109 elevator trim

[Flanker35M]

S!

Well, this forum differs very little if any from others so blame the kettle or pot Only worse was maybe UbiZoo. I admit sometimes being a bit too aggressive in postings, but working on that I really enjoy reading discussions with good points/info/data/whatever where the EGO of the posters is pushed aside and issues are seen as they really are, not as a matter of pride etc.

This Bf109 trim issue could be settled more or less if this guy mentioned could share his insight with the plane and flying WW2 planes in general. Ideal would be if the community would have people who are heavily involved with WW2 planes, either flying and restoring/repairing them or both. A true treasure trove of which all would benefit in a positive way.

[irR4tiOn4L]

Originally Posted by Flanker35M

S!

Well, this forum differs very little if any from others so blame the kettle or pot Only worse was maybe UbiZoo. I admit sometimes being a bit too aggressive in postings, but working on that I really enjoy reading discussions with good points/info/data/whatever where the EGO of the posters is pushed aside and issues are seen as they really are, not as a matter of pride etc.

This Bf109 trim issue could be settled more or less if this guy mentioned could share his insight with the plane and flying WW2 planes in general. Ideal would be if the community would have people who are heavily involved with WW2 planes, either flying and restoring/repairing them or both. A true treasure trove of which all would benefit in a positive way.

Agreed, I just wanted to say those things so that arguments would be forestalled.

I should say one thing on the trim issue though - even though I said balance has little application, changing an issue (short trim times) that is inaccurate on all planes (from what has been said) on only one plane (BF109) works against balance and does not work to promote overall realism, even if one issue (bf109 trim) is sorted.

I think you have to be careful to maintain macro realism, even at the expense of micro realism. Sometimes, when you are dealing with something that will affect balance, you have to be careful to implement changes in a balanced way.

What this means is that if the trim is wrong on all planes, it should not be just the 109's that is singled out for attention. I have so far seen this swept under the rug in this thread, as if the 109's trim was somehow a bigger problem than that of other planes. But I'm not convinced that is true. Especially considering that pilots have reported that the 109's trim wheel was quicker and easier to use than that of many other competing designs, it should not be the case ingame that it becomes the hardest plane to trim.

[Al Schlageter]

http://www.wwiiaircraftperformance.o...ricane-109.pdf

see 5.

Note the comment by the pilot of the 109 saying the trim adjustment was heavy. In other words, it was not easy to rotate the wheel.

No wonder the 190 went to an electrical trim for the stab.

[irR4tiOn4L]

Originally Posted by Al Schlageter

http://www.wwiiaircraftperformance.o...ricane-109.pdf

see 5.

Note the comment by the pilot of the 109 saying the trim adjustment was heavy. In other words, it was not easy to rotate the wheel.

No wonder the 190 went to an electrical trim for the stab.

That was in a dive, where the 109's controls were all very heavy! That is not representative of how heavy the trim might be in a horizontal maneuver. Additionally, others have said the large wheel made it easier than competing designs, and I don't think we should be looking at the 109 trim in isolation.

What SHOULD be taken into accound in CLOD, and is not, however, is the reputed heaviness of the 109's controls in a dive. I've never had to use trim to pull out of a high speed dive in CLOD, and I feel that I should.

What is also interesting out of your linked notes is that the 109 lacked oxygen gear - would this result in a higher effective ceiling for the red fighters?

Extremely interesting also is the pilot's notes on the tendency of the Hurricane pilot to black out where the 109 pilot would not. Initially I read this as pulling more G's, but in actuality, they are saying that the pilots of a hurricane sat more vertically and had a tendency to black out even in similar g maneuvers! I definitely don't see blackout tendencies modelled in the sim, and that would make it rather interesting, wouldn't it, if the 109's pilots could sustain more g without blacking out!

We shouldn't pay attention to just one aspect of that pilot's report.

[Igo kyu]

Originally Posted by irR4tiOn4L

What is also interesting out of your linked notes is that the 109 lacked oxygen gear - would this result in a higher effective ceiling for the red fighters?

No.

What is said is that the RAF lacked oxygen bottles with connectors compatible with Luftwaffe oxygen systems.

Without oxygen, 18,000 ft is a hard ceiling for pilots, and even 17,000 is iffy.

