LA-5 FN Climb Speed.

[Roland_HUNter]

Greetings!

 

I am doing climb tests these days and have tested the La-5 FN several times, but something is not right.

Please others please confirm if the test is true:

 

The manual says:
Climb rate at sea level: 20 m/s
Climb rate at 3000 m: 16.7 m/s
Climb rate at 6000 m: 12.5 m/s

Note 4: climb rates and turn times are given for Boosted power.

 

Test on: Normandy, D-Day map,
Starting at 010 meter, I start climb with boost and with 280 km/h, counter rudder to the right.

Closed outlet, 100% Inlet, and 50% oil rad.

The result is:
1000 meter in 40 sec, what is 25 m/s.

3000 meter in 150 sec, what is 20 m/s.

I tested it many times, I always got the same result.

If everybody else get the same result, I suggest the FM should be revised.

[the_emperor]

finding credible (partly due to my lack in russion and often seem not corrected for compressability at altitudes) FM reports on the La-5fn (soviet aircrafts in general) are not that easy to find.

But the La-5fn seems to be rated for 5.3min (4.7min with boosted mode, only allowed to 2000) for climb to 5000m.

Maybe that could be tested for reference

[the_emperor]

I need ~ 4:15min to 5000m (Kuban Autumn) with boosted mode (so ~19,6m/s average climb speed)

the La-5fn FM seems to bee on the very generous side considering climb speed/ roll rate and WEP time (10min). overall a very potent beast

Edited December 8, 2023 by the_emperor

[Roland_HUNter]

2 minutes ago, the_emperor said:

I need ~ 4:15min to 5000m (Kuban Autumn) with boosted mode (so ~19,6m/s average climb speed)

the La-5(fn) FM seems to bee on the very generous side considering climb speed/ roll rate and WEP time (10min). overall a very potent beast

Yes, but based on the manual, it should be 3-5 m/s less.
And in IRL, many pilots defeated the LA-5 with the 109s superior climbing capability.

With this datas, the La-5FN climbing better than a 109.

[the_emperor]

And the cooling capacities also seem to be very generous. 
but overall I have not enough credible FM reports to draw any conclusion whether the FM ingame is correct or not. 
here is a german report of a captured La-5fn but as always with captured planes it might not be in the best condition engine wise:

 

[Roland_HUNter]

8 minutes ago, the_emperor said:

And the cooling capacities also seem to be very generous. 
but overall I have not enough credible FM reports to draw any conclusion whether the FM ingame is correct or not. 
here is a german report of a captured La-5fn but as always with captured planes it might not be in the best condition engine wise:

 

It says 16-17 m/s at cruising power.
And 540 km/h on 1000 meter...hmmm...
540 could be right with nominal engine mode but to slow for boosted.

[Gavrick]

3 hours ago, Roland_HUNter said:

Closed outlet

Outlet cowl flaps must be open during climb.

[Roland_HUNter]

33 minutes ago, Gavrick said:

Outlet cowl flaps must be open during climb.

Why? We've done the test with closed. If we could, then everybody can use it like that in combat.

[the_emperor]

9 hours ago, Gavrick said:

Outlet cowl flaps must be open during climb.

No need. The La-5fn works perfectly with outlets fully closed in all situations. 
maybe that is an issue worth looking at?

[the_emperor]

~5:30m to 6000m and ~7:30min to 7000m 

on Kuban Summer outlet shutters fully closed, oil rad at 50%.

climb speed at 250/240kph indicated.  no overheating, not even close.

Edited December 9, 2023 by the_emperor

[1PL-Husar-1Esk]

The overheating is weak in most plans , opposite to the reality . Good overheating model could replace unrealistic timer mechanic. Everyone happy and sim more realistic. Plus more complains from noobs which  who damage theirs engine in the airfield ?

7:35, do that in game and checked the temperature vs this footage.

 

 

?

Edited December 9, 2023 by 1PL-Husar-1Esk

[Holtzauge]

I don't think 25 m/s initial climb rate for the La-5FN seems so unreasonable: In my C++ simulations, I get 24 m/s with WEP and 20 m/s with military power.

 

These numbers are assuming a weight of 3305 kg and 1850 hp WEP, and 1579 hp military power. Now my guess is that those are pretty ideal power output numbers, and it could well be so that under field conditions many engines did not performs at those levels. OTOH, those are the spec numbers I have and which are the best available AFAIK, so those are the numbers I use.

