440km/h ias at 6K, Yak 1b?

June 7, 2017

Ah, the ol' "if a Soviet fighter is competitive, it's obviously overmodeled" argument.

+1. Thank you for pointing this out.

June 7, 2017

these topics keep popping up.

bottom line, the Yak-1b, like all planes in BoX comes within 5% of climb rates/speed based on RL flight tests:

In real life max speed test performed with radiator flap set 'by airflow', that corresponds ingame 50%/35% for oil/water radiators.
IRL data for Yak-1 s127 - max speed at 4km altitude - 591 kph TAS, ingame - 490kph IAS / 599kph TAS. 8 kph or 1.3% TAS mistake.
IRL data for Yak-1 s127 - max speed at 6km altitude - 572 kph TAS, ingame - 436kph IAS / 594kph TAS. 22 kph or 3.8% TAS mistake.
Where is "50-40 kph mistake"?

https://forum.il2sturmovik.com/topic/26139-new-yak/?p=410889

Unless someone comes up with actual hard data showing the modeling is incorrect, such as the wrong ClMax in the 190, the Yak-1b FM will not change.

In Game, the 109 F4/G2/G4 190 A3/A5 have a higher top speed than the Yak-1b at all altitudes and the 109 F4/G2/g4 have a higher climb rate than the Yak-1b.

If a 109/190 driver gets shot down by a Yak-1b, he is doing something wrong, it is not the flight model.

Edited June 7, 2017 by Sgt_Joch

June 7, 2017

What boggles my mind is how fast the Yak is able to regain speed while the 109 struggle doing so

Interesting theory: One way to test if this holds water could be to use some IRL Finnish Me-109G2 trial data posted by LLv34_Flanker from here:

“Turn results achieved at 1000m altitude.

Type of turn Time Start speed End speed Bank angle

Fast 180deg. turn 10" 450km/h 380km/h 90deg

Fast 360deg. turn 18" 450km/h 330km/h 90deg

Cont. 360deg. turn, max power 22" 360km/h 360km/h 70deg

Acceleration and deceleration in horizontal flight

Acceleration of the plane is good; deceleration is relatively slow especially in slower speed regime.

Start speed End speed Time Power setting

300km/h 440km/h 27" Maximum

440km/h 510km/h 35" Maximum”

For comparison: My C++ simulation results for G2:

Note: I don’t simulate the spool up of the engine but the simulation goes immediately from power required at starting speed to full thrust so it seems reasonable to add 1-2 s to my acceleration time results which bring them pretty close to the Finnish trials I think.

Start speed End speed Time Power setting

300km/h 440km/h 26.3" Maximum

440km/h 510km/h 31.8" Maximum

Type of turn Time Start speed End speed Bank angle

Cont. 360deg. turn, max power 22.7" 360km/h 360km/h 70deg

And then my C++ simulation results for Yak-1 series 69 (Don't have the series 127 modeled yet):

Again: I don’t simulate the spool up of the engine and the simulation goes immediately from power required at starting speed to full thrust so it seems reasonable to add 1-2 s to my acceleration times below when comparing to the in-game results:

Start speed End speed Time Power setting

300km/h 440km/h 30.7" Maximum

440km/h 510km/h 47.9" Maximum

Observations: The C++ Yak-1 s69 is a bit slower in acceleration from 300 to 440 Km/h but much slower to reach 510 Km/h but that is not so strange given its closer to the top speed for the s69 than for the G2.

I think the Finnish IRL Me-109G2 results validates the C++ modeling so it would be interesting if someone could test the ingame acceleration of the Me-109G2, Yak-1 Series 69 and 127 and see how they compare to the IRL and C++ simulation data.

June 7, 2017

Manfred, what do you think of the over-performance of the 109's in BoS?

They should not over-perform as well of course. All planes which are faster by a relevant number (e.g. more than 3%) should be corrected.

But I bought the Yak-1b, just to test it. And when I see how stable this plane is, plus how it's retaining its energy and see its lowspeed handling then the speed advantage of the 109s (wobble wobble) is almost nothing worth anymore. Also on Berloga they constantly use flaps and apparently get no speed penalty for it.

And tests people post here (which I appreciate) don't tell the complete truth. One thing is what you can test in a somehow artificial situation (flying straight and level) and the other thing what happens during a dogfight.

But I think my criticism is pointless at the moment right before the FM update. Let's wait and see. I hope for the best!

June 7, 2017

They should not over-perform as well of course. All planes which are faster by a relevant number (e.g. more than 3%) should be corrected.

