Special Aircraft Service

Individual Mod Downloads for IL-2 1946 => Other Mods => FM Discussions => Topic started by: Laufer on August 22, 2012, 11:44:17 AM

Title: Rogožarski IK-3 FM
Post by: Laufer on August 22, 2012, 11:44:17 AM
Hello,

I want to ask modders about possible update of plane Rogožarski IK-3. Actually there is few funny things about it. IK-3 by all details I read and find in books and all over internet is better and faster than Hurricane Mk I and Me-109 E, Me-109 E is only faster in vertical climbing. When AI (computer) flies it, it's almost OK, but when player(human) flies it, there is no chance of shooting down Me-109. I made campaign with this plane and many people complain about this, same problem I have, could you please, improve its performance, to make it real ? Could you make some update in future?

In hope you will understand this problem, thanks in advance,
Regards, Laufer.
Title: Re: Rogožarski IK-3 FM
Post by: Bombnick on August 22, 2012, 02:37:19 PM
I am much interested in performance of the real IK-3 too. I hope it wouldn't be too much of a trouble for you to bring forward at least some documents (test reports) and/or pilot reports from books you mentioned.

I am a bit skeptical about IK-3 performance being that superior to Emil - it had about 25 % less engine power with similar weigth at best. If it was indeed faster than Emil in a horizontal flight I'd be very surprised.
Title: Re: Rogožarski IK-3 FM
Post by: Laufer on August 22, 2012, 03:42:27 PM
I didn't express myself good, IK-3 is superior in dogfights proved by pilots who fought in April war 1941 over Belgrade. Also with IK-3 it's hard to shoot down Bf-110, and Hurricane can shoot him in no time, what is ridiculous

Sources I have are in Serbo/Croatian, BUT here is wikipedia, speed of IK-3 is 526 km/h and Bf-109 E is 560 km/h which is not great differences so IK-3 can't get him, am I right?

http://en.wikipedia.org/wiki/Rogo%C5%BEarski_IK-3

http://www.battleofbritain1940.net/0013.html

Title: Re: Rogožarski IK-3 FM
Post by: Dreamk on August 22, 2012, 03:56:49 PM
The problem is among other things in its emd, based upon the emd of the Morane 406, but the Hispano Suiza Y29 of the IK3 was a different engine, much more performant than the HS-Y31 of the Morane. 
The nomenclature 31 is due to a change in the French engines designation that happenned in 1936, and does not imply that the model is more advanced than the Y-29, a model designed for the foreign market with 910 Hp at take off and 920 Hp at 3 600 m, as copmpared with the 830Hp at take off and 860Hp at 3150m of the HS-Y31. The HS-Y49 that equipped the Arsenal VG-33 had identical performances to the HS-31, the only differences between them being modifications of the carburators/fuel admission system.
A most critical aspect is the propeller mounted on these planes - French official tests evidenced that performances varied greatly when these planes were equipped with different propellers.
Title: Re: Rogožarski IK-3 FM
Post by: Laufer on August 22, 2012, 04:08:39 PM
Beside all, if you take historic fact that of 6 built IK-3, only 3 were lost in dogfights, I mean honestly it says a lot. Luftwaffe on 6th April, 1941. lost between 42 and 48 planes (source: "Plamen nad Beogradom" by lt.Colonel  Kostic) and book ('Naše nebo aprila 1941.' by ing. Petar Bosnic) and Yugoslav Air Force lost 8 planes.

But the problem isn't just with this plane, talking about game, you have same problem with F-86 vs. MiG-15...also with F-86 you can't beat MiG-15 what is also un-normal, am I right?

