (as long as you manage your temps). I'll admit I've used unbreakable more often, because otherwise its one, maybe two passes and dive for home and hope they don't follow. Without those crazy combat/takoff power timers it is a competitive if quirky fighter, if flown right. I'd rather not use unbreakable at all, so hopefully they fix it soon. As Soviet p39 pilot Golodnikov said about following the factory engine limits "It seems that everything depends on what you wanted out of it. Either you flew it in such a manner as to shoot down Messers and Fokkers, or you flew it in a way that guaranteed 120 hours of engine life."

 

EDIT: The new engine mod is an improvement! still a challenge, but much more time to work with. In combat I park it at 3000 RPM/42in with 60% flush radiator and full rich mixture(helps with cooling) when i start high, and carefully add power in bursts as needed to regain energy

 

 

Edited May 23 by ZPA_Malan

[Gambit21]

IRL the P-39 was a decent fighter below 10k.

 

[EAF19_Marsh]

I loved it in 1946 online in the old SEOW. But co-E with human G2s were a struggle and that seemed about right.

 

The engine limit issue is ridiculous. The developers need to read a book about the Eastern Front and the reality of how machinery was operated and maintained. Any idea of 'factory / manual norms' is risible.

[69th_Mobile_BBQ]

I don't fly the P-39 often but, I did take another look at it upon seeing this thread.   

The P-39 has 15 minutes of combat power - same as the P-51, P-47 and P-38.  That's 15 minutes of 100% RPM setting with no worries about the RPM setting and only having to manage the throttle. Add to that, returning to regular continuous settings do have a recharge, and cumulatively, you operate as-needed bursts of combat power well-exceeding 15 minutes during the course of a flight.  The main difference between the "big boys" I listed is that you get 2 minutes of emergency (100/100) power instead of 5.   

Granted the throttle/manifold pressure setting is the "fragile" part of the equation but, overall, that's still better than many of the 109 models in-game timers-wise. 😮 The 109s may have more power at lower settings or at max in certain situations but, the power the P-39 has is quite adequate.  Considering that 109 combat time is, for most models, much shorter than 15 minutes, I call that a win for the P-39. 

 

----

As far as timers go, ANY simulation model that represents wear-and-tear on the engine computationally, is going to be based on a number pool that diminishes over time hence, a TIMER.  The only difference in building a new system will be based on how well said timer is masked and what hidden-mechanic leeway/overtime "luck" is programmed into it.  Yes, even the warbirds models in a different popular sim that bases its engine wear on "over-temperature" damage still has this. The difference is when the timer is activated and how the player perceives the results. 

The simple fact is that it's just like games that cleverly mask their loading screens so you don't notice as much of a loading screen or think it's truly "seamless". It's still there. There is no getting around it.  Example: Elite Dangerous - The frame shift drive start-up and slow-down sequence is a loading screen as well as the time you spend hyper-jumping from star to star.  

Maybe, you can ask for more "slop/luck" in the system once the timers get dangerously low, but constantly griping that the Devs got it wrong and need to fix this "problem" will always fall on deaf ears.  This is not because the Devs are bad or wrong. This is because the only way to "remove the timers" is to change the way those timers are perceived by the players in-game.  Until truly "quantum" computers become household items we can play our simulators on, timers will always be there, sorry to have to tell you. 

Edited October 8, 2024 by 69th_Mobile_BBQ

[Gambit21]

59 minutes ago, 69th_Mobile_BBQ said:

 

As far as timers go, ANY simulation model that represents wear-and-tear on the engine computationally, is going to be based on a number pool that diminishes over time hence, a TIMER.  The only difference in building a new system will be based on how well said timer is masked and what hidden-mechanic leeway/overtime "luck" is programmed into it.  Yes, even the warbirds models in a different popular sim that bases its engine wear on "over-temperature" damage still has this. The difference is when the timer is activated and how the player perceives the results. 

