Hurricane Roll Rate
 

Just did a quick comparison, very rough at this time cause i have to head out, but it appears to me that the hurricane's roll rate is significantly lower than it otherwise should be.

i cant garauntee that this isnt caused by some other issue such as controller input, but the fact that i can achieve other roll rates in differnt aircraft suggests that isnt a factor.

For a full 360 roll i'm counting approx 9seconds. giving it a roll velocity of 40deg/sec

compared to the spitfire 1, which is about 5.5 seconds which = roughly 60deg/sec

the 109 is between the 2, coming in at about 6.5 seconds = ~55deg/sec


now from my previous sim time i would have expected the hurricane to be comparable if not slightly better than the spitfire, and obviously the 109. I did a quick search online for roll rate date the only thing i could find in a hurry was this

http://mitglied.lycos.de/luftwaffe1/...f/rollrate.pdf

which suggests comparable roll rates for the spitfire and hurricane. This corroborates with descriptive accounts of ways of evading a BNZ 109 for hurricane pilots from what i understand.

why is this obvious? 109s should just barely out roll a spit with non clipped wings at maneuvering speeds and they're equally awful at 400mph.

It appears from the 3d model that the hurricanes we have in the sim have metal wings. However, it's not immediately obvious that the 3d models and the flight models directly correspond (eg look at spinners on the different Spitfire Marks; they all look the same despite the fact that they probably shouldn't).

So the first question is whether the performance in the sim is meant to reflect a metal or a wooden wing. The second question is whether the ailerons are metal or fabric covered; fabric covered ailerons tended to "balloon" and greatly reduce in effectiveness at high speed.

Finally, I would observe that IRL the handling of aeroplanes is an extremely subjective business. Some years ago I used to fly gliders at a certain club which owned 2 ASK13s. One seemed much nicer than the other. I spent ages trying to work out why. In the end, I discovered that the reason was that the airbrake handle on the "good" aeroplane was recessed, whilst on the "bad" aeroplane it stuck out about 2".

This meant that when I flew the "bad" aeroplane, my left leg was about 2" further to the right, and I therefore had about 2" less left stick travel available than in the "good" aeroplane. The subjective result of this was that I found the "bad" aeroplane a heck of a lot more difficult to fly (especially because we tended to fly left hand circuits).

From an aerodynamic perspective, the two aeroplanes were basically identical, but the subjective handling experience was like night and day.

Personally, I find the Hurricane rather heavy in roll, but in the absence of really concrete data (both from historical references and from the sim) I don't feel in a position to complain about it.

I the short term, you'll find that rudder helps, especially if you add a little up elevator.

that above count was done at the same alt, same conditions, same speed. all with full fuel and ammunition load


generally speaking i've not seen the hurricane roll rate be anything faster than that at all alts and speeds so far in game.

hardware imo is not the issue, because if it was, i would be stating issues in roll rate for all aircraft not just one. its the same config after all.

theres some varying information around from what i've been able to look up in the immediate timeframe, suffice to say its fairly obvious that all 3 were considered roughly compareable in roll rate, the discrepencies in data ive searched is minimal and theyre all around the 55-60 deg/sec mark. with the 09 slightly better at some speeds, the spitfire better above about 320mph. I guess the point mainly here is that for comparable conditions, i would think a 50% slower roll rate as unusual for the hurricane.

dont get me wrong, if its supposed to be that way and there's solid evidence of that then no worries. would be good if some other peeps could try it out and see if they see any marked differnces

Major Werner Mölders, JG 51, compared the British fighters to his own prior to the Battle:

It was very interesting to carry out the flight trials at Rechlin with the Spitfire and the Hurricane. Both types are very simple to fly compared to our aircraft, and childishly easy to take-off and land. The Hurricane is good-natured and turns well, but its performance is decidedly inferior to that of the Me 109. It has strong stick forces and is "lazy" on the ailerons.
The Spitfire is one class better. It handles well, is light on the controls, faultless in the turn and has a performance approaching that of the Me 109. As a fighting aircraft, however, it is miserable. A sudden push forward on the stick will cause the motor to cut; and because the propeller has only two pitch settings (take-off and cruise), in a rapidly changing air combat situation the motor is either overspeeding or else is not being used to the full.


The RAE reported: "At 400 m.p.h. the Me.109 pilot, pushing sideways with all his strength, can only apply 1/5 aileron, thereby banking 45 deg. in about 4 secs.; on the Spitfire also, only 1/5 aileron can be applied at 400 m.p.h., and again the time to bank is 45 deg. in 4 secs. Both aeroplanes thus have their rolling manoeuvrability at high speeds seriously curtailed by aileron heaviness."

http://www.spitfireperformance.com/bank45.gif


http://i51.tinypic.com/24yxzjo.jpg

those are the same graphs ive managed to find today .