That is a problem which must be updated, for F-86 and IK-3, if it isn't updated till know, talking of F-86...
Title: Re: Rogožarski IK-3 FM
Post by: Dreamk on August 22, 2012, 04:19:29 PM
you have same problem with F-86 vs. MiG-15...also with F-86 you can't beat MiG-15 what is also un-normal, am I right?
The Mig 15 was in fact superior to the F86, but the pilots quality made all the difference.
Title: Re: Rogožarski IK-3 FM
Post by: Laufer on August 22, 2012, 04:26:20 PM
Mig-15 was superior in dogfights, fast turns etc. one word chasing but NOT faster than F-86. That's what I'm talking about.
Title: Re: Rogožarski IK-3 FM
Post by: Radoye on August 22, 2012, 04:51:47 PM
IK-3 1st series was inferior to Emil in all aspects except turn performance which was indeed excellent. It was somewhat better matched with the Hurricane (about equal speed - i'm comparing it to the standard Hurricane Mk.IA not the hybrid Yugoslav produced machines - slightly better turn performance for IK but lacking in climb performance ceiling and range). In a turning combat the IK pilot can hold its own against both Hurricane and Emil but in real life situation no Emil pilot would decide to turn with the IK, he can use his superior speed, climb and dive to engage and disengage at will.

These problems would've been addressed with the 2nd series which was in production when the war broke out (one 2nd series machine was delivered on the second day of the war, it was actually a conversion of the #7 IK-3 1st series machine), this had an uprated engine, reactive exhaust and some aerodynamic refinements (mostly the underbelly oil cooler) which pushed the top speed up to cca 540 km/h and slightly improved climbing but still preserving the turn performance.

Now that one would certainly have a better chance against Emils!
Title: Re: Rogožarski IK-3 FM
Post by: Bombnick on August 22, 2012, 06:47:37 PM
Sources I have are in Serbo/Croatian,

This shouldn't be a problem at all, if there's any interesting test reports in those books, snap a picture and show it ;).

What we are looking here are numbers from original documents rather than descriptions.

Quote from: Laufer
you have same problem with F-86 vs. MiG-15

Only the F-86F in 1953 catched up with / surpassed the MiG-15. Earlier versions of F-86 were inferior to the MiG with diving being a glaring exception. But we are derailing the thread with this.
Title: Re: Rogožarski IK-3 FM
Post by: Maro on August 22, 2012, 11:59:13 PM
For IK-3 is good make own cockpit too.
Title: Re: Rogožarski IK-3 FM
Post by: Laufer on August 23, 2012, 05:23:02 AM
Literature I used with stories of pilots and IK-3 possibilities are mostly from this books:

http://airserbia.com/vvkj/index.php?str=literatura

But here, it seems stories aren't accepted as relevant prove, then again all info about performance can be found on many sites over internet, there isn't problem about that IK-3 was slower little bit than Me-109, but we are talking about game, not so much about real plane possibilities, anyway we won't fly on it :) because its performance has been proved by dead Luftwaffe pilots over Belgrade, just game, AI problem, if in game Hurricane can beat Me-109 not to talk about Me-110 and we know that Hurricane is worse than IK-3, I don't see why IK-3 can't beat Me-109 then...am I right?
Title: Re: Rogožarski IK-3 FM
Post by: Dreamk on August 23, 2012, 05:37:03 AM
From the start the IK3 was very similar to the D520, only better - the French never succeeded to overcome the huge aerodynamic problems of the D520 (above all the brutal stall without warning that was the plague of the D520), but truth is that the Yugoslavs are one more year to finalize development of the IK3. The design was more than similar, as was the engine, and thence the performances. And the tests made by the British between D520 and Bf109, together with IK3 combat reports, can serve as a basis for he IK3 performances
Title: Re: Rogožarski IK-3 FM
Post by: Radoye on August 23, 2012, 06:30:09 AM
...because its performance has been proved by dead Luftwaffe pilots over Belgrade...

7 operational IK-3's have claimed 11 unconfirmed victories for the loss of 4 of their own (+ another 3 destroyed on the ground to prevent capture). Percentage-wise that's a great score.

But most of the damage against Luftwaffe over Belgrade has been done by Yugoslav Emil pilots who were able to sneak near German bomber formations unrecognized and wreak havo, while the IK's with their distinctive silhouette were immediately fired upon.

