109 elevator trim

[Varrattu]

Originally Posted by VO101_Tom

Hi.
.. When i roll the wheel from +8 to -3, it takes seconds...

I´m sure you mean -8 to +3.

The following photo shows the tailplane incidence of the BF109E-3a WNr 2422.The photo was taken at the Swiss Air Force Museum in Dübendorf.

[VO101_Tom]

Originally Posted by Varrattu

I´m sure you mean -8 to +3.

yep, you right.

[5./JG27.Farber]

Originally Posted by Varrattu

You're lucky to fly in virtual world ...

See that big metal flap moving in the background? Thats the flaps. We are talking about Elevator Trim - its the other wheel.


ROBO: I dont use the "trim-trick", I dont think its practical. If some of you guys do and some RL pilots do, then whats the problem. For me, it doesnt suit my flying stlye, I dont like getting down and dirty.

[Robo.]

Originally Posted by 5./JG27.Farber

I dont like getting down and dirty.

The problem I see is not in the turnfight but in BnZ. And even if you personally don't use it, it should be modelled correctly, don't you agree?

[5./JG27.Farber]

Originally Posted by Robo.

The problem I see is not in the turnfight but in BnZ. And even if you personally don't use it, it should be modelled correctly, don't you agree?

When Osprey was talking to me about it on Steam he said 109's where using it to out turn him.

So... How long should it take? -Thats the real question. Bearing in mind you dont use all of it. Lets say half, how long does it take to roll out half of it?

[Robo.]

Originally Posted by 5./JG27.Farber

When Osprey was talking to me about it on Steam he said 109's where using it to out turn him.

Oh yes, you can outturn a Hurricane if you want, because you can apply nose-up trim very very fast. It is very useful and responsive in other manoevers, too - vertical or horizontal scissors etc... Do you need to hit a Spitfire that is breaking hard while you're diving on him at 450km/h? Apply full nose-up trim and you'll have plenty lead on him. This probably applies to all aircraft, and as you can do things no one could do in so called real life, this is certainly wrong. The 109 is specific because of the trim wheel design and purpose (e.g. pilot was not able to achieve full nose-up trim position so fast, which is more of a HW issue restricted via antropomorphic controls already.)

Originally Posted by 5./JG27.Farber

So... How long should it take? -Thats the real question. Bearing in mind you dont use all of it. Lets say half, how long does it take to roll out half of it?

I don't know. It took 4 complete revs (or cca 5 3/4 revs) of the wheel to get from full up to full down trim. (It took about 22-25 seconds to deploy flaps fully (see varratuu's video again, he was refering to the wheel operation))

I can only assume that it was full 2 revolutions from neutral position to full up. Now watch the animation (less than one rev) and the immediate effect we have got in game. Neutral position (0), +3 was nose down, -8 was full up - assuming the 0 is neutral for cruise flight, it would be even more than 2 full revs to get from neutral to full up, it would be more like 3 and half full revolutions. I would need to verify this and do some more research but I am sure someone will have that knowledge.

Now try to take a Hurricane and do the same, the trim wheel is very similar in fact as was typical for many aircraft of that era - and have a look at the trim indicator and wheel animation. Response is pretty similar. It's not too bad, there is even this small delay modelled, sort of.

[robtek]

I think there would only be a problem if the nose up trim gave the 109 the ability to outturn the spit/hurri in a sustained turn, which would be clearly wrong.
A "dynamic" turn is only limited by the pilot, the structural integrity of the ac and the effectivity of rudder, elevator and ailerons.

[5./JG27.Farber]

Robo, dont confuse the operation of the landing flaps with the operation of the trim wheel. They share a spindle but thats it, they are geared differently. So I dont think that video has any relevance.

[VO101_Tom]

Originally Posted by robtek

I think there would only be a problem if the nose up trim gave the 109 the ability to outturn the spit/hurri in a sustained turn, which would be clearly wrong.
A "dynamic" turn is only limited by the pilot, the structural integrity of the ac and the effectivity of rudder, elevator and ailerons.

It's not. If you roll the trimm wheel full "tail-heavy", the 109 drop its speed within seconds. You can pull some lead, if the enemy is close, but you have no chance to keep the corner speed, no chance to follow negative G maneuvers, and absolutely no chance to catch the enemy in mirror-spiral.

[Varrattu]

This thread is realy good footage for another episode of MYTHBUSTERS.

We are talking about a game and not about a simulation. Aircraft simulators you will find at airports like Heathrow or Frankfurt...

If you want to have more than a game, please spend more money. Find the next airport in your region and ask a pilot to climb or dive with you at about 5 or more meter per second to get a feeling for further discussions about G´s. For those who are still interested in RL aerodynamics, I recommend serious sources, i.e. PERFORMANCE & STABILITY of AIRCRAFT:

http://books.google.de/books?id=IuGI...idence&f=false

~S~