But I bought the Yak-1b, just to test it. And when I see how stable this plane is, plus how it's retaining its energy and see its lowspeed handling then the speed advantage of the 109s (wobble wobble) is almost nothing worth anymore. Also on Berloga they constantly use flaps and apparently get no speed penalty for it.

And tests people post here (which I appreciate) don't tell the complete truth. One thing is what you can test in a somehow artificial situation (flying straight and level) and the other thing what happens during a dogfight.

But I think my criticism is pointless at the moment right before the FM update. Let's wait and see. I hope for the best!

How many hours do you have flying the Yak-1(b) in online servers? How many times have you come up against capable BF-109 or Focke-Wulf pilots that really know what they're doing, and do you consider yourself to be one of those?

June 7, 2017

I think you'll find more than a few capable pilots who agree with Manfred. Sure if you fly in straight lines and run away until you can zoom down from 8000m then LW aircraft are superior and everything is fine and dandy. If you happen to buy into the myth that 109s only ever flew BnZ and any Germans who flew into a dogfight were chewed to pieces by anything with a red star on the wing then its great too.

There are certainly issues with the FMs, the least of which have to do with top speeds of the various aircraft.

And before you try and throw a disguised attempt at insulting flying ability in my direction as well, yes I have flown the Yak, against some very skilled opponents as well.

June 7, 2017

Interesting theory: One way to test if this holds water could be to use some IRL Finnish Me-109G2 trial data posted by LLv34_Flanker from here:

Acceleration and deceleration in horizontal flight

Acceleration of the plane is good; deceleration is relatively slow especially in slower speed regime.

Start speed End speed Time Power setting

300km/h 440km/h 27" Maximum

440km/h 510km/h 35" Maximum”

For comparison: My C++ simulation results for G2:

Note: I don’t simulate the spool up of the engine but the simulation goes immediately from power required at starting speed to full thrust so it seems reasonable to add 1-2 s to my acceleration time results which bring them pretty close to the Finnish trials I think.

Start speed               End speed            Time            Power setting

300km/h                     440km/h                 26.3"                 Maximum

440km/h                     510km/h                 31.8"                 Maximum

And then my C++ simulation results for Yak-1 series 69 (Don't have the series 127 modeled yet):

Again: I don’t simulate the spool up of the engine and the simulation goes immediately from power required at starting speed to full thrust so it seems reasonable to add 1-2 s to my acceleration times below when comparing to the in-game results:

Start speed               End speed            Time            Power setting

300km/h                     440km/h                 30.7"                 Maximum

440km/h                     510km/h                 47.9"                 Maximum

Observations: The C++ Yak-1 s69 is a bit slower in acceleration from 300 to 440 Km/h but much slower to reach 510 Km/h but that is not so strange given its closer to the top speed for the s69 than for the G2.

I think the Finnish IRL Me-109G2 results validates the C++ modeling so it would be interesting if someone could test the ingame acceleration of the Me-109G2, Yak-1 Series 69 and 127 and see how they compare to the IRL and C++ simulation data.

I just ran a quick test of the Bf 109G2 and Yak-1 s. 69 to try and match this.

Map: Stalingrad autumn

Altitude: 1000m ASL

Load: Fuel 100%, default armament.

Engine settings Yak: 100%rpm, 100%mixture, did 2 sets of tests, one with radiators 50% open (keeping both fluids at around 100^oC) and one with radiators fully closed (overheated trying to get to 510km/h.

Engine settings 109: Throttle at 100%, prop and radiator on auto.

The results:

Bf 109G2:

Start speed End speed Time Power setting

300km/h 440km/h 25.1 sec Maximum

440km/h 510km/h 43.8 sec Maximum

Yak-1 s. 69 w. 50% radiator:

Start speed End speed Time Power setting

300km/h 440km/h 34.6 sec Maximum

440km/h 504km/h 1:35 min Maximum (Note: Unable to reach 510 km, top speed achieved at 1:35 was 504km/h)

Yak-1 s. 69 w 0% radiator:

Start speed End speed Time Power setting

300km/h 440km/h 32.3 sec Maximum

440km/h 510km/h 1:02 min Maximum (Note: Engine overheated)

Can we please stop repeating the myth that the Yak accelerates better than the later 109s? Even on combat power the G2 accelerates better than the s. 69.

Edited June 7, 2017 by Finkeren

June 7, 2017

I think you'll find more than a few capable pilots who agree with Manfred.

