Spitfire XIV flight model

[JtD]

21 minutes ago, ZachariasX said:

The point is that the nose of the Spit follows the stick noticeably slower than, say, the 190A3 or above all, the Tempest. The whole easing forward is only due to the pilot having to pull more than 4 g to make the nose come up as fast to reach 4 g, as with other planes that "just" pull a 4 g input abd they reach that fast with no "over pulling". And this is what is in opposition to the behavior of an aircraft with neutral controls.

 

No, it is not. Neutral stability in the sense used means that it the aircraft is slow to reach a new point of balance. Use the ball-on-a-surface metaphor.

Positive stability is the ball in a bowl. If you tilt the bowl, the ball moves to the new position, where it stays.

Neutral stability is the ball on a flat plate. If you tilt the plate, the ball gets moving and does not stop until you put the plate level again.

Negative stability (instability) is the ball on an inverted bowl, you move it, and the ball falls off unless you're really quick with repositioning the bowl below the ball.

 

The quickness of response is not stability, it's a different characteristic. Unstable aircraft don't necessarily react quicker than stable ones. You can move both plates and bowls quickly or slowly. You do this with control layout. For instance, if the Spitfire had an elevator half the size, the aircraft would have the same stability, but would be much less responsive. On the other hand, if you made the Spitfire more stable, you'd have the same responsiveness.

 

However, in as in a more stable aircraft, you'd eventually need a larger elevator angle to reach the stall. Going back to the ball-on-a-surface-metaphor, if you tilt the bowl by 5 degress, the ball will start moving as quickly as it does on the flat plate inclined by 5 degress. But since in the bowl it will stop at a certain point, you will need to further incline the bowl, until the ball falls out. Whereas the ball will fall off the plate at any angle.

Likewise, in a deep bowl (high stability), if you want to move the ball by 4 cm (to 4g load), you'll incline the bowl steeply and the ball will quickly roll to the new position. In a shallow bowl (low stability but still positive), if you want to move the ball by 4 cm, you'll incline the ball a litte and then you'll have to wait for ages until the ball very, very, very, very slowly moves to the new position. It's much easier to get the ball out of the shallow bowl though (stall the aircraft with less stick travel).

 

Not sure if I made this understandable.

[Holtzauge]

The below attached picture is from NACA report W L 334 on the flight characteristics of the Spitfire Mk V showing a rapid 180 deg turn.

 

Look at the elevator stick position: It does not move much but it does move a bit when the turn is initiated and it’s NOT returned upon reaching 3 g but stays in the turn position until going out of the turn.

 

So we have a small stick movements only and that is faithfully modeled in the sim as well. This makes the Spitfire in-game hard to control since everything is by movement, not by force.

 

However, look at the force diagram: The pilot has to pull back with something like 12 lb and HOLD that during the turn which means it does not matter that the stick MOVEMENT is small because it’s basically FORCE controlled.

 

My pet theory is that this is why pilots IRL loved the Spitfire and said that it followed their every wish and we struggle: We have the small movement modeled but not the benefit of the force control and feedback.

 

This is just how a modern F-16 fighter is controlled BTW: By force not movement. As an interesting side note, AFAIK the first prototype sticks were really totally force controlled and did not move at all but in the production models they introduced 1/16” movement or so because pilots flew/like that better.

 

Now it would be madness to (in the interest of “realism”) release a F-16 PC sim with a 1/16” stick travel for 9 g load factor and by the same token I think that this is part if not what ails the Spitfire FM in BoX also: From the pilots viewpoint both are force controlled in pitch and this needs to be addressed in the sim by making them “artificially” movement controlled.

 

Of course this will drive the sim “purists” bananas but I rest my case on the F-16 conundrum: If you don’t have force control in the sim sticks, then you have to use the PC sim F-16 stick solution meaning control by movement instead.

 

 

 

Edited April 26, 2021 by Holtzauge

[Aurora_Stealth]

Spent some more time with it and after a while of putting the XIV through its paces I noticed what you were saying @ZachariasX (I think); like a kind of slow swaying effect from side to side once the aircraft is sustaining G and a slight mushy effect? noticeable once you're a few seconds into the manoeuvre and at slow-moderate speeds under G. Seems to occur regardless of fuel carried.