[Roland_HUNter]

6 hours ago, Holtzauge said:

I don't think 25 m/s initial climb rate for the La-5FN seems so unreasonable: In my C++ simulations, I get 24 m/s with WEP and 20 m/s with military power.

 

These numbers are assuming a weight of 3305 kg and 1850 hp WEP, and 1579 hp military power. Now my guess is that those are pretty ideal power output numbers, and it could well be so that under field conditions many engines did not performs at those levels. OTOH, those are the spec numbers I have and which are the best available AFAIK, so those are the numbers I use.

The manual says 20 m/s with boosted.
WW2 reports says even less, 16-17 m/s.

[the_emperor]

20 hours ago, 1PL-Husar-1Esk said:

Good overheating model could replace unrealistic timer mechanic. Everyone happy and sim more realistic. Plus more complains from noobs which  who damage theirs engine in the airfield ?

 

That would be indeed a nice way to solve the timer mechanic problem. with a complex engine modelling, especially in the heat department, the game could get some new life.

Maybe with the next game.

But back to topic, the La-5fn (heat)model should probably undergo a closer inspection.

[Holtzauge]

13 hours ago, Roland_HUNter said:

The manual says 20 m/s with boosted.
WW2 reports says even less, 16-17 m/s.

 

And they may both be right: It all depends on the condition of the engine tested and the weight of the airplane.

 

As far as I remember, the 16-17 m/s figure for the La-5FN comes from a German trial of a captured specimen? And in this case remember that this is not an uncommon result from tests of captured aircraft: The British did not get the same performance out of the captured Bf 109E that they tested as the German specs says. 

 

If I run a Fw-190A8 with the same power loading as the La-5FN has on paper, i.e. reducing the weight from circa 4300-4400 kg to 3305 kg instead, then this very light Fw-190A8 would climb at 24 m/s as well. But AFAIK the Fw-180A8 as flown by the Germans was almost a ton heavier due to them adding a lot of armament and armor for the role they wanted the Fw-190A8 to play, so no wonder it does not climb as well.

 

So again, if the La-5FN has an engine producing 1800 hp and we assume a weight of around 3300 kg, then according to the laws of physics, it should climb at around 24 m/s. But if this is representative of typical La-5FN in the field, that is of course another question altogether.

 

 

[Roland_HUNter]

4 hours ago, Holtzauge said:

So again, if the La-5FN has an engine producing 1800 hp and we assume a weight of around 3300 kg, then according to the laws of physics, it should climb at around 24 m/s. But if this is representative of typical La-5FN in the field, that is of course another question altogether.

If this is possible, then still something needed to be fixed. Either the manual or the plane.
 

As I mentioned at the beginning, I have never read about such a high climbing capacity.
But I have read that they left the La-5FN with G-6s climbing ability.

[Holtzauge]

59 minutes ago, Roland_HUNter said:

If this is possible, then still something needed to be fixed. Either the manual or the plane.
 

As I mentioned at the beginning, I have never read about such a high climbing capacity.
But I have read that they left the La-5FN with G-6s climbing ability.

 

Which manual is that? I assume you mean the one which you referred to earlier and which says 20 m/s sea level and 12.5 m/s at 6 km climb rate with boost?

 

Would be helpful if you could post some information from that manual (either a link to the complete manual or relevant pages) so we can see where this info comes from and the conditions they assumed in connection to those numbers.

[Roland_HUNter]

4 hours ago, Holtzauge said:

Which manual is that? I assume you mean the one which you referred to earlier and which says 20 m/s sea level and 12.5 m/s at 6 km climb rate with boost?

Yes, ingame manual

[1PL-Husar-1Esk]

4 hours ago, Holtzauge said:

 

Which manual is that? I assume you mean the one which you referred to earlier and which says 20 m/s sea level and 12.5 m/s at 6 km climb rate with boost?

 

Would be helpful if you could post some information from that manual (either a link to the complete manual or relevant pages) so we can see where this info comes from and the conditions they assumed in connection to those numbers.

 

[the_emperor]

Some date of tested La-5s

but it looks like the the time to 5000m is around ~5min with ~20m/s up to 1000m for nominal mode.

I dont know whether the boosted mode was suitable for a climb to altitude in regards to the cooling of the engine.

I game I can climb in boosted mode with shutters fully closed without any overheating

 

 

 

 

Edited December 10, 2023 by the_emperor

[Holtzauge]

OK, well the in-game "manual" has proven unreliable before so I would not place too much faith in it. In  many cases it seems you simply need to do tests in-game to determine what the actual performance is in-game which you have done so we have that to compare to.