Yes, and it appears that quite a lot of the ones who complain the loudest, share one thing in common...they almost never fly VVS. They might be a damned good BF-109 or Focke-Wulf pilot, because that's all they ever fly, but I suspect many of them have very inflated ideas about how "good" the Russian planes are compared to their own. Hey, I'm all for historically accurate flight models, and if some plane's flight model is determined to be wrong then I hope it's fixed, but it seems that it is very difficult to separate unbiased reporting of genuine flaws in flight models versus plain old whining because someone thinks they ought to be the next Hans Marseille, and they aren't.

Edited June 7, 2017 by Iceworm

June 8, 2017

The view to the back, maneuvering, speed, the weapons, just makes me wonder, what kind of plane Yak-3 was (which my grandfather praised, as he was serving at a/f during the war) if Yak-1b is performing like this...

The Yak-3 was basically a 1B on steroids, shorter wings (9.2m wingspan instead of 10m), around 200 Kg lighter and with a 100-150 HP more powerful engine, plus some aerodynamics improvements like repositioning the radiators (and maybe others). It was around 40 km/h faster at sea level (570 km/h), 47 km/h faster at 2000m (614 km/h), and 50 km/h faster at 4500m (top speed 650 km/h).

It also climbed better, at the deck 21 m/s (1B: 17m/s), at 3000m 18.5 m/s (1B: 15 m/s), at 6000m 11.7 m/s (1B: 9.5 m/s). At low to medium altitudes it has similar climbrate to the in game Bf 109 F/G, while being faster.

So yeah, comparing to the in game stats of the 1B, it's a noticeable perfomance increase.

I think the problem in general is the radiator performance, in all planes. If you use historical radiator settings the planes all seem to achieve their historical speeds. The 109s' auto radiator barely ever opens, it seems, even in a vertical climb at combat power. It is only possible to overheat some planes if you fully close the radiators. (p40, 109e7 for example)

This could be possible I guess.

I made a couple of tests with the 109 F-4 in Stalingrad autumn (15°C) and summer (25°C).

In Autumn (15°C):

Cruising at Nominal settings on the deck (1.15 ata), the F-4 mantains the automatic radiator 100°C target temperature with 10% water radiator open.

Cruising at Combat settings on the deck (1.3 ata), it mantains 100°C with 17% water radiator open.

In Summer (25°C):

Cruising at Nominal settings on the deck, F-4 has 15% water radiator open.

Cruising at Combat settings on the deck, F-4 has around 24% water radiator open.

I did an extra test with climbing at Combat settings, with 250 km/h climbing speed, the radiators opened to around 55% during the climb at low altitude.

Maybe someone has IRL data on the F-4's radiator efficiency to compare.

Edited June 8, 2017 by -=PHX=-SuperEtendard

June 8, 2017

The Yak-3 was basically a 1B on steroids, shorter wings (9.2m wingspan instead of 10m), around 200 Kg lighter and with a 100-150 HP more powerful engine, plus some aerodynamics improvements like repositioning the radiators (and maybe others). It was around 40 km/h faster at sea level (570 km/h), 47 km/h faster at 2000m (614 km/h), and 50 km/h faster at 4500m (top speed 650 km/h).

It also climbed better, at the deck 21 m/s (1B: 17m/s), at 3000m 18.5 m/s (1B: 15 m/s), at 6000m 11.7 m/s (1B: 9.5 m/s). At low to medium altitudes it has similar climbrate to the in game Bf 109 F/G, while being faster.

So yeah, comparing to the in game stats of the 1B, it's a noticeable perfomance increase.

This could be possible I guess.

I made a couple of tests with the 109 F-4 in Stalingrad autumn (15°C) and summer (25°C).

In Autumn (15°C):

Cruising at Nominal settings on the deck (1.15 ata), the F-4 mantains the automatic radiator 100°C target temperature with 10% water radiator open.

Cruising at Combat settings on the deck (1.3 ata), it mantains 100°C with 17% water radiator open.

In Summer (25°C):

Cruising at Nominal settings on the deck, F-4 has 15% water radiator open.

Cruising at Combat settings on the deck, F-4 has around 24% water radiator open.

I did an extra test with climbing at Combat settings, with 250 km/h climbing speed, the radiators opened to around 55% during the climb at low altitude.

Maybe someone has IRL data on the F-4's radiator efficiency to compare.

Where are you taking the yak-1b climb rate from? 17m/s is a game number and it seems to be an overoptmistic number according to:

Gordon, Khazanov, "Soviet Combat Aircraft of the Second World War", vol. 1, has a summary of 4 flight tests done on the Yak-1 with the 1,180hp rated M-105PF engine between mid-42 and early 43.

time to climb from ground level to 5 km.

test 1- test weight: 2,917kg, time: 6.4 minutes;

test 2- test weight: 2,780kg, time: 4.7 minutes;

test 3- test weight: 2,900kg, time: 5.6 minutes;

test 4- test weight: 2,884kg, time: 5.4 minutes.