 

The swaying effect feels to me like the high torque and prop wash of the engine oscillating across the airframe. I'm wondering if its the torque/prop wash that is causing this effect while under G's and to need to tighten up a little more once into the manoeuvre. Although, it should be said even with some of the earlier marks of Spitfire (which is mentioned notably in the Battle of Britain); despite having neutral stability it was still required for a pilot to tighten up the manoeuvre somewhat to get the best sustained turn out of it. The reason I heard, was that pilots were reluctant to cause an accelerated stall; which is how I feel when the aircraft starts getting mushy and swaying like I see here with the XIV.

 

Food for thought anyway.

Edited April 26, 2021 by Aurora_Stealth

[Avimimus]

On 4/25/2021 at 9:38 AM, Holtzauge said:

IMHO the developers would do better if they made the BOX planes behave more like the lighter Fw-190 series (e.g. low fuel, no wing guns A3) in-game. The current chewing gum, rubber band suspended Spitfire Mk XIV FM seems like a retrograde step back in time if you ask me.

 

Well... the Fw-190A3 is light and has a shorter nose - and was harmonized as an air-superiority fighter. Later Fw-190 designs had compromises to allow better functioning as a fighter-bomber, and had increased weight as changing requirements in terms of fuel, armour, armament, and engines... leading to them being a bit nastier and heavier on the controls.

 

The Spitfire was originally light and had a shorter nose - and was harmonized as an air-superiority fighter... and as time went on it had larger engines installed, was equipped for changing requirements in terms of range, durability, fighter-bomber armaments... leading to them being a bit nastier and heavier on the controls.

 

On the whole, performance and sustain turn rates tended to climb - but that was mainly because of a larger engine pulling harder - while the airframes of these aircrafts themselves tended to suffer from ever worsening weight distributions and higher wing-loadings.

 

Maybe, if you want a Spitfire that is like the Fw-190A3 - you should ask for a Spitfire II (or failing that, pick up the Spit Vb collector plane).

[ZachariasX]

10 hours ago, Avimimus said:

Maybe, if you want a Spitfire that is like the Fw-190A3 - you should ask for a Spitfire II (or failing that, pick up the Spit Vb collector plane).

I just want a Spitfire to fly like a Spitfire.

 

It is perfectly fine that the Mk.XIV is not as crisp in handling as the baby Spits. But instead of a very crisp to a less crisp handling, it went from sub-par all the way to the bottom of the stack. Of course I'd like having a Mk.II, but I should prefer correcting what we have first. And I don't think this is hard to do because they did it on other planes. Namely planes I would not expect to be as responive as the Spit.

[Holtzauge]

2 hours ago, ZachariasX said:

I just want a Spitfire to fly like a Spitfire.

 

It is perfectly fine that the Mk.XIV is not as crisp in handling as the baby Spits. But instead of a very crisp to a less crisp handling, it went from sub-par all the way to the bottom of the stack. Of course I'd like having a Mk.II, but I should prefer correcting what we have first. And I don't think this is hard to do because they did it on other planes. Namely planes I would not expect to be as responive as the Spit.

 

The two seat Spitfire you flew, how did the pitch behave compared to the figure I posted above for the Mk V? IIRC you said before that the stick did not need to be moved much but that it felt quite controllable in pitch anyway? I'm thinking if it did behave a bit like the Mk V chart, that one could learn to live with a short travel as long as it takes some force to move it and hold it in the turn. In addition, while I have an extension on my sim stick which I think helps immensely, these WW2 crates usually have quite long sticks so that should help some as well.

[ZachariasX]

1 hour ago, Holtzauge said:

The two seat Spitfire you flew, how did the pitch behave compared to the figure I posted above for the Mk V? IIRC you said before that the stick did not need to be moved much but that it felt quite controllable in pitch anyway?

It is very similar to that as described in the figure you posted.

 

The late Merlin Spits do have slight bit longer load arm, but they are also a tad heavier. Hence when profilic authors of the era would descrive the IX as slightly less maneuvreable than the V (or II) then it also means we're talking about an aircraft that gained ~20% in weight already from the early iterations, while not differing much in other things. If they were doing aerobatics, they would do so between 350 and 500 km/h with any aircraft Mark. Hence, I would expect that the added power doesn't really do much in plain aerobatics. But weight surely does.

 

I Imagine the added power will at least compensate for the weight gained in sustained turns, but I seriously doubt that the couple of inches gained on the nose make up for anything at all.