1: the 109 is superior in roll rate below approx 280mph (ias or tas not specified), comparable in the 280-310mph bracket, while the spitfire is marginally superior above 320mph

2: Unless im reading the legend wrong, kinda a rough image, the spitfire and hurricane are comparable in roll rates at IAS of 200mph and above.

experience for me thus far is the hurricane is 30-50% slower in the roll at various speeds above 200mph to the spitfire.


the subjective accounts are varied, the one you quote contradicts other accounts.(and the images posted)

While working out this Hurricane roll thing, see if there is ANY difference in initial roll rate between full ammo and no ammo. In previous IL-2 engine initial roll rate was not modeled.

Just curious ...

Well I am no expert, and I know that the original IL-2 isn't exactly a historical source, but I always found hurricanes to roll like pigs.

Of course I never flew them that much and my memory isn't great and I might well be remembering flying a IIc with the huge heavy cannon wings so take this with a grain of salt.

Be wary of info from the RAE produced during war, the British were very good at misinformation and smoke and mirrors so are generally on the conservative side of true figures when it comes to publishing spec for British stuff, so I would suggest that 45deg roll in >1.9sec or more is misinformation when there is no end of footage of 360deg rolls in ~5sec during gentle air display in 60+ year old aircraft. ;)

well then its a good thing the RAE weren't the only ones to write down their test results then isn't it?

You will find almost all performance characteristics documented for British military equipment is on the conservative side of what its true value is and that has been the ethos long before ww2, this is also true for no end of different countries military equipment.

Perhaps if you wanted more true values you would perhaps use the RAE ME109 times then find the test by the war time German equivalent of the “RAE” on captured spitfires, given there is no need for the British to occlude true performance figures of ME109 test results & the same is true of the Germans with true spitfire performance figures.

Also with respect to very heavy ailerons etc at speed (spitfire and hurricane), what may be heavy or physically limiting during testing over the relative safety of your own country soon becomes much lighter at the same speed when in combat as the adrenalin is racing threw your system, so the implication is a physically strong pilot engaged in combat will achieve better roll rates at high speed than a weaker pilot in the same situation BUT both will achieved better comparative roll rates than the “tests flights” due to the adrenalin of combat giving strength. ;)

so then wheres my "adrenalin button" in the game?

next patch, be sure. :rolleyes:

This is for a Spitfire Mark VA, with metal ailerons, tested by NACA in 1941. Not a Mark I with fabric ailerons.

I have a British mid-1940 report for the Spit I/Hurri I, basically it says the Hurricane is much better with regards to aileron control, though both are 'locked in cement' at high speed. Couldn't upload it yet..

Not true. These chart above is for SPit MK1/ Hurri MK1 with fabrics ailerons.


Here is roll rate for Spitfire with metal ailerons:

http://i53.tinypic.com/2vb6h78.jpg

kwiatek what relevance does that chart have on the game? it only shows spitVs. when there is a late 41/42 africa or channel mod with LF spitVs and 190A2s/3s then we can worry about that.

iirc the first test of metal ailerons were done on a spit2 in early 41.

To show that the previous chart he posted was *not* a Spitfire with metal ailerons.

The conversion to the Merlin 45 engine would not affect the roll rate.

not really no. i've found brit reports are fairly standard. the only airforce who is often conservative i have found is the germans but only in some cases. examples being the finnish tests of their F4s and G2s were all quite a bit higher than the german tests (above standard deviation).
which are all similar to the british tests. as are US tests
same goes for all planes then, right?

The roll chart you posted - from http://mitglied.multimania.de/luftwa...f/rollrate.pdf - above is for the Mark VA W3119 tested by NACA and the report says metal covered ailerons.

See page 2 and 13: http://mitglied.multimania.de/luftwa...pit_flying.pdf

not that is particularly relevant, but Jeffrey Quill first tested a spit in Nov 1940 with metal ailerons and then flew it to Tangmere, where it was also flown by the commander of 602 squadron Sandy Johnstone.

afterwards a crash program was initiated to fit all front line spits with these ailerons.

Metal ailerons were started to be fitted in around April 1941 to Mark Vs.

i'm curious as to what your basing that on, cause it doesn't tally with what i'm reading in front of me.

Spitfire the History, page 142, Chapter "A temporary expedient" (ie. Mark V)

Letter dated 18 June 1940 (my bad, not april) from Sholto-Dougles, C-in-C of FC is quoted, saying that despite decision taken in November 1940, Spitfires are still delivered with fabric covered ailerons and its only now that production line started to use metal ailerons. Large number of Spitfires need retrofit, but Supermarine is only able to retrofit at 10 sets of ailerons per week.