 

And while the La-5FN seems to be a bit on the optimistic side, I can't see that it's that far off from the numbers in the Russian performance table @the_emperor posted earlier (the one with both German and Russian planes)? Because as I understand it you measured a climb time of 4:15 (I assume 4.25 min) to 5000 m in-game?

 

I just ran a couple of simulations with my C++ La-5FN model and I get 5.27 min to 5000 m without boost, and 4.67 min with boost which is pretty much spot on compared to the 5.3 and 4.7 min mentioned in that table.

[the_emperor]

9 hours ago, Holtzauge said:

Because as I understand it you measured a climb time of 4:15 (I assume 4.25 min) to 5000 m in-game?

4min 15 sec to 5000m

in Boosted mod (kept the 2500rpm in the second charger stage on)

Yes, seems like the climb performance seems credible.

 

 

[Holtzauge]

Summing up, it looks like my C++ La-5FN simulation model agrees sufficiently well with the historical table you posted @the_emperor, and here are my estimated climb rates at different altitudes with boosted engine:

 

Sea level: 23.8 m/s

 

3000 m: 16.2 m/s

 

6000 m: 12,0 m/s

 

In addition, my estimated climb time to 1000 m is 41.53 s so an average of 24.1 m/s

 

So in conclusion, the average climb speed of 25 m/s up to 1000 m @Roland_HUNter mentioned in the OP, while certainly slightly optimistic, still seems rather reasonable and it looks like it’s the in-game aircraft specification/description that needs an update, not the flight model.

[LLv34_Flanker]

S!

 

Finnish pilots flying Bf109G-2 and G-6 outclimbed the La-5F/FN consistently in combat. It simply could not follow or stalled out. The climb rate of around 17m/s has been on many sources as well as that the WEP is usable/allowed only up to 2000m. Roll rate for La-5 in general in IL-2 BoX is from a fantasy world as it can roll FASTER than Fw190A, which was fastest rolling plane in WW2 in most flight envelopes, peak value 160deg/s but on average well over 100deg/s. Only clipped wing Spitfire could compete in a very narrow speed regime. This chart can be found at WW2 aircraft performance page.

 

La-5FN was tested by TsAGI and NII VVS. It did not reach the prototype speed of 583km/h at sea level, barely struck 540km/h if a good plane. The average speed of production La-7 reached 580km/h, but not the prototype 609km/h etc. Roll rate was a bit harder to find(did dig a lot when was helping modding original IL-2), but it seemed to be around 110deg/s at best compared to hilarious values in game now. Also the roll response is like of an aerobatic plane, not a big fighter. Roll rate of 110deg/s falls pretty much in line with Finnish pilots saying La-5 rolled slightly better than 109G, but Yak was faster. 109 rolls best around 90-100deg/s depending on speed.

[Holtzauge]

3 hours ago, LLv34_Flanker said:

S!

 

Finnish pilots flying Bf109G-2 and G-6 outclimbed the La-5F/FN consistently in combat. It simply could not follow or stalled out. The climb rate of around 17m/s has been on many sources as well as that the WEP is usable/allowed only up to 2000m. Roll rate for La-5 in general in IL-2 BoX is from a fantasy world as it can roll FASTER than Fw190A, which was fastest rolling plane in WW2 in most flight envelopes, peak value 160deg/s but on average well over 100deg/s. Only clipped wing Spitfire could compete in a very narrow speed regime. This chart can be found at WW2 aircraft performance page.

 

La-5FN was tested by TsAGI and NII VVS. It did not reach the prototype speed of 583km/h at sea level, barely struck 540km/h if a good plane. The average speed of production La-7 reached 580km/h, but not the prototype 609km/h etc. Roll rate was a bit harder to find(did dig a lot when was helping modding original IL-2), but it seemed to be around 110deg/s at best compared to hilarious values in game now. Also the roll response is like of an aerobatic plane, not a big fighter. Roll rate of 110deg/s falls pretty much in line with Finnish pilots saying La-5 rolled slightly better than 109G, but Yak was faster. 109 rolls best around 90-100deg/s depending on speed.