 

If you add a ton instead of half a ton, that would set further limits on plain goofing around without really keeping your speed up, hence it is obvious that the Spit would become a less handy aircraft in the sense that you need to fly it faster to stay in safe margins. A Spit IX (especially with no guns&ammo) is a remarkably handy aricraft and you can operate her from surprisingly small spaces. I would not say the same of the Griffon Spits that require more room and spped to operate safely. (Not saying you can't.)

 

But none of that has any influence on how readily it follows stick input, it just makes no sense.

 

What is even more remarkable, is that in the PN the Spit Mk.XIV has lower (indicated!) stall speeds (all up) than the Mk.IX:

 

Mk.IX: 90 / 93 / 100 mph (training load, 7150 lb / full service load + blister tank, 7800 lb / max. load plus rear fuselage, 8700 lb)

Mk.XIV: 85 / 93 / 98 mph (typical service load, 8375 lb / typical + rear tank, 9000 lb / max. load 9772 lb)

 

What I can sayis that the Mk.XI at a tourist-loadout settle are easily flown slower in approach than suggested by the PN. I mentioned the speeds in my write-up as they apeared to me on the dials.

 

In principle, using @unreasonable's Clmax calculator (thanks again!) I see an increase of about 5 mph TAS by adding half a ton to the Spitfire. There is absolutely no doubt that the Mk.XIV is a bit more limited in slow flight over the Merlin Spits (the baby-Spits being alost 10 mph lower in stall speed!) hence while the plain PN numbers don't tell us much about what the weight does, physics do tell us so and it is obvious that it is a good idea keep the XIV faster than you'd get away with in the baby-Spits. And this I think is all you need to read into when some wrote the Griffon Spit being "less maneuvrable". Also you need more residual control authority to deal with elevated power and torque. But this does not mean anything other than "keep her a tad faster". Throughout the bench, the Mk.XIV has smaller safety margins over the Mk.IX. That is the issue. You die from doing less things wrong. However in no way would it fly worse as such. How would the unison bottom line comment of the pilots be "fantastic aircraft!" if the flying qualities would be lesser?

 

Regarding power and weight, as said, the 109K4 has almost all of the power and torque and certainly all ofthe weight of the Spit XIV yet it doesn't behave like that. The Tempest has more of everything, a lot more even. And it is one of the quickest to react to stick input. I have yet to see one aircraft you're cleared to fly aerobatics with that lags stick input to such a degree. Nobody would fly it. I wouldn't for sure.

 

There is no evidence whatsoever that making her point in the direction you want is affected in any way whatsoever. What we have now is like playing Counterstrike, but your mouse input is lagging. Not slower. But lagging. Some like it. Imagine.

 

What we have now is an arbitary choice and not a physical inevitability.

[Algy-Lacey]

19 minutes ago, ZachariasX said:

Mk.IX: 90 / 93 / 100 mph (training load, 7150 lb / full service load + blister tank, 7800 lb / max. load plus rear fuselage, 8700 lb)

Mk.XIV: 85 / 93 / 98 mph (typical service load, 8375 lb / typical + rear tank, 9000 lb / max. load 9772 lb)

 

I think that the above in bold, the blister fuel tank, accounts for the increase in stall speed of the mark IX in this instance. Otherwise I like your explanations and rate them highly as not many of us have taken the controls of a Spitfire.

 

I hope that we can petition the Developers to have the Spitfire XIV's Flight Model adjusted. It would be great if we could ask a warbird pilot who has flown a Mk XIV or Mk XIX to give their opinion on the flight model of this particular variant, but I have yet to read anywhere that real life XIV is sluggish to respond to stick input, so it should be adjusted accordingly?

Edited April 27, 2021 by Algy-Lacey
clarification

[Avimimus]

First, one has at least 150 kg more mass in the engine (the equivalent of mounting a 250lb bomb under the nose).

 

Second, one has a redesigned tail to try to compensate for that.

 

Third, one has a significant jump in wing-loading (see diagram)

 

So it really shouldn't be handling like earlier model spitfires. The distribution of mass is different (more spread out - which is bad for maneuverability and stability), it has a new tail, and the wing loading is higher.

 

It should be slower to get the nose moving (lots of mass on a long moment arm), the nose should tend to keep moving more on its own (less influenced by the airflow over the wing - due to the higher wing loading). I'm not convinced that anything is wrong.

 

 

  

6 hours ago, ZachariasX said:

I just want a Spitfire to fly like a Spitfire.

 

It is perfectly fine that the Mk.XIV is not as crisp in handling as the baby Spits. But instead of a very crisp to a less crisp handling, it went from sub-par all the way to the bottom of the stack.

 

I think you miss my point. I was saying: The same could be true of a Fw-190 going from the A3 to the A8... in fact your example of the Fw-190A3 is the perfect reason why the Spits handling has changed so much over the course of the war.

[unreasonable]

Just had my first 20min flight in a XIV - take off is.... interesting, landing straight forwards except for the usual almost stationary ground loop.   

 

I did not find the plane unresponsive at all, standard load out full fuel, I think in the whole flight I used about 1cm of travel in pitch with my G940, although I never went above about 4g. It is not a question of liking lag or sluggishness, but not everyone feeling that it is there.   It clearly does "feel" heavier than the earlier Spitfires, but why not?

 

In common with the other GB Spitfires I do find the planes strangely nose heavy so very hard to trim in pitch for stable flight.

 

I suspect peoples' individual HOTAS set up may make a considerable difference: but as usual if anyone wants to lobby for changes they will have to come up with some empirical comparison showing an error, or nothing will be done. 

 

On the Clmax:  Plugging in the numbers for maximum and minimum operating weights, plus the range of stall speeds in the tech specs tab, gives a Clmax range from 1.37 (min weight) to 1.35 (max weight) a little higher than the IX at 1.34 and 1.33 respectively.  Stall AoA is 19.0 vs 18.8 for the IX 

 

Not sure why they should be higher - I expect we also have the ASI-CAS issue to deal with again - but not much out of line with previous Spits.  (Nowhere near Tempest levels of insanity).

 

[JtD]

I've been able to throw the Spit XIV through some turns and pull outs in game and found very little to be fundamentally wrong. Anything that can be compared to actual numbers compares fairly well and can be explained by near neutral stability and a sensitive elevator. Some things could arguably be tuned a little for my understanding, but I found nothing completely wrong (as far as measurable numbers go).

 

What I don't get out of the game are realistic control forces or a feeling for the aircraft. In particular the former would be essential for evaluating realism of a Spitfire FM.

 

However, the case can be made for the odd relative behaviour between a Mark V and a Mark XIV. My test: Flying 320 IAS at sea level with auto level on and full tailward trim, I released the auto level while in slow motion and timed the reaction of the resulting pull up. The V instantly reacted and reached about 4.5g's within a good second. When I released the XIV I first wondered if I had indeed disengaged auto level, but it turned out I did, and it eventually reached 3.8g's after about two seconds.

From what I read in historical data, the time the Spitfire needed to settle at a certain g level was somewhere in between 1 and 2 seconds, so the V is a bit quick, the XIV a bit slow. I'd put both of them within the margin of uncertainty, but on opposite ends of the spectrum, and that's what's odd.

 

Zach's issue is there and understable.

Edited April 27, 2021 by JtD

[unreasonable]

If I try that with the XIV or V, hands off the stick, on turning off the level auto, I dive gently into the sea. Even after increasing the spring centring to 100%

 

That is on minimum fuel, with default control curves.  I think the G940, has quite a heavy head and normally a slightly forwards lean, so it is actually signalling nose down even when hands off, with trim completely tail heavy. Mine is old and worn out, I suspect. (Like me).  To fly level I need hands on and slight backwards pressure - with the Dr.1 and Camel I have to push all the time.

 

Whatever the cause, it means I cannot replicate that result. 

[Holtzauge]

Those of us who have been around for a while may remember the evolution of the Me-109G series FM: This was the BoX plane with the mother of all rubber band suspensions. There was a very pronounced coupling between roll and yaw and if you wing tipped with ailerons using no rudder the nose would yaw all over the place and gradually wobble back when you stopped your control input. Long debates raged on the forum if this was accurate or not. Brings back memories of the Fw-190 Clmax discussion as well: According to a large segment of the forum population, the Fw-190A was totally historically accurate and people were just not flying the Fw-190A as it should be flown that’s all. It was never meant to be turned with: That was why it was floundering all over the place. However, after a process akin to pulling teeth the Fw-190A was finally changed and it became possible to turn the Fw-190A in a fashion we today take for granted. The same thing happened with the Me-109G FM: It’s today MUCH better than it was back then and the “rubber bands” significantly stiffer. So it IS possible to get things changed. They CAN do it. This brings us back to the Spitfire Mk XIV: Everyone has their own opinion, me included. IMHO I think it is pretty clear from videos that IRL WW2 crates are not suspended from rubber bands. IMHO this is a PC FM effect period. You can agree or disagree. I just posted a couple of videos which I think shows this difference between IRL and sim-world but there are many others on YouTube you can watch. Last but not least: We are fortunate to have a devoted BoX sim pilot here who has flown the real thing and if he says its crisp and there is no lag and he thinks the current rendition needs work then that weighs heavily with me. In fact, I would not be surprised if the BoX Mk XIV evolves over time and that in the same way as what we have now is lauded as a good representation in the forum, the same will be true for the later editions as well. Only they will feel and behave quite differently. This seems to be a fundamental characteristic of forum debates on the FM and handling and in some sense why it’s so fun to participate as well. Will the BoX Spitfire Mk XIV handling evolution follow the Me-109G path? Only time will tell……..

