Spitfire IX Stick Forces

[Ala13_ManOWar]

In the perfect world the DCS modules fly in, the ailerons would be matched.

IMHO in the perfect World the DCS modules fly in a feature or quirk should be modelled, but certainly I understand many people won't understand like they don't understand other modelled features and quirks in some other modules :thumbup:.

 

S!

[Friedrich-4B]

Thank you for posting it, it shows very clearly how quickly the high the stick forces become on the Spitfire with metal ailerons, here there is already 60 lbs stick force when rolling to the left at 145 mph IAS, and the same force at 160 mph IAS when rolling to the right. Finding matching pair of ailerons on the Spitfire tended to be somewhat of a random affair through the war.

 

And Kurfurst gets this from one graph (with no explanatory note) from one airframe out of what, some 24,000 Spitfires and Seafires built?

 

As for the so-called problem of matching ailerons being random throughout the war? Totally wrong; the fabric ailerons were difficult to match because:

 

a) their structures were not as stiff as those of the metal ailerons...

b) there was often the need to glue lengths of cord to the trailing edges of the fabric covered aileron to get the trim right.

 

Both problems disappeared with the metal covered ailerons, making them far, far easier to match.

 

In any case, as far as control harmony goes it was a rather odd combination since applying the same force in pitch would likely overload the air frame. Some Spitfire pilots described this as handling the stick with a delicate fingertip in pitch, while arm wrestling the ailerons. I hope FBB controls will give some of that feeling back to our virtual pilots.

 

Hopefully Kurfurst can provide some real data/documentation to back all this up. I have far more confidence that Yo-Yo, with his access to real data (rather than possible pilot anecdotes) knows how the Spitfire IX handled and how it should feel. :smilewink:

[Krupi]

Thank you for posting it, it shows very clearly how quickly the high the stick forces become on the Spitfire with metal ailerons, here there is already 60 lbs stick force when rolling to the left at 145 mph IAS, and the same force at 160 mph IAS when rolling to the right. Finding matching pair of ailerons on the Spitfire tended to be somewhat of a random affair through the war.

 

In any case, as far as control harmony goes it was a rather odd combination since applying the same force in pitch would likely overload the air frame. Some Spitfire pilots described this as handling the stick with a delicate fingertip in pitch, while arm wrestling the ailerons. I hope FBB controls will give some of that feeling back to our virtual pilots.

 

This might also help.

 

 

Utter garbage Kurfürst remember that graph is from a very old and worn-out Spitfire, I wouldn't take it as representative.

 

Regarding the ailerons, as each aircraft is slightly different the ailerons were tweaked to match that aircraft as perfectly as possible. This was done on a series of test flights before delivery.

 

I would also like to see some document pertaining to "wrestling" of the controls as that is the first I have ever heard of such matters.... Sounds very unbelievable.

Edited May 27, 2016 by Krupi

[Friedrich-4B]

Here is the piece which makes me question the NACA information

 

https://books.google.co.uk/books?id=Yf17NyVsJcIC&pg=PT144&lpg=PT144&dq=spitfire+aileron+lb+force&source=bl&ots=uuQUXfkv_j&sig=Edqct8_NiKkoPs_l2NZTUQHNGXI&hl=en&sa=X&ved=0ahUKEwiulebA3-TMAhVHNhoKHQYDDDoQ6AEIHDAA#v=onepage&q=9%20lb%20force&f=false

 

I am not sure how good this book is, however the metal ailerons are said to have reduced forces at 350 mph compared, only 9 lb compared to 43 lb of the fabric ones... Of course we don't know at what rate the roll was as it is not mentioned making comparison to the charts useless

 

I need to get Geoffrey Quills book that will hopefully go into this further.

 

Unfortunately Isby didn't use a reference for the 9lb vs 43 lb comment, because ref 35 only shows Jeffrey Quill's book, which doesn't go into detail about the stick weights (see attached).

