Is the BF-109 flight unstabl in real histroy?

...you can stall everything, bf 109 included. It is easy to stall bf 109

I don't understand. Where does it say that the 109 can't be stalled?

I don't understand. Where does it say that the 109 can't be stalled?

it says that it cant be stalled by accident. which is not correct.

Difference is that bf 109 stalls elevator first, and wings remain not stalled.

I think dcs bf109 is the close as you can get to real thing.

I think reason why bf109 got stick forces is that those are important in this plane, in p-51 stick forces are relatively light and pilot can exceed structural limits w/o problems, probably same with fw190 and spitfire.

it says that it cant be stalled by accident. which is not correct.

Difference is that bf 109 stalls elevator first, and wings remain not stalled.

Looked through all my docs and reports and didn't find any hint that the 109G can't be stalled.

Don't know where the elevator stall theory comes from, but this doesn't match any stall description of the 109G.

If the tail would stall (and if it would stall before the wing does), there would be a severe nose drop, no wing drop and no loss of aileron control. None of these things happen from what I've read.

Furthermore stall (or non-stall) behavior depends on the stab trim setting as well. Since the adjustment range is 8deg, it might be possible that you can't stall the 109 if the stab trim is too much nose down.

That's one of more detailed contemporary G-2 reports I have:

The idle power stall characteristics of the aircraft are very benign and affected little by undercarriage and flap position. Stalling warning is a slight wing rock with the stick floating right by about 2 inches. This occurs 10klph before the stall. The stall itself is a left wing drop through about 15 degrees with a slight nose drop, accompanied by a light buffet. All controls are effective up to the stall, and recovery is instant on moving the stick forward. Stall speeds are 155kph clean and 140kph with gear and flap down. In a turn at 280kphwith display power set, stall warning is given by light buffet at 3g, and the stall occurs at 3.5g with the inside wing dropping. Again, recovery is instant on easing the stick forward.

So what is it if not claming that cant be stalled by accident?

Stalling bf109 in DCS alwayes ends up in nose drop. And ailerons are loosing effectiveness at high AOA as i noticed, in tight turns i use rudder to roll plane left or right.

1.So what is it if not claming that cant be stalled by accident?

 

2. Stalling bf109 in DCS alwayes ends up in nose drop.

Looks like a comprehension/language problem to me. Can not be stalled by accident means IMO that it doesn't stall without warning and without the pilot noticing that he's approaching the stall.

It can't be stalled unintentionally, contrary to the Fw190.

AFAIR the 190 stall behavior was the reason why many pilots preferred the 109. It could be flown closer to the edge of the envelope, since the 190 gave little to no warning.

2. And what makes you think that this is being caused by a stalled tail?

Looks like a comprehension/language problem to me. Can not be stalled by accident means IMO that it doesn't stall without warning and without the pilot noticing that he's approaching the stall.

It can't be stalled unintentionally, contrary to the Fw190.

 

AFAIR the 190 stall behavior was the reason why many pilots preferred the 109. It could be flown closer to the edge of the envelope, since the 190 gave little to no warning.

 

2. And what makes you think that this is being caused by a stalled tail?

I don't know, I have this feeling in DCS that BF 109 hangs up in the air with stick full back, i don't have this feeling with any other plane in dcs.

It happens to me in turns often when you keep turning and suddenly it feels like you would drive you car in to off road, you still flying but in weird way.

When im trying to drop wing intentional it wont do it, so or tail is stalling first or wings are stalling at the same time every time. And tail can recover instantly after a little decrease in AOA, then hangs up on the verge of stall.

I know that wings slats are responsible for this

I don't know, I have this feeling in DCS that BF 109 hangs up in the air with stick full back...

That's from another G-2 test done at Wright Field:

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Test of stall was made with wheels and flaps up and wheels and flaps down.

UP. About 120 m.p.h. the aircraft began to lose height. The nose did not fall appreciably and there was no tendency to drop a wing and there was still aileron control.

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The stall behavior you are describing doesn't look like a stalled tail to me, but simply running out of elevator/pitch authority.

If the whole stabilizer/elevator assembly would stall, the resulting pitch down would be pretty violent and since the airfoil used isn't exactly a thick one, I doubt that it would immediately recover once stalled.

That's from another G-2 test done at Wright Field:

------------------

Test of stall was made with wheels and flaps up and wheels and flaps down.

 

UP. About 120 m.p.h. the aircraft began to lose height. The nose did not fall appreciably and there was no tendency to drop a wing and there was still aileron control.

------------------

 

The stall behavior you are describing doesn't look like a stalled tail to me, but simply running out of elevator/pitch authority.

