Thoughts on the P39...

[SYN_Luftwaffles]

I love it! Some of us enjoy flying planes for other reasons than "is bezt plane!" 

[Porkins]

The P-39 has her flaws, but when you lob one of those 37mm shells just perfectly and it hits a target and shears off its wing or tail with one shot, it's a thing of beauty. 

[Gambit21]

That it is gordo.

[Field-Ops]

5 hours ago, Windmills said:

I wonder what actually triggers this sort of explosion, I've only seen it happen once to a target I was shooting and that was on the first day of this patch. Never in the hundreds of other kills previously.

 

It has to be an incredibly unlikely thing that triggers it, not sure if its even intended to happen with how rare it is.

 

4 hours ago, 216th_Lucas_From_Hell said:

It's been introduced a fair while ago, and happens if a bullet of yours hits and detonates the target's high-explosive ammunition. Since most aircraft either don't have cannons or have them mounted in the nose, these don't happen very often. The Fw-190 and I-16 with ShVAK cannons however are easy to hit like that.

 

Yea, it looks like the 109 in the video had gun pods so there was cannon ammo in his wing. It happens to me from time to time when just using MGs on IL-2 wings. Video not the P39, just to display the ammo explosion.

 

 

[fjacobsen]

For me the P-39 is way better to fight in that the P-40.

 

Fighting at 2000 m against BF-109 G4 and FW-190 A3 is going quite well - often  getting 3 kills.

[Blitzen]

Not exactly a technical observation ( but I do wish I could get more speed out of the 'Cobra..) but I can tell you that in my last 109G campaign mission I was caught down low & slow by a hard turning P-39 pilot, & although I was able to shake him, the pom-pom-pom!!! of his cannon fire behind me ( yes I could hear it !) was a real wake up call. I knew one hit from that 37 & my short career would be done for!

 

[TRRA15]

On 3/19/2018 at 7:36 PM, SYN_Luftwaffles said:

I love it! Some of us enjoy flying planes for other reasons than "is bezt plane!" 

What he said.

[GridiroN]

I think it's FM needs a look. I think it's energy retention is a bit too poor for a plane of its weight, chassis and horsepower, but I hit a FW190 in the face last night with a 37 and he literally exploded so I'm still loving this thing. 

 

It's hard to remember to increase manifold BEFORE RPM or else you overrev and break the thing though. 

[Pict]

I like it.

 

If at some point down the track, they happen to add an option of a 20mm instead of the 37mm, I would probably like it even more  

[BlitzPig_EL]

2 hours ago, GridiroN said:

I think it's FM needs a look. I think it's energy retention is a bit too poor for a plane of its weight, chassis and horsepower,

 

 

That's quickly becoming my take as well.  It's not exactly a lightweight, and it is very aerodynamic, so why does it lose speed so quickly?

[Ehret]

Just now, BlitzPig_EL said:

 

That's quickly becoming my take as well.  It's not exactly a lightweight, and it is very aerodynamic, so why does it lose speed so quickly?

 

In continuous turns?

 

The P-39 has a symmetric airfoil wings - there was a discussion in the forum about this feature some time ago. Such airfoil generates more drag.

I have found that the P-39 has rapid instantaneous turning rate - when at speed even a moderate pull may results in a black-out. High G turns will bleed velocity very quickly.

 

Edited March 21, 2018 by Ehret

[56RAF_Roblex]

4 hours ago, GridiroN said:

 

It's hard to remember to increase manifold BEFORE RPM or else you overrev and break the thing though. 

 

You sure?  I have always done it the other way round, increase rpm then throttle and decrease throttle then rpm.

 

Just checked the original manual and it does say "To increase engine power during flight set the mixture control lever in the Auto Rich position, Adjust the propellor control lever to the desired rpm and increase manifold pressure as desired"   To decrease power during flight you must adjust the throttle to the desired manifold pressure then adjust the propellor control lever to the desired rpm.

Edited March 21, 2018 by 56RAF_Roblex

[=362nd_FS=RoflSeal]

1 hour ago, 56RAF_Roblex said:

 

You sure?  I have always done it the other way round, increase rpm then throttle and decrease throttle then rpm.

 

Just checked the original manual and it does say "To increase engine power during flight set the mixture control lever in the Auto Rich position, Adjust the propellor control lever to the desired rpm and increase manifold pressure as desired"   To decrease power during flight you must adjust the throttle to the desired manifold pressure then adjust the propellor control lever to the desired rpm.

