Bf-109F-4 and a bleak time for RAF

mad_max · 12-20-2006, 07:17 PM

Flyboy,

Olivier's book will totally be one you will want. He's straightened out quite a few folks
posting some wrong thoughts about the 109. He is the most unbiased person I've seen
posting on boards. Want to learn some good tidbits, then visit the boards he posts on
and search for his posts. They all got different tidbits in them. I could put a nice little
paperback together just from his postings.

Kurfurst,

You accuse alot of folks of being someone they aren't. I'd suggest taking a big breath
and let it out slowly. I'm giving you a job well done on your website, but I don't agree
with some of the deductions that you come up with. I do no different to Mike Williams and
his website.

BTW I have never been kicked off one board yet and don't plan to. Please you've done
good, but you need to calm down and not be so bitter in life. It's nice to see you've eliminated
the webpage where you trash on Mike. A good start..now just let it go and be happy.

Regards,

Soren · 12-20-2006, 07:51 PM

Quote:

Originally Posted by Jabberwocky

Really funny.

Especially when the test says in the first paragraph of pg 4: "performance at this altitude at about 28 to 30 s for the stationary full circle without altitude change. This is equivalent to a shortest time for a full circle at emergency power and 1000 m of about 25 s."

A 25 second turn at 1000m would put the tested aircraft some 6 seconds, or 31.5%, behind the Russian tests for 19 sec for the same type of aircraft.

The report also mentions the "the aforementioned [troublesome] turning characteristics of the La 5", which you can draw what you will from.

According to Soviet tests the FW-190A8 could do a 360 degree turn in 21-22 seconds. So this leaves me wondering how accurate this assesment of the La-5FN really is, when the report also states that "The times for a full circle are better than those of the Fw-190A8 at ground level and worse than those of the Bf-109"

Inconsistencies stacked up on inconsistencies. It all depends on how you want to interpret the data...

Jabberwocky,

If you haven't noticed it yet, all German turn-times are higher than Soviet ones for the same aircraft, the reason being that the clock was started earlier by the Germans than by the Russians - Compare the Russian Fw-190 A-8 turn time with the German for the same a/c for example.

There's no way this can be interpreted incorrectly.

But as always, the end result of a test is never better than the pilot carrying out that test - The one that dares to push it right to the limit is the one who will bring home the best results. That is why test results are no better than pilot-accounts.

And about the troublesome turning characteristics, well, you're going to have to point out to me where that is written cause I sure can't find any such comments.

Btw, the La-5FN in question was in excellent condition.

FLYBOYJ · 12-20-2006, 07:56 PM

Quote:

Originally Posted by mad_max

Flyboy,

Olivier's book will totally be one you will want. He's straightened out quite a few folks
posting some wrong thoughts about the 109. He is the most unbiased person I've seen
posting on boards. Want to learn some good tidbits, then visit the boards he posts on
and search for his posts. They all got different tidbits in them. I could put a nice little
paperback together just from his postings.

Max, you're probably very correct and his book sounds worth-wild - my point is I have seen dozens and dozens of folks attempting to argue aircraft performance based on performance charts, sometimes not fully understanding what they are talking (but acting like and "expert") about because they have never used those charts in conjunction with operating a real aircraft. I have flown jets (L-29s and L-39s to name a few) and there are at least a half dozen performance charts within their flight manual. For the most part you only need to extrapolate a small segment of that information to safely operate the aircraft - the same holds true for WW2 aircraft.

Quote:

Originally Posted by mad_max

Kurfurst,

You accuse alot of folks of being someone they aren't. I'd suggest taking a big breath
and let it out slowly. I'm giving you a job well done on your website, but I don't agree
with some of the deductions that you come up with. I do no different to Mike Williams and
his website.

BTW I have never been kicked off one board yet and don't plan to. Please you've done
good, but you need to calm down and not be so bitter in life. It's nice to see you've eliminated
the webpage where you trash on Mike. A good start..now just let it go and be happy.

Regards,

Gentlemen, despite my prejudices as mentioned with regards these types of discussions, be rest assured when it gets out of hands the Mods will quickly act upon "the situation" and take quick and decisive action to those we feel are a disruption to this forum. Heated debut within reason is always welcomed...

FLYBOYJ · 12-20-2006, 07:59 PM

Quote:

Originally Posted by Soren

the La-5FN in question was in excellent condition.

Good point Soren - one has to consider the condition of the aircraft, fuel, pilot ability, weather conditions, and even maintenance, further clouding the issue...

Soren · 12-20-2006, 08:07 PM

Quote:

Originally Posted by Chingachgook

Soren,

Well, lets see what you have found...

109G turns "better" than La5FN in German test.

Spitfire LF IX turns slightly faster than La5FN in Soviet test.

109G does not turn as fast as La5FN in Soviet test (but 109G has wing gondolas? source? - I am not saying it didn't I just want source).

That is interesting, you have found something new. It is not conclusive but still interesting. It is a "this is to that so that is to this" equivocation.

Just a few observations.
1.Not sure why you felt it important to include the La7 - was much lighter than La5... No German La7 test?
2.Not sure why you omitted the Vb... It turns not as fast as XI in Soviet test (but out turns IX in radius in RAE tests) it would have made your case look better in some ways...
3. Spit was not at 25lbs boost - at 1690hp it would be 16 or 18lbs), but I am not sure how much that would effect the test (alt dependant). More power would help turn rate.
4. No quantitative values on the German test, we do not know how much better the G was over the La5FN.
5. Still no LF XI vs 109G/F direct comparison. Two tests under different protocol - but I like the idea of comparing them.
6. Soviet test was of turn speed through 360degrees, no radius quantified. Was German test concluded based on radius and not turn rate?

The Greman test was obviously about turn rate, as the one which turned 360 degree's the fastest is the better turn fighter.

Quote:

IMHO, Yak3 @ 17sec might have been large radius and fast turn rate, this might explain why it did well even with higher wingloading (did anyone mention taper angle of wing plan shape?). R value would have been nice to know but russkies left this out. Did Yak3 have as small an R value as XI? We just don't know...

Chinny, the higher the taper ratio the more troublesome your aircraft will be to turn as it will suffer from tip stall - Hence why the La-5/7 has slats, cause without them it would have some nasty and unpredictable stall tendencies, like those suffered by the Yak.

The 'e' factor AKA Oswald efficiency factor represents the planform efficiency of the wing, and it is incoperated in the Cdi calculation I presented earlier.

So don't worry, nothing has been left out.

Quote:

btw, slats do deploy one before another on 109 and that unequal deployment WAS disconserting to pilots (and still was pressent on Buchon ie G2 wing). I did say it was designed that way did I not? Yes I understand why the slats deploy one before the other - ment to delay (or tame) the stall, keep outboard of wing flying... My father (tech sgt) did mantainance on F-86 in USAF which had slats, and did big wing retrofits during Korea (first to get rid of slats then I think they fitted them again on bigger wing).

The unequal deployment of the slats is not at all what the inexperienced pilots were concerned about - it was the loud bang and slight notch it gave when the slats deployed that scared them, aborting the maneuver emmidiately afraid the a/c was about to stall - what experienced pilot knew was that all you had to do at this point was keep pulling cause the a/c wasn't even close to stalling.

Chingachgook · 12-20-2006, 08:10 PM

Soren · 12-20-2006, 08:19 PM

I'd hate to rain on your parade Chinny but you freaked out already in the first thread you ever participated in on this forum, seemingly because someone didn't like the Spit as much as you.

Ofcourse its always easy to rid yourself of all accusation by claiming you love the a/c you actually hate and vice versa - only problem is I had you figured out from the beginning.

Chingachgook · 12-20-2006, 08:21 PM

Soren · 12-20-2006, 08:26 PM

Quote:

Originally Posted by Chingachgook

One of my aerodynamic engineer buddys says that taper angle does help in a big way for turn rate but I do not remember why - E retention? (he is out for Xmas now). Yes I do believe he said that it causes tip stall (or was it root stall?) Never heard anything about Yak3 having bad stall issues (?).

It causes tip stall Chinny, not root stall.

And about the Yak, well what have you heard about it ?

Chingachgook · 12-20-2006, 09:13 PM

Hunter368 · 12-20-2006, 09:19 PM

Soren he is trying to hold out a olive branch......take it and end this.

Soren · 12-20-2006, 10:08 PM

Hunter,

If that was a try at holding out a olive branch then it was a very poor one I must say. Even when trying to make peace he can't refrain from making insults and completely unfounded claims.

Hinton doesn't fly the 109 as much as Chinny assumes, and he certainly doesn't throw it around either.

______________

But ok Chinny, no hard feelings from my part. Now lest debate the matter at hand shall we ?

mad_max · 12-20-2006, 11:48 PM

Don't know how many have watched this, but this video is awesome. Just listen to
that DB singing! Music I tell ya music.

Aviation Video: Messerschmitt Bf 109 - Private

And if not enough for you yet, another two.

YouTube - messerschmitt 109 G

YouTube - Messerschmitt 109 G

Imagine taking your own 109 up the first time, then getting the rush
of this landing. Once would be enough for me.

Enjoy.

mkloby · 12-21-2006, 07:03 AM

Even though a tapered, or elliptical wing causes tip stall - that doesn't mean that there aren't measures you can take to produce more gentle stalling characteristics - take stall strips for example.

davparlr · 12-21-2006, 10:30 AM

Quote:

Originally Posted by Soren

Did you get the Performance docs I sent you btw Davparlr ?

Yes I did. I haven't had time to digest it yet but a quick scan shows impressive performance. Thanks alot!