 

Also of interest are Quill's comments about longitudinal instability encountered on Spitfire Vs in 1942, describing how the inertia weight was used to fix this; he goes on to explain how enlarging the elevator's horn-balances meant that the inertia weights could be dispensed with.

 

(NB: some self-proclaimed "experts" have dismissed Quill's opinions as either being irrelevant, because he was a mere test pilot, not an engineer, or as propaganda, because he worked for Supermarine and wouldn't say anything bad about the Spitfire! :doh: )

quill_aileron.pdf

[Krupi]

Awesome Friedrich, fascinating stuff.

 

I received Quills book yesterday, it is going to be very interesting.

 

I also have received a fascinating article which I will be posting when I get the time, I think you will appreciate it.

[Friedrich-4B]

Awesome Friedrich, fascinating stuff.

 

I received Quills book yesterday, it is going to be very interesting.

 

I also have received a fascinating article which I will be posting when I get the time, I think you will appreciate it.

 

Cheers Krupi; the edition of Quill's book I posted from is a rather elderly edition from the local library - mine went missing last year, so I'm also awaiting the arrival of a new copy.

Incidentally, Quill does mention that ailerons had to be 'tuned' to each Spitfire, because even small production variations in such areas as the hinges, wing shrouds, aileron nose-balance profile etc could have a "spectacular effect" on the lateral handling of each Spitfire. While interesting, it's not going to be relevant to Ed's Mk IX.

[Krupi]

I have only just started reading it however when I come across it I will post the info here :)

 

Regarding the article I mentioned please see below, it is an extract from an article in Pilot Magazine written by John Allison entitled Hurricane, Spitfire & Messerschmitt.

 

In the article he compares various subjects such as the cockpit, take off and landings as well as performance. Regarding the performance he actually used a force gauge to record the forces on the stick.

 

 

It appears that he is specifically comparing the Spitfire XVI (TE184 G-XVIA) and a 109 G2 (trop 10639 aka Black 6) in regards to the stick forces.

Edited June 3, 2016 by Krupi

[Krupi]

Cheers Krupi; the edition of Quill's book I posted from is a rather elderly edition from the local library - mine went missing last year, so I'm also awaiting the arrival of a new copy.

Incidentally, Quill does mention that ailerons had to be 'tuned' to each Spitfire, because even small production variations in such areas as the hinges, wing shrouds, aileron nose-balance profile etc could have a "spectacular effect" on the lateral handling of each Spitfire. While interesting, it's not going to be relevant to Ed's Mk IX.

 

Stroke of luck a whole chapter is set aside for Ailerons.

 

Chapter 15 - Aileron problems.

 

Page 198 talks about the tuning of ailerons (I don't have a scanner so will just write it here).

 

"On first take-off a new production Spitfire would usually be found to be flying severely 'one wing low', sometimes to the extent that it was almost a two handed job to hold it. The aircraft would immediately be brought in to land again and a trimming strip, comprising a piece of cord sewn inside a length of fabric, would be attached to the upper trailing edge of the aileron on the wing which was 'low'. It usually took several flights to achieve the right length of strip to make the aircraft fly level in the cruise. Then the flight schedule would be continued culminating in a dive to the limiting speed of 470mph. Usually (but not always) if the aircraft had been successfully trimmed at cruising speed, it remained in trim at this very high speed. But sometimes it would develop a strong bias one way or other. In these circumstances an aileron had to be changed and discarded, or tried again on another aeroplane. Very small production variations in the hinges, the slotted shrouds in the wing, profile of the aileron nose balances and the aileron profile aft of the hinge could have a spectacular effect on the lateral handling of each production aeroplane.

 

So the ailerons virtually had to be individually 'tuned' by the test pilot (who had to know what he was about) and it usually took several flights to achieve satisfactory results...."

 

It seems this was in regard to the fabric covered ailerons as the chapter then goes on to discuss that the ailerons were much too heavy at speed. The rest of the chapter details the search for a solution i.e. metal ailerons... he goes on to say that both he and Joe Smith the solution was still not perfect leading to further improvements on the Mk21.

