DVL data on Bf 109 roll rates

[Angus]

The Hurry in 1940 would probably still have had fabric ailerons as well,- or on second thought, maybe not? There were many many kinds of wings in service, metal gradually becoming the norm.
Could be the washout, size, or more factors perhaps.
It's elevators were heavier,- however it was reported to turn on it's tail. Very balanced controls and easy to fly.
Landed 7 kills in a Hurry last night

[Knegel]

Originally posted by Kurfürst
Actually it seems strange too. The Spit stick leverage was very short, only the upper part could be moved for the aileron - about 20 cm at best, giving very poor leverage vs. a normal flight stick. Outright stupid if you ask me, the least effective way to convert the pilot`s muscles into force.

Ie. silicon graphics representation, viewed from the back, pilot throwing the stick to the right :

Spit`s fligth Stick:

leverege:
<->
...O
./
.I
.I
.I
.I

Most other WW2 fighters :
leverage
<---->
..... //
...../
..../
.../
../

Hi,

leverage dont count here!!

We have results with different stickforces, so the leverage dont count. 50lb at the handgrip are 50lb, no matter what leverage!
The lbs dont get measured at the bottom of the stick!

The leverage only is worth a look, if we wanna try to explain why planes had different rollratios, but wingarea, wingaspectratio, size, form and position of the alerons are far more important, at least if we assume that the constructors  gave the pilot as much movement and as much leverage as the cockpit did allow(long stick = big leverage but smal variation = good for highspeed manouvers, short stick = smal leverage but much variation = good for slowflight manouvers, boosted alerons are different again).

On the page i did post some posts before is a complete HurriII test!

I did add the 50lb roll curve to the NACA document above!

The Hurri was ok at highspeed, but the max rollratio was rather poor.

According to the test the Hurri did need smal stickforces to get 0.4-0,8rad/sec, but above a special aleron delfection the stickforces got very big, thats why the max rollratio is bad, but the highspeed roll is ok.

Greetings, Knegel

[Angus]

So, a longer stick with the same lbs makes more lbs on the control cables right. Hence the U.S. Fighters with their geared down control, - a larger travel to do the same force. So, the Spitty was set up worse in that way, - more power was needed on the cables to inflict the same roll as a 109. Howewer.....
The Spit pilots usually jabbed their elbow to the fuselage side, - it fitted quite well, - thereby being able to apply more force to the stick, - that's what I mean.

[Knegel]

Hi,

dont you think the 109, FW190 , P47, Yak1 or whatever pilots didnt use such 'tricks' to get a greater stickforce??

The thing is: While a hard combat, they had to roll right left right, at same time with turning and using siderudder. At highspeed such tricks are for sure good, where most rollratios was very slow anyway, but at combatspeed (150-350mph IAS) light sticks was a big advantage. They didnt clipped the Spitwings cause it looks more agressive!  

Greetings, Knegel

[Squire]

"Actually it seems strange too. The Spit stick leverage was very short, only the upper part could be moved for the aileron - about 20 cm at best, giving very poor leverage vs. a normal flight stick. Outright stupid if you ask me, the least effective way to convert the pilot`s muscles into force."

The RAF used the style of stick you are describing in ALL of its fighter a/c, there was nothing wrong with the design.

At wars end in 1945, the Spit XIV and Tempest used the same style of control stick they did in 1939...there was no need to change the basic design. Or they would have.

The P-51 (Mustang III) doesnt use it because the P-51 was manufactured in USA, same with other lend lease a/c, and they did not replace the control columns as policy.

The Spitfires wing, like all other fighters wings, had good, and bad attributes to them...like all the other fighters in WW2. None of them turned like an A6M Zero but rolled like an Fw190, as the flight data clearly shows...

"The Bf109 had a poor rate of roll because of its narrow cockpit, you couldnt move the control stick all the way to one side" - See, I dont need any sources at all to just fire off a baseless claim. Its easy!

Regards.

[OttoJ]

If the British stick setup was good, why then is it no longer in use while the German/American one is?

[Angus]

What do you mean?
The rollrate was, if anything, enhanced with the way a Spitfire stick was set up. Make it shorter and yo will suffer.
And the wing clipping was made to meet the high rolling 190, NOT the 109.

Well, there may be some here who think the 109 and 190 rollrate is in the same ballpark maybe,- Crumpp, - where are you?

[OttoJ]

Originally posted by Angus
What do you mean?
The rollrate was, if anything, enhanced with the way a Spitfire stick was set up. Make it shorter and yo will suffer.