You see, the game yak-1b I think weights 2.932kg so it should be around the first test. I would like to know how these numbers compare to Holtzauge simulation ...

Cheers

June 8, 2017

Where are you taking the yak-1b climb rate from? 17m/s is a game number and it seems to be an overoptmistic number according to:

Gordon, Khazanov, "Soviet Combat Aircraft of the Second World War", vol. 1, has a summary of 4 flight tests done on the Yak-1 with the 1,180hp rated M-105PF engine between mid-42 and early 43.

time to climb from ground level to 5 km.

test 1- test weight: 2,917kg, time: 6.4 minutes;

test 2- test weight: 2,780kg, time: 4.7 minutes;

test 3- test weight: 2,900kg, time: 5.6 minutes;

test 4- test weight: 2,884kg, time: 5.4 minutes.

You see, the game yak-1b I think weights 2.932kg so it should be around the first test. I would like to know how these numbers compare to Holtzauge simulation ...

Cheers

Actually, if those tests were done between mid '42 and early '43, the equivalent of those Yaks would be our Yak-1 s. 69, not the Yak-1b (which is a series 127)

In any case, I did a very short test (only one attempt each so by no means conclusive) with both Yaks to see, where the results would land.

Both tests done at Stalingrad Autumn.

Climb speed 270km/h IAS falling to 260km/h above 4000m, because the Yak's climb rate absolutely tanks above that altitude and if I had kept going at 270 the times would have been above 7 minutes.

Engines running at max RPM, supercharger gear shift at 2600m, start leaning mixture at 3500m, keeping slightly rich mixture, both coolants kept slightly above 100^oC (so not with radiators fully open as would have been done during historical tests - I wanted to err on the side of the complaints)

Times from 0 - 5000m:

Yak-1 s.69: 5 minutes 54 seconds for an average climb rate of 14.1m/s

Yak-1b: 5 minutes 32 seconds for an average of 15.1m/s

Seems like this falls squarely within those test results. A sustained climb rate of 17 m/s seems plausible for the Yak-1b, but only below 3000m, higher than that and the Yaks climb like bricks.

Of course, if you fly with radiators fully open, as would have been done during a climb test, the results would have been worse, but then again, that might cancel out any sloppy flying on my part.

Edited June 8, 2017 by Finkeren

June 8, 2017

We should also consider that the 17 m/s value is at sea level. As the plane increases altitude, it's climbrate decreases (0m: 17 m/s, 3000m: 15 m/s, 6000m: 11.7 m/s these are the in game specs, as I was comparing the real Yak-3 vs in game Yak-1B).

So by taking the time it takes to reach 5000m that value is the average between the high climbrate at low altitude, and the lower climbrates at higher alt.

June 8, 2017

We should also consider that the 17 m/s value is at sea level. As the plane increases altitude, it's climbrate decreases (0m: 17 m/s, 3000m: 15 m/s, 6000m: 11.7 m/s these are the in game specs, as I was comparing the real Yak-3 vs in game Yak-1B).

So by taking the time it takes to reach 5000m that value is the average between the high climbrate at low altitude, and the lower climbrates at higher alt.

Exactly. And my own little test seems to conform perfectly with those numbers given.

I fail to see any issue with the Yak's climb rate.

June 8, 2017

Exactly. And my own little test seems to conform perfectly with those numbers given.

I fail to see any issue with the Yak's climb rate.

I must agree with you. In-game Yak's climb performance is accurate according to in-game performance documentation.

Tested that myself few months ago.

Edited June 8, 2017 by LLv34_adexu

June 8, 2017

I must agree with you. In-game Yak's climb performance is accurate according to in-game performance documentation.

Tested that myself few months ago.

Glad we are on the same level here

Just like the acceleration claim, it is one that I hear so often. Some people are throwing around the idea that the Yak climbs "too well" as if it was established fact, when it is anything but.

June 8, 2017

Actually, if those tests were done between mid '42 and early '43, the equivalent of those Yaks would be our Yak-1 s. 69, not the Yak-1b (which is a series 127)

In any case, I did a very short test (only one attempt each so by no means conclusive) with both Yaks to see, where the results would land.

Both tests done at Stalingrad Autumn.

Climb speed 270km/h IAS falling to 260km/h above 4000m, because the Yak's climb rate absolutely tanks above that altitude and if I had kept going at 270 the times would have been above 7 minutes.