Edited June 3, 2016 by Krupi

[Kurfürst]

Utter garbage Kurfürst remember that graph is from a very old and worn-out Spitfire, I wouldn't take it as representative.

 

I am afraid its merely your opinion that constitutes 'utter garbage' so far, similar to your unsubstantiated claims about "tired etc." aircraft. Now, its understable, since you have shown to be extremely wishful about the Spitfires qualities, and you have been just shown several actual tests that show its actual aerodynamic qualities about aileron forces. I bet you do not like the reality, so you call it garbage and such. Since the NACA Spitfire tests are one of the most detailed and professionally done test available on the actual flying quirks and qualities of the Spit, its natural that some of the most biased Spit fans will try to dismiss it, ironically, as some sort of amateurish rubbish which I would rather use for their opinion instead. :lol:

 

Now, YoYo have been already provided and found very detailed documents on the actual qualities of the Spitfire and as a true professional I have no doubt that he will base the Spitfire on his professional understanding of these documents, rather than the amount of cherry picking and whining in DCS:Spitifire threads. This was the case in the past.

 

BTW, this extract of the paper I have posted is not, in fact, from the NACA tests of the Spitfire VA from 1941, but a later British tests of a much later mark from 1943, which should be obvious from the fact that the plane's aileron qualities are being compared with a Mustang.

 

In summary, we have your totally unsubstantiated opinion that the metal aileron Spits stickforces were somehow light, against the trials made by professionals at NACA, RAE and Boscombe Down...

 

Regarding the ailerons, as each aircraft is slightly different the ailerons were tweaked to match that aircraft as perfectly as possible. This was done on a series of test flights before delivery.

 

Providing matching ailerons is again something that should have been done on Spitfire production, but like many things, it just wasn't. It was a well recognized quirk of Spitfire production, whether was an early fabric aileron or a later metal aileron and the problem kept persisting later in the war even with Griffon powered variants, as the below excerpt from a late 1943 Spitfire trial shows.

 

...........4.21 Controls and general flying. The type of fin and rudder incorporated in this aircraft caused a decrease in the change of directional trim with speed compared with JF.319. Rudder forces were of a similar magnitude. The ailerons, despite an absence of reflexing, were noticeably heavier. Variations in the weight of ailerons on Spitfire aircraft are common and are due to manufacturing differences between individual sets. This aircraft presumably had an inferior pair of ailerons; it is desirable that such ailerons should be rejected during production testing.

 

Balancing Frise type ailerons was not an easy thing any case, they are sensitive beasts.

 

I would also like to see some document pertaining to "wrestling" of the controls as that is the first I have ever heard of such matters.... Sounds very unbelievable.

 

To the unreasonable man, perhaps it might sound unbelievable, because he might want to believe in a fairy tale instead of reality, which was that no less 71 lbs stick force was required to produce about 10 degrees aileron deflection, which was about 1/3 at 400 mph (compared to 23 lbs force on the Mustang), certainly not a very good thing. For comparison to the abhorrent aileron forces experienced on the early Spits with fabric ailerons (see below curve).

 

 

71 lbs on either metal or fabric ailerons is a very considerable sideways force by most reasonable men, especially if its accompanied by very little fore-and-aft force on the elevator (i.e. for a normal sustained turn, only about 10-15 lbs force). Hence why Jeff Ethell decribed the Spit controls as the following:

 

"The elevator is very light while the rudder is stiff and the ailerons even more so. Every Spitfire I've flown takes a bit more muscle to roll than most fighters. As speed increases both rudder and ailerons get heavier, resulting in a curious mismatch at high speed...one has to handle the almost oversensitive elevators with a light fingertip touch while arm-wrestling the stiff ailerons. Pilots had to keep this in mind during combat, particularly when going against the FW 190 which had a sterling rate of roll and exceptionally well harmonised controls. That being said, the aircraft is very well balanced and delightful to manoeuvre. Whipping a Spit around the clouds ranks right up there at the top of aviation's great experiences."

