Dropping Flaps??

[BnZs]

and i suppose kurt tank did not understand this engineering principal ?

Irrelevant to the point we are discussing.

yes i do if the 190 could handle 150mph at 60 degrees of deflection resistance than physics reasonably dictates that they should be able to handle 3x that speed at 1/6th that deflection.

It does not follow.

actually flap durability is very predictable, how do you think they calculate the limits to design them in the first place?

Therefore, maybe we should pay attention to the limits in the POH?

[thorsim]

kurt tank is irrlevant to the design of the FW-190, really? that is an interesting perspective ...

prove it does not follow, go ahead lets see you math. ...

not when the tactical trial data conflicts with the POH ...

or use the POH strictly to determine EVERY aspect of flight for EVERY aircraft no deviating at all ever ...

otherwise you are just cherry picking which data you wish to be strictly POH with and which data you are not.

Irrelevant to the point we are discussing.

It does not follow.

Therefore, maybe we should pay attention to the limits in the POH?

is this the real problem guys?  

while we're discussing making planes better.

[Stoney]

I have to point out that if we followed my "corner velocity" guideline, we would not even need to debate P51 flaps and more to the point there'd be no real use for them at those speeds.

Your "corner velocity" guideline is nothing more than normalizing flap deployment speeds.  My point is that if we iterate higher flap deployment speeds away from what's listed as a limit in the POH, we'd have to iterate it for every aircraft, including those American rides with their already high flap deployment speeds.  There's simply no way to be consistent.

[hitech]

Thor wrote.

do you have trial data that is in conflict with the POH as in the case of the 109?  a 100% 200+mph disparity?

yes as far as the 190 and 109 flap settings in AH go, i know they are wrong, people who know, know they are wrong and have posted as such.

Ok gents I am done with this discussion. Hyperbole and false statements abound and hence it is no longer worth the discussion.

Thor to put it simply you are showing extreme LW bias. You assume that the chart you have posted is in conflict with flight manuals. You have no idea if this is true or not. All you know is they show different numbers, but you have no idea why they have different numbers. To date you still have show one chart and only one with out ANY surrounding descriptions.

You wish to find data on your airplane supporting your argument that 1 plane should be changed. You wish us to completly change our methods with only 1 chart that we have no idea why it was produced.

This type of posting, almost by definition is showing bias.
and then this.

then it seems to me the parasitic/induced drag relationship in regards to the flaps needs to be reviewed.

You now call our complete flight model into question with out even 1 simple reason why, not one data point, not one point of knowledge of real planes, nothing, but according to you we should revisit our entire flap modeling. You do again to try back up your argument that you want the 109 modeling changed. Notice no where in your entire posting have you mentioned any problems with any other plane besides LW planes?


HiTech

[wgmount]

So you want to talk structural limits, ok, maybe a little math also. In 1942 the speeds that dogfights occurred were so high that the lightness and harmony of the controls and ac structural integrity became the 2 dominate factors to success. But let's not forget there is also a human being inside the ac and the g-forces involved. here is the way to calculate g-forces using the modern lift equation. pay attention because your argument is moot because whether you can put your flaps out at 500km/h is not going to matter.

The modern lift equation states that lift is equal to the lift coefficient (Cl) times the density of the air (r) times half of the square of the velocity (V) times the wing area (A).
L = .5 * Cl * r * V^2 * A the Fw 190 is 1.58 * 18.3 * .5 * 1.225 * 112^2 = 222152.045 N
Convert result in Newtons into kgf: 222152.045 Newtons = 22653.2 kgf
Divide result with a/c weight to get Max G: 22653.2 / 4270 = 5.3
Max G at 112 m/s (400 km/h): 5.3

Using the same equation the Max G at 125 m/s (450 km/h) is 6.6 G, so already at this speed the pilot will be blacking out in a full performance turn.

At 500 Km/h it is 8.25 at 650Km/h it is 13.8g's

Man, you made me get my engineering 101 textbook out to look that up. I'm done too.

[BnZs]

kurt tank is irrlevant to the design of the FW-190, really? that is an interesting perspective ...

The statement you made about Kurt Tank's engineering knowledge was irrelevant to the question being discussed.

prove it does not follow, go ahead lets see you math. ...

You are the one seeking to change the flight model. You are the one making a statement that needs some sort of proof, "If the flaps can withstand 150mph IAS@60 degrees deployment, THEN they can withstand 450mph IAS@10 degrees deployment". YOU are the one who needs to "show some math".

or use the POH strictly to determine EVERY aspect of flight for EVERY aircraft no deviating at all ever ...
otherwise you are just cherry picking which data you wish to be strictly POH with and which data you are not.
is this the real problem guys?  

That is what HTC does with flap deployment speeds and WEP limitations. The alternative to just guess at what speed the flaps "should" fail and the engine "should" come apart. If effects the 190 which in your opinion "should" be able to deploy flaps at higher airspeeds, if also effects say R-2800 equipped aircraft which "should" (going by tests) be able to run at 70'' MP until the cows come home. (IOW, Hitech doesn't have it out for the German aircraft you silly Luftwhiners )

BTW, since the 190 is the plane under discussion, it is clear looking at the flap design that they were *not* primarily intended as an aid to maneuvering. The split type of flaps increases lift but also adds alot of drag. Their primary advantage I've read is simplicity of design and that they don't cause as much need for re-trimming when deployed.

[thorsim]

Rule #4

[thorsim]

not sure how the deployment of flaps adds a g load on the aircraft, could you explain?

i don't think i have discussed anything else here.

