Is the D.520 super weakened compared to IRL?

Machinery of War Discussion
1

So I’m about to unlock the Dewoitine 520, BR 3.0, fighter aircraft, and was surprised of its low dynamic performances, most notably the climb rate, compared to fighters before it.

(numbers without modifications)
Our boy here climbs at 6.9m/s, which is impressively low to me.
It’s nearly equivalent to a potez 630 which, mind you, is a twin engine two crew aircraft.

Meanwhile the two fighters before, the MS.400 series and the VG.33C-1, and its main historical german adversary, the BF109 E series, all surpass that by a lot

  • 9.4m/s for a MS410
  • 10.4m/s for the V.G.33C-1
  • 14.3m/s for both BF109 E1 and E3 (14.1m/s for the E4)

What bother me, beyond the fact it’s actually slower to ascend than some bombers
(my M.B174 climbs faster without modifications even loaded with bombs)

Is that I did some basic digging through wikipedia articles and its associated sources only to find no numbers supporting it being that low. The engine was more powerful than the one on VG33s and MS410s so even if it was heavier by 5% to 10% in gross weight, its superior engine would not justify actually being much slower to ascend than those two.

The numbers I got to find in associated articles straight mention between 11.3m/s and 14.3m/s of climb rate and here we are half that number. Why ?

Another fact is that the D.520 was known in Europe to be one of the more manoeuvrable aircrafts, being a solid match against a BF109 even tho slower yet you are here with something turning only 1 sec shorter but can’t remotely climb as fast so you will lose because the guy eventually have that critical speed and position advantage over you.

That BF109 E most likely justify its climb speed to its historically better engine, but I found a report where it says during a study in 1940 comparing a french recovered BF109 E to french aircrafts of the time. A BF109 E was better in climbing, yes, but “better” isn’t the word that one would use in goddamn 6.9m/s vs 14.3m/s -_- . That same report also do mention the D.520 to have the upper hand in some cases, mostly turn combat.

The D.520 had severe faults putting it behind in performances, namely cooling issues and landing gears doors opening during high-G manoeuvers. But I do not think it should put you so much behind in performances, especially in AB where you play at your best performances game long. We’re to a point I’d actually rather stay and play in br 2.0 with my MS410…

I could dig more but I had enough material to start the post here to ask for our D.520 to get his natural 13m/s climb rate, good middle ground to be decent, still lower than a BF109 because it always was lower. I believe it should also benefit from a reduced 360° turn duration because how else would it come back as more manœuvrable.

Sources:
Wiki page for D.520
Wiki pages for BF109, VG.33 and MS400 series

Do check the wiki pages in both languages, they have complementary infos on there

D.520 journal in-depth brochure

You can find the article mentionning the recovered bf109 vs 30s and 40s french aircraft study yourself, I will not post it because the one i have is not https

Have a good day

2

Firstly Wikipedia isn’t an accepted source, if you believe numbers to be faulty you can bug report it here (just search a bit first so that you don’t report something that is already reported and known about): (Gaijin.net // Issues)

A guide on how to report bugs can be found here: ([Navigation] Technical Knowledge Base | War Thunder Wiki)

Do note the sources needed for such a change:
Screenshot 2025-04-23 192328

Secondly, BR is determined by efficiency, meaning how much score/SL/RP a vehicle on average earns per flyout, some planes can perform way better than others due to factors not obvious at first glance or through numbers alone. An example would be more effective ammunition making hits more likely to get you a kill (in this case a 20mm canon compared to the BF109’s 7.92mm guns). It might also be the combat flaps that it has available that the V.G.33C-1 doesn’t, etc.

Don’t focus to hard on pure numbers and don’t dismiss a vehicle before you have tried it :)

3

What’s important in Wikipedia is the articles it makes its pages from, which is what I consulted

While I do see your point with BR, I don’t think you should ignore the fact an aircraft climbing twice as faster than you is more potent than yours climbing slower than some bombers

The point about 20mm doesn’t stand here either because E-3 and E-4 BF109s, which is what you fight against as a D520, have it.