Engines running at max RPM, supercharger gear shift at 2600m, start leaning mixture at 3500m, keeping slightly rich mixture, both coolants kept slightly above 100^oC (so not with radiators fully open as would have been done during historical tests - I wanted to err on the side of the complaints)

Times from 0 - 5000m:

Yak-1 s.69: 5 minutes 54 seconds for an average climb rate of 14.1m/s

Yak-1b: 5 minutes 32 seconds for an average of 15.1m/s

Seems like this falls squarely within those test results. A sustained climb rate of 17 m/s seems plausible for the Yak-1b, but only below 3000m, higher than that and the Yaks climb like bricks.

Of course, if you fly with radiators fully open, as would have been done during a climb test, the results would have been worse, but then again, that might cancel out any sloppy flying on my part.

Thxs Finkeren. It makes sense. I just thought the figures were for sea level and not average climb. Could you make a similar test for the G2 for comparison purposes, if its not too much trouble ...

Cheers

June 8, 2017

Thxs Finkeren. It makes sense. I just thought the figures were for sea level and not average climb. Could you make a similar test for the G2 for comparison purposes, if its not too much trouble ...

Cheers

I don't have time right now, but actually I made a test back in December when the Bf 109G4 came out, because someone claimed, that the G2 climbed much better than the G4 (turned out that it didn't)

Maybe I can locate those numbers somewhere. Else I might have time for a quick test tonight.

June 8, 2017

Where are you taking the yak-1b climb rate from? 17m/s is a game number and it seems to be an overoptmistic number according to:

Gordon, Khazanov, "Soviet Combat Aircraft of the Second World War", vol. 1, has a summary of 4 flight tests done on the Yak-1 with the 1,180hp rated M-105PF engine between mid-42 and early 43.

time to climb from ground level to 5 km.

test 1- test weight: 2,917kg, time: 6.4 minutes;

test 2- test weight: 2,780kg, time: 4.7 minutes;

test 3- test weight: 2,900kg, time: 5.6 minutes;

test 4- test weight: 2,884kg, time: 5.4 minutes.

You see, the game yak-1b I think weights 2.932kg so it should be around the first test. I would like to know how these numbers compare to Holtzauge simulation ...

Cheers

the Yak-1 s. 127/1943 standard model is the one tested in #3 and #4.

Test #1 is the s. 69, although we know the climb times are on the low side because of overheating issues/using 2550 RPM at lower altitudes.

Test #2 is the 1942 Yak-1b mod, a small number of lightened Yaks. It was never a standard production model and is not in the game.

June 8, 2017

A bit late to the party today since I had some stuff that needed to get done before I got home but I can only agree with the conclusions so far:

I just ran a quick test of the Bf 109G2 and Yak-1 s. 69 to try and match this.

Map: Stalingrad autumn

Altitude: 1000m ASL

Load: Fuel 100%, default armament.

Engine settings Yak: 100%rpm, 100%mixture, did 2 sets of tests, one with radiators 50% open (keeping both fluids at around 100^oC) and one with radiators fully closed (overheated trying to get to 510km/h.

Engine settings 109: Throttle at 100%, prop and radiator on auto.

The results:

Bf 109G2:

Start speed End speed Time Power setting

300km/h 440km/h 25.1 sec Maximum

440km/h 510km/h 43.8 sec Maximum

Yak-1 s. 69 w. 50% radiator:

Start speed End speed Time Power setting

300km/h 440km/h 34.6 sec Maximum

440km/h 504km/h 1:35 min Maximum (Note: Unable to reach 510 km, top speed achieved at 1:35 was 504km/h)

Yak-1 s. 69 w 0% radiator:

Start speed End speed Time Power setting

300km/h 440km/h 32.3 sec Maximum

440km/h 510km/h 1:02 min Maximum (Note: Engine overheated)

Can we please stop repeating the myth that the Yak accelerates better than the later 109s? Even on combat power the G2 accelerates better than the s. 69.

Thanks for taking the time to do the tests Finkeren . So this indicates that the Yak-1 s69 is not overperforming in BoX in acceleration. In fact if anything is overperforming it’s the Me-109G2: 25 s seems very optimistic I think but then the G2 also seems to climb too well in game…..

Where are you taking the yak-1b climb rate from? 17m/s is a game number and it seems to be an overoptmistic number according to:

Gordon, Khazanov, "Soviet Combat Aircraft of the Second World War", vol. 1, has a summary of 4 flight tests done on the Yak-1 with the 1,180hp rated M-105PF engine between mid-42 and early 43.

time to climb from ground level to 5 km.

test 1- test weight: 2,917kg, time: 6.4 minutes;

test 2- test weight: 2,780kg, time: 4.7 minutes;

test 3- test weight: 2,900kg, time: 5.6 minutes;

test 4- test weight: 2,884kg, time: 5.4 minutes.