Great book btw, suggest order from publisher, dirt cheap. Mordin out. ;)

interesting, i was reading 'The Spitfire Story' by Alfred Price page 78, also very good reading.

guess it took them a while to 'initiate'

thanks for the book suggestion, will check it out.

EDIT

wow, if this is the book, might have to shop around, £75 pounds is a bit steep!

http://www.amazon.co.uk/Spitfire-His.../dp/0946219486

Sry but i dont see any conection with these both raports.

First raport is about Spitifire, Hurrciane, P36 and P40 - with not detail about types and no detail about type of airleons - if it was fabric or metal ones.

Second raport is clearly about Spitfire MVA with metal ailerons - but as i said i dont see conection between both raports.

Very poor roll rates of Spitfire from first raport suggest that it was with fabric covered ailerons. These confirm second roll rate chart which i posted with Spitfire MK V with metal airleons where roll rate is clearly improved over fabric covered ( from first test).

I got also another roll rate chart where roll rate of Spitfire MK V with metal airleons is about 100 deg/sec.

The two charts assume different stick forces, so it's hardly surprising that they look different. Agreement between the Spitfire Va(?) in the first chart and the full-wing Spitfire Vb in the second chart is pretty good at about 150 mph where both have their ailerons pegged on the stop.

It is also worth pointing out that there is quite a big difference between test roll rate and the roll rates achieved in service because of the nature of test procedure.

In this period, stick forces were generally measured by sending the test pilot into the air with a calibrated spring (often requisitioned from the nearest butcher's shop).

In order to get sensible results, tests need to be conducted under controlled conditions. It is no good just saying "roll as fast as you can", because that will tell you more about the pilot than the aeroplane.

So tests were conducted to a procedure, and the details of that procedure could dramatically affect the results (e.g., you can almost always roll a lot faster with help from the rudder than without it).

Likewise, force measurements needed to be performed with some care. Obviously you can only conduct measurements within the useful range of your equipment. If the scale only reads to 50 lbf then you can't measure 50 lbf properly, because once you hit 50 lbf on the scale, the actual meaning is >=50 lbf.

Of course, these aeroplanes weren't designed for the convenience of test pilots, so finding enough elbow room for constant force roll tests probably wasn't trivial.

All of these factors tend to reduce the measured roll rates somewhat; as such, "conservative" figures need not be the product of any kind of misinformation or conspiracy, and in fact might well emerge even against the wishes of the test organisation.

Comparisons with modern aeroplanes at airshows doesn't really stack up. Most "WWII" aeroplanes you can see flying today are not maintained in original condition (it's unrealistic to expect operators not to embody the latest airframe and engine modifications to reduce their costs and improve safety), and they often don't have guns and ammunition in their wings when performing at airshows ;) . To get a real sense of this, compare and contrast the BBMF's oldest Spitfire with the Battle of Britain vintage Spitfire in the Imperial War Museum in London which AFAIK has be de-modded to genuine 1940 standard...

Oh dear, I must have read the first chart in too much of a hurry, I was under the impression they were both at 50lbs. My apologies Kurfürst, madrebel. Thanks for the detailed explanation though Viper! :) The second chart will actually be very very useful to us if these later aircraft are added as a maximum steady roll rate chart since we know that the maximum figure in the force-displacement stick model in CoD is 50lbs, it's mentioned in the manual:

Mind, the 30lbs one is just as useful for testing assuming we set the roll axis as linear and apply 3/5ths pressure using an external program or something similar (eg. set the 100% deadzone in stick settings to cover the last 2/5ths of stick travel).

Hmm, both reports are made by NACA, both reports are authored by William H. Philips. The first (Spitfire MkV metal ailerons) report dates January 1942. On page 13 it says that at 6000 ft altitude, 30 lbs stickforce, 59 degrees/sec was obtained.

The second (P-40 Hurri, Spit P-36) dates November 1942. Again made by NACA, both authored by the same William H. Philips.The roll chart of P-36, Hurricane, P-40, Spitfire shows ca. 65 deg/sec at 10000 ft altitude (as opposed to 6000 ft in the first report), 30 lbs stickforce. The report also references to NACA 868, the well known lateral control characteristics summary report, which notes that roll rate increases with altitude, and gives the neccessary conversion methods.

Quite simply the second report uses the figures obtained on the Spitfire Mark V with metal ailerons, tested by NACA earlier, and converted it to 10 000 feet.



First raport is about Spitifire, Hurrciane, P36 and P40 - with not detail about types and no detail about type of airleons - if it was fabric or metal ones.

Second raport is clearly about Spitfire MVA with metal ailerons - but as i said i dont see conection between both raports.

Its an assumption, but no, both reports show the same Spitfire with metal ailerons. In fact both reports show the same roll rates obtained.

Indeed the roll chart you posted for another Spitfire Mark V tested in the UK shows far higher roll rate than any other test result or source, UK or US. Its a pity we do not know anything about this Spitfire, but it seems this aircraft was either extraordinary good in this regard, or it had some non-standard aileron setup. We can only guess.

50 lbs = 22Kg is the maximun force a human can do in a "lateral" movement of the arms in the stick right? Since you are talking about ailerons deflection i guess its ok.

For pull or push (back and forward) is not quite a pull. Certainly i can grab 50kg with both hands for some seconds. (50 kg is a cement sack). Are you capable to grab a cement sack? The possible force to be applied in the elevatot i guess is much higher.

But certainly is very unpleasant to grab 22 kg to sides or 50 kg back and forward in a combat. Much of the pilot concentration must go to trying deflect the controls while tracking the enemy. Gunnery in this conditions is near impossible. This is a sensation we ll never experience in a sim.

Read the chart. The pilot used 50 lbf rather than 30 lbf. It is therefore hardly surprising that a higher roll rate was achieved because constant helix angle could be maintained to a higher TAS. Agreement between the charts is actually extremely good if you take this into account.

I already pointed this out in my last post, had you but taken the time to read it...

BTW:

• Roll rate is just a function of helix angle and TAS.
• Helix angle is a function of wing design and control deflection.
• Stick force to a first order approximation is proportional to Q.
• Deflection limited roll rate is therefore just proportional to TAS
• Force limited roll rate is inversely proportional to Q
• Roll rate achievable at altitude will vary in proportion to (TAS/EAS)

However, altitude itself doesn't "cause" this; the aeroplane knows nothing about its position relative to the geoid or to MSL. The relationship is simply caused by air density variation, and therefore it's quite possible for roll rate to be affected by the weather.

On a related note, the reduced helix angle associated with any given absolute roll rate as TAS increases is responsible for the reduction in roll damping at high altitude; again, the underlying mechanism is the TAS/EAS relationship, which means that roll damping is also a function of the weather conditions.

NB, the simplistic relationships explained above deliberately ignore the effects of compressibility upon stability & control. In particular, shockwave formation can dramatically reduce the effectiveness of control deflections by reducing the ability of control deflections to influence the flowfield upstream of the shock; stick forces are not reduced in proportion to the reduction in control effectiveness, and therefore pilot reports tend to read as though the controls have suddenly become heavier, when in fact they've just become less effective. But I digress...

Viper2000

Its worth remembering the >30lb < 50lb used are designed to replicate the strength of the average right arm trying to pull the stick to the right in a right hand roll, in a left hand roll with the same right arm you can literally double the force applied to the stick in a left hand roll so in the region of 60lb to 100lb or if you use both hands you are realistically looking at up to 150lb both ways and that’s without the affect of adrenalin wile being shot at and Its certainly not undocumented pilots pulling high speed direction and orientation changes etc using both hands. ;)

I'm just saying that the 2 charts are in agreement with each other when the different stick forces upon which they are based is taken into account.

I'm not suggesting that either figure is representative of the limit of pilot capability. Indeed, as I have already stated in this thread, you can't measure the limits of capability, and you certainly couldn't do so in a repeatable fashion across a variety of types because you'd see different forces for each as a function of cockpit design etc..

I don't quite see why are you addressing this to me, as I was commenting on the origin of your 'Spitfire' - which we now know to be a Spit VA with metal ailerons, not a canvas covered one. ;) You're storming a castle with open gates..

Because I don't think that the fast rolling Spitfire is actually any faster than the other; I think they're basically the same and differ only in the stick forces applied. Therefore I don't think that there's anything particularly "exceptional" about the results.

If you look at the curves in the deflection limited region, you'll see that the roll rates are basically the same, so the difference is simply caused by the different stick forces applied in the tests. :)

Regardless of this 50 lbs is the maximum we can pull in CoD in every direction, I'm afraid.

how come nobody is complaining about the unbalanced pitch control of the spitfire? you know, the control being so light that it is possible to exceed CLmax in all conditions of flight if you aren't careful.

instead we're worrying about how much force a pilot hopped up on adrenaline can apply to the heavy aileron but not mentioning how easily that pilot could rip his own wings off if not careful.

As far as I know that's right...the Spitfire is very well known for having a ludicrously light elevator especially by comparison with its heavy ailerons.

indeed and unfortunately its something no sim i have ever played properly models. its like they use one curve for all control inputs. i'm hoping for more from CoD.

British Hurricane and Spitfire report from October 1940, describing high speed behaviour of the controls.

http://rapidshare.com/files/45631956...tober_1940.rar

* ducks for cover *

Leg iiiiit!

link dead for me.