Pure numbers don’t matter when the gap is small and you may compensate with fly and attack style. However I do believe it does when the gap is being behind nearly everyone in the class.

4

Well, you’re just gonna have to try it and see how it goes, as i said, it might surprise you :P
It’s likely up there in BR for a reason.

5

I believe you, otherwise I would’ve swapped nation.

But I also believe it shouldn’t be behind reality on that number :)

6

Then you can report it through above links and guides with appropriate sources :)

7

I’m doing that as we speak :)

1 Like
8

So as I was digging the hole deeper to make sure I have greater sources backing myself, I managed to find historical caracteristics manual for D520s. It can be found on the public domain, dates from around 85 years ago and is marked as archives so I believe it respects the general rules of technical documentation for military vehicles
Notice Tech D520

So admitting linear flight caracteristics, 6000m in 8.30" translates to a climb rate of about 11.8m/s

3 Likes
9

The D.520 itself is largely fine, if a bit substandard for a 3.0.
Compared to other contemporaries, the D.520 is one of the slowest and the worst climbing single-engined fighters at the BR, however it’s by far the lightest and one of the most manoeuvrable fighters, only being bested by the Spitfire and Hurricane amongst other 3.0’s. It also dives phenomenally well, extremely stable with very little risk of wing shearing from overspeed.

The biggest flaw is absolutely the ammo capacity of the Hispano 404, at a mere 60 rounds. While the gun hits quite hard and is very accurate, you can’t use it for very long and you’re left with some pitiful 7.5’s when it runs out. Granted you have a lot of ammo in those 7.5’s, but they’re amongst the weakest of the aircraft LMG’s. It also can’t carry any bombs, which makes it borderline useless for CAS / ground attack.

Now I’d be remiss if I didn’t mention that the French tree is lacking all the excellent variants of the D.520 that would make for far more competitive planes.
Chiefly; the D.524, SE.520Z, D.551, D.554 and M.520T. All of these aircraft would make for excellent indigenous fighters but alas, Gaijin refuses to add any of them.

3 Likes
10

That’s all good points here (I will test that plane even if it climbs like a dead cow, I ain’t grinding for nothing) and I absolutely follow on the fact the hispano ammo is a massive flaw of the french line rank I and II (I play MS 400s extensively, trust me, i know :D)

Now French lacking many of those aircrafts you named isn’t much of an issue to me personally, even tho i’d love that tree of ours to be greater. Objectively, most of the french aircraft list of the 30s and 40s did not pass the prototype phase and if they did it was in very select numbers as far as I know, and most of their variants came too late to be of use, or got flat-out abandonned. D520Z perfect example, even tho I’d love a D520 with an engine juiced by some additional 500hp, very cool sounding

11

Isn’t climb rate practically the result of power/weight?

If it has less engine power but is much lighter it shouldn’t be that much worse than a Bf 109 E right?

Chat GPT gave me this:

Bf 109 E-4: ~423 hp/ton
D.520: ~360 hp/ton

12

According to the data above and other data I won’t spam here for thread pollution it wasn’t that much worse IRL so i’m making a good ol’report to gaijin and see what they have to say about it

1 Like
13

So the document above that gave an average time of 8.30" to climb to 6000m ? I found in the same manual an actual flight report which shows very interesting data

Here read D520 climbing performances. It writes a table Temps de montée in which an altitude H in meters is associated with the time T to reach it.

Between each altitude measure, a climb rate W is associated.