The simple fact is that it's just like games that cleverly mask their loading screens so you don't notice as much of a loading screen or think it's truly "seamless". It's still there. There is no getting around it.  Example: Elite Dangerous - The frame shift drive start-up and slow-down sequence is a loading screen as well as the time you spend hyper-jumping from star to star.  

Maybe, you can ask for more "slop/luck" in the system once the timers get dangerously low, but constantly griping that the Devs got it wrong and need to fix this "problem" will always fall on deaf ears.  This is not because the Devs are bad or wrong. This is because the only way to "remove the timers" is to change the way those timers are perceived by the players in-game.  Until truly "quantum" computers become household items we can play our simulators on, timers will always be there, sorry to have to tell you. 

 

I would agree with you if the timer was randomized a bit and if the real life performance of the engines in question were not so drastically divergent from this current timer implementation. 

[69th_Mobile_BBQ]

9 minutes ago, Gambit21 said:

 

I would agree with you if the timer was randomized a bit and if the real life performance of the engines in question were not so drastically divergent from this current timer implementation. 

 

Anecdotally, from my experience, there is some "grace time" built into at least some of the planes.  I don't know if there's a chance for overtime in every plane, but I have gotten more minutes out of some planes after the "emergency time limit exceeded" warning came up in the technochat. 

[ZPA_Malan]

Any extra time is random chance and can't be relied on.  Whatever the names of the various modes, there isn't necessarily an equivalence in using them, they aren't even labeled consistently. The p39 has 4 engine modes, whereas the later fighters you mention have 3. this makes conserving time before turning into a LaGG3 more challenging.

 

Nominal (unlimited time): 2600 RPM, 37.2 inch Hg (<75% throttle)

Military power (up to 15 minutes): 3000 RPM, 42 inch Hg (75-84% throttle)

Take-off power (up to 5 minutes): 3000 RPM, 51 inch Hg (85-94% throttle)

Maximum Possible power (WEP - up to 2 minutes): 3000 RPM, 60 inch Hg (>95% throttle)

 

More importantly, those fighters are all more competitive or outright faster than the 109s they are facing at the time, and have smaller speed drops between engine modes. which makes sense, they were better fighters. The p39 drops 60kph between WEP and nominal on the deck, the others mostly 10-20kph.  the G-4's 30 minutes of speed at combat power is well above the nominal speeds you'll drop to in 15 or less, plus it can always climb faster. Which isn't to say the p39 should have a higher top speed or be arbitrarily easy, just that it suffers more from the timers. And there's direct quotes from pilots that they didn't follow those time limits closely in combat - at the cost of more engine overhauls, not dropping out of the sky.

Edited October 9, 2024 by ZPA_Malan

[[CPT]Crunch]

Why can't the timer be based on oil and water temps?  As in it doesn't even start until you actually hit a thermal limit.

[the_emperor]

1 hour ago, [CPT]Crunch said:

Why can't the timer be based on oil and water temps?  As in it doesn't even start until you actually hit a thermal limit.

>ou are right. as (too much) heat is what kills the engine as it leads to detonation, oil deterioration and bearing failures etc...

If you keep the engine in the green limits they should be able to fly until you run out of fuel.

Wear and tear are not part of the game. every plane is brand new and gets discarded after landing...

 

Edited October 9, 2024 by the_emperor

[69th_Mobile_BBQ]

4 hours ago, [CPT]Crunch said:

Why can't the timer be based on oil and water temps?  As in it doesn't even start until you actually hit a thermal limit.

 

Temperature isn't the only factor in what makes an engine that is running full-on blow.  

[ZPA_Malan]

2 hours ago, 69th_Mobile_BBQ said:

 

Temperature isn't the only factor in what makes an engine that is running full-on blow.  

what exactly is it that makes it blow with the throttle 3/4 of the way forward? Having engines stop if you exceed WEP time or heat and otherwise have some chance of damage from overuse would be a much more reasonable timer system, but its not the system we have.