That's because if you increase MP before RPM, your engine will begin to detonate, which is not simulated ingame. Most people ingame tend to jam the throttle open immediately like a dude about to loose his virginity instead of increasing it slowly and allowing the prop pitch controller to keep up and not over rev the engine. It hurts engines like the Allisons most since they don't have the fast pitch change like the Germans engines and have unlike the Soviet engines, have limits.

Edited March 21, 2018 by RoflSeal

[Legioneod]

I enjoy it but I still can't get past the unrealistic engine limitations. I find it doesnt go much faster than 250 at normal power meanwhile most 109s I can cruise at 300mph no problem.

[Blitzen]

54 minutes ago, Legioneod said:

I enjoy it but I still can't get past the unrealistic engine limitations. I find it doesnt go much faster than 250 at normal power meanwhile most 109s I can cruise at 300mph no problem.

YupI know it had terrible high altitude performance , but it had to be better than this down on the deck,no?

[Finkeren]

With only 1000hp at SL on nominal power, it is very seriously underpowered. That is about half the power/weight ratio that the La-5FN has. No wonder it is slow at that engine setting.

 

On military power it is a decent fighter and on emergency it is downright great, but only for 2 to 5 minutes, then it’s back to having a bit less power than the LaGG-3 to haul about a much heavier aircraft, and after another 15 minutes even that is gone.

[56RAF_Roblex]

9 hours ago, RoflSeal said:

Most people ingame tend to jam the throttle open immediately like a dude about to loose his virginity instead of increasing it slowly and allowing the prop pitch controller to keep up and not over rev the engine.

 

Preaching to the choir     I have done  it twice since Kuban came out     Normally I increase the throttle gradually but on both occasions it was caused by me chopping the throttle abruptly to avoid overshooting my victim then slamming it forward again when he started pulling away.  It just goes 'Klunk' and stops.      I did it once long ago with a Mig-3 in the same situation.   

Edited March 22, 2018 by 56RAF_Roblex

[danielprates]

On 18/03/2018 at 12:26 AM, -=PHX=-SuperEtendard said:

The P-39 relies in how much you can get out of it's emergency modes (5 min or 2 min), in these settings at low altitudes it has good speed.

I tested the P-39's speed and compared it with the Bf 109 G-2 and Yak-1B

 

 

 

Do not take it above 5000 meters though xD

 

Can you give me some notes? I always have a lot of difficulty getting my planes go as fast as they ares supposed to, regardless of how I tweak shutters, radiators, mixture, RPMs and everything. 

 

 What's the aircraft configuration you use to test those speed limits? I am guessing no ordnance whatsoever, but how much fuel? Also, I am imagining those are true airspeed data, instead of the instrumen'ts air speed. How to you calculate the TAS? 

 

 

[GridiroN]

13 hours ago, Finkeren said:

With only 1000hp at SL on nominal power, it is very seriously underpowered. That is about half the power/weight ratio that the La-5FN has. No wonder it is slow at that engine setting.

 

On military power it is a decent fighter and on emergency it is downright great, but only for 2 to 5 minutes, then it’s back to having a bit less power than the LaGG-3 to haul about a much heavier aircraft, and after another 15 minutes even that is gone.

 

True, but on all 3 of it's combat power modes it's basically identical to a FW190. Even with a draggy airfoil it should do better than it currently does, logically speaking. It currently cannot even follow a 109 in a cuban. 

 

It can do fine against a FW though if used properly and if the 190 pilot actually wants to fight and not dive away. 

 

On 21/03/2018 at 6:31 PM, 56RAF_Roblex said:

 

You sure?  I have always done it the other way round, increase rpm then throttle and decrease throttle then rpm.

 

Just checked the original manual and it does say "To increase engine power during flight set the mixture control lever in the Auto Rich position, Adjust the propellor control lever to the desired rpm and increase manifold pressure as desired"   To decrease power during flight you must adjust the throttle to the desired manifold pressure then adjust the propellor control lever to the desired rpm.

 

I've broken it twice by RPM'ing up to 3000 and then trying to increase MP in combat. Likely because the governor cannot keep the RPM low enough to not break it as I increase MP....and I'm not throttling quickly either. As @RoflSeal said this is not realistic, but it does work better in this sim.

Edited March 22, 2018 by GridiroN

[303_Kwiatek]

On 18.03.2018 at 4:26 AM, -=PHX=-SuperEtendard said:

The P-39 relies in how much you can get out of it's emergency modes (5 min or 2 min), in these settings at low altitudes it has good speed.