IIRC it turned out that the 109 was much better than the Spitfire at very high altitudes, which was a surprise to the RAF because they hadn't tested captured aircraft at high altitude because they didn't have oxygen bottles that fitted the aircraft.

[irR4tiOn4L]

Originally Posted by Igo kyu

No.

What is said is that the RAF lacked oxygen bottles with connectors compatible with Luftwaffe oxygen systems.

Without oxygen, 18,000 ft is a hard ceiling for pilots, and even 17,000 is iffy.

IIRC it turned out that the 109 was much better than the Spitfire at very high altitudes, which was a surprise to the RAF because they hadn't tested captured aircraft at high altitude because they didn't have oxygen bottles that fitted the aircraft.

Thanks for that clarification, the pilot's notes didn't make that clear as far as I could see - only said "owing to the absence of oxygen apparatus in the M.E. 109".

My other points stand though I suppose.

[Robo.]

Originally Posted by Igo kyu

IIRC it turned out that the 109 was much better than the Spitfire at very high altitudes, which was a surprise to the RAF because they hadn't tested captured aircraft at high altitude because they didn't have oxygen bottles that fitted the aircraft.

Ah, makes sense. I thought though that Merlin performed better than DB higher up due to higher full throttle height and supercharger designs of bothe engines. I might be wrong but it seems that above 16.500 feet, the Spitfire was faster than the 109 even with 87 octan fuel and also climb performance was slightly better. It was later Spitfire marks and Friedrichs where I've read accounts of Germans being some 2000ft higher and RAF unable to climb any further but I was not aware of any advantage of the Emil over early Spitfire marks. If you could point me out to some sources that would be great!

[Kurfürst]

Originally Posted by Robo.

Ah, makes sense. I thought though that Merlin performed better than DB higher up due to higher full throttle height and supercharger designs of bothe engines. I might be wrong but it seems that above 16.500 feet, the Spitfire was faster than the 109 even with 87 octan fuel and also climb performance was slightly better. It was later Spitfire marks and Friedrichs where I've read accounts of Germans being some 2000ft higher and RAF unable to climb any further but I was not aware of any advantage of the Emil over early Spitfire marks. If you could point me out to some sources that would be great!

Depends. The Spitfire in the period of the BoB went on with just two Merlin engines, the III and XII. The latter IIRC was marginally better for lower altitudes and worse for higher altitudes.

On the German side its a bit more complicated - most books will tell you that they used 'DB 601' but in reality 109s/110s had a number of DB 601 variants installed during the Battle:

DB 601A-1 with old type supercharger - this had a rated altitude of just 4000m.
DB 601A-1 with improved type supercharger - this had a rated altitude increased to 4500m.
DB 601Aa - this had increased boost pressures, which meant it developed about 10% more power than the 601A-1 below rated altitude, operating at 1.35/1.45ata instead of 1.30/1.40 ata, but similiar altitude performance. I believe this is the variant we have modelled.
DB 601N - this one was fitted to 109s and 110s and used 100 octane fuel, and had both increased boost pressures, higher compression ratio and a more powerful supercharger with a rated altitude of 4800 m. Off all engines during BoB, British or German, this had the best altitude performance. The one fitted to the 109F had a better supercharger and a rated altitude of 5200 iirc.

In addition, during the Battle the Luftwaffe cleared increased RPMs for the DB 601 A and N-series engines, and this would increase altitude performance (the supercharger's rotation speed was linked to the engine speed, so increasing the engine speed also increased the supercharger performance)

[Robo.]

Originally Posted by irR4tiOn4L

That was in a dive, where the 109's controls were all very heavy! That is not representative of how heavy the trim might be in a horizontal maneuver. Additionally, others have said the large wheel made it easier than competing designs, and I don't think we should be looking at the 109 trim in isolation.

I agree, but from the accounts and the above video it would seem that although being big, it was not very fast in adjusting the trim. Also, comparing the 109 design to competing designs (with trimtabs), it was rather different and more effective as such (with more surface to work with), although slower and more difficult to operate at higher speeds - adjustments would happen in jumps and it would not be easy to trim when the speed has buit up already. Also, French tests mention that even vertical manoeveurs trim was needed where D.520 could easily turn with the stick only etc.

Originally Posted by irR4tiOn4L

What SHOULD be taken into accound in CLOD, and is not, however, is the reputed heaviness of the 109's controls in a dive. I've never had to use trim to pull out of a high speed dive in CLOD, and I feel that I should.

