Leading Edge Slats on the Me-109

[ACE-OF-ACES]

Originally Posted by Crumpp

II/JG53 Rolf,

My suggestion would be just to ignore AoA, ie, TAGERT.

Yes, just like the Bf109 myth site you provided as proof ignored Erwin Leykauf quote!

[Crumpp]

to sum it up:
1) Slats were designed to open unevenly because the aerodynamic effects were uneven on both wings, especially in high AOA.
2) Slats helped at stall speeds at low speeds, discussion is held about high speed with not much evidence for either case in this thread.
3) Slats could have malfunctions as any other part of a plane - not all planes and pilots have the best ground crew. The slat then could open partially which could cause inexperienced pilot to stall/spin.
4) Recovery from the spin of slats equipped 109 was considered easy.
5) This whole thread was started because of stall and spin characteristics of bf-109 in CLOD game

Good summary.

I would add:

2) Slats helped at stall speeds at low speeds and ensured gentle stall behaviors, discussion is held about high speed with not much evidence for either case in this thread.

4) Entry into a spin was difficult and Recovery from the spin of slats equipped 109 was considered easy.

[taildraggernut]

Originally Posted by Crumpp

Really?

Wow, you should tell the engineering departments of every major university because they are teaching the wrong information.

Maybe you should tell one of the pioneers of stability and control engineering. A British engineer who strived during the war and after to get the RAE on a defined standard after his experience working with the NACA. What is even more funny is the fact stick force per G, which Gates developed, was adopted by the NACA as part of the 1942 standard!

The United States NACA adopted a British engineers ideas and made them standard long before the British RAE listened to their own guy! That was the basis of his invitation to come to the United States and observe the stability and control developments at the NACA.

Here is the first page of the proposed standards for longitudinal stability, in fact.

I think World War II in Europe ended in May 1945. Pretty sure September 1947 is after the conflict was over....

Theres standards and then theres standardisation, you can have standards without standardisation, it simply means there was not a universally applied standard, I asure you the British aircraft industry was not a free-for all where they let the tea ladies get in on the act because it 'looked pretty', there were people who were very aware of what stability and control was within the RAE.
I am not arguing a point about whether a universal standard was adopted, I'm arguing against your bizarre claims the British had 'no' standards and therefore the RAE reports on the 109 may as well have been performed by monkeys.....until of course you want to 'cherry pick' anything positive.

[taildraggernut]

Originally Posted by Crumpp

Exactly!

You have an airframe designed for one engine that is now having to work with another one.

This is why STC's are required and you just cannot swap motors in certified design airplanes.

The merlin prop swung at a lower rpm, weight is different, and the thrustline was higher. At least it turned in the same direction.

You do understand airframe are built to counteract the effects of spiral slipstream and torque?

That is why engine mounts/firewalls are angled and verticle stabilizers angled.

Mounting an engine with different properties results in different handling qualities.

Why are we even discussing this and what does it have to do with effect of the slats?

Is it just your justification for using an example which has nothing to do with the original topic?

The point is the aircraft had slats, the same ones on the 109, the same ones you claim could not result in a spin, the same airframe from Mark Hannas quote you were more than happy to include to reflect the 109's behaviour, you do this all the time, completely contradict yourself.

are you really saying that the Spanish simply 'nailed' a merlin into the aircraft and thought 'to hell with the consequences'?

and how much did the basic 109 airframe design change through development when they used RR kestrel engines and Jumo's?

[raaaid]

for what ive understood slats are an all or nothing thing

but in the game the get just half way deployed sometimes

[TomcatViP]

Originally Posted by VO101_MMaister

You are amazing guys... How the hell did you end up on the spit`s high speed stall characteristic in a thread about the leading edge slats of the 109?????

There are no spinproof airplanes, there ones which are hard to put in a spin. The wing is stalled when the airflow become turbulent over the whole upper wing area and so it looses its lifting effect. The slats ensure a laminar flow over the outer wing around the ailerons at low speed so you have some more control before the wing stall. No magic here. It can postpone the stall but it won`t eliminate it.

The spin is when only one of the wing is stalled due to the asymmetrical flow. The slats could open independently, so they could prevent a spin by opening only on the wing which was just about the stall. But again it was only postponing the spin in this case and gave you more control.

On the other hand the slats could make a fuss, when only one of them opened due to some mechanical failure, and it resulted an asymmetrical lift and so an unpredicted spin at low speed. Also they raised the drag when they were open, what meant quicker de-accceleration.

I have never flown an aircraft with slats, so no practical experience here, but as I understand Crumpp did, and he gave a quite good description about the acting of such an airplane.

[...]

Thx for reminding this.

Spin is not only the result of the stall of one wing. The drag diff. is also important (stall = high drag). If only one Slat is deployed then this a factor aggravating the likelihoods of a spin.

But regarding the deceleration, remind that at low speed 1000hp is by far enough to offset the drag penality such as in the case of a WWII fighter. So far that the size of the slats were reduced in span on the F to put them out of the propeller stream.

[NZtyphoon]

Originally Posted by Crumpp

II/JG53 Rolf,

My suggestion would be just to ignore AoA, ie, TAGERT.

Originally Posted by taildraggernut

I am not arguing a point about whether a universal standard was adopted, I'm arguing against your bizarre claims the British had 'no' standards and therefore the RAE reports on the 109 may as well have been performed by monkeys.....until of course you want to 'cherry pick' anything positive.

Everybody, My suggestion would be just to ignore Crumpp, ie, GENE.

Long story short, there will be no further improvements to the flight qualities of any of the aircraft in CLOD, whether it be the Bf 109, or the Spitfire unless there are people who are willing and able to modify the product to represent the flight qualities desired by the players. My guess is no matter what improvements are made there will still be those who will not be satisfied until every tiny nuance of all aircraft is replicated to the nth degree.

[fruitbat]

Originally Posted by NZtyphoon

Everybody, My suggestion would be just to ignore Crumpp, ie, GENE.

i did, a while back....

[Gabelschwanz Teufel]

Originally Posted by fruitbat

i did, a while back....

It only works if everybody does it or the ones that don't will stop quoting him.

[Crumpp]

are you really saying that the Spanish simply 'nailed' a merlin into the aircraft and thought 'to hell with the consequences'?

There is nothing they can do about the airframe changes without a complete redesign of the aircraft.

Why do you think they called the Avia S-199 the "Mule"?

The Ha-112 was a different airplane.

The higher thrust line, weight differences, and difference in rpm results in different dynamic pressure ranges in the spiral slipstream than the airframe was designed. It will have different flying qualities.

I guess you hate me for pointing out that fact!!

Try flying a piston engine porter and a turbine porter if you don't think engine makes a difference in flying qualities.