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Spitfire strange elevator.

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7 minutes ago, JtD said:

To do a proper looping from that starting speed you'll need to have about 120 mph going over the top. Good luck.

 

At full power, with 170mph entry speed: about 90mph at the top.

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I'm betting it's a pretzel sort of thing, not a looping.

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34 minutes ago, JtD said:

I'm betting it's a pretzel sort of thing, not a looping.

 

... you know we are not in an aerobatic compétition and that the goal is not to make a perfect round loop? ;)

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1 hour ago, F/JG300_Faucon said:

 

Now I have a bit more time to answer:

 

For the stall: I’m not talking about classic idle stall on upright level flight path. It’s normal that once you reach a precise AoA, wings stall. 

The weird thing about the FM is that you can’t reach that AoA under certain conditions (top of a loop, for example).

 

For the rudder, I understand you prefer not to explain/talk about something if you don’t have informations.

But as I said, you can easily:

- Notice that you can make turns when taxiing only with the propeller blast. And that you need half of the rudder (or less) to hold your line during take off.

- Find pilots notes, manuals, etc, that state you need full right rudder at take off. 

- Propeller blast is insufficient to turn when taxiing, it’s a fact.

- Notice all other aircrafts need full rudder for take off.

 

I have all the Spitfire manuals, and not one of them says that you need full right rudder on take off. Actually the Mk.II manual  says that the swing can easily be corrected "by coarse rudder control". Trimming in right rudder is entirely optional. Not only that, but looking at several videos of real Spitfires taking off, I do not notice it there either. What you get is the occasional rapid dab of right rudder.

 

The Spitfire rear wheel is free castering: note that in the manuals there are neither instructions to lock it before take off nor is there a lock anywhere in the cockpit. The Spitfire II manual (AP1565B - which has much fuller written descriptions than the manuals for the later marks),  says that the plane should be advanced a little at low revs before opening the throttle for the take off run in order to straighten the tail wheel.   

 

 

Edited by unreasonable

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1 hour ago, F/JG300_Faucon said:

 

At full power, with 170mph entry speed: about 90mph at the top.

 

by full power you mean 3000rpm and max boost?

 

the pilot's notes for Spit IX with Merlin  61,63,66, 70 or 266 engine give this speeds

 

682822100_SpitIXaerobatics.png.dd369d78fecebcf23d809c520b20f3e2.png

 

and Rick Volker former display pilot of the canadian haritage team spitfire gave this testimony 

 

rick_v10.jpg

and another quote from Mr Feuilherade display pilot of the SAAF museum Spitfire:

 

"...

Basically, the Spitfire has no vices, and it really is very pleasant and easy to fly. The controls are so light and powerful that it feels as though your hand is hardly moving on the stick if you throw the aircraft around. I am quite convinced that is why the Spit was so good in combat, as you can fly it to the limits all day without your arm getting tired. Even at speed, you can hold it in a max rate turn on the light buffet, with a gentle two-fingered pull in the stick. As a comparison, at the end of my instructor’s course in the SAAF, we practised aerobatics in a Harvard for a few days in a row, for the end-of-course aerobatics competition. After a few days my arm was sore! You think you are maintaining a pressure on the stick, but involuntarily, your arm relaxes. Remember this was also in a Harvard, which handled pretty well compared to most general aviation aircraft. This is one reason the Spitfire was considered effortless to fly. The "broken" stick (only the top part moves for roll control) also works well, as your arm is not moving all over the cockpit. With the clipped tips the roll rate is brilliant. My display routine involved a pass down the crowd line at about 300 feet AGL, where I would do a straight roll. With a ghost of an upward pitch, check, and stick hard over, she rolled rapidly through 360 degrees. Out front the nose stayed planted, rolling on the reference point with no yaw divergence.

I’ve mentioned the rudder earlier, but to add, it is extremely powerful indeed and requires very little use once she’s up and running. Both elevator and rudder trim are powerful and require small trim wheel movements to adjust. The rudder trim is a smaller wheel then the elevator trim wheel, which is slightly lower and further back.

