stick forces-please make them optional

[DB 605]

Rudder usage is extremely important to roll performance. Try it with coordinated rudder usage.

 

Of course, i know. But that time tested IRL was without using rudder, hence i did same thing.

 

Here's quote from the article:" Roll performance is similar to a Hurricane or elliptical wing tipped Spitfire. A full stick roll through 360 degrees at 460kph takes 4 to 4.5 seconds without using rudder, and needs a force of around 20 lbf. One interesting characteristic is that rolls at lower speeds entered at less than 1g, such as a roll-off-the-top or half Cuban, have a markedly lower roll rate to the right than to the left. Therefore, I always roll left in such manoeuvres."

 

Another interesting quotes: "The Bf109G is heavy to manoeuvre in pitch, being similar to a Mustang."

"The roll rate is very good and very positive below about 250 mph. Above 250 mph however the roll starts to heavy up and up to 300 or so is very similar to a P-51. After that it's all getting pretty solid and you need two hands on the stick for any meaningfull roll rates. Pitch is also delighful at 250 mph and below. It feels very positve and the amount of effort on the control column needed to produce the relevant nose movement seems exactly right to me. The aircraft is perfectly happy carrying out low-level looping maneuvers from 300 mph and below. Above 300 mph one peculiarity is a slight nose down trim change as you accelerate. The rudder is effective and if medium feel up to 300. It becomes heavier above this speed but regardless the lack of rudder trim is not a problem for the type of operations we carry out with the aeroplane."

- Mark Hanna of the Old Flying Machine Company flying the OFMC Messerschmitt Bf 109 G (Spanish version).

 

As control forces are currently modelled to pitch for 109 only, it may mean some surprises to Mustang pilots in future too...

Edited March 1, 2015 by DB 605

[SlipBall]

Of course, i know. But that time tested IRL was without using rudder, hence i did same thing.

 

Here's quote from the article:" Roll performance is similar to a Hurricane or elliptical wing tipped Spitfire. A full stick roll through 360 degrees at 460kph takes 4 to 4.5 seconds without using rudder, and needs a force of around 20 lbf. One interesting characteristic is that rolls at lower speeds entered at less than 1g, such as a roll-off-the-top or half Cuban, have a markedly lower roll rate to the right than to the left. Therefore, I always roll left in such manoeuvres."

 

 

thats interesting because I remember timing the roll in CLod, and those were the same results

[Crumpp]

Roll performance is similar to a Hurricane or elliptical wing tipped Spitfire. A full stick roll through 360 degrees at 460kph takes 4 to 4.5 seconds without using rudder, and needs a force of around 20 lbf. One interesting characteristic is that rolls at lower speeds entered at less than 1g, such as a roll-off-the-top or half Cuban, have a markedly lower roll rate to the right than to the left. Therefore, I always roll left in such manoeuvres."

 

 

His anecdote does match pretty closely measured performance of the Bf-109E series.

 

As for the "without rudder"....

 

That statement is puzzling because that would make the test invalid for comparison with measured roll rates. It would be meaningless data and it is impossible that it would be better than measure coordinated roll rate.

 

Are you sure "without rudder" does not mean without excess rudder....in other-words a correctly done coordinated roll.

 

I have seen others on different forums confuse the term "rudder fixed" thinking it meant "without rudder" when it in fact means coordinated rudder usage.

[Crumpp]

Dave Southwood was an experienced and trained test pilot. It seems highly unlikely he would make that mistake.

 

It seems far more likely his statement is misinterpreted by us.

[Yo-Yo]

For 109 roll adjustment German reports with exact measurements were used. And I must say that these reports are the most detailed report that have time recordings of bank angle and roll rate with certain stick forces and deflections.

[DB 605]

Dave Southwood was an experienced and trained test pilot. It seems highly unlikely he would make that mistake.

 

It seems far more likely his statement is misinterpreted by us.

 

This is of course possible.

[DB 605]

For 109 roll adjustment German reports with exact measurements were used. And I must say that these reports are the most detailed report that have time recordings of bank angle and roll rate with certain stick forces and deflections.

 

Okay, maybe i just need to get used to it then :)

 

Pitch control forces are not modelled yet to fw 190 and p-51, right?

[Crumpp]

For 109 roll adjustment German reports with exact measurements were used. And I must say that these reports are the most detailed report that have time recordings of bank angle and roll rate with certain stick forces and deflections.

 

Thanks for the feed back Yo-Yo!

 

:thumbup:

[Friedrich-4B]

This is of course possible.