I tested the P-39's speed and compared it with the Bf 109 G-2 and Yak-1B

 

 

 

Do not take it above 5000 meters though xD

 

Interesting test.

 

Maby not about Cobra but it looks that Yaks are seriously overspeed at high alt.   Yaks with M-105 PF engines  should got sharp speed curve and from 4000m it should be noticable drop in speed casue high drop in power.   Supercharger in M-105PF got second gear peak about 2700 m then power is droping. So Yak1 with PF engine should got maxium speed at second gear of supercharger about 3,500-4000m then there should be very noticable drop speed and power.

 

In BOS Yak-1 ( Yak1B) could keep speed as we see on graph up to 6 km where IRL it should got drop speed from 4 km. Wonder how it is with Yak-7B casue developers said it is within 1% error comparing to RL thing.

 

For comparision Yak-1 and Yak-7B VVS data

 

 

 

[Ehret]

10 hours ago, GridiroN said:

 

True, but on all 3 of it's combat power modes it's basically identical to a FW190. Even with a draggy airfoil it should do better than it currently does, logically speaking. It currently cannot even follow a 109 in a cuban. 

 

It can do fine against a FW though if used properly and if the 190 pilot actually wants to fight and not dive away.

 

Do you trim, close windows and set radiators optimally?

(60% for water and 45% for oil coolers have lowest drag)

 

In my experience the Aircobra is a great diver - even better than the Kittyhawk. The P-39 is especially good in shallow dives. In spite of the symmetric airfoil and less hp than the La-5FN (or FW) she still can approach 570km/h @ SL in a level flight. This is not a sign of an excessive drag, imho.

Edited March 23, 2018 by Ehret

[Mac_Messer]

12 minutes ago, Ehret said:

 

Do you trim, close windows and set radiators optimally?

(60% for water and 45% for oil coolers have lowest drag)

I find that setting very hard to maintain at combat power.

 

At continous the aircraft doesn`t perform anyhow.

[Higaluto]

On 3/18/2018 at 12:34 PM, a_radek said:

Only had a few berloga rounds with it for testing 3.01. But so far, I'm very happy with the way it turned out. Much better than I expected.

 

Can't seem to aim with the 37, will take time to get a feel for it. But the 50's are usually enough. Think I want a dual stage trigger.

 

I find performance adequate to exploit any mistake a co-E 109 driver makes. But you need him to make one and you can't afford one yourself, or he will quickly be on your six.  And it's in that situation the p-39 really surprised me. 

 

Scissors, not so much as it will bleed it's E quickly. But once a 109 is behind you, a barrel roll (full aileron, not much elevator) makes the  109 look sluggish. Even at low speeds. Rear vis is good enough to do this while keeping eyes on pursuer and this way I find it surprisingly easy to deny your tail a shot and force an overshoot without loosing much E. 

 

The generous dive limit is amazing to have. All in all the 39 for me was a nice surprise and it oozes character.

 

I dont think dual stage triggers works, i tried it in last version could not get it to work.

 

i have a warthog stick

[LLv24_SukkaVR]

6 minutes ago, Higaluto said:

 

I dont think dual stage triggers works, i tried it in last version could not get it to work.

 

i have a warthog stick

 

What are you talking about? I have Warthog as well and it works just fine. Just bind mg to first stage and mg + cannon to second.

[Max_Damage]

Continious and combat power settings are absolutely worthless. In fact you have to use combat setting outside of combat to get any altitude at all.

 

Emergency has allowed me to chase down a focke wulf on deck but only once.

 

Rear visibility is what kills me every time. There s no such thing as rear visibility in a p39.

[Ehret]

Just now, Max_Damage said:

Rear visibility is what kills me every time. There s no such thing as rear visibility in a p39.

 

Move you head fully back to the rear left (or right) and look diagonally to bypass those big bars.

Other trick is looking back (or peeking at the mirror) while doing 360 degrees roll.

Or... set in graphics options the mirror quality to "simple" and enjoy a perfect backward visibility while it lasts...

 

Edited March 23, 2018 by Ehret

[303_Kwiatek]

Founded interrsting info about P-39 L in VVS service  ( cited from P-39 IN THE USSR by Yefim Gordon )

 

 

"Meanwhile, new models of the Airacobra were tested at NII VVS. In July 1943, engineer P.S. Opoprienko and test pilot V.Ye. Golofastov put P-39L-1 42-4666 through its paces. They reported that the aircraft was well equipped for bad-weather flying – it was fitted with the MN-26 DF set and had wing, tailplane, and propeller blade de-icing.