The aircraft has very gentle stall characteristics, with no wing drop tendency. You get a nice buzz on the stick as you approach the stall, giving you plenty of warning, and enabling accurate holding of a turn on the buffet (i.e. max rate). The aircraft really does feel like a willing participant in the air and you instinctively know it will always give its best for you. I can now understand how pilots grew to love it so much. Being able to out-turn from under the guns of a -109 or FW 190, well, you sure will get to love an aeroplane like that! At low power settings the engine is actually remarkably quiet, but as you open the throttle into positive boost settings, there is a wonderful growling that starts coming from under the rudder pedals up front... "

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2 hours ago, unreasonable said:

have all the Spitfire manuals, and not one of them says that you need full right rudder on take off. Actually the Mk.II manual  says that the swing can easily be corrected "by coarse rudder control". Trimming in right rudder is entirely optional. Not only that, but looking at several videos of real Spitfires taking off, I do not notice it there either. What you get is the occasional rapid dab of right rudder.

 

https://forum.keypublishing.com/forum/historic-aviation/74484-supermarine-spitfire-take-off-and-landing-guide

Be prepared to move your right foot forward for FULL RIGHT RUDDER to counteract swing effect from the Merlin engine.  "

On the videos, I see almost full right rudder, but for a short time of course. Generally, they apply slowly the power so they don't need a lot of rudder at the very beginning of take off run. The amount of rudder needed depends on how much power you have, how fast you move your throttle, and your speed. So it will change, more or less, at every take off, and also depending on how the pilot manage his take off.

But anyway, let's forget about how much rudder you need... It's not the only thing.

In game, at the beginning of the take off run (full power, slow, maximum helicoidale blast), if you apply full rudder, it's so powerfull that you can't get out of the runway. 

To make it simple: Propeller blast (or rudder efficiency/reactivity) is just too powerfull. I know something about it because I fly tailwheel aircrafts 95% of the time. On the take off videos, you can see those rapid dab of right rudder won't push the aircraft out of the runway axis. 

 

For taxi, from same link: " use the RUDDER PEDALS to control the distribution of pressure to the right and left wheel brakes "

 

@Arsenal53 Thx for those documents. 

For the take off, I read "push in hard right rudder"...

I'm wondering if we could find a document which talk about the elevator efficiency at very low speed... But the thing is, neither during war time and even more now, pilots wouldn't try to pull full back stick in those configuration "just to see"... But I'm flying a load of aerobatics (it's almost all my flight hours), and I'm 100% sure this lack of elevator efficiency is weird. 

 

2 hours ago, unreasonable said:

Not only that, but looking at several videos of real Spitfires taking off, I do not notice it there either.

 

2min48 ... :rolleyes:

 

 

Edited by F/JG300_Faucon

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He has full right rudder (or very close) for a fraction of a second at 2:51 - just a few frames.  Most of the time he is using closer to 50% - no doubt he could have taken off just fine without that fraction of a second. My point being that you do not need full right rudder to take off in a real Spitfire, nor do you need full rudder in many other BoX planes, contrary to your previous assertions. Being "prepared" for something does not mean that you will have to do it, or get an opportunity to do it, as every Boy Scout knows. 

 

I agree with you that the Spitfires are easier than usual to taxi using rudder alone, although it is possible to taxi a Yak 1 with an unlocked tail wheel without brakes, unless you want to turn left! I have no idea why this is the case or if it is correct. Yes the Spitfire has differential braking controlled the rudder bar - it does in the game too, you can see the pressure gauge and it works just fine.

 

Of course it is good to have someone who flies aerobatics in tail draggers discussing the game: no doubt you could have much to talk about with @AnPetrovich the head FM developer, who, I believe, does too.  Perhaps you would be better off logging into the Russian forum FM section and using Google translate: remarks there are far more likely to be looked at by him, although they are pretty intolerant over there of claims that the FM is wrong unless backed up with documentation, unlike here.

 

 

 

 

 

 

 

 

 

 

Edited by unreasonable

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3 hours ago, unreasonable said:

He has full right rudder (or very close) for a fraction of a second at 2:51 - just a few frames.  Most of the time he is using closer to 50%

 

Well, I see he's using full or almost full rudder more than one time (4/5 times in fact)... We could talk for a long time about how much rudder we think he's using... This is useless. 

For sure there is much more rudder than we need in game. ZERO doubts about that.

 

3 hours ago, unreasonable said:

no doubt he could have taken off just fine without that fraction of a second.

 

This is the only and worst part of your message... I mean, do you experience take off with tailwheels as a pilot IRL? I'm flying tailwheel aircrafts all the time and to me it wouldn't be "just fine", but may be I'm wrong :sleep::sleep:

 

3 hours ago, unreasonable said:

My point being that you do not need full right rudder to take off in a real Spitfire, nor do you need full rudder in many other BoX planes, contrary to your previous assertions.

