Dropping Flaps??

[bozon]

So you wouldn't be opposed to allied ac going past 5 min of wep?

Planes can get more than 5 minutes of WEP. Just not continuous.

[thorsim]

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.  

i am in the process of proving they are wrong.  

i already showed you the data sheet with the allowable deployment speeds for the 109, over twice what yours are.  

the guys bringing FWs back into flying conditions are very comfortable stating that 500kph was easily within the limits of the 190s system (as i have posted) the guys doing the recreations of the 190s concur, and i will hopefully be producing the needed documentation to make that clear to you as well.  

you said you are willing to review data as i am able to produce it, and i believe you, however there are some here who seem to refuse to see that other data may be useful and start stating that i am trying to "normalize" a feature which i am not.  i am only trying to shed some more light on this particular issue, in the hopes of clearing up some things that i believe to be incorrect, and having a direct bearing on the game-play and emerson factor in AH.  

i am looking for correctness, yes hitech i believe that these understated flap deployment speeds like many other things in operating manuals were looked at and treated as guidelines especially as the fighters matured, and their pilots became more and more comfortable with them.

we can all state examples of that.

i also believe in fairness where there is conflicting data that some sort of compromise should be made.  i do not think this will fundamentally hurt the game or its credibility after all other offerings have come to this conclusion already.  
quite frankly, on this issue imo it is much less of a credibility problem imo to be 50mph over some data than to be so far under the flap deployment speeds that a particular plane can not deploy its
combat/maneuver/flight flap settings until after it is slow enough to extend its landing gears.  

imo that is a clear sign that the deployment speeds are suspect.

as far as the overall modeling goes, when statements like this are made ...

In our game, to really succeed in some knock-down scissors fights you have to be prepared to drop full flaps and raise them up again in a number of seconds.

then it seems to me the parasitic/induced drag relationship in regards to the flaps needs to be reviewed.  somebody keeps asking for examples in pilot reports, i would very much like to see how common pilot reports or how many pilot manuals approved that amount of flap deployment during combat.  there should be a very narrow margin between max flap deployment speeds and stall speeds in these aircraft.  way too narrow to ever make it into a pilots handbook other than when included in some sort of warning.
 
so yes i wonder why so much static in regards to the top end deployment speeds on a couple of FMs, when the flaps in general display such a deviation from the real world consequences associated with deploying flaps in combat, especially large or even maximum deflections.

no offense

++S++

t

Thorism wrote:

Why the static is simply the way  you started the this topic. You did not start with data nor a valid argement. But simply and attitude of  

"I know this is wrong so change it because I know it is wrong."

You have changed your discussion method as of late.

Thor to be clear, your argument is now that you believe flaps should be modeled to what they could structurally stand and not to what how manufacture suggested they should be used?

If this is not your view then please explain more.

HiTech

[Stoney]

i am looking for correctness, yes hitech i believe that these understated flap deployment speeds like many other things in operating manuals were looked at and treated as guidelines especially as the fighters matured, and their pilots became more and more comfortable with them.

So, for example, what would the "new" P-51D flap deployment speed be?  At what speed, above that listed as a limit in the POH, could it effectively use the first increment of flaps?  Because, if 400mph is the book limit, then surely it could operate them safely at 450mph?

I'm being sarcastic of course, but what's the new criteria for performance data?

[thorsim]

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

if you do have such conflicting data then i would say split the difference until the matter can be settled conclusively. 

that is what i would do, and the beauty of it is that no matter which data is correct you have addressed the situation very quickly and you solution can't leave you too far off the accurate mark whatever ends up being the conclusive accurate deployment speeds.

of course this is not my decision to make, it is just what i would do.   

So, for example, what would the "new" P-51D flap deployment speed be?  At what speed, above that listed as a limit in the POH, could it effectively use the first increment of flaps?  Because, if 400mph is the book limit, then surely it could operate them safely at 450mph?

I'm being sarcastic of course, but what's the new criteria for performance data?

[colmbo]

there should be a very narrow margin between max flap deployment speeds and stall speeds in these aircraft.  way too narrow to ever make it into a pilots handbook other than when included in some sort of warning.
 

