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-   -   Leading Edge Slats on the Me-109 (http://forum.fulqrumpublishing.com/showthread.php?t=35549)

taildraggernut 12-10-2012 05:09 PM

Quote:

Originally Posted by robtek (Post 486463)
If you reduce it to that, the key point is that the 109 is controlable all the time, even in a high speed stall, and its adversaries aren't, which is a great achievement by itself and should be represented in game.

I'm not sure why you get that impression of it's adversaries, the NACA report on the MkV (which was the worst Spit in terms of stability) was actually quite good, the 109 is not in control all the time, if an aircraft is stalled it has technically lost control and the reports show the 109 could stall with an uncomanded wing drop, an uncomanded motion is by definition not in control, what should be represented in the game is something close to reality and that reality is that both 109's and Spits had very desireable stall handling qualities with both aircraft being pretty benign and in the Spitfires case having particularily good stall warning, I might add that if you were to believe Crumpp then the 109 also loses elevator control.

Quote:

STALLING CHARACTERISTICS IN MANEUVERS


The stall warning posessed by the Spitfire was especially
beneficial in allowing the Pilot to reach maximum
lift coefficient in accelerated maneuvers
.Because of the
neutral static stability of this airplane, the pilot obtained
no indication of the lift coefficient from the motion
of the control stick, nevertheless, he was able to
pull rapidly to maximum lift coefficient in a turn without
danger of inadvertent stalling.
Figure 17 shows a time history of a 180 ° turn in
which the stall was reached. The stall in accelerated maneuvers
was very similar to that in the gliding condition.
with gun ports closed, the pilot was able to pull the stick far back without losing control or interrupting the
turn. The airplane tended to pitch down when stalled and
to recover by itself if the stick were not pulled back.
It would be possible for a pilot pursuing an enemy in a
turn to bring his sights on him momentarily by pitching
beyond the stall without fear of rolling instability.


with gun ports open, a right roll occurred if more
than about 10°up elevator were applied. This reaction
caused the airplane to roll out of a left run and into a
right turn.


Time histories of these maneuvers are shown
on figures 18 and 19. In spite of the lateral instability
that occurred in turns with gun ports open, the pilot
was able to approach maximum lift coefficient closely because
of the desirable stall warning.


The maximum lift
coefficient reached in turns from level flight with flaps
up was 1.22. The airplane could be flown beyond the stall
at even lower lift coefficients.


This value of maximum lift coefficient is closer to
that reached from stalls in straight flight with power
off than the value renched with power on because the slipstream
effects in high-speed turns are relatively small,
The lower value of the maximum lift coefficient offsets, to
some extent, the benefit gained by the Spitfire from its
low wing loading in making turns of small radius. Good
stall warning characteristics appear to be essentiai on an airplane with neutral static stability. In airplanes
tested previousiy, which had neutral static stability and
poor stall warning, inadvertent stalling in rapid maneuvers
was practically unavoidable, The stalling characteristics
of the Spitfire are therefore its redeeming feature.

It should be desirable, however, to obtain these characteristics
without sacrificing a high value of the maximum
lift coefficient.

CONCLUSIONS


The Supernarine Spitfire airplane possessed stalling
characteristics essentially in compliance with the requirements
for satisfactory stalling characteristics given
in reference 1 These characteristics may be summarized
as follows:

1. Warning of the complete stall was provided by the
occurrence of buffeting that set in at speeds several miles
per hour above the minimum speed and by the rearward movement
that could be made with the stick after the start of
the stall flow breakdown without causing violent motions
of the airplane.


2. Stall recovery could be made by application of
down elevator, although the recovery from a roll was somewhat
slower than has been measured on some previously
tested airiolanes.

3. The airplane exhibited no dangerous ground-looping
tendencies in landing. Tail-first landings could be readily
made without the occurrence of either lateral or directional
instability due to stalling.

The airplane posessed some unusual characteristics
in stalls that are not required in reference 1. The motion
beyond the stall was not violent and an unusual
amount of lateral control was available in many flight
conditions, even when full up elevator was applied. The
good stalling characteristics allowed the airplane to be
pulled rapidly to maximum lift coefficient in accelerated
maneuvers in spite of its neutral static longitudinal
stability.

I am struggling to find an aspect in that report saying the Spitfire should spin wildly out of control

TomcatViP 12-10-2012 05:30 PM

Quote:

Originally Posted by *Buzzsaw* (Post 486310)
Modern slats may be intended to achieve improvements in lift at low speeds in the same way as the 109's slats, but they are not all the same design as the 109's. Gaps are almost imperceptible in comparison to the 109's when not deployed, when deployed, they move forward almost seamlessly, there is nothing in the way of the large open gaps displayed by the 109's slats when deployed. Modern leading edge flaps are a completely different system. These modern leading edge flaps are also computer controlled, with a degree of sophistication in their deployment which makes the 109's slats appear crude at best.

Slats of the 109 era do confer some benefits, but they also impose penalties.


I guess you was typing to fast and that charcters outrun your mind.

Hve a look to an F4E wing (or an A4). ;)

robtek 12-10-2012 05:32 PM

As usual the answer is only refering with evidence that is supporting the posters opinion and hair-splitting.
1. Did the 109 recover from a high speedstall with only minimal control input? The RAE report says so. Hardly a uncontrolled flight situation then, i'd say.
2. Did the early Spitfire depart from controlled flight in a high speed stall with a flip over and a following spin? Afaik all sides so far have admitted that.

There is no dispute that the controlled stall in the Spitfire was not hard to manage, but then, that was not asked for.

taildraggernut 12-10-2012 05:35 PM

Quote:

Originally Posted by robtek (Post 486473)
As usual the answer is only refering with evidence that is supporting the posters opinion and hair-splitting.
1. Did the 109 recover from a high speedstall with only minimal control input? The RAE report says so. Hardly a uncontrolled flight situation then, i'd say.
2. Did the early Spitfire depart from controlled flight in a high speed stall with a flip over and a following spin? Afaik all sides so far have admitted that.

There is no dispute that the controlled stall in the Spitfire was not hard to manage, but then, that was not asked for.


Please, can I respectfully ask that you don't descend into this mad poo flinging fest that arises every time someone simply has a different oppinion and shows evidence to back up why they have that oppinion.

I merely reminded of the good qualities of the Spitfire handling after you had basically claimed otherwise..

Quote:

Originally Posted by robtek (Post 486463)
If you reduce it to that, the key point is that the 109 is controlable all the time, even in a high speed stall, and its adversaries aren't, which is a great achievement by itself and should be represented in game.

Quote:

1. Did the 109 recover from a high speedstall with only minimal control input? The RAE report says so. Hardly a uncontrolled flight situation then, i'd say.
Both the 109 and Spitfire had this quality.

Quote:

2. Did the early Spitfire depart from controlled flight in a high speed stall with a flip over and a following spin? Afaik all sides so far have admitted that.
I don't admit to this, as far as I'm concrned the MkV was the worst Spitfire for longitudinal stability, earlier Spits by default will have had better qualities.

ACE-OF-ACES 12-10-2012 05:54 PM

I am still waiting on Crump's to tell us what he tells his so called students..

As in what does he tell them the purpose of leading edge slats are..

1) The purpose of leading edge slats is to reduce the chance of a stall
2) The purpose of leading edge slats is to reduce the chance of a spin

I think most agree the purpose of leading edge slats is to reduce the chance of a stall

Where as it appears that Crump is saying the purpose of leading edge slats is to reduce the chance of a spin

I think it would be interesting, and telling, to have Crump explain this line of reasoning..

Especially in light of the fact that there are many accounts of how leading edge slats CAUSED spins!!

Where, for what ever reason, the leading edge slats did not deploy evenly and thus induces (CAUSE) the plane to spin..

Not to mention the accounts of the leading edge slats POPPING out suddenly such that they 'changed' the aerodynamics such that the pilot had to quickly adjust his controls.. In essence startling the pilot such that he may have over compensated and CAUSE the plane to stall or even spin

In summary

It appears this is another cause of Crump cherry picking Luftwaffe attribute..

Where here only talks about the PROS of a certain attribute and totally ignores the CONS of a certain attribute

TomcatViP 12-10-2012 06:15 PM

AoA with such a name you shld know that it is both. And then with logics in mind it's the 2nd arguments tht is the most valid

In the absurd an anti spin decice IS a device reducing the chance of a spin to occur

You know, flight manuals are full of such simplification. A pilot is not a always a Phd holder in physics. It can eitherbe a carpenter, a greedy politicians or a nightclub hotess!

ACE-OF-ACES 12-10-2012 06:38 PM

Quote:

Originally Posted by TomcatViP (Post 486481)
AoA with such a name you shld know that it is both. And then with logics in mind it's the 2nd arguments tht is the most valid

In the absurd an anti spin decice IS a device reducing the chance of a spin to occur

You know, flight manuals are full of such simplification. A pilot is not a always a Phd holder in physics. It can eitherbe a carpenter, a greedy politicians or a nightclub hotess!

So using your logic..

The purpose of the breaks in my car are NOT to stop my car..

The purpose of the breaks in my car are to prevent me from getting speeding tickets..

Hmmm..

Sorry but no sale!

Ill stick with the intended purpose of the breaks in my car and not the multitude of what if's purposes the breaks in my car can be associated with to try and make a point..

Nice try though! You and Crump get a gold star for effort!

robtek 12-10-2012 07:07 PM

Sorry AoA, but with such arguments you are soo far out, that you will find it hard to see the objective, imo, of course.

And Taildraggernut, you are promoting the theory that the Spitfire didn't flip over and started a spin if pulled too hard in a high speed turn?? Really???
Afaik this was used by experienced pilots as a last ditch maneuvre to escape from a 109 on their tail.

taildraggernut 12-10-2012 07:14 PM

Quote:

Originally Posted by robtek (Post 486491)
Sorry AoA, but with such arguments you are soo far out, that you will find it hard to see the objective, imo, of course.

And Taildraggernut, you are promoting the theory that the Spitfire didn't flip over and started a spin if pulled too hard in a high speed turn?? Really???
Afaik this was used by experienced pilots as a last ditch maneuvre to escape from a 109 on their tail.

Are you suggesting that Spitfire pilots had to exploit a lateral instability as opposed to deliberately entering the spin by actually making pro-spin inputs? really?

putting an aircraft into a spin is a technique available to any pilot in any aircraft as a deliberate manouver.

ACE-OF-ACES 12-10-2012 07:43 PM

Quote:

Originally Posted by robtek (Post 486491)
Sorry AoA, but with such arguments you are soo far out, that you will find it hard to see the objective, imo, of course.

Don't be sorry

In that I fully expected you and yours standard off topic reply in an attempt to take the focus off what I said..

Not to mention how you and yours totally ignored the points I brought up about the historic accounts of the Bf109 slats causing more spin issues than they solved..


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