 

I very much hope the FFB joystick owners can fully experience that quirk, i.e. mismatch of lateral and fore and aft forces by the proper adjustment of the force curves. It would be a first for DCS - Il-2 for example did not model it because of gameplay reasons.

Edited June 3, 2016 by Kurfürst
Add fabric aileron data

[Krupi]

I suggest you read my last two posts Kurfürst.

 

Your claims of 71lb do not seem to tie up with any metal aileron data or an actual pilots account (John Allison who has flown both the Spitfire and 109).

[Kurfürst]

I suggest you read my last two posts Kurfürst.

 

Your baseless claims of 71lb do not seem to tie up with any metal aileron data so an actual pilots account (John Allison who has flown both the Spitfire and 109).

 

Yada-yada-yada-baselessclaims-yada-yada-yada.

 

Lets see your "metal aileron data" and then we can chat.

[Krupi]

Please do not try and make this personal Kurfürst I am not an "unreasonable" person I am fully aware that the Spitfire like all aircraft have flaws it is the nature of engineering that by improving one aspect of an aircraft leads to degradation in an other.

 

I am not attacking the 109 as you seem to think I am, from what I can tell you are buried in every WW2 aircraft forum defending the 109 from any perceived slight even when there is none.

 

Both aircraft were cutting edge at the time, John Allison goes on in the article to say how surprised he was at the low speed performance of the 109 thanks to the slats however he goes on to say he would personally prefer the Spitfire and acknowledges that his article cannot capture everything that is needed to truly compare the aircraft armament etc...

 

The simple fact remains that the 109 was always a heavy aircraft to handle that is something that I have read in all the books I own, the Spitfire improved with metal ailerons however both aircraft became heavy at high speeds especially compared to the 190.

Edited June 3, 2016 by Krupi

[Kurfürst]

I am not talking about the 109 here at all.

 

I am talking about the Spitfire's aileron forces (all marks up to the 20-series with the redesigned wing), which were heavy while the elevator was extremely light and sensitive.

 

Also what I am trying to do is to open your eyes to that the metal ailerons did not improve on that heaviness much, if at all, but they improved on the ailerons effectiveness (=roll rate per degree of aileron deflection). Meaning that if you managed to arm-wrestle and deflect the ailerons on the later metal ailerons Spits, they actually had effect, unlike the earlier and poorly designed fabric ailerons (poorly designed because making the ailerons with fabric was not problem itself, many aircraft had them, including stellar rollers).

 

Now as for making this personal, you started to go down on that road, remember? Maybe you should ponder on using in less disparaging remarks in your posts and we will be fine. ;)

[Krupi]

From the data I have read including now the Supermarine test pilots the metal ailerons did have a large impact "transformed" was in fact the word used and the pilots agreed so much so that Douglas Bader used his political strings to ensure his squadron were the first to receive them.

 

So forgive me if I don't agree with you when you say they didn't have an impact they clearly did.

 

According to Quill some pilots actually complained that the ailerons were now too light.... Make of that what you will.

Edited June 3, 2016 by Krupi

[BIGNEWY]

both of you need to take a deep breath.

 

Discuss even argue your points, but do not make it personal.

[Krupi]

I have my answer from John Allisons and your very much appreciated help to those that posted useful data here.

 

When my control column is finished I will be using 30lbs for roll and 10-15lbs for pitch :thumbup:

 

Thanks again for everyone's help here, once my project is underway I will post some images :pilotfly:

 

P.S. If anybody wants the full article from Pilot Magazine just drop me a PM.

Edited June 3, 2016 by Krupi

[Schmidtfire]

Why is this even a heated discussion? Im sure that both of you will be dissapointed by some obscure detail on the Spitfire when it arrives. Let ED release the module first, it's their baby and they decide what is plausible behavior.

