Not everyone around here speaks German, and given that the chart is labelled with Spalt- und Spreizklappe, and the legend contains it as well, it is useful information for everyone to understand the chart.

You presented a value from flaps extended polars, as you say the stall happens at ~17.5°, which is only the case with flaps extended. Good to know it wasn't intentional.

Slats open as chosen by the designer. It is absolutely possible to give them progressive characteristics so that they indeed bang open. This is reported by many pilots in case of the 109, and while I haven't flown one, I trust their word over yours.

I also have no clue how much simplified the polar is, it can contain everything or nothing. The information that can definitely be taken out is the one you and I agree on, the AoA the slats open at.

You're welcome to educate everyone on how you extract the other information.

No, in addition to what CaptainDoggles wrote, the cooler flap is set at 60°.

I think the "banging open" behaviour is from novice pilots yanking the stick and rapidly traversing through the range of angles of attack at which the slats actuate. Or perhaps debris in the tracks causing it to stick for an instant.

I doubt very much that the slats were an "either fully open or fully closed, nothing in between" type of system. They're like a drawer in your kitchen. If you pull it out rapidly it'll bang once it hits the end of the track, but it's still possible to open it half-way.

IIRC they also went from a pivot-arm type of mechanism on the early models to a roller-track mechanism on later variants (I think starting with the Gustav). Possibly the early models were more prone to sudden/violent actuation than the roller track mechanisms on the later aircraft.

Good Lord. Experts run amok....

The designs for the radiator flaps of the F series were tested as well during this investigation. In fact the aircraft, for those test's the aircraft was fitted with an F series cowling (intake), wheel well covers, and the various radiator flap designs being considered.

A little digging will uncover the fact the radiator flap ended up being a split flap on the production aircraft.

None of that has anything to do with the baseline polar determined from WNr 1929 in standard Bf-109E-3 configuration.

Wannka Wannka Wannnka....:rolleyes:

JtD is correct on the cooling flaps being at 60 degrees. There would be a camber change over flaps up configuration if the landing flaps were down.

:-|

Figure it out yourself. You have no clue how to read a polar and I am not going to teach you.

A little basic knowledge and anyone can tell you are "out der FLAPPIN" as we used to say in the Army when somebody was completely wrong. In this case, it is quite ironic you are FLAPPIN over flaps!!

:)

The effect of trailing edge flaps is to increase the camber of the wing.

What is the effect of a camber increase on a lift polar??

It shifts the whole polar to the right! That means it LOWERS our Angle of Attack!! You cannot have the same Angle of Attack flaps up as you do flaps down....

Check out figure 5:

http://adg.stanford.edu/aa241/highli...liftintro.html

It is not physically possible with TE flaps to have the same general CLmax presented by the RAE in clean configuration with a polar with the TE flaps down at the same Angle of Attack.

Which incidentally also matches the 2D data from the NACA family of airfoils.

BTW you can see the data point Mtt plotted for the plain airfoil and for the slats on the polar. The Bf-109 did not have full length LE slats so it did not get a dramatic CLmax increase.

Sheesh, was just asking for clarification.

Cool, thanks for the info

I think you think I'm attacking/disagreeing with you.

:?

- Could the pilot control the leading edge slats?

;)

Some interetsting info about Bf 109 slats from my bookmarks:

http://www.virtualpilots.fi/feature/...09myths/#slats

http://109lair.hobbyvista.com/techre...lats/slats.htm

You are welcome.

Not at all. It was supposed to be light hearted and not serious. I guess I blew it on that count.

:o

Geez....

look at the video....

Do you see me hitting the "slat button" or pulling the "slat lever".....

NO!!

Just like the finnish ace you quote but misinterpret his reply....

They work by air pressure at a specific angle of attack! Watch the video again and Guess how the pilot can control that air pressure??

I actually filmed the amount of stick movement required in that aircraft between slats fully opened and closed. Admittedly I did a horrible job at it as the camera moves all over the place but the last 5 seconds is intended to show the amount of stick travel required.

http://www.youtube.com/watch?v=-vbqgfjyW2Q

Here is the first part of your pilots quote....

http://www.virtualpilots.fi/feature/...09myths/#slats

Look at that, same control I used in my aircraft! No slat button or lever though!!

You can easily control the amount of slat you deploy with some practice. That being said, my first solo flight I almost jumped out of my skin when they deployed on approach. If you are not used to it and you move the wing rapidly through the AoA required to open the slots, they can open with a bang. I thought something fell off the aircraft at first.

Inertia makes them open on the grd.