You see, the game yak-1b I think weights 2.932kg so it should be around the first test. I would like to know how these numbers compare to Holtzauge simulation ...

Cheers

I don’t think 17 m/s sea level climb rate for the s127 sounds optimistic: I don’t have it modeled in C++ but given it’s aerodynamically cleaner than the s69 which does more than 16 m/s then 17 m/s sounds perfectly reasonable and may even be a bit on the low side.

For the s69 I get a climb rate of 16.2 m/s at sea level and 14 m/s at 3 km and a climb time of 5 min 59 s to 5 Km altitude (i.e. 13.9 m/s average) in the C++ simulations which seems to tab quite well with what Finkeren posted here. So again, nothing indicates that the Yak is overperforming in climb either.....

June 8, 2017

Thxs for the simulation Holtzauge

June 8, 2017

Thxs for the simulation Holtzauge

You're welcome!

June 8, 2017

I know sarcasm is hard to get over internet.

Please read once more, IN-GAME plane climbs as it was modeled IN-GAME.

I really don't care to write to these forums anymore. Let's just everyone trust USSR Stalin time reports and enjoy best flight sim in the world.

LW planes actually sucked and they are over performing in-game. Yaks are fine. During BoB LW pilots asked actually for a Yak squadron, not Spitfire squadron.

June 8, 2017

Thxs Finkeren. It makes sense. I just thought the figures were for sea level and not average climb. Could you make a similar test for the G2 for comparison purposes, if its not too much trouble ...

Cheers

Just did a very quick one under the same conditions as before, except I aimed for for a slightly higher climb speed of 275-280km/h at combat power

0-5000m took 4 minutes, 20 seconds for and average climb rate of 19.2m/s.

That's very slightly worse than I would expect based on the numbers given in the specs, probably .5m/s off, which could easily be ascribed to my sloppy flying.

In any case: If you find that you can't outclimb a Yak in a Bf 109G2 on combat power, there are really only 3 possible answers:

1. You are a terrible pilot.

2. He entered the climb with a large energy advantage over you.

3. He is carrying significantly less fuel (or weapons/ammo) than you are.

June 8, 2017

I know sarcasm is hard to get over internet.

Please read once more, IN-GAME plane climbs as it was modeled IN-GAME.

I really don't care to write to these forums anymore. Let's just everyone trust USSR Stalin time reports and enjoy best flight sim in the world.

LW planes actually sucked and they are over performing in-game. Yaks are fine. During BoB LW pilots asked actually for a Yak squadron, not Spitfire squadron.

If you trust the specs given in the game, what are we doing all this testing for? Just present your superior source material that clearly shows how the in-game specs are wrong.

Personally, I think we are much better off trusting "Stalin time reports". Those reports were made in an effort to improve plane designs to try and win a war, they were not propaganda tools.

June 8, 2017

If you trust the specs given in the game, what are we doing all this testing for? Just present your superior source material that clearly shows how the in-game specs are wrong.

Personally, I think we are much better off trusting "Stalin time reports". Those reports were made in an effort to improve plane designs to try and win a war, they were not propaganda tools.

If you consider how many things were clearly wrong modelled and meanwhile fortunately corrected, skepticism is generally advisable I would say. And particularly you were one of the persons who continously defended things which are revised and extended now

But I admit that lot of things are really good now and the testable figures are overall in line. The rest are things which are not easily to test or to prove (e.g. lowspeed handling, wobbling, etc.), but that doesn't mean they are not there.

Get me right, I don't want to argue at the moment. With the new direction the sim is going I have hope that with the next FM update also those issues will become better. So let's wait and see what we get in July. Then it makes more sense to discuss FMs....

June 8, 2017

The one thing I can see as a possible issue is the Yaks behavior at or near the stall. It is very forgiving and docile, meaning that pilot errors have relatively small consequences. This might be wrong, but it is very hard to prove.

I personally don't experience the Bf 109 wobbling that everyone's talking about, so I can't comment on that, and I never fly the Yak using flaps either.

June 8, 2017

The 109 has a lot of torque in a small airframe, and very small vertical stabilizer, so it might not be a stretch to assume it would lose some directional stability at low speeds. We do know that the real thing experiences something called "Aileron Stitch" when the slats come out, and while I really don't know what that is, it doesn't sound good. I've heard a lot about this "wobbliness" and don't know if they got it right or not, but I haven't seen much to convince me that something is wrong. The plane surely gets mushy at low speeds, but it doesn't strike me as flying too differently than the K4 that they have in DCS. I don't happen to have any time in a real BF-109 to compare....