[Krupi]

Why is this even a heated discussion? Im sure that both of you will be dissapointed by some obscure detail on the Spitfire when it arrives. Let ED release the module first, it's their baby and they decide what is plausible behavior.

 

This discussion had nothing to do with ED it was to do with the handling of the Spitfire in real life, the stick forces cannot be modeled by ED software unfortunately :smilewink:

 

I just wanted to know the stick forces so I can model the difference in harmony on my stick.

Edited June 3, 2016 by Krupi

[Ala13_ManOWar]

What I wonder is why people can't just answer the quite simple question Yo-yo made in first place, you would like to see it behaving one way or another? (read Yo-yo explain if you don't know what he asked first by this time :P ) That's all… Why have every thread to end in the same discussion?

 

S!

[MiloMorai]

What I wonder is why people can't just answer the quite simple question Yo-yo made in first place, you would like to see it behaving one way or another? (read Yo-yo explain if you don't know what he asked first by this time :P ) That's all… Why have every thread to end in the same discussion?

 

S!

 

It is lobbying by those that want to see the Spitfire castrated.

[Cripple]

This discussion had nothing to do with ED it was to do with the handling of the Spitfire in real life, the stick forces cannot be modeled by ED software unfortunately :smilewink:

 

I just wanted to know the stick forces so I can model the difference in harmony on my stick.

 

And some of us and very interested in doing much the same...

 

 

(Thanks, Krupi et al for the research. Look forward to a definitive answer.)

[Friedrich-4B]

Now, YoYo have been already provided and found very detailed documents on the actual qualities of the Spitfire and as a true professional I have no doubt that he will base the Spitfire on his professional understanding of these documents...

 

:thumbup: Excellent, Kurfurst will be thus in total agreement with Yo-Yo's professional understanding of the said documents, and his professional verdict on how ED's Spitfire IX will handle:

 

:)Fortunately, Mk IX is slightly stable, anyway, the required stick travel is not high... but nothing extraordinary.

 

Very pleasant to fly, very controllable, predictable and steady.

 

Some day I will try to shift CoG to Mk V or Mk IX with rear tank position... but do not think it will be a kind of trouble.

 

 

BTW, this extract of the paper I have posted is not, in fact, from the NACA tests of the Spitfire VA from 1941, but a later British tests of a much later mark from 1943, which should be obvious from the fact that the plane's aileron qualities are being compared with a Mustang.

 

Hopefully Kurfurst has the full test and the context of these tests?

 

Providing matching ailerons is again something that should have been done on Spitfire production, but like many things, it just wasn't.

 

Wrong, wrong wrong! Matching the ailerons was done during production testing of each Spitfire.

 

It was a well recognized quirk of Spitfire production, whether was an early fabric aileron or a later metal aileron and the problem kept persisting later in the war even with Griffon powered variants, as the below excerpt from a late 1943 Spitfire trial shows.

 

...........4.21 Controls and general flying. The type of fin and rudder incorporated in this aircraft caused a decrease in the change of directional trim with speed compared with JF.319. Rudder forces were of a similar magnitude. The ailerons, despite an absence of reflexing, were noticeably heavier. Variations in the weight of ailerons on Spitfire aircraft are common and are due to manufacturing differences between individual sets. This aircraft presumably had an inferior pair of ailerons; it is desirable that such ailerons should be rejected during production testing.

 

Balancing Frise type ailerons was not an easy thing any case, they are sensitive beasts..

 

What the "well recognized quirk" was hasn't been specified by Kurfurst, unless he's trying to claim that the Spitfire test pilots didn't bother to test the ailerons by citing an isolated example of a much used prototype.

 

Blah, blah, blah...because...no less 71 lbs stick force was required to produce about 10 degrees aileron deflection...yada, yada yada...

71 lbs on either metal or fabric ailerons is a very considerable sideways force by most reasonable men, especially if its accompanied by very little fore-and-aft force on the elevator, blah, blah, blah...