Why do you think this?  Hell, even on the lowly Cessna 150 the flaps can be fully deployed at 100mph...stall speed is way down around 50.  Full flaps on the B-24 can be out at 155mph...stall is around 85mph.  B-17 flaps full at 144...stall around 75.  Do you consider doubling the speed over stall as a "very narrow margin"?

[thorsim]

well col you got any more pertinent examples, how about the pony with a combat load out?

in any case yea 50mph the difference between falling out of the sky and being in that state would probably warrant a warning or two, don't ya think?

what does the b-24 POH say about a full cross control roll at sea level with flaps fully deployed at say 110mph ...

two thumbs up?  ???

Why do you think this?  Hell, even on the lowly Cessna 150 the flaps can be fully deployed at 100mph...stall speed is way down around 50.  Full flaps on the B-24 can be out at 155mph...stall is around 85mph.  B-17 flaps full at 144...stall around 75.  Do you consider doubling the speed over stall as a "very narrow margin"?

[Gaston]

   Quote Gyrene81: "Gaston, look real close at that video...there is no atmospheric resistance on those wings or the flaps while that guy is turning that wheel..."

    -An absolutely valid point I overlooked.

   Quote Thorsim: "not sure why there would be much of a difference in the combat flap being used or the el trim gyrene they are two wheels connected to the same axle ..."

    -On the contrary, there would be a large difference in the air load to overcome, between altering  by a few degrees an edge-first surface like the tail trim effect on the tailplane, and moving down a large flap surface completely into the wind... Even then, the aerodynamic forces on the tailplane were so great that to trim out of a dive, the trim was best set BEFORE the dive, as the forces involved would otherwise quickly "freeze" even those small easy movements...

    Because the non-MW-50 Me-109Gs were not holding speed in turns well enough to compete very well in level sustained turns, I would not allow lowered flaps on them other than for landing, as historical pilot accounts say.  

    MW-50-equipped 109Gs would have flaps as an option at low speeds only, to take into account the air load, making them clearly superior-turning to non-MW-50 109s, which is historically accurate. Hartmann said the 109G could compete in the West ONLY with MW-50, and his gruppen immediately suffered heavy losses, including himself, when MW-50 use was discontinued...

    FW-190As turned best below 250 MPH IAS in comparative tests, so that would be the plausible limit for combat flap use.

   The P-51 seems a difficult subject, as there is a large range of deployable speeds and flap angles, but, like other fighters, the bigger effects appear to be confined to the lower speeds, combined with the pilot using a REDUCTION of engine power, along with a coarsening of the prop pitch, in several combat accounts, with the biggest turn performance boost occuring in this way below 200 MPH IAS! The Merlin Mustang did not like these speeds, but with all these actions by the pilot, it could apparently compete and more in level turns, on the deck, below 200 MPH against the Me-109G...

   A Polish pilot declared the use of flaps on the Mustang "useful, but they made the stall dangerous", which again suggest lower-speed use.

   I'm sure a lot of info is available on Mustang flap settings, as it is one of the few fighters for which flap use is prominent...

   To me it seems their effect above 200 MPH was less dramatic, but they could be used up to 400 MPH, so it's a bit of a quandary on this one aircraft which is famous for using them...
   
   Gaston

    

[boomerlu]

So, for example, what would the "new" P-51D flap deployment speed be?  At what speed, above that listed as a limit in the POH, could it effectively use the first increment of flaps?  Because, if 400mph is the book limit, then surely it could operate them safely at 450mph?

I'm being sarcastic of course, but what's the new criteria for performance data?

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.

If we are comfortable with flaps deployable at 400 mph IAS (say from some kind of structural simulation or model or fit to statistics), it shouldn't be a stretch to allow 260 mph flaps.

[BnZs]

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.

If we are comfortable with flaps deployable at 400 mph IAS (say from some kind of structural simulation or model or fit to statistics), it shouldn't be a stretch to allow 260 mph flaps.

The purpose of having flapped over-engineered to the point they are deployable at 400mph even though they don't add really anything at that speed is to make damn sure they can be used at 200-300mph.

If you have no credible data to show that the flaps on a Fw-190 could be safely deployed at speeds higher than what HTC data tells them, then there is no case. You can't credibly argue "but they *COULD* take 260mph" without evidence.