  • It took 1 minute 08 seconds, to reach altitude 1000m from altitude 0m, giving a climb rate of 14.7m/s for this step
  • It took 1 minute 14 seconds, to reach altitude 2000m from altitude 1000m, giving a climb rate of 13.5m/s for this step
  • It took 1 minute 42 seconds to reach altitude 6000m from altitude 5000m, giving a climb rate of 9.8m/s for this step

If we want to fit it to a game by making an average of all value. All 8 values give an average, flight tested, climb rate of 11m/s for D.520s for altitude 0m to 7500m.
Notice Tech D520_2

Or we go all hog in and only use 0m to 4000m because the average fights don’t happen higher and we pull out the average 12.65m/s climb rate, Vive la France! :p

Diving in this rabbit hole was actually much funnier than I thought it would be

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14

The climb rate is the result of engine power getting lower with altitude, as well as the air getting thinner.

There must be something wrong with the flight model, if the weight of the plane and the engine power and prop efficiency are otherwise correct in the game.

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15

I guess, I don’t really know how the relationship between engine power, aircraft weight and aircraft climb rate works in video games.

But since similar aircrafts, such as the MS 400 series and the VG.33 are both around 10m/s, while being slightly lighter but also having a weaker engine, I do believe it mostly is in direct control of Gaijin.

I don’t think the flight model is at play since it doesn’t really has anything special to it compared to other similar aircrafts in the game.

It’s a very curious case because I have now checked around a dozen of pages on the subject, all having an historical source, and the lowest I ever found is an average of 10.7m/s climb rate in a history book, which is still 55% more than what it currently has in the game.

2 Likes
16

Well, climb rate is basically acceleration.
So maybe the prop is modeled to be very inefficient, and only slowly accelerating the plane.

Since power/weight should be more or less correct.

17

Imho you could have saved yourself a lot of time if you would have noticed that you are referring to:

  1. A stat card value (which is not reliable)
  2. A climb rate for a stock (=not spaded) aircraft which is not relevant

You might find this interesting:

This fighter is the classic “jack of all trades, master of none”. It can be an energy fighter, bomber hunter, or even a turn-fighter. It depends on your playstyle, and the kinds of enemy aircraft that are encountered. During the battle you have to keep in mind your best climb speed is 220 km/h (IAS) allowing you to reach a good 18 m/s. Your engine power will always increase due to the linear compressor giving you your best flight performance at 4000 m.

Found here:

D.520 - War Thunder Wiki

I face the D 520 from time to time in my Me 410, the plane is quite good - but way too slow to be a threat. Btw - the 410 A-1 has allegedly a climb rate of ~ 10m/sec (fully spaded). Not true - the plane climbs like a rocket with up to 20m/sec.

In case you want more detailed information about the D 520:

  • Check the old wt forum for aircraft data sheets
  • Install WTRTI and measure climb rate by yourself

Have a good one!

2 Likes
18

I mean, of course I question a stat card value. Why else put stat cards if they serve no use ?

A stat card value is based on whatever math WT formula is responsible for it. Thus its results are supposed to be consistent with the stats of a given fuselage. There is, to me, an actual underlying issue if D.520s display a climb rate of 6.9m/s when every other aircrafts display a more believable result. Even if it turns out he climbs nicely, there’s room for fixing.

Spaded or not my main comparison was putting the D.520 against other non-spaded aircrafts so modifications are not in play in both sides, making this point irrelevant. Even spaded it still has meh climbing rates, according to the data I had

What I basically questionned is why its stats are low compared to others and why is it not comparable, not spaded, to BF109 E series which are basically his actual historical adversary. Even the wiki refers to it as a slow climbing aircraft when it actually was average and compensated with a notably high manoeuvrability, something I understand to not be in the game.

Anyway I did not know 3rd party softwares were allowed (anti-cheat) and I took measure and was pleased to see it’s actually just a card error so thanks for that. This thread is now a “fix your display card” :p

19

Did you test these numbers or is this from a statcard? I know from experience that the 109 E-4 can do 20ms+ at low alt.

edit: ah, you mentioned in another message that it is from statcard. It is automatically lying.

1 Like
20

Like when gaijin fully ignores any and all “causation” or pesky things like “nuance” and balance things strictly based off what a computer tells them to do! I mean, that is why we have IDENTICAL AIRCRAFT AT DIFFERENT BATTLE RATINGS right?