Edited April 27, 2021 by Holtzauge

[JtD]

29 minutes ago, unreasonable said:

If I try that with the XIV or V, hands off the stick, on turning off the level auto, I dive gently into the sea.

 

Did you really apply full tail heavy trim? For me it's like that if I use default trim, which is around 10% or so. You could unplug the stick for this test, if it really screws this up. Just leave auto level on and accelerate, (I'd use a somewhat lower speed than 320 in this case because of impatience).

 

Because I didn't say it above, my V was fully loaded standard loadout, the XIV I used with 70% fuel (hope that means the rear fuselage tank is empty). This still leaves the XIV near 30% heavier than the V, so less g for the same stick input is what I expected and got. If you don't like that, you'd have to fly the XIV 10-15% faster than the V, for similar lift coefficients.

[unreasonable]

Just now, JtD said:

 

Did you really apply full tail heavy trim? For me it's like that if I use default trim, which is around 10% or so. You could unplug the stick for this test, if it really screws this up. Just leave auto level on and accelerate, (I'd use a somewhat lower speed than 320 in this case because of impatience).

 

Because I didn't say it above, my V was fully loaded standard loadout, the XIV I used with 70% fuel (hope that means the rear fuselage tank is empty). This still leaves the XIV near 30% heavier than the V, so less g for the same stick input is what I expected and got. If you don't like that, you'd have to fly the XIV 10-15% faster than the V, for similar lift coefficients.

 

Yes, the cockpit trim indicator is right at the top of the dial and my trim wheel at the stop. If I use nose down I will dive directly into the sea, not passing Go!  I might dig out one of my old non-FFB sticks and see if that behaves differently as well. This is not a problem in normal flight - it just means I need slight pressure on the stick at all times. 

 

So my understanding of your results is that you got less G for the same stick/trim position for the XIV than for the V, which you expected, but the difference is unexpectedly great - is that right?  Any idea how much you difference you would expect if they were both in the most plausible position?

[JtD]

No, g load is good enough for me, given that aerodynamically the aircraft are not 100% the same. One could investigate this further, but I don't have sufficiently detailed historical data anyway. I can't argue 5% or 10% accuracy in this regard.

 

The issue is that the XIV needs around twice the time the V needs to reach the final g load and noticeably lags more before showing any reaction after releasing it from auto level. The difference is big enough that I initially thought I accidentally tested the V at 1/4th speed and the XIV at 1/8th.

[unreasonable]

Trying again without going out of auto level at the start - so no stick inputs before release, only trims and throttle set - I do see what you mean.   

 

I think @Gavrick seemed to be the Supermarine representative in the developer team - best bet might be to see if we can get him to comment. Alternatively put in an official bug notice, see if that gets a response. Not sure if any of the developers reads these threads.

[-=PHX=-SuperEtendard]

3 hours ago, JtD said:

Because I didn't say it above, my V was fully loaded standard loadout, the XIV I used with 70% fuel (hope that means the rear fuselage tank is empty)

 

Just to clarify, as it has been mentioned in different posts, the Spit Mk XIV in game is an earlier production one without rear fuselage tank, only the standard front fuselage and leading edge wing tanks, for a total of 505 liters / 111 imperial gallons of internal fuel.


 

[Kurfurst]

Comparing to the behaviour of XIV to the V is pointless in my opinon. The Mark V had very little stability reserve, it was on the verge of being longitudally unstable (hence many related fixes), the IX, and especially the XIV had literally a ton of weight packed into it / mostly towards the nose, heavier engines and props and all. The XIV was noted to be much more stable compared to earlier Marks, which was considered a good thing. It should be far less 'snappy' due to that. 