Another setback was the lack of ammo - there was no incendiary ammo available for the machineguns (only ordinary ball ammo) and there was a shortage of 20mm shells so much that after the first day of the war Yugoslav planes (IK's and Emils alike) took off with only 6 20mm rounds per gun instead of the usual full load. This too had an impact on their efficiency.

Breakdown of the 11 IK-3 victories by type:

Ju 87B: 2
Do 17Z: 2
Ju 88A: 3
Me 109E: 2
Me 110D: 2

About half of these were shot down on the first day of the war, 3 more on the second and the rest for the remaining few days of the war.

But despite all of this most important factor we need to consider was the pilot performance. Because in a hands of a good pilot even an essentially inferior machine can defeat the most modern opponent.

It is an enduring myth among the peoples of former Yugoslavia that IK-3 was "the best fighter plane on the whole world". It was most certainly not.

But it was good for what it was - a light fighter of a size similar to MS.406 utilizing a similar engine and armament, and it was clearly superior to 406 in every imaginable performance aspect by some margin.

And especially with the future upgrades - 2nd series and beyond, look at the postwar Ikarus S-49A which was nothing but an IK-3 with a cut-down rear fuselage, bubble canopy, VK-105 engine (itself a development of the Hispano-Suiza) and armed with 1 x 20mm and 2 x .50cal machineguns for an idea about the potential of the initial design - had the war fortunes went some other way the IK-3 would still be a capable fighter well into the second half of the WW2.

Not the "best in the whole world" - but still pretty good.
Title: Re: Rogožarski IK-3 FM
Post by: warhawk on August 23, 2012, 07:46:03 AM
Actually, the twelve built examples (not including the prototype) were all of the pre-production series, delivered in two batches (6 planes each), which differed only in some details, not in flight performance.

First series (25 aircraft) was ordered and production was getting prepared when the Axis forces invaded.
Production examples would have had a different engine (DB601 and RR Merlin were considered, the first version was actually built - a single Rogoschmitt...  ;D)
 
Title: Re: Rogožarski IK-3 FM
Post by: Radoye on August 23, 2012, 04:58:41 PM
I assume we have the 1st series?
Yes what we have in the game is representative of one of 12 1st series IK-3's as originally delivered.

Not the original prototype (lost in accident), not the modified #7 (2nd series prototype) nor the 24 airframes being in different stages of completion.

Actually, the twelve built examples (not including the prototype) were all of the pre-production series, delivered in two batches (6 planes each), which differed only in some details, not in flight performance.

First series (25 aircraft) was ordered and production was getting prepared when the Axis forces invaded.

Essentially this is correct - all 12 pre-series machines differed in small details, but not in performance.

However locally this pre-series is being referred to as the "1st series" and the 24 series aircraft (+ modified #7, the only machine ever completed to the new specs to make it a total of 25) were known as the "2nd series".

Production examples would have had a different engine (DB601 and RR Merlin were considered, the first version was actually built - a single Rogoschmitt...  ;D)

Yes there was some consideration to use a Merlin or a DB on further series production of IK-3 (as well as a fully developed DB-Hurricane project known as LVT-1, built and flown and ready for series production) but nothing serious happened by the time Germans invaded - by serious i mean technical drawings, calculations or any work beyond the initial idea.

The one DB-IK that was "completed" was only a mock-up never intended to fly, it was done by mating one of the incomplete airframes from 2nd series production with the nose section from a worn-out Me 109, to be displayed in a museum in Berlin. It was transported there by rail and was destroyed by Allied bombs later in the war.

