Me 109 compared to Soviet fighters' manoueverability

[spiculum]

The Me 109G had similar dimensions, weight and wing loading as the Lavochkin and Yak fighters but why was its turning and rolling ability so much worse than theirs?
There are mostly accounts on the Messerschmitt's inferiority in terms of manoeuverability.
In general the Me 109 was not known as a turn fighter. Was its design so bad?

[Alfred.MONZAT]

It reductive and incorrect to state that the turn radius depends exclusively to wing loading. Lots of practical tests prove otherwise.

I remember reading in reports that the La-5 was a little worst or equal to the Bf 109 G in turn radius but was a little superior in rolling.
The lightweighted Yaks were superior in turn radius IIRC.

The Bf 109 was not specialy good in turn but was not specialy bad (it's still worst than most British, Russian and Japanese designs but better than most US designs). Anyway, as WWII proved (particulary the Germans and the Americans), with right tactics you don't need good turning capabilities, speed is more important (even climb capabilities or dive capabilities seems to be more valuable).

[spiculum]

I asked the same question at another forum where someone responded "The wing design (of soviet fighters) allowed them to hang in turns under full control when the root was stalled or partially stalled.
They also had the wing designed to keep the ailerons effective through stall."
I asked what aerodynamical feature the triangular wing geometry of Yaks and Lavochkins gave them this advantage and why other nations haven't adopted it.
But he could not give an answer.
Maybe someone here knows?

[Graham Boak]

Seems a description of the action of a slat (109) or washout (Spitfire) rather than anything unique. Getting good behaviour at the stall had become more important by then: highlighted by the tip stall behaviour of the DH airliners. If the root stalls before the tip, then the ailerons will remain effective.

I suspect good ailerons combined with light weight and shorter spans were the key features, with the absence of heavy weights (guns, ammo) in the wing helping. This was specifically stated by Yakovlev as something to be avoided. Illustrations of this can be seen in the sluggish behaviour of the Bf109 with underwing "gondolas", and the common removal of one pair of cannon from Hurricanes, and the Spitfire Mk.Vc.

[spiculum]

Like the Me 109 the Lavochkins had slats. So advantage has to be in the wing geometry of the latter some somehow. The mentioned poster also wrote this: "They made very good use of washout and had more wing mass closer to the fuselage."
You inferred that, too.
At Focke Wulf they also wanted to have the armament near the center of gravity for the same reason.
But I wonder if the german and allied designers knew about these factors. Why would they not implement triangular wings in their late fighter designs such as the Me 309 MB-5?
Was the washout of german fighter wings worse?
The germans tend to have small wings with a bit of a high aspect ratio. The rest of the allied fighter designs tend to have rather broad wings.
Benefits and detriments of the particular designs?

[Juha]

If one look some results of Soviet turning time tests from here: http://juhansotahistoriasivut.weebly...mes-tests.html
it seems that the Soviet planes were good but not necessarily exceptional. Spitfire F. and LF. IX, Airacobras and P-40C also turned well. And as I said, those are results of Soviet tests made at 1000 m, which favoured Soviet planes because they were optimized for lower altitude combats. In the west air fighting usually happened at higher altitudes, so airframes and engines were usually optimized for combat there.

[Alfred.MONZAT]

Thanks for these valuable data Juha !

[spiculum]

Cool. According to the results the Me 109F did not fare that badly. But I also wonder about the mediocre roll rate of the Messerschmitts compared to others. It is quite a small fighter, in size about like the Soviet planes. Yet it is outrolled by the Spitfires which featured a much larger wing with armament installed.
Such a configuration is detrimental to roll rate.
I reckon that since the 109 wing was of one-spar-construction with large cut-outs for the underwing radiatosr and for the outwards retracting landing gear the torsional stiffness of the wing was more compromised than with most other fighters resulting in bad overall manoeuverability at high speeds. This coupled with the relatively small ailerons resulted in a bad roll rate.
The Messerschmitt engineers seemed not particular interested in agility producing features as can be seen in other designs such as the 210/410 and 309.

[Alfred.MONZAT]

Originally Posted by spiculum

But I also wonder about the mediocre roll rate of the Messerschmitts compared to others.

I wonder what's your source for the Bf 109 having a mediocre rate of roll, as from what I've read it is good. Inferior to the roll rate of the La-5 but the La-5 is itself only outclassed by the incredible rate of roll of the Fw 190.

[spiculum]

The 109 was not the most manoeuverable of planes. It is commonly known I'd say that it suffered from excessive control stiffening at high speeds, more so than other fighters.
The stiffening was such that it could hardly change direction any more when going fast thus limiting its function as a fighter in those realms.
The Spitfire despite its wing was always a good roller with the clipped wing versions even more so.
Online you can find many depictions of this chart posted.