My point precisely. Not in a dive I would say but at high speed even in horizontal flight. The behaviour in the dive had nothing to do with the compresibility effect, it was purely loss of effectivity as the speed build up afik. On full real settings I would expect to need to trim before I enter the dive otherwise I would encounter difficulties. I would expect the trim control to be slower (and heavier IRL) as the speed is rising. In the sim I can get full nose up at any speed with the move of my thumb, the aircraft reacts immediately and too swift leading to unrealistic manoeveurs.

The 109 was very agile in the hands of a good and experienced pilot and is more difficult to master than some other designs. This is sort of the case in the game already (at least that's how I see it), one thing that ruins this for me is the trim and few other things that make flying the 109 much less challenging. But let's stay with the trim:

1. THE RANGE. The real thing had the range of 12 degrees from -3 to +8 degrees, neutral being 0, (Take off setting was between 0-1). The indicator and the range is correct BUT it seems to me that the neutral position is not 0 in game. It seems the range is symetrical, therefore the neutral position is at 3. If you set your elevator trim to 0, that will lead to nose-heavy situation in the sim. I believe the 109 should have more range in tail-heavy direction.

2. THE SPEED AND RESPONSE - asstated above, the animation in the sim is certainly wrong (see RAE test quoted beforehand) and the speed and response is too swift as I mentioned earlier. I would expect the trimming becoming more difficult (slower) at higher speeds and ideally, we would have adjustments in 'jumps' as mentioned by Finnish pilots re. hand placement and movement. Anything would be better that what we've got now imho.

Originally Posted by irR4tiOn4L

What is also interesting out of your linked notes is that the 109 lacked oxygen gear - would this result in a higher effective ceiling for the red fighters?

This is most certainly wrong, the 109 has had oxygen equipement as a very modern fighter. Perhaps that particular machine (damaged and acaptured iirc) had it removed or they have had no mask or compatible exuipement to refill it or similar reason, but the oxygen bottle is down on your right hand side with the breather tube and hoses and gauges (blue for oxygen in LW cockpits).

Originally Posted by irR4tiOn4L

Extremely interesting also is the pilot's notes on the tendency of the Hurricane pilot to black out where the 109 pilot would not. Initially I read this as pulling more G's, but in actuality, they are saying that the pilots of a hurricane sat more vertically and had a tendency to black out even in similar g maneuvers! I definitely don't see blackout tendencies modelled in the sim, and that would make it rather interesting, wouldn't it, if the 109's pilots could sustain more g without blacking out!

This is very interesting and important point. I know nothing about pilot's position in the cockpit regarding blackout. The only thing I recall is that in the Spitfire, the pilot was able to lift his feet from the rudder and rest them on a horizontal bar. Apparently that would also make pulling high Gs easier and I've heard on many accounts that the position in the cockpit was very important.

The difference between Hurricane and 109 should be considered in the sim.

[Osprey]

Originally Posted by irR4tiOn4L

Extremely interesting also is the pilot's notes on the tendency of the Hurricane pilot to black out where the 109 pilot would not. Initially I read this as pulling more G's, but in actuality, they are saying that the pilots of a hurricane sat more vertically and had a tendency to black out even in similar g maneuvers! I definitely don't see blackout tendencies modelled in the sim, and that would make it rather interesting, wouldn't it, if the 109's pilots could sustain more g without blacking out!

True and I would like to see a thread/bug on it. The problem is that there is a human aspect to it, blackout varies a lot between people (which is why the Luftwaffe presently test for blackout during pilot candidate selection today). That said I would like to see some extra tolerance built in for 109's on blackout - it makes sense. Robo is correct about the Spitfire pilots raising their feet to increase G tolerance - I have read this in biographies from surviving pilots too, so perhaps there is also a case there too. Alas the poor Hurricane pilot has to suffer again........

Regarding Kurfursts post, I have a habit now of dismissing his posts for bias however on this occasion he should be congratulated for an informative post, one cannot be sure of the evidence but it does look convincing at least None the less, let us not forget this is about elevator trim and not the other aspects of performance which we are all sidetracked on.

I cannot understand Crumps POV though, how can he dismiss a pilot who works with warbirds, including the 109, based on his own personal view of what is logical because he flies a modern light aircraft? Nonsensical.