Edited June 9, 2017 by Iceworm

June 9, 2017

But the Spitfire does not fly like Yak at low Speeds thats the Problem, how many 109 meet you in BOS with Flaps deployed?

June 9, 2017

What does the Spitfire have to do with this?

Edited June 9, 2017 by Finkeren

June 9, 2017

Because Iceworm compare 109K4 with BOS 109 thats why...

June 9, 2017

The 109 has a lot of torque in a small airframe, and very small vertical stabilizer, so it might not be a stretch to assume it would lose some directional stability at low speeds. We do know that the real thing experiences something called "Aileron Stitch" when the slats come out, and while I really don't know what that is, it doesn't sound good. I've heard a lot about this "wobbliness" and don't know if they got it right or not, but I haven't seen much to convince me that something is wrong. The plane surely gets mushy at low speeds, but it doesn't strike me as flying too differently than the K4 that they have in DCS. I don't happen to have any time in a real BF-109 to compare....

that the 109 has a relatively small rudder wasnt an issue for it obviously. as you mentioned yourself, the whole airframe was small, and its relative size isnt something extraordinary at all...the small size also leads to smaller forces the pilot has to overcome to steer it...assuming it would lose directional stability at low speeds...mhhh, the 109 isnt exactly a plane hated by its pilots for its slow and stall speeds characteristics...quite the contrary.

"aileron stitch" doesnt happen when the slats come out....it can happen when only 1 slat comes out, which means that the pilot doesnt keep the aircraft coordinated...and it only happens when the flaps are not deployed.the effect itself is nothing too severe it seems, according to many pilot quotes...quite contradicting to say "we do know about aileron stitch" as obviously you say in the same sentence that you dont even know what its all about...

comparing the K4 of another simulation with the F version we have here does not mean anything, even if they would behave similar, which they dont.

in general, i myself dont really have an issue with the speeds the yaks can achieve....what i do find hilarous though, is their behavoiur once they pull out the flaps in the vertical. watching them how they lift up the aircraft near stall speeds when extended completely is just funny...whats even more funny though is, to watch that the same flaps seem to lose their lift instantly once they stall and are upside down in inverted flight...they still manage to keep the nose above the horizon, "roll the stall out", and once they have their heads up again, the flaps magically give lift again.....hard to proof with numbers that something is wrong. but its just soo obvious that there is an issue, and denying or ignoring it, will just harm the IL2 brand imo.

Edited June 9, 2017 by 9./JG27DavidRed

June 9, 2017

Good video from game and tacview would help to point out this matter and maybe get needed attention by Devs.

June 9, 2017

But the Spitfire does not fly like Yak at low Speeds thats the Problem, how many 109 meet you in BOS with Flaps deployed?

true, but that is because BoX is a game, not real life. Flaps cause drag and low speed. In RL, pilots would not get into slow acrobatic turning fights at ground level like you see all the time in MP.

The Devs have already limited the flap effect, but there is a limit.

The main purpose of flaps is for landing, so:

1. flaps still need to provide enough lift/drag so you can land safely at historical speeds;

2. you have to be able to deploy flaps at 300 kmh or less without any damage.

You also have to remember that the Yak was a very easy airplane to fly, that was very important in the VVS since the majority of pilots had little training/experience, so what you see in game matches historical data.

But again we are back to the original question, if someone is a 109 pilot, why are you getting into a low speed turning fight with a Yak?

June 9, 2017

There is a very big difference between an aircraft using flaps for landing and an aircraft at the top of a chandellle just above stall speed and on the edge of critical AoA. You can feel the aircraft starting to get mushy and hear the buffeting suggesting a departure is near. At this point deploying the flaps in the yak settles the aircraft and allows it to turn further almost as if it's a +10 energy button. The pneumatic flaps in the yak deploy fully to an angle of at least 60 degrees (probably more like 70-80). That much drag all at once should certainly not stabilise an aircraft riding the edge of the envelope. I'd think you'd more likely cause more harm than good trying that.

As to why turn with yaks...? Because I f%^#in can that's why. Like I said earlier 109s being BnZ only isnt really true.

IMO a lot of people avoid this type of fight which is exactly why many of them don't come against some of the issues we are talking about here.

