109 elevator trim

[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 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.

[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)

[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.

[Robo.]

Originally Posted by Kurfürst

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.

Interesting, I always thought that FTH was the main obvious difference between A-1 and Aa versions.

I am not too sure about the develompemt of German superchargers but from what I remember the A-0 (not used in the sim or during the BoB in the 109s) has had FTH of 4000m, then improved supercharger of A-1 made it to 4500m. 601 Aa was at 4000m again with better low alt performance instead. I am bit confused here with what you're saying.

Still, early Merlins had higher FTH than any of the above engines, hence my assumption the RAF had slight advantage at high alt.

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.

The DB 601A we've got in game is appartently modelled at 1020PS so I suppose it's the A-1 version with FHT at 4500m.

Originally Posted by Kurfürst

DB 601N

We haven't got this one modelled (perhaps better to compare with Merlin XX at slightly later stage of the conflict), there are no E-4/N (or E-7/N) or Hurricane Mk.II in the sim.

[Martin77]

the interesting thing on this test is, the frencht test THIS airplane before (WerkNr 1304), (with higher results) and reportet that they damaged the plane and must break off the climb test ( motor cooling). And then shipped it to england.
Who knows if the has the correct power?
And no pilot reports the shaking when the slats came out? perhaps they´re not functional?

[justme262]

I still don't understand... let me get this straight

Ok I'm in a BF109 diving at high speed on a hurricane with neutral trim and forward pressure on the stick to hold the nose down, he sees me and breaks right. I roll right and pull back on the stick gradually accelerating the turn and increasing the angle of attack till eventually one wing or the other stalls and I spin. Does trimming the whole horizontal stabilizer delay the high speed stall? Can my plane achieved greater angle of attack with the stabilizer trimmed by wheel compared to the elevator raised by stick?
If either way I reach same maximum angle of attack and stall in same place then what's the difference?

In real life the elevator forces go up at high speed so I can see an advantage to a pilot trimming the nose up at high speed but in this "sim" none of the fighters have heavy controls at high speed so why not just pull back on the stick.

[irR4tiOn4L]

Robo and Osprey, I am saying that when making changes that are in the right direction (realism), we should nonetheless time and implement changes in a manner that respects overall realism - ie, the matchup between aircraft and relative performance, as well as the overall hierarchy of problems in order of importance.

Why are we focussing on the 109 trim here? I have seen no good argument in this thread for why the 109, an aircraft with a huge trim wheel and similar trim times to other planes in the game, should be singled out for changes, and why these should be above fixes to its and other aircraft's performance. Given that all the aircraft in the game trim quite quickly, if the 109 is wrong, its likely they are all wrong (some even more so). This discussion should go beyond just the 109 and the fix should go beyond just the 109, otherwise we are punishing an aircraft with slower trim adjustment that was actually QUICKER to adjust trim in in real life!

Similarly with control heaviness. True, the 109 was worse than contemporaries here. But we can't just fix the 109 to historical performance and leave it at that. It's likely that other aircraft are also pulling too easily/experience too little control heaviness, and to change this on only one aircraft is sacrificing macro realism for micro realism. We'll have one great, realistic plane to fly, but that'll be all.

And that's not even taking into account the undermodelling (apparently, based on discussions here) of all these aircraft, including the 109 (possible exception being Spit IIa). Why should trim be fixed before the performance and speed of the 109?

Look at the Spitfire IIa - because it is probably the most accurate in terms of performance among a crop of inaccurately modelled underperformers, many online servers don't even allow it because it has no equal. Fat lot of good lopsided modelling made there. While I support every effort toward realism, I don't support the implementation of these changes on a timetable that is designed to respond to complaints from multiplayer which focus on only the overmodelled aspects of a favoured opponent's aircraft - a slippery slope. This kind of thing should be done transparently across all aircraft in a manner that focusses on the most major to the minor departures from reality. Trim is somewhere down that order, and having to research the proper values on all aircraft (especially if the trim became heavier, ie slower, with the heaviness of the controls) could take time. I am not sure I support the 109 being changed in the interim on poorly researched values, or only on the 109 and not other aircraft, for the sake of some players' competitiveness online.


Still, and to be clear, I do support fixing trim on the 109 and other aircraft. But maybe not on the timescale and order of importance that some others might. Yes, I hear the complaints about the 109 turning too easily in a dogfight online through the use of trim. But I also hear that the performance of most planes is off, blackout and other effects are not modelled correctly and all planes might be too light on the controls and too easy to trim. I think general performance should be fixed first, then trim heaviness/ease should be changed to historically accurate levels. On all aircraft.

I mean let's not forget, 109 pilots might be abusing trim at the moment, but Hurricane, spit and 109 pilots are flying aircraft that are too slow and spit and hurri pilots are abusing the now incorrect modelling of carburetors and dont have to deal with mechanical guages, which also affects the ability of 109 pilots to use negative g to get away or even have the spit/hurri pilot accidently swamp their engine. We need to be careful about how we go about fixing these issues (or even winding back realism, like was done with carburetors and mechanical guages) in response to player complaints from multiplayer. I think some might not like to hear it, but they should accept that it could take a while to fix something like trim if other issues are being addressed.