The P-39L had other improvements too. Combat reports had led to changes in armour protection (armour plate was added to the cockpit and removed from unimportant areas) and the introduction of a stiffened nosewheel fork. The cockpit, oil tank, and armament bay were heated by air from the engine. The 1,150 hp (858 kW) Allison V-1710-35 (E4) powering early P-39 models was replaced by a V-1710-63 (E6) rated at 1,325 hp (988-kW) for take-off. As with most Airacobras delivered in 1943, the P-39L-1 had a 37-mm M-4 cannon firing through the propeller hub, two 12.7-mm Colt-Browning machine-guns in the nose and four 7.62-mm Colt-Browning machine-guns in the wings.

Unlike earlier and later Cobra tests at NII VVS, the aircraft was filled with US 100-octane avgas and the performance in the take-off mode (i.e., at full military power with turbo pressure increased from 1,070 to 1,150 mm Hg) was also recorded. This boosted speed from 490 km/h (304mph) to 530 km/h (329 mph) at ground level and from 554 km/h (344 mph) to 591 km/h (366 mph) at 3000 m (9,840 ft). At the time, high octane fuel was nowhere to be found in front-line units, so pilots were advised against using full military power. In general, the test reports were deemed satisfactory; the report indicated that at low and medium altitude, the P-39L-1 was almost equal in performance to the current Bf 109G-2 and Fw 190A-4. "

[ShamrockOneFive]

38 minutes ago, Higaluto said:

 

I dont think dual stage triggers works, i tried it in last version could not get it to work.

 

i have a warthog stick

 

Worked just fine on my old X-52 stick before it died. Half depress the trigger, then go into the binding for all guns (or whatever you want), and then when the game is waiting for the binding further depress the trigger. Voila.

[Trooper117]

53 minutes ago, Higaluto said:

 

I dont think dual stage triggers works, i tried it in last version could not get it to work.

 

i have a warthog stick

It certainly does work... my warthog got remapped last week and I have mg's on first stage and cannons when trigger is fully depressed..

[BlitzPig_EL]

I flew the G6 last night in a co-op I DL'd.

 

Went up against A20s, P39s, Spits, and Yak7s.

 

I think I'm switching to the dark side.  The A20s fell from the sky like rain, and if I could not kill the escorts I could just run away from them at will.  I want to like the P39, I really do, but, in the contrived context of a game, er, sim, sorry...  Any benefits it had in real life don't matter a whit.  Really what can the P39 actually do against a 109 or 190?  Not much, that's what.  Sure it can dive well, but that assumes you can get on top of them to begin with.  Good luck with that.

 

I guess I'm just tired of feeling like a fish in a 3000 meter fish bowl with the German cat looming over the open top of the bowl ready to pounce.

Edited March 23, 2018 by BlitzPig_EL

[Mac_Messer]

I know what a G4/G6 can do so I know how to fly the P39, especially what not to do.  It certainly does have a performance window it can face the 109 on even terms, but you have to lead the fight to get to that window. Not to mention having a good aim.

 

If not that, just fly any Yak, you`ll feel much better.

[A_radek]

8 minutes ago, Mac_Messer said:

If not that, just fly any Yak, you`ll feel much better.

Or.. succumb to your original idea, switch to blue and feel like god
 

43 minutes ago, BlitzPig_EL said:

I think I'm switching to the dark side.  The A20s fell from the sky like rain, and if I could not kill the escorts I could just run away from them at will.  I want to like the P39, I really do, but, in the contrived context of a game, er, sim, sorry...  Any benefits it had in real life don't matter a whit.  Really what can the P39 actually do against a 109 or 190?  Not much, that's what.  Sure it can dive well, but that assumes you can get on top of them to begin with.  Good luck with that.

Been down that same thought, but sooner or later, you in your 109 will get whacked by a 39 and god it feels awful. As if an elderly lady beat you up with a spoon. 

[CrazyDuck]

2 hours ago, BlitzPig_EL said:

in the contrived context of a game, er, sim, sorry... 

 

2 hours ago, BlitzPig_EL said:

what can the P39 actually do against a 109 or 190?  Not much, that's what. 