[ZachariasX]

I can think of two aircraft: one started out with a 450 kg engine and ended up with a 950 kg engine and obviously loses none of the snappyness while another aircraft that was designed to be snappy and bulit on a 750 kg engine and that ended up with a 900 kg engine.

 

The latter is obviously not supposed to be snappy anymore because it only gained 250 kg in the front instead of 500 kg, right?

 

Sure.

 

And no, I don‘t want to see any aircraft reduced regarding their snappyness in this game for any reason.

Edited April 27, 2021 by ZachariasX

[CSW_606_Temp]

Wing Loading 172kg per sqm was still great value. P-51, P-47, Bf 109 G-14/K-4 or FW 190 A-8/D-9 have 200+! It is no reason for bad characteristic in tight turn or combat maneuvres. I see weird acrobacy performance like as balancing this game. No want plane, which is better in all characteristics over all luftwaffe aircrafts. 

[unreasonable]

6 hours ago, CSW_606_Temp said:

Wing Loading 172kg per sqm was still great value. P-51, P-47, Bf 109 G-14/K-4 or FW 190 A-8/D-9 have 200+! It is no reason for bad characteristic in tight turn or combat maneuvres. I see weird acrobacy performance like as balancing this game. No want plane, which is better in all characteristics over all luftwaffe aircrafts. 

 

Then you would be wrong. They team have explicitly stated that they do not do balancing.  If there is a problem with the Spitfires' FMs,  it is in some specific way they have modelled part of the FM.  That kind of comment tends to get threads locked. Understandably, the developers do not like being accused of lying.

 

If you have some useful information to add on how the Spitfire should perform compared to the game, by all means add it. FMs only get changed when the developers are presented with clear measurable evidence of what is wrong.  

[6./ZG26_Klaus_Mann]

I don't necessarily think the FM is wrong per se, but that the Way Il-2 Controls work makes it a bit strange to fly. Il-2 only partly registers the Joystick Position as the Control Stick Position, but also as a Force Input, so full Right Deflection on the Joystick models i.e.: 25kg of Stick Force to the Right. Release the Force, the Stick snaps back forced by Aerodynamics.

With the Elevators it's similar, and the Neutral Stability Thing means that the Stick doesn't Center as powerfully as Conventional Elevators do, if at all.

[Bremspropeller]

14 minutes ago, 6./ZG26_Klaus_Mann said:

I don't necessarily think the FM is wrong per se, but that the Way Il-2 Controls work makes it a bit strange to fly. Il-2 only partly registers the Joystick Position as the Control Stick Position, but also as a Force Input, so full Right Deflection on the Joystick models i.e.: 25kg of Stick Force to the Right. Release the Force, the Stick snaps back forced by Aerodynamics.

With the Elevators it's similar, and the Neutral Stability Thing means that the Stick doesn't Center as powerfully as Conventional Elevators do, if at all.

 

That's my impression, too.

[6./ZG26_Klaus_Mann]

Just now, Bremspropeller said:

 

That's my impression, too.

Because once you use a lot of Noseheavy Trim (50 to 100%) she turns quite stable.

[JtD]

With the Spitfires historical marginal longitudinal stability, the stick centers (or wherever trimmed to) as with any other aircraft, the angle of the attack of the aircraft however does not return to 0 (or whatever trimmed to) that quickly. One stick position may correspond to a large range of angle of attack, but for each angle of attack there's a clear force free stick position.

 

And the issue from my point of view is less about absolute figures, but mostly about relative behaviour to the earlier Marks.

Edited April 29, 2021 by JtD

[ZachariasX]

6 hours ago, JtD said:

And the issue from my point of view is less about absolute figures, but mostly about relative behaviour to the earlier Marks.

Personally, I don't mind the early Marks being as they are, as it really gives a slight but characteristic oddity to the elevator controls, something I felt clearly by having for the large part also Joystick muscle memory, where you have perfect control harmony. What we have there is not correct, but I feel at least it transcends a correct feeling. Also, at some point it is good enough and having AnP working at other modules is not a bad thing in itself.

 

However, I really should like to point out that I specifically tried to reproduce any kind of wobble and rubberbanding in flight and told the pilot so before the flight, for him having an idea what the heck that cazy dude in the back is doing. I could not make the aircraft wobble or rubberband in any way. What is realistic is an immediate and proportional pitch or roll movement according to stick input, g's also following immediately on attitude change. Any deviation from that is a deviation from reality.