So you want to talk structural limits, ok, maybe a little math also. In 1942 the speeds that dogfights occurred were so high that the lightness and harmony of the controls and ac structural integrity became the 2 dominate factors to success. But let's not forget there is also a human being inside the ac and the g-forces involved. here is the way to calculate g-forces using the modern lift equation. pay attention because your argument is moot because whether you can put your flaps out at 500km/h is not going to matter.

The modern lift equation states that lift is equal to the lift coefficient (Cl) times the density of the air (r) times half of the square of the velocity (V) times the wing area (A).
L = .5 * Cl * r * V^2 * A the Fw 190 is 1.58 * 18.3 * .5 * 1.225 * 112^2 = 222152.045 N
Convert result in Newtons into kgf: 222152.045 Newtons = 22653.2 kgf
Divide result with a/c weight to get Max G: 22653.2 / 4270 = 5.3
Max G at 112 m/s (400 km/h): 5.3

Using the same equation the Max G at 125 m/s (450 km/h) is 6.6 G, so already at this speed the pilot will be blacking out in a full performance turn.

At 500 Km/h it is 8.25 at 650Km/h it is 13.8g's

Man, you made me get my engineering 101 textbook out to look that up. I'm done too.

[moot]

You posted all of 1 chart, without its context.  A couple of us told you this is what it would lead to.  No supporting evidence, no leverage.

[thorsim]

i brought up kurt tank because you brought up[ a general rule of engineering that you were suggesting was not met in the design of the FW190 ...

that is showing the math.  

you are failing to recognize the conjecture on your part/s where you are assuming that a structure is weaker at an unstated setting than it is at it stated structural limits.  once again i believe that general engineering rules would make that highly unlikely.

i only have pointed out that the POH criteria is not standing up to the smell tests in some cases, i have shown data that calls the POH into question, nobody has even shown the data from the POH or any other corresponding data to support the POH.  

i am not sure what your interpretation on the design intent has to do with the actual design intent or with what speed at which they could be deployed.  as for split flaps vs. other flaps you are welcome to prove your point there as well, there seem to be disagreements about that as well.

either way, the reasons to deploy flaps, much like the POH, does not necessarily have anything to do with the speed at which they can be deployed ...

 does it?

The statement you made about Kurt Tank's engineering knowledge was irrelevant to the question being discussed.

You are the one seeking to change the flight model. You are the one making a statement that needs some sort of proof, "If the flaps can withstand 150mph IAS@60 degrees deployment, THEN they can withstand 450mph IAS@10 degrees deployment". YOU are the one who needs to "show some math".

That is what HTC does with flap deployment speeds and WEP limitations. The alternative to just guess at what speed the flaps "should" fail and the engine "should" come apart. If effects the 190 which in your opinion "should" be able to deploy flaps at higher airspeeds, if also effects say R-2800 equipped aircraft which "should" (going by tests) be able to run at 70'' MP until the cows come home. (IOW, Hitech doesn't have it out for the German aircraft you silly Luftwhiners )

BTW, since the 190 is the plane under discussion, it is clear looking at the flap design that they were *not* primarily intended as an aid to maneuvering. The split type of flaps increases lift but also adds alot of drag. Their primary advantage I've read is simplicity of design and that they don't cause as much need for re-trimming when deployed.

[thorsim]

Rule #4

[boomerlu]

Your "corner velocity" guideline is nothing more than normalizing flap deployment speeds.  My point is that if we iterate higher flap deployment speeds away from what's listed as a limit in the POH, we'd have to iterate it for every aircraft, including those American rides with their already high flap deployment speeds.  There's simply no way to be consistent.

Right, I'm saying this could apply for all aircraft - what do you mean there's no way to be consistent? Some would be lowered, some would be raised but in the end they would all be at corner speed.

Now we get into the subjective matter of whether those high flap deployment speeds on US birds are actually useful. In any case, I'm not hoping for anything anymore. This topic has kind of degenerated.

[thorsim]

Rule #4

that's ok ...

[gyrene81]

i only have pointed out that the POH criteria is not standing up to the smell tests in some cases, i have shown data that calls the POH into question, nobody has even shown the data from the POH or any other corresponding data to support the POH.

One piece of scanned paper from a larger document without any context as to the criteria or circumstances that were used is not data that calls anything into question. It simply shows that on a single occasion in 1940 a test was conducted and produced a single set of results, every piece of relevant data to support that piece of paper is missing. For all you know, that is a projection of what was thought should be possible given the criteria known to the engineers at the time, not the actual results. Take a real close look at the n= notation next to the lines along the upper part of that curve.

Here is another page from the overall report, I'm still looking for more pages:

either way, the reasons to deploy flaps, much like the POH, does not necessarily have anything to do with the speed at which they can be deployed ...

 does it?

Yes it does. The reason to deploy them is just as pertinent as the reason for the flaps to exist in the first place. A method to dynamically change the maximum lift coefficient of an airfoil as it moves through the air. The increased maximum lift coefficient lowers the stalling speed of an aircraft which makes it possible for the aircraft to land safely. Hence the reason the common name and use for flaps is "landing flaps".

[thorsim]

projection like you are doing now? gyrene ?

sorry can't read yours, got a bigger scan? ...

as far as my "projection" the translation said approved limits, not projected limits, or suspected limits ...

it sounds like my page could be the results, does it not?

i would very much like to see the rest of the document though, btw how did you conclude that they are parts of the same document, since you only have 1 pice of paper?

just curious ...