 

It is also very possible that Dave Southwood was quoted correctly and that he did perform fixed-rudder rolls, as set down in NACA's testing procedures described in a 1943 document 3G24, and in the 1947 Report #868:

 

1943 page 7:

 

 

#868 pages 14 & 15

 

 

Its always possible for someone to ask Dave Southwood himself exactly what he meant: https://uk.linkedin.com/pub/dave-southwood/93/a11/385

[Crumpp]

fixed-rudder rolls

 

Guess what holding the rudder in its trim position means???

 

Think of where the ball is at if the rudder is in trim.

 

A fixed rudder roll is a coordinated rudder!! :music_whistling:

Edited March 2, 2015 by Crumpp

[Crumpp]

It is also very possible that Dave Southwood was quoted correctly and that he did perform fixed-rudder rolls,

 

Dave Southwood was correct. Just do not misunderstand it.

[Crumpp]

Friedrich-4/B

 

Your confusion stems from not understanding the term "fixed". It does not mean it is not allowed to move.

 

It means the control surface is not floating as it would be rudder or stick free.

 

Rudder or stick fixed means the pilot is holding the control surface in the position he desires and the control surface is not allowed to float.

 

Here is a test of the P-51D-5 comparing the rudder fixed and rudder free stability with a horn balance vs tall tail design.

 

http://www.dtic.mil/dtic/tr/fulltext/u2/a801234.pdf

[9.JG27 DavidRed]

i have to say, personally, i like the fact now that the 109 cant roll anymore that fast as before and pull that tight at any speed as before...

it makes online flying against the mustang interesting again!

 

BUT:

i still feel there would a better way to implement this....

before the patch, we had a 1:1 stick:virtual stick deflection.

(and yet the aircraft pulled and rolled different fast at different speeds as well) this was way more intuitive for people without ffb sticks i think.

 

with the current implementation, you have no feedback at all anymore, except when looking at your cockpit frame.this now leads to even more wings breaking than before.

[fastfreddie]

i have to say, personally, i like the fact now that the 109 cant roll anymore that fast as before and pull that tight at any speed as before...

it makes online flying against the mustang interesting again!

 

BUT:

i still feel there would a better way to implement this....

before the patch, we had a 1:1 stick:virtual stick deflection.

(and yet the aircraft pulled and rolled different fast at different speeds as well) this was way more intuitive for people without ffb sticks i think.

 

with the current implementation, you have no feedback at all anymore, except when looking at your cockpit frame.this now leads to even more wings breaking than before.

 

I was flying the Mustang yesterday with a K-4 and Dora on my tail ... it wasn't very hard to evade their attacks with the simple hard up and left turn. Dora could never make that maneuver to begin with and it appeared the K-4 couldn't do it either as it tried but couldn't pull anywhere close enough to follow. Hopefully they address the wing breaking bug soon enough because it seems worse than before.

[9.JG27 DavidRed]

well, i dont think they made the wings breaking earlier with this patch...its the result of the stick forces implementation. we are dealing with curves now on our sticks.curves that change with speeds.without a FFB stick, you are totally lost now, except when you look at your cockpit frame to get some information.otherwise you have no idea anymore how hard you pull....

[IvanK]

Dave Southwood describes BF109G2 handling. 109 stuff starts at 4:00

These are a great series of lectures:

 

 

https://www.youtube.com/watch?v=qLrpcamspLw

[Anatoli-Kagari9]

Regarding roll tests...

 

Fixed rudder IS fixed rudder.

 

Entry to the test is made with the aircraft flying S & L or in descent in some circumstances, BUT, the rudder is in it's trimmed position ( the aircraft flying coordinated before entry ), and then is held there during the rolls. I do not think rudder is used whatsoever to coordinate, if not for other reasons because, if it would, it would then require some bicycle work... The rudder input ( to stay perfectly coordinated ) during a roll is not fixed, but alternates from left to right or right to left during the roll ...

[Friedrich-4B]

Your confusion stems from not understanding the term "fixed". It does not mean it is not allowed to move.

 

Seriously? This is just arguing for the sake of arguing; In one sentence Crumpp tells me I don't understand the word fixed yet, two sentences later:

 

Rudder or stick fixed means the pilot is holding the control surface in the position he desires and the control surface is not allowed to float.

 

How many other ways is it possible to define fixed for control surfaces in flight? Otherwise, the only way of ensuring the rudder stays truly fixed is to use a control lock - eg; the Boeing Model 299 (prototype for what became the B-17) crashed in late 1935 because the gust locks on the control surfaces hadn't been disengaged.