Edited April 29, 2021 by ZachariasX

[sturmkraehe]

On 4/27/2021 at 4:33 PM, Holtzauge said:

Those of us who have been around for a while may remember the evolution of the Me-109G series FM: This was the BoX plane with the mother of all rubber band suspensions. There was a very pronounced coupling between roll and yaw and if you wing tipped with ailerons using no rudder the nose would yaw all over the place and gradually wobble back when you stopped your control input. Long debates raged on the forum if this was accurate or not. Brings back memories of the Fw-190 Clmax discussion as well: According to a large segment of the forum population, the Fw-190A was totally historically accurate and people were just not flying the Fw-190A as it should be flown that’s all. It was never meant to be turned with: That was why it was floundering all over the place. However, after a process akin to pulling teeth the Fw-190A was finally changed and it became possible to turn the Fw-190A in a fashion we today take for granted. The same thing happened with the Me-109G FM: It’s today MUCH better than it was back then and the “rubber bands” significantly stiffer. So it IS possible to get things changed. They CAN do it. This brings us back to the Spitfire Mk XIV: Everyone has their own opinion, me included. IMHO I think it is pretty clear from videos that IRL WW2 crates are not suspended from rubber bands. IMHO this is a PC FM effect period. You can agree or disagree. I just posted a couple of videos which I think shows this difference between IRL and sim-world but there are many others on YouTube you can watch. Last but not least: We are fortunate to have a devoted BoX sim pilot here who has flown the real thing and if he says its crisp and there is no lag and he thinks the current rendition needs work then that weighs heavily with me. In fact, I would not be surprised if the BoX Mk XIV evolves over time and that in the same way as what we have now is lauded as a good representation in the forum, the same will be true for the later editions as well. Only they will feel and behave quite differently. This seems to be a fundamental characteristic of forum debates on the FM and handling and in some sense why it’s so fun to participate as well. Will the BoX Spitfire Mk XIV handling evolution follow the Me-109G path? Only time will tell……..

 

I remember that rubber band discussion and I remember that when BoS came out the planes really felt like balancing on a stick.

 

Now we have a flight model that doesn't have much coupled roll-yaw response at all and I think this is not correct either. I guess they tweaked some stuff on their FM to remove the wobble but the FM got doctored so well that some aspects of realistic FM disappeared.

 

I also find that stall behavior is now far different from what I'd expect. It seems now that planes usually tend to go into a flat spin first before doing more normal stall spin. Hopefully your are well above ground when you reach controllable spin movement.

[Holtzauge]

22 hours ago, sturmkraehe said:

 

I remember that rubber band discussion and I remember that when BoS came out the planes really felt like balancing on a stick.

 

Now we have a flight model that doesn't have much coupled roll-yaw response at all and I think this is not correct either. I guess they tweaked some stuff on their FM to remove the wobble but the FM got doctored so well that some aspects of realistic FM disappeared.

 

I also find that stall behavior is now far different from what I'd expect. It seems now that planes usually tend to go into a flat spin first before doing more normal stall spin. Hopefully your are well above ground when you reach controllable spin movement.

 

Yes, past experience shows that in-game FM can be tuned. However, amassing quantifiable data to show if speed or climb rates etc. are off is one thing, trying to find "hard" data to show that the "feel" of the airplanes is off is another one entirely. NACA reports like the one I posted the figure from above is probably as close as we are going to get. Other than that, I think videos taken from inside the airplanes and anecdotal evidence is as close as we are going to get to find proof that the airplanes are to rubber-bandy in their present form. So instead of chasing "hard" anti-rubber band data, I will stick to chasing the wind and nailing Jello to the wall I think.

Edited May 3, 2021 by Holtzauge

[sturmkraehe]

I think it is extremely good to use any available document with hard-proof facts and implement it in the sim.

 

However, as I mentioned somewhere else, it is not a good idea to rely only on documented stuff. Why? Because documents available to us are scarce and incomplete for several reasons:

- some documents are not available because perhaps lost in archives

- some documents have been lost

- not everything relevant to the behaviour of an air plane has been measured or found worth to be documented

 

If the devs only stick to documented data, there'll be large holes in the fm. There is where one needs anecdotes (not only one but consistent oneS with big s) and physics. 

[sturmkraehe]

I frequently experience that even later human-piloted 109  versions turn inside me and not for a short time but sustained. Only when I get near stall speed I seem to have a small turn advantage because I stall later. And even after some sustained turning they manage to repeatedly pull further for some short firing window. I've tried slow velocities, fast velocities. I either go in a stall or blackout or mostly both at the same time. 

