On Soviet turning time tests. Comments Please (1 Viewer)

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"A disadvantage to some degree?" Sorry but if you need two hands to fly an aircraft, you're loosing the ability to effectively bank and thus complete coordinated turns. This was a problem in the MiG-15 and 21and is a MAJOR disadvantage.

You didn't need to hands to fly it, come on, don't twist what I say now. You can also easily bank at high stick pressures by using two hands, but it's gonna take more effort than usual compared to an a/c with light stick forces. The a/c with lighter aileron forces will be able to enter different turns quicker and therfore shake off the attacker easier. Hence why the Fw-190 was such a deadly a/c, it was bloody hard shaking one off your six.
 
You didn't need to hands to fly it, come on, don't twist what I say now. You can also easily bank at high stick pressures by using two hands, but it's gonna take more effort than usual compared to an a/c with light stick forces. The a/c with lighter aileron forces will be able to enter different turns quicker and therfore shake off the attacker easier. Hence why the Fw-190 was such a deadly a/c, it was bloody hard shaking one off your six.
And for the reasons you just stated you've made my point. You know as well as I you are not going to make accurate or precise maneuvers if you have to use two hands on the stick. It's like flying with a "death grip" on the stick or the yoke, even with trim you're going to be all over the place.
 
I agree, accurate and precise manuevers are not to be made, but then again we're not talking formation flying here either ;)

The std. evasive maneuver in the Bf-109 was also pretty simple: A hard climbing turn.

The roll into the banking position is where the 109 is slow, and thus it was about pulling back hard whilst adding as much aileron forces as possible, executing a form of half barrel roll.
 
The std. evasive maneuver in the Bf-109 was also pretty simple: A hard climbing turn.

The roll into the banking position is where the 109 is slow, and thus it was about pulling back hard whilst adding as much aileron forces as possible, executing a form of half barrel roll.
And with the 145 pound soaking wet 19 or 20 year old pilot Luftwaffe pilot in 1944 with maybe 150 hours flight time attempting that. In our discussions we're comparing these aircraft by seconds in the bank or turn. Do you really think this characteristic of the 109 will only be a slight inconvenience?
 
Well if we're comparing the a/c then why are you mentioning pilots ? Shall we compare them fairly or not ?

As for the roll rate;

If the timer was started at level flight, meaning the roll in was necessary, then this would have a bad effect on the 109's time because of the poor roll rate at speed. The Bf-109 first shined once it was in banking position and the stick was pulled back. Hence why the std. evasive maneuver was a sharp pull up into a climbing turn.
 
Well if we're comparing the a/c then why are you mentioning pilots ? Shall we compare them fairly or not ?
Its simple Soren, the 109 had a characteristic that placed it at a disadvantage as indicated herein. The situation is amplified with a novice flying the aircraft for obvious reasons. This goes back to my first point and this is if you're "double fisting" the stick at high speeds and your opponent is not, well, enough said.
 
Here's some info that backs up the Soviet turn time tests on the Spitfire. The following clip is from R&M2381, June 1940.
Note the turn time, 18.5 seconds (at normal power). Also note Clmax of 1.75.
 

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Claidemore,

That document shows the Clmax with the engine at full power, thus it's not the real Clmax. The thrust of the engine accelerates the the air over the inner parts of the wing, making the wing produce more lift in this region than compared to freeflow. The figure was calculated from indicated stall speed at full throttle which is lower than when gliding.

At full throttle many WW2 fighters could hang in the air at surprisingly low speeds.
 
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Considering the freeflow Clmax of the 109 was 1.70 and the Spitfire's was 1.36, then I'd say around 2.00 to 2.10 at full throttle for the 109.
 
The Clmax figure of 1.7 for the Spitfire was achieved with the 960hp Merlin, not the 1050hp one in use by the time hostilities started. At that horsepower, clmax would be 1.85 for the Spitfire. RAE charts from R&M2361 show the 1200 hp 109E at 1.95 under power in a turn. So your assumed value of 2.0 for clmax of the 109F4 is probably pretty close.
Interestingly, as G forces increase, the difference between clmax of the two planes decreases, at 5G it is 1.45 for the 109 and 1.42 for the Spitfire. I believe this is because of the elliptical wing of the Spitfire. That chart shows just under 20 seconds at 3G for the 109 (complete agreement with german specs) and just under 18 for the Spitfire Mk1. Lines up with the Soviet test pretty good too.

In any case, when comparing P40E to 109F4, the difference in turn time is no more than 1 second. This is where pilot skill comes into play. In the low speed turning fight, the pilot who can keep the turn closest to the stall will win.
The real advantage of the P40 is in the breaking turn at high speed. It's superior roll rate gives it a very good chance of getting into the turn quicker than the 109.

The figures of max G computed for the two planes (7.44 and 6.43) don't have much relevance in real life. Both figures are above the blackout level.
 
Claidemore,

Considering that the 109s Clmax was higher than the Spitfire's by a factor of 0.34 at freeflow I believe it will stay at this. So if the Spitfire at full throttle reached a Clmax of 1.85 then the Bf-109 would reach one at around 2.15 to 2.20.

In terms of turn performance once in the banking position there's no doubt what'so'ever that the Bf-109 would outturn the P-40 at any speed, while being close to Spitfire which was only marginally better.

Also remember that the British Clmax figures are calculations based on the turn performance achieved in British tests, and we all know that these are highly unreliable as the pilots were vary about going beyond slat deployment. Hence why a 190 Jabo did much better in their tests.

As for the Soviet tests, they are interesting, but they aren't any form of proof. Measuring turn performance is a tricky deal, esp. if the timer is started in level flight.
 