 

From Stability and Control: Flight testing

 

Page 6.25 (a) Rudder-Fixed Rolls

1. Pilot trims all control forces to zero in straight, laterally level flight at a predetermined indicated airspeed (record switch on).

 

2. Pilot very abruptly moves the aileron control to a predetermined deflection set by a control stop while holding the rudder fixed in its trim position...

 

NB: This is the reference used; none other than the 1943 NACA report posted earlier:

 

 

Page 6.27 (e) Rudder-Free Rolls

The procedure for rudder-free rolls is identical to that of rudder-fixed rolls except that the pilot removes his feet from the rudder pedals before trimming the airplane and does not touch the pedals until the recovery part of the maneuver.

Edited March 2, 2015 by Friedrich-4/B
Boeing 299

[Anatoli-Kagari9]

[ discard ]

Edited March 2, 2015 by jcomm

[Anatoli-Kagari9]

I hope the upcoming Spitfire uses this filter the best way to reproduce what RW tests described, like:

 

"The elevator is very light, while the rudder is stiff and the ailerons even more so. Every Spitfire I have flown take more muscle to roll than most other fighters. As speed increases, both rudder and ailerons get heavier, creating a curious mismatch at high speeds... on has to handle the almost oversensitive elevators with a light fingertip touch while arm-wrestling the stiff ailerons."

[VO101_MMaister]

You guys who think that we should have 1:1 stick motion regardless the control forces what do you think about the black out effect in simulators?

I am asking becouse it is exactly the same thing. Putting the limitations of the human body into the simulation.

Aircraft designers make aircrafts for human beeings -considering all the ergonomical factors of the human body- and not for supermen able to pull 200kg constant. In a real bf109 you cannot pull more than 2-3inches on the column when you are flying 4-500km/h, becouse you are not supposed to. It was the designers intention. He could have installed a linkage with bigger ratio between the column and the elevator so the pilot could use full deflection at the highest speeds but it would have been chatastrophic. This is what simulation creators try to give us back.

 

Let`s go back to the black out. You accept that you cannot pull more than 9G in a sim becouse you get black out. You understand that it is becouse the limitation of the average Joe`s body and it has been modelled in the simulators since 1990. You don`t claim that it should be not there. Even if it is optional probably you never switch it off.

 

Well we finally came to the point where other human factors can be implemented in the simulators. I think it is a good thing. Until we all have realisticly loaded FFB controls and super 3D motion cockpits which can black us out we need to live with to find other solutions. Is it a compromise? yes of course, but not a bad one i think.

[Kurfürst]

I also did few 360 degree rolls at 400km/h and 450km/ at around 500m height, it now takes 5-6 secs without rudder while time in reality should be closer to 4,5 sec according to Dave Soutwood test flying with Black 6 (Bf 109G-2/trop).

 

TAS or IAS? I think D.S. meant IAS.

 

Peak roll rate should be at in the speed range of 500-620 km/h TAS, a little above 80 deg/sec - or roughly 450 km /h IAS. Perhaps very, very slightly greater because this is for the roll of the 109F, and if not else the G/K wings were stiffer and there should be less loss due to wing elasticity.

 

Also try 3000 m meter altitude for testing, because this is where the figures are for (as are the NACA 868 aggregate of various roll tests). Rolling rate slowly decreases with altitude and vica versa. At 10 000 meter the difference is quite noticeable.

[Crumpp]

Pilot....while holding the rudder fixed in its trim position...

Key phrase.....

 

:thumbup:

 

The aileron is fixed by the stops. The rudder has no stop except where the pilot puts it to maintain coordinated roll. You do not bicycle either. If you have to do that, you have over controlled the entry.

 

Lead the bank with enough rudder to eliminate the nose moments on the longitudinal axis as you apply aileron.

Edited March 2, 2015 by Crumpp

[Anatoli-Kagari9]

Crumpp,

 

my experience comes only from gliders. In gliders no roll ( coordinated ) is possible without using opposite rudder as you reach around 90º bank.

 

On a WW2 fighter with the roll rates that the Fw190 or even the 109 can achieve everything happens at a much higher rate... I don't think that where in the text is written ( "holding the rudder fixed in it's trim position" ) means anything else than, exactly, keeping it fixed!

 

Will the aircraft loose alt that way ? It will most probably!

Will adverse yaw cause the nose to wobble ? It certainly will, a bit, but...

 

fixed means F-I-X-E-D... I guess ?

[Crumpp]

fixed means F-I-X-E-D... I guess ?

 

Fixed means fixed by the pilots foot as he puts in the amount of rudder required to keep it trimmed.