Bf-109 " FM changed"

[Roland_HUNter]

Hello everyone, I don't know how many of you noticed but the bf-109 could turn better and could glide better at slow speed when the 3.201 update arrived.

After the second hotfix the bf-109 getting brick again.

Why?

What I mean "brick":Example: when the update came out, I started turning with a yak in a left hand turn sustained turn. I could pull more beceose of the slats, when he banked to the right because of the engine torque(Yes the Yak engine torque is moving the plane to the right).

After the second update I tested the same procedure, now: My Bf-109 coulnd't pulled as hard as i did before, and  now my plane starting to blank to the left in a left turn, when a yak is just continuing the turn without a right blank.

What happened and why?
PS:Sry for the repost here.

[LukeFF]

2 hours ago, -[HRAF]Roland_HUNter said:

What happened and why?

 

Nothing changed. We go through this with every update, with people swearing up and down that something changed. 

[Roland_HUNter]

-.-'

I passing my time away for testing, If i woudl fly only 1 hour per day I would say you're right.

[bzc3lk]

Nothings changed except the allies have better performing aircraft that give the impression that German aircraft are "flying bricks". People will have to change their tactics to compensate for the differences in airframe performance advantages and disadvantages. Most people will levitate to the latest aircraft thinking it is the best "wonder weapon" and find in some cases this not the case, sometimes simply due to their flying style. As an example I will pick the G14 over the K4, because to me it "seems" more responsive and suitable to  my style of flying.

Edited October 5, 2019 by bzc3lk

[Roland_HUNter]

Aha. So when the update came out I outturned the p51, Tempest and Yak with Bf 109, now I can't. Ok then. Brick was then and brick now. Okey..okey.

I ll write down here what I did on the general discussion but its got deleted:
Yak-1B:Sustained turn time 19 sec with 270km/h std weight:2887, Wing area:17,15m2
Bf-109F-4:Sustained turn time 20,3 sec with 270km/h std weight:2890, Wing area:16,1m2

Bf-109 should win at low-speed turning, because of the slats. It did, when the update came out, but after the second "hotfix" its the same brick as it was before the v3.201b.

[Roland_HUNter]

" During World War II, German aircraft commonly fitted a more advanced version of the slat that reduced drag by being pushed back flush against the leading edge of the wing by air pressure, popping out when the angle of attack increased to a critical angle. "-->Translate it, into the game: It should lower the "brick" effect on the 109.
Nothing happening in the game.

[LukeFF]

This is hopeless. 

[Guest deleted@50488]

Have you properly set the new trim controls ? or...

 

Might it be due to the new physiology simulation, limiting the forces that your pilot can apply ?

 

 

 

 

Edited October 6, 2019 by jcomm-il2

[354thFG_Rails]

Slats don't necessarily help in low speed turn fight. Slats just delay a stall. The slats being on the outer leading edge in front of the ailerons allows for more control at slower speeds. Not necessarily a tighter turn. Yak would still out turn it due to wing loading and a whole bunch of other aerodynamic forces, but might have less control at slower speeds due to it's wing shape.

[LColony_Kong]

Are you going to just keep starting new threads about the same thing?

[Roland_HUNter]

Just now, YIPPEE said:

Are you going to just keep starting new threads about the same thing?

Where is the first "same" thread troll mate?

[BubiHUN]

11 hours ago, QB.Rails said:

Slats don't necessarily help in low speed turn fight

[Roland_HUNter]

How many the CL Max in the game for the Bf-109? Can somebody tell this info to me?

[unreasonable]

6 hours ago, -[HRAF]Roland_HUNter said:

How many the CL Max in the game for the Bf-109? Can somebody tell this info to me?

 

Why not work it out for yourself? All the data you need is on the Tech Specs page.

 

 

[Roland_HUNter]

8 hours ago, unreasonable said:

 

Why not work it out for yourself? All the data you need is on the Tech Specs page.

 

 

Thank you, but how will i calculate CL with those infos? ?

[unreasonable]

10 hours ago, -[HRAF]Roland_HUNter said:

Thank you, but how will i calculate CL with those infos? ?

 

CLmax = W/ (0.5 * r * A * Vmin^2) - make sure you use the right units: SI given below.

 

W = weight  Newtons

r = air density  kg/m^3

A = wing area  m^2

Vmin = level flight minimum stall speed m/s

 

Use a spreadsheet: easier to see what you are doing wrong when you get silly results.

 

 

 

[LColony_Kong]

11 hours ago, -[HRAF]Roland_HUNter said:

Thank you, but how will i calculate CL with those infos?

An engineer like you should be able to handle it.

[Roland_HUNter]

3 hours ago, YIPPEE said:

An engineer like you should be able to handle it.

Thank you for the arguing again. Hopeless ppl like you always arguing like this. Nothing new.
Still waiting for the Clmax counter-report from you boi. 
 

4 hours ago, unreasonable said:

 

CLmax = W/ (0.5 * r * A * Vmin^2) - make sure you use the right units: SI given below.

 

W = weight  Newtons

r = air density  kg/m^3

A = wing area  m^2

Vmin = level flight minimum stall speed m/s

 

Use a spreadsheet: easier to see what you are doing wrong when you get silly results.

 

 

 

Interesting:
So F-4:28341/(0.5*0.8194*16,1*42.7^2)=2.35 ? I calculated with @4000m alt air density. (https://www.engineeringtoolbox.com/standard-atmosphere-d_604.html)

Edited October 8, 2019 by -[HRAF]Roland_HUNter

[unreasonable]

The stall figures in the tech specs are for sea level (or as near as makes no difference), where IAS = TAS.  The figures in the equation are for TAS. So r is 1.225 

 

You should either use the minimum stall speed plus the minimum operational weight (154 kph at 2545 kg) or the maximum stall speed plus the maximum take off weight (171kph at 3189 kg): converted to N and m/s.   Do this consistently for each aircraft and you will get comparable answers.

 

Your two answers for the F4 are then 1.38 and 1.41 (actually only 0.023 apart: I only round to two decimal places: no point in pretending this is more precise than it is).

 

At altitude the TAS Vmin will be progressively higher as the air thins: knowing the CLmax (fixed) and the air density tables, you can then solve for it. For the F4 at 4000m it is 52.3 m/s = 188kph - which is 154 kph IAS 

 

 

 

 

Edited October 8, 2019 by unreasonable

[Roland_HUNter]

Are u sure its this correct?
Becase with this, with the maximum take off weight, the spit IX has only 1.17 CL max at sea level, what is unbelievable ? 

 

Spit IX CLMax=32940/(0.5*1.225*22.48*45.2^2)

[unreasonable]

The tech spec figures for the MkIX are given in a rather different format to most of the other planes. I used as an equivalent to "maximum take off weight" the empty weight plus the maximum useful load.  2530kg + 1302 kg = 3832 kg. Use that weight with the upper limit of the stall speed and the CLmax  = 1.33, which is the same as for the Spitfire Vb calculated the same way. Which it should be, since it is an almost identical wing. 

 

You are using a weight of 3358 kg which is the "standard weight": 

"Note 3: maximum speeds, climb rates and turn times are given for standard aircraft mass" - but not, note, the stall speeds.

 

What you have to remember is that the developers have been doing this for years: they know what they are doing. While they may occasionally have some poor sources or just make an error, this is rare: you have to be very sure of your material if you are going to say they are making basic mistakes.  

 

 

 

[Roland_HUNter]

With std weight the F-4 is stalling at 154 km/h. The same given in the specs.

[unreasonable]

1 hour ago, -[HRAF]Roland_HUNter said:

With std weight the F-4 is stalling at 154 km/h. The same given in the specs.

 

It is stalling at ~165 kph when I test it at 2890kg. Stall speed is not the point at which a wing drops, which is about 155kph in this case: it is the point at which the lift starts to reduce, so that height cannot be maintained. This happens much earlier.

 

I am going to leave you to it now.

[Roland_HUNter]

https://books.google.hu/books?id=GUI3DwAAQBAJ&pg=PA3&hl=hu&source=gbs_selected_pages&cad=3#v=onepage&q&f=false

 

This book says the Yak-1b had 1.6777 CLMax at 4000 meter.
With your calcualtions this is not 1.6777:

28311,79/(0.5*0.8194*17,15*2070)=1,9465

How? ?

[AndyJWest]

9 minutes ago, -[HRAF]Roland_HUNter said:

https://books.google.hu/books?id=GUI3DwAAQBAJ&pg=PA3&hl=hu&source=gbs_selected_pages&cad=3#v=onepage&q&f=false

 

This book says the Yak-1b had 1.6777 CLMax at 4000 meter.
With your calcualtions this is not 1.6777:

28311,79/(0.5*0.8194*17,15*2070)=1,9465

How? ?

 

I would advise against taking anything in that book as being valid, unless it cites a better source. We've discussed it before, and it appears that the author 'extrapolates' data according to formulae of his own concoction.

[Roland_HUNter]

I can't read the sources sadly I have to buy it for that ? xD

[AndyJWest]

1 minute ago, -[HRAF]Roland_HUNter said:

I can't read the sources sadly I have to buy it for that ? xD

 

Citing a book you haven't read is hardly the way to gain credibility. What you need, if you want to convince anyone of anything, is to find proper material: primary sources, and works by people with recognised expertise in the subject matter. Nothing else is relevant, since the developers won't revise FMs based on it.

[unreasonable]

Original sources are great, but not much use if you cannot interpret them.  Best thing to read and digest would be this: learn to walk before you try to run. 

 

https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/phak/media/07_phak_ch5.pdf

 

 

[gimpy117]

the 109 is a boom and zoom fighter. the YAK is known to be better in a turn. having a 109 out-turn, out climb, and out-run a yak isn't gonna happen. I don't think it would be historic neither, apparently, do the devs. Don't get in a turn fight with Russian fighters. This thread is just a complaint about how the 109 doesn't out perform a yak in every area.   

Edited October 16, 2019 by gimpy117

[Roland_HUNter]

7 hours ago, gimpy117 said:

the 109 is a boom and zoom fighter. the YAK is known to be better in a turn. having a 109 out-turn, out climb, and out-run a yak isn't gonna happen. I don't think it would be historic neither, apparently, do the devs. Don't get in a turn fight with Russian fighters. This thread is just a complaint about how the 109 doesn't out perform a yak in every area.   

If i would complain about this, I would started this topic far before the 3.201 patch ?

[gimpy117]

14 hours ago, -[HRAF]Roland_HUNter said:

If i would complain about this, I would started this topic far before the 3.201 patch ?

doesn't matter it's still true. the 109 isn't as agile as a yak nor should it be. the wing slats are the only reason it can turn as well as it does in the first place. 

[INVADER_WARHAWK]

Reynolds numbers will change with varying speed 

Doing this calculation , you calculate the approximate cl max at low speed 

As speed rises , reynolds numbers also rise and thus the cl max and many other parameters of the airfoil change 

 

Also stall speed may also be affected by the engines thrust

[Legioneod]

Nothing has changed with the 109, just flew the 109 today and it's just as easy to fly now as it was before. Only difference now is that you can't do some of the crazy things like before due to the G modeling which is nice.

[unreasonable]

2 hours ago, INVADER_WARHAWK said:

Reynolds numbers will change with varying speed 

Doing this calculation , you calculate the approximate cl max at low speed 

As speed rises , reynolds numbers also rise and thus the cl max and many other parameters of the airfoil change 

 

Also stall speed may also be affected by the engines thrust

 

Yes, as the developers and most experienced posters in the FM section know perfectly well.

 

The trouble is that it is very hard to find data that we, the public, can use to compare directly with the game for power on stall Vmin or accelerated stalls.  What we sometimes have is a data point for a model plane, wing or airfoil, from a wind tunnel test,  and/or a power off stall IAS from a manual or flight test.  From those, there is still a non-trivial issue of deciding on appropriate instrument corrections, but you can estimate the power-off CLmax, and compare between aircraft as a rough check that anyone can do to see if that data point in the game looks reasonable, or the planes are being treated more or less consistently. 

 

If power off Vmin for a plane looks out of place, the chances are that the rest of the behaviour of the plane will also seem odd.  See the Tempest related threads for an example.

 

 

 

 

[MasserME262]

Sometimes after a patch I feel a plane flying different, whether an axis or ally one, and then after a hotfix, I feel it again as it used to be before the patch.

 

Sad is, I have zero test or evidence, just "I feel" that, take it or leave it.

 

Maybe devs change something by mistake and fix it back in hotfixes days after without communicating any of those changes, I know some people does that at my workplace... Not me of course ?

[NiiranenVR]

The 109 G6 is Better and not fixed back Again 

 

For a while ago it was flying like a brick    slow speed / fall down 

Now it's more like the others - Dogfight , make a turn around in slow speed , and then full speed without ' Down on eath ' 

Edited December 4, 2019 by Ivanowitch-VR
E' LukeFF "What do you want to make those eyes at me for" , you scare me to death ??