Bf 109 F series

[Tante Ju]

We are getting very far from Bf 109F subject. Obviously Mr William work developed very controversial reputation over years between fan of axis and allied aircraft, result of his debated articles that are seen by many to strongly favour allied aircraft and are perhaps inaccurate. It is not important question here and I do not think either side will convince the other, so any criticism of this controversy should not be further in this thread as moderator noted very clear already..

So, lets all get back to far more interesting subject while mod allows!

 

[Tante Ju]

Ever thought about the FACT, that the base of the FW 190 was very much better then that of the first Bf 109 series and later of the Bf 109G series, so is wasn't necessary to change anything on the aerodynamic. The FW 190 was in all it's life much much easier to fly as any Bf 109 series and it was much much better to the sticks from the beginning till the end at high speed maneuvers. This can you easily see at flight school report and many statements from LW experts.

Hi DonL,

I do not think its so black and white. The LW considered the advantages of the Fw 190 handling over the Bf 109 (mostly: lower stick forces at high speed, higher roll and more robust construction), but they were not homogenous. Stall characteristics of the Fw 190 were very poor in comparison, showing tendency of unexpected flick rolls while the 109 was benign in this regard. The 190 pilot on the landing pattern to deal with higher approach speeds and unexpected sink rate, though it was free of the ground looping tendencies of the 109. So I would not describe the 190 much easier to fly, but rather just having different quirks.

There is statement on this from german experts. Kurfürst - Vergleichsfliegen Bf 109 E, Bf 110 C, Spitfire, Hurricane und Curtiss.

Also the story of Fw 190A was somewhat similar to the story of the bulgy 109G-6, the 190 lost some 20-25 km/h speed due to increased drag of airframe between A-5 and A-8.

 

[Juha]

... Re relevance to the 109F, I see the 109K as about as far as you can get from the 109F's ideal compromise between the designs strengths - ease of production and maintenance, performance - and it's potential weaknesses - armament limitations, deteriorating flight characteristics etc.
When I think of the 109F I invariably also think of it's great rival, the Spit V. My understanding is that the 109 out-performed the Spit at lower altitude but as most combat took place at higher altitude the Spit was able to hold its own. But it occurs to me that there was one other RAF fighter of the time that might have outperformed the 109F when they met. That's my teaser - off to post another thread.

IMHO 109F-4 was faster than a normal Mk V across the altitude bands and especially at higher altitudes. Not a big surprise because Merlin 45 and 46 had one-stage supercharger.

Juha

 

[Shortround6]

What are the actual differences between a "F" airframe and and early "G" without pressurized cockpit?

Not just a different contour to the engine cowl but actual differences besides the DB 605 engine? AS in could you stick a DB605 (with proper cowl and and oil coolers and such) on a "F" and turn it into a "G"or a DB 601 installation on a "G" and turn it into an "F"?

Few "F"s had the GM-1 Installation, not all "G"s had it. Could the weight and position of the GM-1 installation affect flying "qualities"?

 

[Juha]

Hello SR6
IIRC G-2 had a bit stronger wing than F-4, being covered by a bit thicker sheets, at least at roots. Internal wiring allowing the use of wing armaments (gunpods, rockets) as standard etc.

Juha

 

[Njaco]

and CobberKane just got a week's vacation for that comment at FlyboyJ. Joe warned everyone and the Mods agree - no more nonsense!

 

[FLYBOYJ]

Good grief, if I'd known that questioning the 109K as an uber-fighter was going to get such a vitriolic response I would have stayed quiet. On the other hand, I go all weak at the knees when Flyboy get all alpha male, so I guess it was worth it...

I just caught this. NJACO gave you a week, I'm giving you a month. One more incident and you're gone.

 

[Tante Ju]

What are the actual differences between a "F" airframe and and early "G" without pressurized cockpit?

Very little. In fact the 109G replacement part list booklet refers back the 109F part list booklet for those items not listed. New welded canopy, reinforced wings, the G got laminar fuel tank armor and front bullet proof glass as standard (Fs were retrofitted) and the radiator boundary layer was deleted on the G. There was a squared wheel well on the G - it was intended to have wheel well covers. The G was probably even a bit better since it had an internal armored glass as opposed to the external ones retrofitted to 109F.

Not just a different contour to the engine cowl but actual differences besides the DB 605 engine? AS in could you stick a DB605 (with proper cowl and and oil coolers and such) on a "F" and turn it into a "G"or a DB 601 installation on a "G" and turn it into an "F"?

In fact the famous Black Six started out as a late production 109F according to its history, but finished as a G. There was very little difference between the 605A and the 601E, external dimensions were identical, the 605 for all practical purposes was just an up-bored 601E with minor improvements.

Few "F"s had the GM-1 Installation, not all "G"s had it. Could the weight and position of the GM-1 installation affect flying "qualities"?

Russian trials returned practically identical turn times for F4 and G2, so I doubt there was much difference in flying qualities... GM 1 added some weight, but apart from that.

All in all I consider the 109G the very subject of this thread, an improved 109F - with wheel well covers and a 605A with full potential. An easy 700 km/h plane... in 1942.

 

[GregP]

I thought the only real differences between the DB601 and DB605 were the 605 had 4 mm greater bore, turned slightly higher revolutions, has a hiogher compression ratio, and a more powerful supercharger. And that was it. The DB605 used the same case and mounting holes and was designed from the outset to run on B4 (87 Octane) fuel. Later, in 1944, they came up with a version allowing C3 (100 Octane) and boosting systems like MW 50 and GM-1.

They did have a different propeller reduction gear for the twin engine fighters and also came up with a projected 2-stage supercharged unit (DB621), built a 3-stage unit (DB628 ) but abandoned it in 1944, and also built a turbocharged unit (DN625). They even tried a pair of coupled DB628's called the DB620. None of these went anywhere, but developmental work continued on the DB 605.

The DB605 with all the improvements was about 330 pounds heavier than a DB 601.

I'd really like to be able to stop the editor from replacing my "eight-)" with a smiley face.

 

[razor1uk]

Until the emote codings (if ever) are redone Greg, just remember to put a space before the end bracket - I too find it annoying, but not as much as the di-sgusting emote even more annoying when you type it as one word and get disgusting.

 

[Shortround6]

Thank you for the information. On book I have says that the GM-1 system in the F was in the wing ( two different systems actually) and good for 10 minutes maximum. either eight small bottles or two circular tanks, weight of fluid was either 34 or 42 KG and weight of the whole system 46 or 75KG.

I haven't been able to find the weight/s of the system in the G series aircraft. We do have this from the Kurfurst web site from the short manual/ instructions on the GM-1 system.

"Beware the Start! Plane is tail heavy by the GM-1 system and
therefore to trim nose down to 1 1/2."

Now the GM-1 is not used on every flight and while the weight of the system may not affect the ultimate turning times or turning ability it may affect low speed handling? Perhaps like flying a Cessna or Beechcraft at the full aft limit?

I am not trying to run down the 109 here but trying to find out why/what the differences are between the "F" and "G" that might explain the the alleged reputation the later "G"s had. Why they needed bigger landing gear , and so on.

The P-51s were NOT supposed to be landed with the rear tank full or near full. The GM 1 system may not be anywhere near as a bad as a P-51 with a full rear tank but something may have been going on that affected elevator response at slow speed/landing configuration.

Understanding that might give us some idea what might (or might not) have been done to the 109F.

From the

 

[Shortround6]

The DB605 with all the improvements was about 330 pounds heavier than a DB 601..

The last 601 (E) may have been a bit heavier than the early ones and the first 605s a bit lighter than the later ones, and that is the change from the "F" to the first "G"s.

This is what gets a bit confusing ( at least to me) is that there were at least two 601s used in the "F"s and several different 605s used in the "G"s (not counting experimentals) and the landing gear was changed twice (?) on the G's so which change/weight increase was responsible for which landing gear change ?

 

[GregP]

Hi Shortround,

I think there is a lot of informaiton available in English about the P-51 and other American and British planes. Conversely there is much information NOT available in English on the Bf 109 and there is also quite a bit of either misinformation or outright disinformation on the Bf 109 out there. Some is probably a holdover from early mistakes.

I have seen people take William Green to task for this, but his later works seemingly corrected much of that. I've head a lot of folks who liked Martin Caiden, but he also tried to "fill in the gaps" when he was missing some information and, in some cases, seems to have just made things up in order to finish a book.

The little nuances of Bf 109 information are mostly probably still in German for the most part, but that doesn't account for the great disparity in performance attributed to it. I can find flight test by different organizations out there in which the speed and rate of climb for a single model are so different as to almost be ludicrous. Naturally the Bf 109 fans take the highest number and the detractors like to take the lowest number, leaving us in an argument with little resolution.

I've seen some data not labeled as to whether it was IAS or TAS, also an issue with US and British tests, though not too widespread.

Too bad there aren't more tests where the roll rate at different speeds is show along with the time to complete a 360° turn at various heights and speeds. These might BE available but, if they are in German and it is scanned and not copyable text, it is tough to get a translation from BabbelFish or other online translator. Many of the very excellent USAAF and US Navy post-WWII documents are that way ... sanned and not copyable.

What I'd really like to see is a single place where primary source data are translated and kept together. Personally, I trust the German data as I trust the British and American data. If the Americans or British wanted to show a better domestic product, they simply limited the manifold pressure for the foreign plane, but at least the manifold pressure is usually noted in the data, so we can tell when this type of stuff is being done.

As for the German data, I can read the charts and numbers, but am unaware of any special circmstances or limitations since I don't read German. But I'm sure the data are accurate and reliable. Of course, I'd prefer to see Luftwaffe tests over, say, Messerschmitt, Junkers, Arado, etc. data. The Luftwaffe would have no reason to lie to itself while a manufacturer might want some data to help sales along, just as in Allied countries. Still, primary source data would be very welcome.

In restoring our Hispano Ha.1112 Buchon, we have come across many needs. For instance, we spent a year looking for the landing gear uplocks. We have the manuals but the drawings are simple illustrations, not fabrication drawings. So, we couldn't just have one made at a machine shop since we didn't HAVE a suitable drawing. We had to locate an existing pair of uplocks and obtain them.

This lack of good data carries over into restoration.

Right now we are making a new instrument panel in which our chosen instruments will fit. We will save the original, but nobody rxcept a museum (like us ... we HAVE a display of original WWII instrument panels complete with instruments) is going to set up an original 1960's Ha.1112 panel these days, what with so many new great instruments out there. We stole the wingtips from our Bf 109G-6 in Arizona and when the Ha.1112 is flying again and we have time, we need to fabricate new ones and return the originals to the Messerschmitt. We already made new wheels from Aluminum instead of magnesium, so the Messerschmitt still has its original wheels. Again, we had no fabrication drawings, so we took an original wheel and had a machine shop duplicate it in Aluminum.

 

[razor1uk]

Sounds like you need someone with AutoCAD to jury rig a draught/design or the uplocks - that and micrometric verniers, calipers and radius gauges to supply them with info...

 

[Aozora]

IMHO 109F-4 was faster than a normal Mk V across the altitude bands and especially at higher altitudes. Not a big surprise because Merlin 45 and 46 had one-stage supercharger.

Juha

The Malta campaign showed that given the right tactics the Spitfire Vs, even with the Vokes tropical filters, could hold their own against F-4s, albeit the F-4 was definitely faster. Over France it was a different story, although it was the 190 that really exposed the performance deficiencies of the single-stage Merlin.

 

[GregP]

AutoCAD isn't going to help much. It will if you can borrow a part, but without the part, the landing gear must be assembled to the landing gear bracket in order to get a meaurement, and the access room is just not there. It is very tight and you'd not be able to get good meaurements. You could try and I wish anyone luck. Really, it is tight.

We COULD have borrowed some parts, had them measured and then created a fab drawing ... but once we found the parts it wasn't necessary. When the plane is groundlooped (last time was due to right brake failure, not pilot error), the locks aren't usually damaged ... it snaps off the gear on the most forward side and damages the gear but not the downlock on the other side.

All we did was to misplace the parts. If we had not FOUND parts, we would have gone through the fab drawing stage, but there was plenty to keep us busy until we found the downlocks. First we had to repair the landing gear with new brackets. The we had to repair the damaged wings and landing gear items. Since none are available, we had to fabricate all the repairs and make new pieces. That took awhile and required custom wood fab molds be made. Meanwhile we found the downlocks. No problem.

Here is a shot of the old panel from back in June 2007. Since the airframe is basically that of a Bf 109G with a Merlin on the front, the former owner had the small placard made and he installed it there. We didn't.

You can see we have a knots airspeed indicator, rate of climb in feet per minute, attimeter in feet and manifold pressure in inches of Mercury absolute, just like all our other warbirds. Really, the numbers aren't much different from familiar US or British numbers when you convert them all to the same units. They are, in fact, amazingly similar

Here is a shot that shows a small bit of damage to the starboard wing root, but doesn't convey the extent of the damage, The bracket in the wheel well goes on the 4 bolts at the top center ... but the enire tab is bent and there is some missing reinforcement where the root rib was broken, plus a LOT of generally bent stuff:

Today it is all repaired and the wing and gear are back on the fuselage and the panel is out of the aircraft having a new one made. It will not have a placard mis-identifying the aircraft when we are finished.

 

[Civettone]

Very very easy no engines were available! Alone this statement shows me how minor is your knowledge about the development and production of the LW engines.

Neither any DB 603 was produced in numbers till end 1943, beginning 1944 nor the Jumo 213 was entering mass production before end of 1943.
The DB 603 engine was strictly for the Me 410 and Do 217 at the beginning and only with the mass produced Jumo 213 was an engine available.
You should look at the produced engines and the timeline, the production of 1942 (DB 603, Jumo 213), was a blow in the wind and at 1943 the production and tooling was changed, but the produced numbers were very smal!

I do not think my knowledge is that minor. I have the figures for DB 603 production - I have shared them here before - and it clearly shows that it was mass produced in 1943. By the end of 1943, over 350 engines were being produced monthly. That is not very small. Production would have been increased if there was a need for it, just like happened with Dora's Jumo 213 in the second half of 1944.


Kris

 

[Juha]

Hello Kris
but there were many Do 217Ms standing engineless while waiting for their DB 603s.

Juha

 

[Civettone]

Okay, but when was that? 1943 or 1944?
Also, during 1943, there were some reliability issues concerning the DB 603. Only fixed toward the end of 1943 (IIRC)

Production picked up at the end of 1943 and increased throughout 1944.

Kris

 

[Juha]

Hello Kris
I would like to give a better answer but Griehl's Do 217-317-417 book isn't the easiest one to find a specific info and I'm in the hurry. B ut 10 Feb 44, 270 Do 217s, lacking engines, were cancelled.

Juha