 

Isn't this precisely why this is a sim (simulating war where unfairness is striven for) and not a gamer friendly, balanced and fair game?

 

I just finished Saburo Sakai's Samurai. I know this is completely different theater, and Zero is a completely different bird than German fighters of 1943, and that Sakai's skill can in no way be considered a representative one, but through his eyes it's clear that P-39 isn't much of a fighter when it comes to equal initial E fighter vs fighter combat; F4Fs were considered far more dangerous, maybe even P-40s. The only situation where P-39s were dangerous to skilled Japanese pilots over New Guinea in 1942 was when they had lots of initial E advantage, dove from the sun, shoot their way through Japanese, and continued the dive without even thinking about engaging in a dogfight.

 

And here we have the same fighter pitted against the best fighters in the world in 1943...

Edited March 23, 2018 by CrazyDuck

[Tag777]

That is similar to the tactic that Pokryshkin developed against the German fighters and bombers: altitude, speed, maneuver, fire!! Except that against Germans the P-39 has a tighter turn radius and against the Zero is exactly the opposite.

Edited March 23, 2018 by Tag777

[senseispcc]

The P-400 was the first model of P-39 how entered Soviet service in June 1942 in the northern sector.

The P-39-L1 entered service end 1942 but in great numbers on the Kuban front in 1943.  Some not a lot where engage in the region of Kursk during this battle.

The Soviet air force did modify their P-39 very quickly by removing some armor plating, removal of the four .30/7.62mm wing guns, even changing the radio sets and replacing the 37mm cannon by a 20mm one.

At the time and it seems even later the P-39 did represent 5% of the Soviet fighter force maximum.

The P-39 was a plane like most of WW2 planes in constant evolution more so on by the Soviet front where many front modifications where made.

But most important is the fact that at the time of the introduction of the P-39 the Soviet tactics did also change a lot and the introduction of them was also a great factor in the inversion of the air battle on the east front.

And some of this factors are difficult if not impossible to include into a game.

16 hours ago, Tag777 said:

That is similar to the tactic that Pokryshkin developed against the German fighters and bombers: altitude, speed, maneuver, fire!! Except that against Germans the P-39 has a tighter turn radius and against the Zero is exactly the opposite.

 

Yes, but in the and with the P-39 Pokryshkin did use a vertical combat maneuvers, dive, recover, dive again...it was a solid plane for this type of acrobatics. And could store a lot of energy. 

Edited March 24, 2018 by senseispcc

[56RAF_Roblex]

46 minutes ago, senseispcc said:

even changing the radio sets and replacing the 37mm cannon by a 20mm one.

 

Yes please!  I cannot get on with that 37mm gun.  Sure it is nice when you get a hit and get an instant kill but if you I took an average of how many shots you I take over 100 combats I bet the shots per kill ratio would not look so good :-)   I generally do not use it unless on ground attack or when I am really close to my target and even then I have managed to fire six shells point blank and miss them all.   A 20mm cannon with a faster rate of fire & flatter trajectory would suit me fine :-)

[Ehret]

Just now, 56RAF_Roblex said:

A 20mm cannon with a faster rate of fire & flatter trajectory would suit me fine :-)

 

It would be the 20mm Hispano with the 60 rounds drum magazine, I presume.

[III/JG53Frankyboy]

and the soviets didnt replace the 37mm with 20mm Hispanos.

They used the weapons that were installed in the particular version.

[ICDP]

I am flying a Kuban career in the 45th IAP which consists of a mix of P-40E and P-39L fighters.  At first I hated the P-39 because it requires a fair bit more micromanagement that the P-40E.  But once you get to grips with the RPM, prop pitch and radiator juggling act it actually does become noticeably more capable than the P-40E.

 

The only advantage the P-40E has is that it can be flown with less consideration because the P-39 is quite sensitive in comparison.  The P-39 requires a much more subtle touch to get the best from it.  Though with the considerable increase in combat and emergency power, the P-39 can at lease have a chance of escaping Bf109Gs.

 

 

 

 

 

 

 

 

 

Edited March 25, 2018 by ICDP

[-=PHX=-SuperEtendard]

On 22/3/2018 at 3:05 PM, danielprates said:

 

Can you give me some notes? I always have a lot of difficulty getting my planes go as fast as they ares supposed to, regardless of how I tweak shutters, radiators, mixture, RPMs and everything. 

 

 What's the aircraft configuration you use to test those speed limits? I am guessing no ordnance whatsoever, but how much fuel? Also, I am imagining those are true airspeed data, instead of the instrumen'ts air speed. How to you calculate the TAS? 