Edited June 9, 2017 by 9./JG27DefaultFace

June 9, 2017

But again we are back to the original question, if someone is a 109 pilot, why are you getting into a low speed turning fight with a Yak?

why not? because of the prejudice that a 109 should not turn against a yak?

Edited June 9, 2017 by 9./JG27DavidRed

June 9, 2017

When you deployed flaps yak will balon up imidiately, lower the speed higher it be, if you ask me why 109s try turning with yak is obvious - good pilot like David can outmaneuver me and many others easily. Low speed handling plus BF slats provide that if this is can be done in real 109 I don't know . Good theory can be enough for me...

June 9, 2017

Just did a very quick one under the same conditions as before, except I aimed for for a slightly higher climb speed of 275-280km/h at combat power

0-5000m took 4 minutes, 20 seconds for and average climb rate of 19.2m/s.

That's very slightly worse than I would expect based on the numbers given in the specs, probably .5m/s off, which could easily be ascribed to my sloppy flying.

In any case: If you find that you can't outclimb a Yak in a Bf 109G2 on combat power, there are really only 3 possible answers:

1. You are a terrible pilot.

2. He entered the climb with a large energy advantage over you.

3. He is carrying significantly less fuel (or weapons/ammo) than you are.

Well I just did a C++ simulation for the Me-109G2 and I get a climb time of 4 min 45 s to 5 Km altitude (i.e. 17.5 m/s average). So again, it's the Me-109G2 and not the Yak that is overperforming in climb in BoX. In fact I think the delta of 1.7 m/s or circa 10% is a lot and should be fixed ASAP.

And about the others issues brought up here: Sure, there may be issues with the low speed handling in BoX and I too have a hard time reconciling all the Yak flapping that you see both the AI doing and that you also see in videos posted from MP with IRL flight mechanics but all this is hard to pin down and give constructive feedback on. OTOH climb rate is a hard number that is verifiable and as far as I can see it is significantly off on the G2 and it would be nice if there was the same kind of uproar about a German plane overperforming as it is when they are underperforming......

June 9, 2017

Not according to this:

Climb rate and time.

Initial climb rates measured were 20.6 m/sec at SL, increasing to 24.7 m/sec at 1700m altitude. Climb to 5000m in ca. 4 min 6 secs.

The climb results - 4 mins 6 seconds to 5km altitude - are in generally good agreement with the measurements of Bf 109G-1 trials at E-Stelle Rechlin (time to 5km : 4 min 11 seconds), at ERLA Flugzeugwerke in Germany (4 min 30 secs); as well as with the results obtained with the captured Bf 109G-2 WNr. 14 513, by the NII VVS in the USSR (4 min 24 secs).

Are these figures wrong? If so, here can I find more appropriate numbers?

They seem to be what we have in game according to Finkeren's test.

Edited June 9, 2017 by JAGER_Riksen

June 9, 2017

......

Well, perhaps I'm not clear on what you think is "wrong" with the flight model of the BF-109? Directional stability, stall behavior, what? Not as maneuverable as you think it should be? And I'm not saying it's completely "right", I'm just trying to be able to distinguish informed fact from whining, because in the latter case, I find that quite a lot of people in online flight sims complain about flight models when they aren't happy about how any given encounter turned out, but it can sometimes be almost impossible to determine if the plane was at fault, or if the pilot simply didn't fly it optimally, or maybe never flies it optimally. You can see this on display all the time. I want all the airplanes to have flight models that are as historically accurate as can be determined, without regard for balance or bias, and the frequent developer diaries give me a fair amount of confidence that this is also their wish.

Since this thread is supposed to be about the Yak, and not the Bf, I apologize for continuing the drift towards the Bf, but hey, the internet and all, you know.

Edited June 9, 2017 by Iceworm

June 9, 2017

Well I just did a C++ simulation for the Me-109G2 and I get a climb time of 4 min 45 s to 5 Km altitude (i.e. 17.5 m/s average). So again, it's the Me-109G2 and not the Yak that is overperforming in climb in BoX. In fact I think the delta of 1.7 m/s or circa 10% is a lot and should be fixed ASAP.

And about the others issues brought up here: Sure, there may be issues with the low speed handling in BoX and I too have a hard time reconciling all the Yak flapping that you see both the AI doing and that you also see in videos posted from MP with IRL flight mechanics but all this is hard to pin down and give constructive feedback on. OTOH climb rate is a hard number that is verifiable and as far as I can see it is significantly off on the G2 and it would be nice if there was the same kind of uproar about a German plane overperforming as it is when they are underperforming......

I think your model is overly pessimistic about the G2. The in-game specs are close to the figures from original testing.

440km/h ias at 6K, Yak 1b?

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