Axis Inertia ... maybe?

[69th_chuter]

Will something replicating this be included?   Of the three man axis inertias roll inertia is the most important.

 

One example:  The 109 was originally designed for a lower, late 1930's kind of speed range and had wing guns.  As the 109 gained more powerful engines the resulting increase in speed had a detrimental effect on control response, notably aileron and elevator.  With the F's development Willi was able to put an emphasis on re-establishing an acceptable initial roll rate* and, among other things, eliminated the wing guns (lateral polar mass) toward this end (and the 109 was never again to have internal wing guns until the projected K-6).  109 F and G's did have gunpods available to them which brought the firepower back up to and superceding the E's but at a loss of performance.  Looking at speed charts and test reports, though, one can come away with the idea that this performance loss was largely just a bit of speed and some weight that hurt turns, although the biggest impact was in, you guessed it, initial roll.  IL2 never even tried to model initial roll rate.  All aircraft ahieved their maximum roll rate in exactly the same period of time, something like 1/4 of a second, even multi-engine planes like the P-38 which had more built in resistance to initial roll because of the mass of the engines being off the centerline.

 

PS.  Roll inertia works both ways in starting and stopping rolls ... 

 

*this would be the time it takes to reach the maximum sustained roll rate OR how many degrees rolled from initiation in a given period of time.

 

 

   Looking Forward

[AndyJWest]

Will something replicating this be included?

 

I doubt very much that a serious flight simulator game produced in the last 10 years has failed to simulate polar inertia - so why should BoS be any different?

[69th_chuter]

lol - do some tests. 

 

First, just go from one plane to the next, say the zeke and then the P-38, and just try to detect any difference between roll accelleration.  Next, take something like a P-47 or P-51 and compare no load roll accel versus roll accel with the biggest bombs you can put on it?  Any difference?  I don't know of ANY flight sim EVER that modeled any variation in initial roll rates.

 

- I was referring specifically to IL2 1946 but you can try any sim you want to.

Edited April 14, 2013 by chuter

[AndyJWest]

" Try to detect any difference between roll accelleration". Um no - I'd rather see hard data, thanks - I've seen enough unverifiable claims regarding FMs to know better than to get into subjective arguments when hard data is obtainable. In the case of IL-2 '46 we have DeviceLink, which would be quite capable of producing the evidence. Has anyone done this?

[AX2]

 

Will something replicating this be included?   Of the three man axis inertias roll inertia is the most important.

 

One example:  The 109 was originally designed for a lower, late 1930's kind of speed range and had wing guns.  As the 109 gained more powerful engines the resulting increase in speed had a detrimental effect on control response, notably aileron and elevator.  

 

 

   Looking Forward

 

When a lie is Repeated many times .. ends being true ?

Sorry for offtopic

 

 

 

 

 

Messeserschmitt AG Ausgsburg, Bureau Flight tests

 

High Speed Test With me 109

Report Nr. 109 05 E43

 

14 Dives was performed

 

Cause:

 

1) Explanation of accidents in the front-line units (Over-compensation of the aleron contros and insufficient elevator autority at high mach numbers)

 

2) The proof of aircraft stability at high mach numbers with aircraft W. Nr. 9228. This aircraft is used by the DVL for high speed pressure distribution test on the wings.

 

 

Execution of the test:

 

The plane ME 109 W Nr. 9228 was used for these test. an ejection seat is build in as additional equipament. to get an exact documentation about the achieved figures, the instruments were photographed and speed& altitude were recorded by an Askania-device.

To reduce the risk of pilot over-compensation, the control movementet was limited to 50% of the reference movement of the ailerons.

 

Condition of the aircraft:

 

For the fist test flights the plane was in the standard condition of a 109F with G-Wings, except for the movement limitation of the ailerons end the ejection seat.

 

For tests above a certain speed (refert to results) stabilizer was changed to a larger one (This enlarged  vertical stabilizer will be incorporated in the BF 109 G production series )

 

The elevator trim tab is enlarged in surface area by 100% compared to standards version, The horizontal stabilizer trim is limited in its upwards range of motion to +1?

Edited April 14, 2013 by Mustang

[69th_chuter]

When a lie is Repeated many times .. ends being true ?

Sorry for offtopic

 

 

 

 

 

For 109F with new wings of 109 G series, and the  development  109 G series

 

A) Low elevator response at high mach ( 906 km/h was reached, an the pilot can pull up the plane,  Bf 109 manage a dive of 906 kms / H )

***Not recomendations needed or changes in the eleveator surface were made for the Luftwaffe.

 

B) Ailerons.movementet was limited to 50%  for Over-compensation,

***not for detrimental effect on control response notably aileron.....

 

C) For increment longitudinal axis stability

***Enlarged tail as planned for 109 G series.

 

D) In dive the BF 109 had tendency to pull up the  nose,  The pilot sometimes found it difficult to keep the nose down in dive... maybe like to all planes ?

 

 

Later, in that same report: 

 

"At dives with the above mentioned figures an oscillation around the longitudinal axis appeared after the enlarged tail was installed.  These movements are probably the result of overcompensation of the ailerons at high mach numbers.  It was not possible for the pilot to reduce this movement around the longitudinal axis with the ailerons because the stick was moving from one extreme position to the other.  The rudder was also generally ineffective and only in the central position did small rudder forces exist.  The over-sensitivity and resulting overcompensation of the ailerons decreased when speeds were reduced."  

 

Document translated by Peter Pissulla.  I think, maybe, the use of the word "compensation" is vague or misleading ...?

 

Anyway, the reason the ailerons were reduced in travel was not because the pilot didn't need so much aileron authority, but because the ailerons were snatching back and forth on their own.  In the end, though, near Mach dive characteristics and limits testing really doesn't have anything to do with roll control within the established flight envelope.  As a reference try reading page 160 of America's Hundred Thousand.  About the P-38 it is stated, among other things, that "Many combat losses, particularly in North Africa, were attributed to this creaky (quoted, not my word - lol) initial rate of roll."   (In IL2 the 109 would have disintegrated long before the dive test speed was reached.)

 

For those still wondering what I'm talking about, exactly, try standing, arms outstretched, and twist back and forth quickly as far as you can then try it while holding a pair of five pound weights (or similar). 

 

I'm not expecting this to make it into the game, quite frankly.  It would have to be calculated (the formulas are out there on the web) and could only be verified by comparative FM testing, so it would always be an open wound for someone.  And IL2 never even got the basic stall right, anyway. 

Edited April 15, 2013 by chuter

[69th_chuter]

" Try to detect any difference between roll accelleration". Um no - I'd rather see hard data, thanks - I've seen enough unverifiable claims regarding FMs to know better than to get into subjective arguments when hard data is obtainable. In the case of IL-2 '46 we have DeviceLink, which would be quite capable of producing the evidence. Has anyone done this?

 

 

Ahh, DeviceLink.  An invaluable tool and would be perfect for this.  The differences I'm talking about, though, should be like between walking and sprinting, nothing one would need a 1/1000th discerning stopwatch for.  Long ago I got to operate, for a short time, a 1959 Cessna 310C.  It had big tip tanks (the tuna style ones - lol) and if ever there was an example of ... well ... I'm dreaming, of course - lol.  Have a nice day everyone. 

 

Edited April 15, 2013 by chuter

[AndyJWest]

So no actual evidence for your claim? Fair enough...

[=IRFC=Jorri]

Try the Nieuport 11 in Rise of Flight with and without rockets, see what difference it makes?