 

50lbs...50lbs...we now have 71lbs...7lbs...any advance on 71lbs of stick force required?

 

Thus, Kurfurst now claims that "no less 71 lbs stick force was required to produce about 10 degrees aileron" can be universally applied to all 5,000 + Spitfire IXs because of one extract from one unspecified report, on an unspecified Spitfire and unidentified Mark of Spitfire, when he has already fulminated at length on how tricky the Spitfire's ailerons were to set up. Perhaps Kurfurst would like to share the entire document with all of us, instead of using a selected "sound bite"?

 

Hence why Jeff Ethell decribed the Spit controls as the following:

 

"The elevator is very light while the rudder is stiff and the ailerons even more so. Every Spitfire I've flown takes a bit more muscle to roll than most fighters. As speed increases both rudder and ailerons get heavier, resulting in a curious mismatch at high speed...one has to handle the almost oversensitive elevators with a light fingertip touch while arm-wrestling the stiff ailerons. Pilots had to keep this in mind during combat, particularly when going against the FW 190 which had a sterling rate of roll and exceptionally well harmonised controls. That being said, the aircraft is very well balanced and delightful to manoeuvre. Whipping a Spit around the clouds ranks right up there at the top of aviation's great experiences."

 

Gosh! One warbird pilot account stating that he had to "wrestle" with the ailerons (mind you, Kurfurst also forgot to highlight Ethell's other statements) Can Kurfurst provide any documented statements from wartime, operational pilots complaining about having to arm-wrestle with the metal ailerons during combat?

 

Back to warbird pilots - here's another opinion: http://www.warbirdalley.com/articles/spitfire-flight-report.htm

 

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.

 

Different strokes for different folks, etc etc...

 

Can we dare to hope that Kurfurst has got some fully documented and reliable statistics to show just how many Spitfires were afflicted with poor ailerons, and just how badly this affected operational Spitfires? Can he also demonstrate why the aileron matching and tuning has anything to do with Ed's Spitfire IX - albeit Kurfurst still wants this to be factored in...

 

I very much hope the FFB joystick owners can fully experience that quirk, i.e. mismatch of lateral and fore and aft forces by the proper adjustment of the force curves. It would be a first for DCS - Il-2 for example did not model it because of gameplay reasons.

 

In other words, Kurfurst very much hopes that ED's Spitfire IX will be a slow, hard to control cow, dominated by heavy, mis-matched ailerons and overly light elevators.

 

Fortunately we can rely on Yo-Yo's professionalism and objectivity, and his understanding of the copious documents and data he has gathered from excellent sources, rather than having to bother with Kurfurst's very small number of highly selective bits and bobs; Kurfurst's mostly undocumented opinions on how the Spitfire handled and performed will not, quite rightly, make the slightest bit of difference to the performance and flight qualities of Ed's L.F. Mk. IX.

Edited June 4, 2016 by Friedrich-4/B
spelling

[HeadHunter52]

Well, with the Krauts talking down to "whining" Mustang drivers, it'll be a sweet song to hear them do the complaining when the skies host Spits and Jugs.

[Hummingbird]

Well, with the Krauts talking down to "whining" Mustang drivers, it'll be a sweet song to hear them do the complaining when the skies host Spits and Jugs.

 

Then along comes the Me262 and we're back at it again....

 

There will always be something for each side to whine about. The sad part is that there are "sides" to stuff such as this at all though.

[Nerd1000]

Then along comes the Me262 and we're back at it again....

 

There will always be something for each side to whine about. The sad part is that there are "sides" to stuff such as this at all though.

Indeed. People seem to forget that it all happened 70 years ago and there's no good reason to keep fighting over everything.

 

As an aside, video game players are a notoriously whiny bunch. I wouldn't be surprised by 262 pilots whining about the 262's disadvantages (slow engine spool-up, low muzzle velocity of guns and wide turn radius) while at the same time the pilots of the piston-prop planes that face them are complaining about fighting a jet. :doh: