Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: DaddyAck on January 31, 2008, 04:37:00 AM
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Does any one know if we have the Bf.109K-4 with the DB.605DB with B4 fuel + MW50 setup creating 1850PS at 1,8 ata at takeoff or the Bf.109K-4C3 with the DB.605DC with C3 fuel + MW50 setup creating 2000PS at 1,98ata at takeoff? Just wondering.
:aok
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The 1.98 ata IIRC, mate.
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Looking speed only, from these charts it looks like we have 1.8ata (w/ MW-50) with 9-12199 propeller. This was a new thin blade propeller which increased top speed at altitude but not at sea level. It may not have been used in operational 109k-4s, however.
1.8ata:
http://kurfurst.allaboutwarfare.com/Performance_tests/109K_PBLeistungen/files/5026-27_DBSonder_MW_geschw.jpg
1.98ata:
http://kurfurst.allaboutwarfare.com/Performance_tests/109K_PBLeistungen/files/5026-18_DCSonder_MW_geschw.jpg
Note the lower full throttle height for 1.98ata (~19500ft compared to our ~22000ft) and higher sea level top speed than what we have.
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Ok it is as I thought we have the K4 with the 1.8ata and not the 1.98ata. I wonder why that is? I would like to have the 109K-4C3 for it's better performance. But hey, whadda I know. :aok
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Originally posted by DaddyAck
Ok it is as I thought we have the K4 with the 1.8ata and not the 1.98ata. I wonder why that is? I would like to have the 109K-4C3 for it's better performance. But hey, whadda I know. :aok
EEEK, can opener ready, worms on hold :) .
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Which one? The one that is teh suckz!
(Ducks and runs).
donkey
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1.8 ata is our k4's max power, so obviously we have #1 :)
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Originally posted by Kev367th
EEEK, can opener ready, worms on hold :) .
let er rip kev. ;)
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Originally posted by DaddyAck
Ok it is as I thought we have the K4 with the 1.8ata and not the 1.98ata. I wonder why that is? I would like to have the 109K-4C3 for it's better performance. But hey, whadda I know. :aok
Ok, here's the deal, we back the C3 fueled, 1.98ata Bf109K-4s and you back the 150 octane fueled +21lbs boost Spitfire Mk XIV, +25lbs boost Spitfire Mk XVI and +25lbs boost Mosquito Mk VI. I am sure USAAF fans have some 150 octane birds they want as well.
Deal?
I thought not.
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Originally posted by DaddyAck
Ok it is as I thought we have the K4 with the 1.8ata and not the 1.98ata. I wonder why that is? I would like to have the 109K-4C3 for it's better performance. But hey, whadda I know. :aok
The K-4 used C3 but only put out 1850hp @ 1.80ata.
http://www.axiomdigital.com/db605.htm
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Originally posted by Karnak
Ok, here's the deal, we back the C3 fueled, 1.98ata Bf109K-4s and you back the 150 octane fueled +21lbs boost Spitfire Mk XIV, +25lbs boost Spitfire Mk XVI and +25lbs boost Mosquito Mk VI. I am sure USAAF fans have some 150 octane birds they want as well.
Deal?
I thought not.
This would result in a lot of mossies and spits burning up on reentry, augering at speeds few planes in AH normally reach. That would be excellent. :aok
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I have fought against the spit +25lbs in IL2, and frankly I am not worried about them. I don't care if you lobby for the +25lbs that is fine, my post was in reguards to our current K4. I was merely asking a question.
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Perhaps, but everytime the 150 octane subject comes up most Luftwaffe fans immediately attack it as "Spitdweebs asking for more easy mode" even though 150 octane was far more common than C3 fuel for Bf109K-4s, in fact C3 fuel for Bf109s appears to have been extremely rare.
For the record, the only aircraft I want to see 150 octane for is the Spitfire Mk XIV so its boost can be set to +21lbs and it might, maybe, then justify being a perk plane. I don't want to see either the Mk XVI or Mosquito VI at +25lbs, nor the Bf109K-4 at 1.98ata.
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Originally posted by Karnak
Perhaps, but everytime the 150 octane subject comes up most Luftwaffe fans immediately attack it as "Spitdweebs asking for more easy mode" even though 150 octane was far more common than C3 fuel for Bf109K-4s, in fact C3 fuel for Bf109s appears to have been extremely rare.
What are you basing that on?
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I think the multiple threads discussing higher boost for any of the planes previously mentioned, and/or the higher octane fuels that were required to create it. Usually, they do turn into purse fights.
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1,98ata K-4s were rare but K-4s using C3 were not.
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Originally posted by MiloMorai
1,98ata K-4s were rare but K-4s using C3 were not.
What are your sources?
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Originally posted by Xasthur
What are your sources?
This board for starters. Try the search option.
There was ~1700 K-4s built but only 4 Gruppen were authorized to use 1.98ata. These 4 Gruppen had ~150 109s of various models with about half operational. No one has come up with a number for 1.98ata converted K-4s.
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Which one is more important, the technical ability to run on increased ATA, or the historical availability of such fuel?
If there were units operationally running on C3 and 150oct why can't we have both since both engines could operationally do it?
Or is the "in numbers more representative" model preferable?
-C+
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Light perk on the 1.98 ATA version?
:noid
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IMO the best eventual solution is to have the 150 octane fueled Spitfires, P-51s, P-38s, P-47s, and Mosquitos and the 1.98ata 109K all perked to some extent. That way everyone gets what they want, but the higher boost versions won't take over the MA.
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Unless some more info has come to light, as far as I am aware there is no HARD evidence that shows even 1 K4 flew with 1.98ata.
Lots of -
could of's,
we can 'safely' assume,
might of,
possibly did.
There is no doubt they would have liked to have 1.98ata, as per the commonly shown document.
Another document dated 3 days later shows them still using 1.8ata, and this is at the end of March 1945.
So given all the supply problems (fuel and plugs) is it even likely it happened considering the 190's HAD to have C3 fuel.
Once/if converted for 1.98ata the K4's couldn't use B4 fuel anymore, at 1.8ata they could use B4 or C3.
Neither was it a simple mod back to B4 standards (from Butch who is a 109 expert).
They did have however a operational testing group of 109G's that did use 1.98ata starting in Jan 1945. (don't know how long it lasted).
It's the same for K4's with Flettners -
Pics show them.
Not one pic has surfaced that show the actuating rod, in fact they were locked shut.
So the next argument was "well pilots could have asked for them to be unlocked"
I suppose they could, nothing to show they EVER did though.
Check back through the threads for plenty of discussion on these topics.
Big difference is there are sqn line books, pilot logs etc that show -
Spit LFIX - 150 octane May 1944
Spit XIV - 150 octane July 1944
Whole of 2TAF cleared for 150 octane Dec 1944.
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"Unless some more info has come to light, as far as I am aware there is no HARD evidence that shows even 1 K4 flew with 1.98ata."
What is the hard evidence you require? There is a chart on Kurfy's site of units cleared for use of 1.98 ATA and AFAIK it is the same chart as in a book (not written by Kurfy btw).
And what friggin' flettners? I've never heard of 109s having flettners nor seen a picture. I see no immediate advantage of having flettners in 109 compared to flap/slat system it normally had.
-C+
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Originally posted by Charge
"Unless some more info has come to light, as far as I am aware there is no HARD evidence that shows even 1 K4 flew with 1.98ata."
What is the hard evidence you require? There is a chart on Kurfy's site of units cleared for use of 1.98 ATA and AFAIK it is the same chart as in a book (not written by Kurfy btw).
And what friggin' flettners? I've never heard of 109s having flettners nor seen a picture. I see no immediate advantage of having flettners in 109 compared to flap/slat system it normally had.
-C+
That is not 'hard evidence'. Cleared does not mean implemented.
for Barbi though, 'cleared = used by the LW; cleared = not used by the Allies'
Geez Barbi went on and on and on about Flettners. If not here, it was over at Ubi.
The rudder on the K-4 used a Flettner tab so I don't know how you could not have see them.
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Originally posted by Charge
"Unless some more info has come to light, as far as I am aware there is no HARD evidence that shows even 1 K4 flew with 1.98ata."
What is the hard evidence you require? There is a chart on Kurfy's site of units cleared for use of 1.98 ATA and AFAIK it is the same chart as in a book (not written by Kurfy btw).
And what friggin' flettners? I've never heard of 109s having flettners nor seen a picture. I see no immediate advantage of having flettners in 109 compared to flap/slat system it normally had.
-C+
That is the chart I mentioned in my previous post.
Another document which shows 3 days later that units were still using B class fuel.
I believe Mike over at Spitfire Performance still has copy of it.
That leaves 6 weeks till the end of the war (with fuel / spares shortages) to modify all the units he is claiming were done.
Kurfy wouldn't have it that Mk I spits used 100 octane during the BoB thats with a 3 month (not 6 week) lead period during relative calm.
He has some good info, but stretches things on the odd occassion.
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There was a proposal that formed part of w OKL, Lw.-Führüngstab, Nr. 937/45 gKdos.(op) 20.03.45 to convert some 109K-4 units to 1.98ata, however a proposal remains just that, an intention a suggestion.
Neil.
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"Another document which shows 3 days later that units were still using B class fuel."
Well, I don't find that hard to believe. Technically they were cleared to use 1.98 ATA and that is enough for me.
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Sorry, I misunderstood and was talking about something else in case of Flettners.
"An arrangement called the Flettner tab had been tried on large airplanes as far back as WW I. This device, which was invented by Anton Flettner, the same man who invented the Flettner rotor for propelling sailing ships, consisted of a small tab mounted at or behind the trailing edge of the main control surface. The pilot's control was connected just to the tab. When the tab was deflected, it moved the main control surface in the opposite direction. Because the hinge moment to deflect a control depends on the product-span times chord squared-it is apparent that very large reduction in the pilot's control effort could be obtained."
The rudder was very effective even in earlier 109s so I cannot see any sense in implementing a Flettner control in its rudder. Maybe elevator but not on rudder...
A useless modification IMO.
-C+
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Guess you have not had the pleasure of applying rudder for any amount of time above the cruise speed the trim tab on the rudder was adjusted for.
There must be some truth to the story 109s pilots had one leg fatter than the other for Mtt to have a rudder Flettner on the 109.
Flettners were also tried on the ailerons. There is suppose to be ~200 K-4s produced with aileron Flettners (Oli Lefebvre). These proved to make aileron control too oversensitive.
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With the "tail twist", you would not need the "boot" at a certain speed, typically the cruising speed right?
So, you would get legs excercize on both legs, typically more on the "high speed" leg right? Slow speed (under the nil, - cruise) would need opposite rudder.
Correct?
I'd much more have the trimmable one...
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"Guess you have not had the pleasure of applying rudder for any amount of time above the cruise speed the trim tab on the rudder was adjusted for.
There must be some truth to the story 109s pilots had one leg fatter than the other for Mtt to have a rudder Flettner on the 109."
It is true that above or below the set speed of trim tab you had to constantly apply pressure on rudder to keep the plane flying straight. So why not just install a simple trim tab adjustable from cpit but to change totally the more complex control system is beyond my reasoning. Also if the rudder becomes too light in slow speeds there's always a risk of over controlling, and even more so if the controls and not balanced enough.
I don't recall reading about the differences pilots experienced when changing to K. So were they indeed locked?
The method of flettners require the only to control of the tab, and the tab movement moves the rudder surface. So if the tab is locked the control wires need to be switched to rudder.
-C+
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Originally posted by Charge
"Guess you have not had the pleasure of applying rudder for any amount of time above the cruise speed the trim tab on the rudder was adjusted for.
There must be some truth to the story 109s pilots had one leg fatter than the other for Mtt to have a rudder Flettner on the 109."
It is true that above or below the set speed of trim tab you had to constantly apply pressure on rudder to keep the plane flying straight. So why not just install a simple trim tab adjustable from cpit but to change totally the more complex control system is beyond my reasoning. Also if the rudder becomes too light in slow speeds there's always a risk of over controlling, and even more so if the controls and not balanced enough.
I don't recall reading about the differences pilots experienced when changing to K. So were they indeed locked?
The method of flettners require the only to control of the tab, and the tab movement moves the rudder surface. So if the tab is locked the control wires need to be switched to rudder.
-C+
The Flettner is more complex???? :eek:
(http://www.simhq.com/_air/images/air_003d_7t.jpg)
Charge, do you know how the Flettner worked? One can't get much more simpler and is certainly more simpler than running another set of cables from the cockpit with pulleys and a wheel.
The Flettner tab certainly does not move the rudder. The movement of the rudder causes the tab to move.
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Quoting myself: "This device, which was invented by Anton Flettner, xxxxxx, consisted of a small tab mounted at or behind the trailing edge of the main control surface. The pilot's control was connected just to the tab. When the tab was deflected, it moved the main control surface in the opposite direction."
http://history.nasa.gov/monograph12/ch6.htm
So if the tab is locked as Kev suggested the rudder cannot move at all. That is unless the Flettner arrangement in K differs from the original idea of Mr Flettner.
I don't know if it does. Never really noticed the whole thing.
-C+
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It doesn't work that way, from everything I've seen and read. The small area of the fletner isn't going to move the large rudder way out into the airstream. The fletner just acts to relieve pressure by catching airflow off the trailing edge and giving it an extra "push"
The fletner is locked in relation to the fuselage. The rudder was still controlled with the usual cables.
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Charge, here is a crude diagram on how the Flettner worked.
(http://img.villagephotos.com/p/2005-12/1114844/Flettner.jpg)
A-D and A-D' is the rudder. The blue is the Flettner tab.
Point A is the rudder hinge line and Points D/D' is the tab hinge line.
Line A-B is fixed to the fin. Line C-D is fixed to the tab.
The rectangle A-B-C-D becomes a parallelogram A-B-C'-D' when the pilot inputs some rudder.
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The balancing tab system seen in the tall tail (and rarely in ailerons) of the Bf 109G and K is usually called as geared tab in anglo-american litterature.
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And today, in the smaller aircraft (as well as bigger?) we use.....CABLES AND WHEEL :D