Title: Re: Rogožarski IK-3 FM
Post by: LuseKofte on August 24, 2012, 12:20:01 AM
I want to state something about kill/ loss rate.
You can never use this statistic in a FM debate, the kill/ lossrate during the war was mainly based on how many enemy planes could you find. In  BOB there where more targets to find for Allied k/l rate in favor for allied, later in war the other way around. In 1944 it was not unusual for a allied fighterpilot to not ever meet a flying german plane at all.
This is Airkills I am talking about, not groundkills. same in eastfront
Title: Re: Rogožarski IK-3 FM
Post by: Radoye on August 24, 2012, 05:42:05 AM
I tend to agree - kill vs loss ratio most definitely should not be the crown argument in an FM discussion. I listed the IK-3 "victims" to show they were mainly bombers, as a counter-argument to the claim of "many dogfighting victories against Luftwaffe pilots over Belgrade".

Yes there are other factors than pure plane performance to consider which can influence the kill/loss ratio and some are already mentioned (tactical situation, pilot quality etc). IK-3 has some of these going for it (their pilots were hand-picked elite, the best of the best, all experienced aerobatics flyers) and some against it (desperately outnumbered, easily recognizable to Luftwaffe pilots unlike the Yugo Emils, lack of 20mm ammo...) and IMHO it has performed quite well under the circumstances.

But does this all mean the FM should be changed? Hell no!
Title: Re: Rogožarski IK-3 FM
Post by: Laufer on August 24, 2012, 07:43:53 AM
Yes, you are all right! FM shouldn't be changed, but AI need to be changed definitely !
Title: Re: Rogožarski IK-3 FM
Post by: LuseKofte on August 24, 2012, 09:56:41 AM
What this game however not do is mirroring the fuelproblem Germans had late war. The engine might be good but the fuel was rubbish. Performance on latewar Luftwaffe airplanes was very limited because of this. I am all for adjusting FM and getting AI better so the game feels more realistic.
Your suggestion of changing FM is not a bad idea, many times a FM tweak is nessersery to get this game better even if the tweak isnt historical
Title: Re: Rogožarski IK-3 FM
Post by: Bombnick on August 26, 2012, 09:13:04 AM
What is the current FM of IK-3 based on? Are there any test reports from 1941 available?
Title: Re: Rogožarski IK-3 FM
Post by: Radoye on August 26, 2012, 11:11:54 AM
I am not aware of any performance charts and such surviving the war.

There are only some written reports from test flights and mock-dogfights which quote some performance figures.

Such as:

Measured absolute top speed 527 km/h @ 5450 m (specially prepared prototype)

Top speed 520 km/h @ 5000 m (average 1st series machine)

Top speed at sea level 421 km/h

Cruising speed 400 km/h @ 5000 m

Climb to 5000 m:
7 minutes flat (specially prepared prototype)
7 min 49 s (average 1st series machine)

Ceiling 9460 m

Range 600 km, endurance 1 hr 15 min

Takeoff run 200 m

And then there are the physical dimensions:

Length 8 m

Height 3.25 m

Wing span 10.30 m

Wing area 16.50 m2

Aspect ratio 6.43

NACA profile 2215/2212/2209

Weights - empty 2170 kg, normal takeoff 2405 kg, maximal takeoff 2630 kg

Fuel capacity 330 l

Oil capacity 38 l

Engine HS 12Y-29crs 925 hp / 690 kW

Armament 1 x 20 mm moteur-canon w/60 rds, 2 x 7.92 mm cowl machineguns w/ 500 rds

All reports cite "excellent agility and turn performance", "easily turns into a Hurricane or Me 109 during mock dogfights" but no hard numbers are given.


What jumps at me from these numbers is the time-to-altitude value which is quite weak compared to the contemporary opposition, IK-3 would be easily outclimbed by both Hurricane and 109. Top speed is thereabouts with the early mark Hurricanes but 109 again has the edge.

Title: Re: Rogožarski IK-3 FM
Post by: Radoye on August 26, 2012, 11:20:05 AM
Looking at the charts in Il-2Compare it seems there is some room for improvement (top speed 526 km/h @ 4800) there but nothing that would make a drastic difference. I mean, you still wouldn't be able to chase down a 109 (and you shouldn't).