 

I don’t doubt that Finnish pilots in Bf 109 G2’s and G6’s at Steig & K. L. outclimbed La-5FN’s without WEP and my simulations comes to the same conclusion. But the question in the OP was if the La-5FN is over-performing in climb with boost engaged and I can’t see that it is. At least if we assume aircraft performing according to specs and that is AFAIK the policy in-game: Aircraft should be modeled as “factory fresh” and not tired old warhorses or lemons. But if TsAGI and NII VVS came to the conclusion that even these factory fresh numbers were optimistic, then I'm sure I'm not the only one but that also the developers would be interested to see those numbers and test results, together with arguments for which results are the representative ones to do the modeling after. 

 

Regarding the roll rates, as I remember it there have been numerous threads on that subject as well, but if the La-5FN is over modeled in that regard then that is probably better handled in another thread than one titled LA-5FN climb speed.

[the_emperor]

Climb rate seems to be allright, maybe a bit on the optimistic side, but ok.

What is more concerning is the heat modelling. I can climb straight to 7000m at boosted mode with shutters fully closed, oil rad at 50%, and a low climb speed of 250/240kph indicated, without even getting close to overheating, on Kuban Summer.

 

@LLv34_Flanker

any chance you could share the sources with us?

that would be great.

[LukeFF]

5 hours ago, LLv34_Flanker said:

S!

 

Finnish pilots flying Bf109G-2 and G-6 outclimbed the La-5F/FN consistently in combat. It simply could not follow or stalled out. The climb rate of around 17m/s has been on many sources as well as that the WEP is usable/allowed only up to 2000m. Roll rate for La-5 in general in IL-2 BoX is from a fantasy world as it can roll FASTER than Fw190A, which was fastest rolling plane in WW2 in most flight envelopes, peak value 160deg/s but on average well over 100deg/s. Only clipped wing Spitfire could compete in a very narrow speed regime. This chart can be found at WW2 aircraft performance page.

 

La-5FN was tested by TsAGI and NII VVS. It did not reach the prototype speed of 583km/h at sea level, barely struck 540km/h if a good plane. The average speed of production La-7 reached 580km/h, but not the prototype 609km/h etc. Roll rate was a bit harder to find(did dig a lot when was helping modding original IL-2), but it seemed to be around 110deg/s at best compared to hilarious values in game now. Also the roll response is like of an aerobatic plane, not a big fighter. Roll rate of 110deg/s falls pretty much in line with Finnish pilots saying La-5 rolled slightly better than 109G, but Yak was faster. 109 rolls best around 90-100deg/s depending on speed.

We've been around and around on this for years now - Gavrick posted his sources back when the La-5FN was built, and they show that the plane matches the source data pretty well for a 1943 production plane.

[the_emperor]

Could this issue with the La-5fn FM then be looked at:

 

[Roland_HUNter]

On 12/11/2023 at 12:51 PM, LLv34_Flanker said:

Roll rate for La-5 in general in IL-2 BoX is from a fantasy world as it can roll FASTER than Fw190A,

Sorry, but this is not true:
At 500 km/h the La-5 FN is a little bit faster, but else: slower.

 

[LLv34_Flanker]

S!

 

RAE test chart. Read LA-5FN Rechlin test as it has indication of roll rate. Do The math.

[JG7_X-Man]

LOL It's been 20 yrs and still fighting the same battles with the devs... 

[the_emperor]

On 12/11/2023 at 6:47 PM, LukeFF said:

We've been around and around on this for years now - Gavrick posted his sources back when the La-5FN was built, and they show that the plane matches the source data pretty well for a 1943 production plane.

Is that data still available?

Cheers

[Sgt_Joch]

3 hours ago, the_emperor said:

Is that data still available?

Cheers

This is what Luke was referring to.

 

Edited February 14, 2024 by Sgt_Joch

[the_emperor]

6 hours ago, Sgt_Joch said:

This is what Luke was referring to.

Thanks @Sgt_Joch

sooo people were asking since 2018 about the stellar roll performance of the Lagg3/La5 series and the La-5fn's questionable 10min boost/WEP time. 

PS: I dont doubt the La5fns level speed performance as many late war german fighters also profit from the "on paper" specs.

Edited February 14, 2024 by the_emperor

[jollyjack]

Well, y'all got me curious now, gonna pop up the A5 and the La5FN in a quick dogfight mission and try them on both sides ...

All 5 fingers crossed and have me some fun. Report back when something is worth mentioning.

 

ADDED: that LaFN seems a real winner ... especially on turns.

Duel La5FN - Fw160a5.zip

Duel Fw160a5 - La5FN.zip

Edited February 14, 2024 by jollyjack