The moving part of the Spit's stick in the roll axis was shorter than the 109's stick. It was also very inharmonic having long stick leverage in the pitch axis, but short stick leverage for roll.

[gripen]

Originally posted by Kurfürst

Aileron linkage was done with metal rods, not cables like on the Spitfire, there was no 'linkage elastacy'.

This is what DVL measured:



Try to live with that.

Originally posted by Kurfürst

*Very high* - compared to what? Not any higher than for the majority of WW2 fighters I have seen.

At 400 mph IAS and with 50 lbs stick force, the Bf 109 had the lowest roll rate if compared to other planes in the NACA chart ie the forces were very high.

Originally posted by OttoJ
The moving part of the Spit's stick in the roll axis was shorter than the 109's stick. It was also very inharmonic having long stick leverage in the pitch axis, but short stick leverage for roll.

The charts above tell directly the roll rate with given stick force. The amount leverage is irrelevant for this discussion.

gripen

[OttoJ]

I'm not into "your" discussion. I'm correcting Angus' mistaken belief that the Spit had more roll stick leverage than the 109.

[Squire]

The Harvard trainer the RAF and RCAF used for advanced flight training used the same style control yoke with student pilots.

...the Tornado uses the same style of yoke, where only the top portion rotates for bank. So it is still used.

Its an ergonomic design choice, just like cockpit instrumentation and canopies are (some are hinged, some slide back, ect ect). You can find any number of "yoke types" in all kinds of a/c, both civil and military. They are not uniform by any stretch of the imagination.  

The P-38 used a "yoke style", the Bf 110 used a standard "stick style", the Mosquito used a "bomber style" yoke in the bomber version and an RAF "fighter style" in the fighter version. They all worked just fine.

[OttoJ]

What?! I can't believe they would use such a stick in the Tornado.

[gripen]

Originally posted by OttoJ
I'm not into "your" discussion. I'm correcting Angus' mistaken belief that the Spit had more roll stick leverage than the 109.

Well, even in that case you are talking about force and movement, so the thing to look for is amount of movement, not directly the leverage because the aileron linkage change the movement ratio.

BTW the Do 335 had functionally quite similar stick as British planes.

gripen

edit: Image added from Aeroflight pages

[Squire]

Mig-29, F-16, Tornado.

They all use different styles and designs, and all work just fine too.

British cars have the steering wheel on the right side, doesnt mean they are inferior. Just different.

[Knegel]

hi,

Originally posted by gripen

The charts above tell directly the roll rate with given stick force. The amount leverage is irrelevant for this discussion.

gripen

Looks like this is somewhat difficult to understand. lol

You be right that the 109F got heavy stickforces at high IAS, thats one reason why it was a very good high alt fighter.
In 6,1km alt 300mph are 420mph TAS, while a combat, where the enemys took notice of each other, the speed did decrease fast after the 1st turn.  400mph IAS rarely got reached(edit: in this alt), fighting at such speeds was difficult in all WWII planes, actually most planes would have broken while a hard movement at this speeds.

The P51 had its adjusting, cause it was adjusted to bring the pilot home at 1st! It wasnt adjusted to bring the best performence while a dogfight, cause the US HQ saw very early that most kills from 1941 onward was made while sneaky fast attacks and if the attack wasnt successfull it was better to be able to get away than to turnfight.    




Angus,
"What do you mean?
The rollrate was, if anything, enhanced with the way a Spitfire stick was set up. Make it shorter and yo will suffer.
And the wing clipping was made to meet the high rolling 190, NOT the 109.
Well, there may be some here who think the 109 and 190 rollrate is in the same ballpark maybe,- Crumpp, - where are you?"

As you pointed out, and as you can see in the document above, the Spitfire wasnt  better(regarding rolling)  than the Bf109F at combat speeds, therefor i guess the clippled wing spit was not only needed vs the FW190, specialy the SpitV did suffer speedproblems, so i guess every advantage was welcome.
Since most planes had enough power to make the blackout, in big degrees, to the turnlimit, the rollratio is the most important axe while evading a attack and while following a evading enemy.

If a rollratio setting is good or bad depends to the way the pilots had to fight. Down low, while tight slow turnfight the P51 had a bad setting, while the 109 had a bad setting for highspeed.

btw, i realy would like to see the direct testcurve for all the planes in the NACA comparison.


Greetings, Knegel