 

If the whole stabilizer/elevator assembly would stall, the resulting pitch down would be pretty violent and since the airfoil used isn't exactly a thick one, I doubt that it would immediately recover once stalled.

yes elevator authority then

Having tried the 109K-4 on the free trial I found this thread that echoed some of my thoughts, so I just wanted to recap and add a bit.

Full disclosure, I have quite a bit of time in IL2. No, I'm not trying to start a war and I am absolutely not claiming IL2 FMs are superior. But I will draw on my experience there for comparison because the feeling I get from flying 109s in IL2 matches my expectations from reading historical accounts.

Yes, I am aware of the "109 myths" page posted earlier. I've referenced it in the past to argue for improvements to the 109 in IL2 in areas I feel that sim doesn't do as well (in particular too early and too strong control stiffening with speed).

This thread was originally about "instability" and I think everyone understands something different here. What I consider my experience of instability in the DCS K-4 is very fast control response and reversal, particularly in pitch. To me the plane feels very light and bouncy, it does not give me much feeling of weight or inertia on the controls. I feel the same about the TF-51 and was told that was normal. But the 109K-4 is an aircraft that became, relatively, heavy for its size and many pilot accounts complain of sluggish handling. Of course it has amazing P/W ratio and that can be felt in climbs and level acceleration, but pitch response feels almost FBW level to me. You can argue all you like that this is because of a lack of "feeling in the seat", but IL2 captures a level of sluggishness I expect. The closest comparison I can make is that DCS 109K-4 feels like flying IL2 109F-4 i.e. a much lighter aircraft on the same wings.

Now, stalling. 109 stall should be very docile, retaining roll control at high AoA due to slats and being easy to avoid and recover from. That's fine, and mostly that feels the same in DCS and IL2: that fantastic feeling of confidence in hard maneuvers and high AoA controllability that only a 109 can give you. But I don't for a second believe the 109 is not possible to stall in real life. In DCS it feels a bit like that. Full stick deflection at almost any speed doesn't produce shudder or wing/nose drop (I'm talking about accelerated stall behaviour as you might get in a hard combat turn). Even with full stick and rudder I can't get it to snap roll. Slats aren't magic, this is still a high wing loading aircraft with it seems (in DCS at least) amazing elevator authority. I should be able to exceed the limits by flying totally ham-handed but instead it feels nearly idiot-proof. As I said the feeling of control in IL2 is similar up to a point, but then the plane kicks you if you go further. Gently and easy to recover, as it should be, but it tells you and you feel it.

One thing I will say though is DCS K-4 beats IL2 hands down in take-off experience. IL2 is far too easy. DCS K-4 got my pulse racing and hit all the quirks and challenges I expected from reading about how 109s handled in this regime.

Like I said at the start, I'm not trying to start a war and these are just my personal observations. DCS K-4 feels amazing to fly but in some ways it surprised and disappointed me because it feels too good and too easy. I may well be completely wrong, but I'd like a constructive discussion about my observations.

I actually thought the K4 from Bodenplatte actually felt rather similar to the DCS one, although I agree the landing on DCS is actually much harder.

IMHO, it can stall bad. I shot the tail off a guy the other day who was in a flat spin with it. Well, better make sure right? :D

I think the thing im noting is how much better a gun platform the Fw190's are. The ME109 is fast, damn fast, and reasonably manoeuvrable, but its not so easy to keep the guns on a target as the 190. It feels what ive read, that it just isnt as good a gun platform as that aircraft.

Its interesting to compare models. I found the IL2 Spitfire to be good, but almost absent the torque effects of the DCS one. On the other hand, the IL2 190's that ive tried seem broadly comparable to the DCS ones, the only advantage they have is that they have aircraft modelled slow enough you can outfight them :D

No disrespect to IL2 either, but it is interesting to compare models.

It is well known that most of warbirds manage engine torque very well.

since your talking about a game with adjustable input you should a least put up some numbers. this discussion goes from 30k feet to low level and from stall to max speed?!?!? you have plenty of instuments and sources ingame. without speed, alt and weight you can barely reproduce a certain sutiation.

and for those who desperately want the 109 gear to fail. it was good enough to drive it like a car on ground. hit the brake and acc at the same time, lift the tail wheel and go. and yes i know it couldnt take it for long AND it wasnt something rooks could do, but it was driveable without fancy surprises. page 99 the book in the link

https://www.amazon.de/Was-gilt-denn-unser-Leben/dp/3932381327

cya ingame

109, at least starting from G, was neutral or even unstable at power-on condition. 109K with full rear tank - much more. So, it is the main source of "elevator high authority".

 

One can easily check if the plane stable or not at different power rates.