 

Then: When I stall there are two options:

 

I manage to catch the stall within less than half a 360° spin or I enter a spin of death that can with some luck only be caught after many, really many twists. Very often I cannot catch that spin within an altitude loss of 3000 ft even if I immediately reduce power to zero and appliy opposite rudder. 

 

Apart from the questionable turn performance the stall behaviour seems ridiculously off.

[6./ZG26_5tuka]

On 5/4/2021 at 8:15 PM, sturmkraehe said:

I manage to catch the stall within less than half a 360° spin or I enter a spin of death that can with some luck only be caught after many, really many twists. Very often I cannot catch that spin within an altitude loss of 3000 ft even if I immediately reduce power to zero and appliy opposite rudder. 

 

Apart from the questionable turn performance the stall behaviour seems ridiculously off.

 

Spin characteristics seems rightfully vicious to me as it is described in the pilot notes.

[sturmkraehe]

4 hours ago, 6./ZG26_5tuka said:

 

Spin characteristics seems rightfully vicious to me as it is described in the pilot notes.

 

thanks! This is interesting read.

 

My point is not so much the altitude loss as such, but the entirely ineffective normal recovery. My belly feeling is that this may be partially due to the rather limited effectivity of the rudder and its limited impact on roll. One uses rudder to give more in air speed to the stalled wing (hence opposite rudder) thus reducing local angle of attack of that wing and hence removing stall on that wing allowing to regain recovery. Another part of the ineffective normal recovery method and maybe the major culprit is the particular evolution of spin movement.

 

As I mentioned in some other posts. The initial spin behavior resembles much much more a flat spin with a good deal of rotation occuring about the vertical axis rather than on the longitudinal one. Only after some time the spin gets into a normal spin mostly about the longitudinal axis. And just to make sure: The text that you quoted writes about rotation about the longitudinal and lateral axis, never about the vertical axis.

 

BTW I recommend not to take the 10,000 ft as a given altitude loss suffered by a spin. It is a safety recommendation that takes into account some unknown margin.

 

Your text also proves that spin recovery is not well in IL2 as recovery only is possible right after falling into a spin. Do two turns and no more recovery.

 

 

BTW in my oppinion the stall behavior is also weird on other planes as far as I can tell from watching other players fall in stalls of death.

Edited May 7, 2021 by sturmkraehe

[CSW_606_Temp]

If Is Spitfire modelled corectely, It is time modeling corectely Bf. Last good Bf in maneuvre was Fridrich.

[sturmkraehe]

Make a thread for 109 (Maneuverability of later 109 looks good but K4 is very wobble happy in pitch which is really weird too)

[Algy-Lacey]

On 4/24/2021 at 7:44 AM, ZachariasX said:

What I described, I see this as a typical sim artefact, where simulated weight makes the aircraft either oscillate („wobble“) or be sluggish to follow the controls as if you had elastic control cables. The latter I see currently present with the XIV.

 

On 4/24/2021 at 7:44 AM, ZachariasX said:

But as said, I have to rule out that the problem is on my part and I will do some more testing. If I end up with conclusive results, I‘ll post a bug report.

 

Hello Zacharias, did you end up posting a bug report? If so, I will find it and add an upvote. Perhaps all those who think the elevator response of the Mk XIV isn't right could do the same?

 

Algy-Lacey

[ZachariasX]

7 hours ago, Algy-Lacey said:

Hello Zacharias, did you end up posting a bug report? If so, I will find it and add an upvote. Perhaps all those who think the elevator response of the Mk XIV isn't right could do the same?

 

Algy-Lacey

No, I just started that thread regarding the issue where I was describing my findings. I am not sure if it is really a „bug“ as such what we are seeing here, but rather a side effect of otherwise intended FM behaviour. Also, I have no flying experience in the Mk14, hence - as sure as I might be - it would technically still be an opinion piece.

 

Given BoN is still under development and assuming the devs know what we are talking here (as well as agree on), I think the last word on the Mk14 is not spoken yet. Especially since they are making a second one now.

Edited May 23, 2022 by ZachariasX

[Noisemaker]

Does anyone else have a problem getting the XIV into a hands free trim configuration?  I find the elevator trim works, but if I trim the rudder to keep the ball dead centre, the plane slowly rolls left (and unfortunately there is no aileron trim to counteract that), requiring constant correction.