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It seems you need to learn to speak english. Give me a break = stop acting stupid
A break for what, are you tired of trying to hide your full ignorance on mechanics of flight matters? It is not thinking about building a realistic flying model that exhausts you so much.


What do you think I mean ?

You mean TOT it's exactly on Cl max point on monday, and close tor Cl max on friday , isn't it?

VG-33
 
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Regarding the Soviet Finnish tests. It is possible and highly likely that the high stick forces had a negative influence on these, esp. if one hand was used, which I believe is almost guaranteed.

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Not at all, with a good triming you have no stick forces on a sustainted turn. You have just to mantain constant your speed, your banking angle, your AoA. The real problems will occur when you would need to change speed on altitude. Moreover soviet test are denouncing a lack of command effisciency and command respunse at high AoA on all the 3 axis. Probably because of the very small messerschmitt control aeras.
 
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Bollocks on all accounts VG-33. A word of advice for you: Learn flight mechanics yourself before you start preaching about it to others!

A max performance turn is made at or very close to the Clmax, pure and simple. You've openly denied this, clearly demonstrating your lack of knowledge on the subject.

Keep digging VG-33.
 
Here's some info that backs up the Soviet turn time tests on the Spitfire. The following clip is from R&M2381, June 1940.
Note the turn time, 18.5 seconds (at normal power). Also note Clmax of 1.75.

Claidmore - what was the Spit weight for this test? As well as published Horsepower for the +/- Horsepower ratings at 12,000 feet?
 
Claidemore,

That document shows the Clmax with the engine at full power, thus it's not the real Clmax. The thrust of the engine accelerates the the air over the inner parts of the wing, making the wing produce more lift in this region than compared to freeflow. The figure was calculated from indicated stall speed at full throttle which is lower than when gliding.

At full throttle many WW2 fighters could hang in the air at surprisingly low speeds.

The Clmax per this chart is for the Stall line - which means at all the presented horsepower settings.

Additionally

1. The propeller accelerates the air mass through the plane of the prop - but introduces mega turbulence in the stream tube via the both the rotation of the prop and tip vortices . The worst place for lift is in the area immersed in the stream tube.

2. Second point - The rotational components of velocity creates upwash on one side and downwash on the other.. how do you propose to explain thepositive difference in 'lift' in this model versus, say, the same ship with a centerline ject engine with no propeller.
 
Claidemore,

Considering that the 109s Clmax was higher than the Spitfire's by a factor of 0.34 at freeflow I believe it will stay at this. So if the Spitfire at full throttle reached a Clmax of 1.85 then the Bf-109 would reach one at around 2.15 to 2.20.

The Clmax of these tests are not wind tunnel values in a controlled atmosperic environment. They are calculated based on the velocity of the airframe at the point of stall in the turn.. and not just the wing! It is the entire wingbody system.

Soren - If you wish to prove your thesis, get the weights of the Me 109s under test, the horsepoer and velocity at stall for a specific altitude and the turn times and you will have your specific Clmax for that condition.. and BTW is will be a valid one independent of whether the 109 tested was perfect or whether the test pilot was the best - it will be close enough within a couple of percent.

The Soviet and Brit tests will be good enough to establish the range of Clmax for the 109 tested.


In terms of turn performance once in the banking position there's no doubt what'so'ever that the Bf-109 would outturn the P-40 at any speed, while being close to Spitfire which was only marginally better.

If there was no doubt, these threads would have vanished long ago.

Also remember that the British Clmax figures are calculations based on the turn performance achieved in British tests, and we all know that these are highly unreliable as the pilots were vary about going beyond slat deployment. Hence why a 190 Jabo did much better in their tests.

No more, no less, than Soviet, US tests or for that matter, German and Finn tests. The only possible true variable would have been condition of the ships actually tested - not pilots skill so much as most test pilots have a high degree of competency and the Test centers were manned by engineers - not political hacks trying to 'prove' a POV

As for the Soviet tests, they are interesting, but they aren't any form of proof. Measuring turn performance is a tricky deal, esp. if the timer is started in level flight.

They are a collection of data. So far I have seen US and Brit and VVS and Finn test results but nobody seems to be able to present the Rechlin Test resluts (and data) demonstrating the German POV..

Soren, we come full circle - how can you discount multiple different nationality tests at test centers as all being incompetent or unskilled or invalid test results without documenting the test data to support your own POV?
 
Not at all, with a good triming you have no stick forces on a sustainted turn. You have just to mantain constant your speed, your banking angle, your AoA. The real problems will occur when you would need to change speed on altitude. Moreover soviet test are denouncing a lack of command effisciency and command respunse at high AoA on all the 3 axis. Probably because of the very small messerschmitt control aeras.

Every aircraft have different control and trim requirements.

The 109 was reputed to be very heavy on rudder and aileron control forces at high speeds but a delight to fly at low and medium speeds. The sizing of control surfaces is primarily focused on low speed control requirements - not high speed.

The design decisions to leave the 109 'as is' might have been entirely due to the concerns for boosted control forces on the airframe. The Germans certainly had the smarts to do what they felt best.

The Mustang was on the other side of the spectrum. The P-51 engineers had to put reverse boost on the rudder to reduce overstressing the tail at high speeds, snap and slow rolls. The net effect was to make it harder for the pilot to kick rudder in dives and other high speed manuevers.
 
Claidmore - what was the Spit weight for this test? As well as published Horsepower for the +/- Horsepower ratings at 12,000 feet?
Weight is not mentioned specifically, just wing loading of 25lbs/sq ft, which would give us 6050 lbs with the 242 sq ft wing of a Spitfire Mk1.
Here's a couple more clips from the report.
 

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