For example, switch on controls indicator window and start from steady gliding at 200, 300, 450 kph checking the stick position.

Then, start to climb at TO power (with centered ball!) at the same speeds. Find diferences in the stick position depending on speed.

 

Neutral plane will have almost the same stick position at any speed. Stable plane - stick will travel forward as speed increases. Unstable plane requires stick forward as the speed decreases.

Will be interesting to hear VC's thoughts after he has done these (repeatable) tests.

Will be interesting to hear VC's thoughts after he has done these (repeatable) tests.

I am unable to do that because the K-4 is no longer on free trial and it didn't impress me enough to persuade me to buy it at this time. I admit my observations are based on more of a "first impression" basis but I don't have vast amounts of free time on my hand. I don't think it's entirely fair to dismiss this, since I was playing in fairly typical conditions, 1k to 3km alt dogfighting, it doesn't take hours of sterile condition testing to draw good conclusions as to how something feels.

Now, I am perfectly happy to take at face value Yo-yos explanation regarding pitch instability with power (I had MW50 on for the majority of my messing around), and to accept that this may be something DCS captures as accurate that IL2 does not to the same extent. The physics makes sense and I don't need to test it to believe that.

However this creates a conundrum for me, since the aircraft still felt very hard to stall (in DCS). If it is unstable in pitch, then it should easily be able to produce the kind of pitch rates that would exceed even the deployed slat AoA limits and cause some kind of shuddering, stall and/or wing drop, benign as this may be due to the design.

The closest I came to a fair equivalent test was this: 400km/h approx 2 km altitude, full throttle, bank 90 degrees left and pull all the way back (as you might if you were turning after a breaking enemy).

Result in DCS: the plane simply turns on a dime and shows no signs of stall, holding stick full back turning all the way down to 150km/h.

Result in IL2: plane initially pitches very fast before the turn is arrested by the stall and there is a slight wing drop. Reducing aft stick deflection recovers and continues the turn, but you can't hold the stick all the way aft as the plane slows and expect it to keep turning smoothly, let alone quickly.

More like a glider? At idle, with full flaps and the gear down?

yes- it feels like a glider. I would totally agree. The speed is much higher. But you can do a perfect slip for short landings and it feels like like in RL in DCS with that module. (of course I don`t know how a 109 feels like- but I know how a glider does it)

First time I hated that module- but now I really love it!

Cheers

Tom

I am unable to do that because the K-4 is no longer on free trial and it didn't impress me enough to persuade me to buy it at this time. I admit my observations are based on more of a "first impression" basis but I don't have vast amounts of free time on my hand. I don't think it's entirely fair to dismiss this, since I was playing in fairly typical conditions, 1k to 3km alt dogfighting, it doesn't take hours of sterile condition testing to draw good conclusions as to how something feels.

 

Now, I am perfectly happy to take at face value Yo-yos explanation regarding pitch instability with power (I had MW50 on for the majority of my messing around), and to accept that this may be something DCS captures as accurate that IL2 does not to the same extent. The physics makes sense and I don't need to test it to believe that.

 

However this creates a conundrum for me, since the aircraft still felt very hard to stall (in DCS). If it is unstable in pitch, then it should easily be able to produce the kind of pitch rates that would exceed even the deployed slat AoA limits and cause some kind of shuddering, stall and/or wing drop, benign as this may be due to the design.

 

The closest I came to a fair equivalent test was this: 400km/h approx 2 km altitude, full throttle, bank 90 degrees left and pull all the way back (as you might if you were turning after a breaking enemy).

 

Result in DCS: the plane simply turns on a dime and shows no signs of stall, holding stick full back turning all the way down to 150km/h.

 

Result in IL2: plane initially pitches very fast before the turn is arrested by the stall and there is a slight wing drop. Reducing aft stick deflection recovers and continues the turn, but you can't hold the stick all the way aft as the plane slows and expect it to keep turning smoothly, let alone quickly.

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Am 25.2.2020 um 11:46 schrieb bbrz:

I

Am 25.2.2020 um 11:46 schrieb bbrz:

If the 109 would have been actually that horrible from its beginnings, I severely doubt that it would have become the standard fighter.

She was loved by many experienced pilots. By those pilots who learned flying pre-war. Above all the earlier versions e.g. E and F. Then she became heavier and heavier in engine and armament. The pilot-education less and worse. Take a look at her long and farg-going evolution. Apart from minor adjustments the frame stayed the same. A K4 must´ve been spectecular in stats and sounds - - but definetely far less enjoyable in handling than her early predecessors. Dont´know if the module-developers ever contacted Walter Eichhorn, most likely the one alive who knows flight characteristics of a 109 best.