Outside of what the manuals tell us, flap durability is really an unknown and to a certain degree unknowable factor.  Just like with WEP times, HTC's "by the book/well within safely tested limits" policy is really about the only way to go. Any limit and attendant damage effect beyond those limits is just a game designer's guess. And I say this as someone who flies a 190 around and could *use* better flaps alot....

[Gaston]

  Quote: "If we are comfortable with flaps deployable at 400 mph IAS (say from some kind of structural simulation or model or fit to statistics), it shouldn't be a stretch to allow 260 mph flaps."

  -Quite true for the 190, but for the Me-109 it is a matter of the practicality and speed of manual deployment against airflow, which should definitely be more restrictive...

   Gaston

[boomerlu]

If you have no credible data to show that the flaps on a Fw-190 could be safely deployed at speeds higher than what HTC data tells them, then there is no case. You can't credibly argue "but they *COULD* take 260mph" without evidence.

I'm not the one who has the data to back it up. I'm hoping thorsim can produce it, whether through some kind of fit, actual documents etc whatever.

Once that happens (assuming it does), then we would not need a complex/expensive structural integrity model for the flaps. We could simply say they are safe at corner velocities and leave it at that.

Again, I'm not trying to provide data. I'm saying, if data is there, this would be the a cheap but useful way to put it into the game.

[colmbo]

well col you got any more pertinent examples, how about the pony with a combat load out?

Aircraft load has nothing to do with flap limiting airspeeds.

in any case yea 50mph the difference between falling out of the sky and being in that state would probably warrant a warning or two, don't ya think?

No I don't.  If you can't manage a 50 mph margin you'll never be able to fly it down final at 1.2 or 1.3 Vso.







[/quote]

[thorsim]

The purpose of having flapped over-engineered to the point they are deployable at 400mph even though they don't add really anything at that speed is to make damn sure they can be used at 200-300mph.

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

If you have no credible data to show that the flaps on a Fw-190 could be safely deployed at speeds higher than what HTC data tells them, then there is no case. You can't credibly argue "but they *COULD* take 260mph" without evidence.

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.

Outside of what the manuals tell us, flap durability is really an unknown and to a certain degree unknowable factor.  Just like with WEP times, HTC's "by the book/well within safely tested limits" policy is really about the only way to go. Any limit and attendant damage effect beyond those limits is just a game designer's guess. And I say this as someone who flies a 190 around and could *use* better flaps alot....

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

-----------------------------------

ahh col ...

Aircraft load has nothing to do with flap limiting airspeeds.

yer right there buddy got me again?  ...

tell me does load out, you know weight, weight distribution and such have anything at all to do with stall speed, stall character, you know the other half of my point there you seemed to have missed.

No I don't.  If you can't manage a 50 mph margin you'll never be able to fly it down final at 1.2 or 1.3 Vso.

oh i'm sorry col did you miss the part of the discussion that mentioned ACM you know air combat maneuvering, rolls inversions hard turns heavy Gs stuff like that ?

hey when are you taking the b24 out for those cross control roll at 110mph at sea level tests, i mean if it's perfectly ok ya know, cuz i'd like to be there to take pictures that would be very very cool ...

and i am missing that data on the pony you know with the stall speeds combat loaded and the flap deployment speeds, did i really give you a chance to be an expert on the pony that you took a pass on?
really ?

wow ...

[wgmount]

while we're discussing making planes better. Can i get some phasers and photon torpedoes for my hogs?

Seriously, Your chart Thorsim said a notch of flaps could be dropped at 700kph? Wasn't the top speed of the Bf109 around 650 at 20k? are you talking dive flaps? what about those aerodynamic wing slats for low speeds?
Also wasn't the 109 designed for high speeds to catch bombers and not for an all out turn and burn fighter?well, anyway what do I know.

Here you can get the opinion of 2 experts and how they have to work like mad to get the flaps down.

http://findarticles.com/p/articles/mi_qa3897/is_199912/ai_n8870616/?tag=content;col1

[thorsim]

must have missed any flap deployment difficulty, care to point it out in that article?

also do you have any reason to believe that a minimal deployment of the 109s flaps would significantly expose them to forces they could not handle even right up to the structural limits of the wing. 

i would be happy to look at any data anyone has to dispute the chart i posted or to explain the disparity between the POH and the designers approved limits. 

anyone?