Edited October 9, 2024 by ZPA_Malan

[69th_Mobile_BBQ]

36 minutes ago, ZPA_Malan said:

what exactly is it that makes it blow with the throttle 3/4 of the way forward? Having engines stop if you exceed WEP time or heat and otherwise have some chance of damage from overuse would be a much more reasonable timer system, but its not the system we have.

 

Obviously, it is possible to fit an engine block with an intake manifold that can produce more pressure than the block and internal workings can handle.  

Since I wasn't clear in my last quote, I meant when the engine is running 100%.  Even so, depending on the engine, just because it doesn't have a built-in safety limiter, doesn't necessarily mean that the engine won't overpressure at lower settings.  The time limits given be the manufacturer mean "after multiple tests, this is the most time we can reasonably tell the pilot that the engine will hold out at these settings but use at your own risk.".  

I'm somewhat surprised that there is no random chance of the emergency power setting occasionally causing the engines (in-game) to fail well before the time is up - which is something that even new engines can sometimes face. 

[the_emperor]

11 hours ago, 69th_Mobile_BBQ said:

Temperature isn't the only factor in what makes an engine that is running full-on blow.  

 

but its the only factor this game can simulate.

(yes, engines failed even when everything is in the green since we are still talking 1940s tech and everyone who dabbles in vintage cards/motorcycles is used to this in some way, but again...this game cant simulate that)

The timers try to "replicate" something that is not in game (wear and tear), and where implemented historically to bring the engine to full fill its service life of 100+ hours and keep the temperatures in check.

So I dont see why we shouldnt have the option to turn an artificial limit off.

If you cant tell me why or what part of my engines fails, when I run out of time...or at least give me a warning from the engine (which the game does not)...give me the option to turn that artificial and arcade like boost mechanic off.

 

 

Edited October 10, 2024 by the_emperor

[Aapje]

9 hours ago, 69th_Mobile_BBQ said:

I'm somewhat surprised that there is no random chance of the emergency power setting occasionally causing the engines (in-game) to fail well before the time is up - which is something that even new engines can sometimes face. 

 

If they did that, they would be bombarded with error reports.

[FeuerFliegen]

On 10/6/2024 at 8:39 AM, Jaegermeister said:

Keep in mind you guys are talking about one of the first 3 aircraft built in this sim over 20 years ago. It was the first one I flew in the demo release.

 

I would also like to see it get some upgrades, at the very least new engine specs like the P-40 and possibly the timer and aerodynamic revisions some others are getting. It would be fun if it was brought up to the same level as some of the more recent planes.

 

Over 20 years?  Can you explain?

I would have thought that this plane was developed no more than 12-18 months before Battle of Kuban was released.  You're saying it was released 12+ years before that?

[BlitzPig_EL]

Jaegermeister is referring to the P39 as released in the original IL2.  It was also in the pre release demo that came in some PC mags way back then.

[actionhank1786]

On 10/14/2024 at 11:32 AM, BlitzPig_EL said:

Jaegermeister is referring to the P39 as released in the original IL2.  It was also in the pre release demo that came in some PC mags way back then.

I crashed that thing so many times after running to my computer to install that demo. 
PC Gamer was my life back then, and I'm so glad it opened my little middle school world up to the Eastern Front as a kid that had only ever really known the very US specific world of WWII history. 

 

I think it may have been an Andy Mahood article, maybe? Along with the accompanying demo disk. It set off a life long interest in so much of WWII I may not have ever really found out about. My wallet may never forgive him, but the rest of me is a fan!

[Jaegermeister]

I was just referring to the fact that the performance of that particular airplane has never really changed compared to other late war planes in the game that were much more competitive. It was good at low level and as mentioned above, it had a warm cockpit, no exhaust fumes, didn't burn easily, a good center firing gun, and it was relatively reliable. The Allison engine was not suited for high altitude, but it was a workhorse and could have been easily pushed beyond the in game limits.

[czech693]

Leave the .30 calibers behind with their extra ammo, and maybe reduce the fuel load to make it lighter and remove the negitive inertia from the wing guns and ammo.