 

 

 

The test I made for the P-39 was with the radiators in neutral position (45% for oil and 60% for water), this gives the least amount of drag. Mixture setting was Auto Rich (around 77% I think), except for the 60" full power which was in Full Rich (100%).

 

I calculate the TAS using this website:  http://indoavis.co.id/main/tas.html It's a bit tricky to use because it only works if you use feet (even selecting meters it will need to have feet input), the other parameters you can use both measurement systems. Since we are testing in standard atmosphere the altimeter setting is 1013.25 hPa or 29.92 inches. At the IAS you can use  mph, knots or km/h it works ok with all of them. The critical part is using the temperature for each altitude you are converting, so I measured the temperatures in game with Bf 110 and Pe-2 which have external temperature gauges, from 1k to 9k (Bf 110 because it climbs better, Pe-2 at the very high alts because 110's indicator only goes to -40 ºC, while Pe-2's goes down to -70ºC), there's a bit of margin of error since the instruments aren't really precise, you need to make out single units between 10º markings.

 

I compared it with a German report of a 109 which listed both IAS and TAS and I got pretty close results to the real life calculated TAS, at the most just a 3 km/h difference, most of time it was 1 or 2 km/h difference. However I'm not sure if this difference is because of my reading of the temperature indicators, or if BoX has a slight error in temperature changes with altitudes, so I wouldn't know the cause of this slight margin of error.

 

On 23/3/2018 at 6:58 AM, 303_Kwiatek said:

 

Interesting test.

 

Maby not about Cobra but it looks that Yaks are seriously overspeed at high alt.   Yaks with M-105 PF engines  should got sharp speed curve and from 4000m it should be noticable drop in speed casue high drop in power.   Supercharger in M-105PF got second gear peak about 2700 m then power is droping. So Yak1 with PF engine should got maxium speed at second gear of supercharger about 3,500-4000m then there should be very noticable drop speed and power.

 

In BOS Yak-1 ( Yak1B) could keep speed as we see on graph up to 6 km where IRL it should got drop speed from 4 km. Wonder how it is with Yak-7B casue developers said it is within 1% error comparing to RL thing.

For comparision Yak-1 and Yak-7B VVS data

 

That's because in that Yak-1B graph I was using "optimal rads": this is adjusting the radiators to keep around 100ªC for both water and oil temperatures, in the Yak the higher you go you can close more the rads so the lower drag counters the drop in engine power from 4k to 6k. In the MiG for example you need to open more the rads with altitude

With the fixed standard rad settings given by the devs which are 50% for oil and 35% for water this is the speed graph for the 1B comparable with IRL data.
 

 

 

 

 

 

The new Yak-7B has a more abrupt performance loss with altitude than the other Yaks. I do not know the actual radiator settings used in the IRL plane, but I went with 45% for water as it's the least drag position, and 70% oil gave me the 526 km/h at sea level which is the in game specs listed speed. So I suppose this is equivalent to the real test conditions of the Yak-7B, but I could be wrong.

 

 

 

 

 

The problem with these radiator settings is that they are just not sustainable at low altitudes, the oil just overheats even at 100% open oil radiator, and you have to open the water one to cool it down to prevent engine damage... the actual sustainable setting is 100% oil and 70% water, this makes the Yak-7B effective top speed drop down to 515 km/h or so at sea level. I don't know if this is intended by the devs, maybe it is, apparently our Yak-7B uses the same oil radiator as the earlier versions with the less powerful Klimovs (the one with the cup-shaped shutter), in the Yak-9 we can see a different oil radiator with a flap-shaped shutter, more similar to that of the Yak-1s. I bet Brano knows more about this.

 

The "less performance loss with altitude" affects other planes as well, the most extreme case is the Fw 190 A-5, at certain point the air speed because of ram air effect increases the manifold pressure setting above full throttle height, making it able to sustain 1.42 ata at altitudes where it should have much lower setting (this doesn't happen with 1.3 ata because it doesn't get enough speed to create this effect). Without wing guns and the oil shutters somewhat closed, the A-5 at full throttle has a top speed of 690 km/h at 8000 meters, something more appropiate of a D-9 or a Ta 152 at that altitude.

 

 

 

 

 

 

This is veering too much into off topic btw, this should be discussed in the FM section really.

Edited March 24, 2018 by -=PHX=-SuperEtendard