 

First, in most (if it's not all) of my messages, I say "full or almost full rudder". This "almost" is important, because yes, full rudder is in fact rarely needed.

Second, most of IL2 aircrafts need this "almost full rudder" at take off.

 

 

Whatever, I see it's quite useless to talk here. I will try to prepare some videos, if I have time, and try to translate something on the russian forum.

Edited by F/JG300_Faucon

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-- cut --

- useless remark, when IL2 GB is actually my preferred sim ALL times, even with it's quirks...

Edited by jcomm

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Just for the sake of comparison, here's a vid of a XIV which shows the take-off run from dead astern (note it's left rudder as the Griffon rotates the opposite way to the Merlin).
 

 

Edited by HBPencil
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7 hours ago, HBPencil said:

Just for the sake of comparison, here's a vid of a XIV which shows the take-off run from dead astern (note it's left rudder as the Griffon rotates the opposite way to the Merlin).

 

Thank you for the video! I will keep it to show the difference with IL2.

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I honestly don't think I use that few rudder in IL2 ?  I believe that from the start of the takeoff run to the end I have to keep it pressed ( right rudder ) all the way down.

 

But I will test further and report back. I have given up on the Spitfire due to the strange trimming mentioned above by JtD. Really hope they have the time to revisit it's flight dynamics some day.

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48 minutes ago, jcomm said:

 

I honestly don't think I use that few rudder in IL2 ?  I believe that from the start of the takeoff run to the end I have to keep it pressed ( right rudder ) all the way down.

 

 

Do you at least read what I’m saying? :)

 

13 hours ago, F/JG300_Faucon said:

Second, most of IL2 aircrafts need this "almost full rudder" at take off.

 

Edited by F/JG300_Faucon

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14 hours ago, F/JG300_Faucon said:

This is the only and worst part of your message... I mean, do you experience take off with tailwheels as a pilot IRL? I'm flying tailwheel aircrafts all the time and to me it wouldn't be "just fine", but may be I'm wrong :sleep::sleep:

Far from wrong. Control effectivity at low speeds is generally excessive in this sim. But it has gotten WAY better since ROF, where it was straightforward to for instance for takeoff just make the Camel lift its tail to go on two wheels, almost pivot turning the crate in direction where you want to take off and off you go.

 

The taildraggers I sat in lose most of their rudder effectivity once the tail comes down. Same for take off. As you start the run, you basically rely on your locked tail wheel and only once the tail comes up the rudder really becomes effective. But during this time, only quick and relatively big corrections with your foot keep you straight and from veering of course in the first place. The „spiked“ yaw input nicely illustrates that. It is an important input, one that you indeed can‘t do without. There is a difference between rudder input needed to trim it right for the run and the superimposed inputs to fight any adverse tendencies that make the plane veer of course.

 

The effective controls also make it much easier to fight torque during takeoff. As the aircraft is just about to fly off the ground, in real WW2 fighters you often see significant aileron responses to keep the plane level, followed by coordinated rudder corrections to keep on going straight ahead. It’s not that torque would be excessive per se, it’s just that you don’t have much control yet to even fight relatively small forces. But as soon as the aircraft gained some speed, it becomes easy to control. In the sim, you can take of as you want, straight through the fields and at 100 km/h you can turn into the runway at impressive angles and do the last part of the run there, no problemo. In the real aircraft, there is lots of satisfaction in just keeping it nice and straight during the run.

 

As stalled turns are a very common occurrence in (sim) air combat, this should be more looked into. But seeing the progress made since ROF, I am confident that the devs will manage that the right way. Playing with global issues of the sim engine might cause significant side effects. If the devs take their time and proceed with care, then that would be the sensible thing to do.

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I'm just thankful that the devs haven't simulated whiplash deaths as with some of the turns that the Spits are doing in game, if this were real, the Germans would have won!

OK, just teasing, but I'm sure one day the devs, as ever, will sort all of these issues out!

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3 hours ago, Haza said:

I'm just thankful that the devs haven't simulated whiplash deaths as with some of the turns that the Spits are doing in game, if this were real, the Germans would have won!

OK, just teasing, but I'm sure one day the devs, as ever, will sort all of these issues out!

 

They will get to the 'Spit Whiplash' injuries just as soon as they have modelled the multiple skull fractures sustained by the 109 pilots as they smash their heads against both sides of the canopy performing their trademark 'nose up negative flick into falling leaf' maneuver at 500kph 😜

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