Bf 109 F series

[Denniss]

F-4 had a t/o weight of ~2850 kg, G-6 trop of 3154. Don't know how much the trop eqipment added to weight but I assume in the range of 50kg.
Basic airframe weight is 2083 vs 2300kg. G-6 trop weights may include the external rack as standard equipment, an F-4 trop load plan has 2150kg as basic airframe weight but it only contains weight with bombs (3254kg with 250kg bomb, requires strengthened tires).

 

[Civettone]

IMHO Finnish pilots agree with most of so called 'problems'

...

Notleistung was permanently accepted in Oct 43 and the t/o weight of 109G-6 was 3100 - 3196kg (depending the docu one looks)

Juha

Well, that kinda knocked me off my feet. Because I distinctly remember this well known website about Finnish experiences with the Bf 109:
virtualpilots.fi: 109myths

And I am talking about empty weight, based on official German test report sheets. Of course the G-6 gained more weigth.

Kris

 

[GregP]

Hope you didn't hurt your bum when you were knocked off your feet ...

 

[stona]

Widening the undercarriage track is a non-starter on the Bf 109.

The undercarriage attached to a cast steel truss (forged in later models) which was part of the fuselage, not the wing. This truss also served as an attachment for the lower strut of the engine bearer and the front attachment for the wing. No copy of the original technical requirements survives but several of the Bf 109s co-designers remembered that the wings had to be removable and the resultant parts be transportable on a standard German railway truck. The fuselage could also be simply towed. This feature had time saving benefits during construction and in the field eased maintenance. For example a wing could be changed without any specialised lifting equipment.

To widen the track would involve a major design change, unlike fitting a different canopy (which was done) or other relatively minor fixes. This is why even the BF 109 T still retained the original undercarriage track.

Cheers

Steve

 

[GregP]

That's EASY. Change the requirements so the landing gear track was wider.

 

[jim]

The question of a better 109 is not a stricly technical one.
The questions are 1) could the germans accept a reduction of the production in order to introduce major improvements? The answer was NO. Actually were unable to introduce even small improvements
2) Had the mother company interest and intention to push hard and fast the aircraft s evolution? NO. It appears Messerschmitt wanted to sell new types. Their main concern was the profit.

Anyway, if the answers to the above questions were YES
The logical next step after the F4 would be the aerodynamic airframe of the K4, even with DB605A. Could be available middle /late 43 . Would be 25-30 km/h faster than G6 on same engine.
A new ,under fuselage radiator could give some additional speed . The freed space at wings perhaps could accept small fuel tanks
Or introduce some type of combat flaps.
Standart main wheels , not the enlarged of the K4. Long tail wheel
Accept the fact that it was a small air superiority fighter. Not use it as multi purpose fighter, with heavy equipment. Its structure and landing gear should be only strong enough to support the standart configuration (with the 605 engine) and a 300lt drop tank. No 30mm cannons,no rockets ,no bombs , no presurized cocpits, no fancy radios . All these required additional structural strength (=additional weight)
Improve its armament by introducing better guns I have read about the proposals and studies of a faster firing and lighter 20mm gun, and more powerful but little heavier 13mm HMG
Introduce flettner tabs IF the wing can handle the forces
Study the possibility for a sliding canopy similar to that of Ania S199. It seems to offer even better visibility than Erla canopy
Study the possibility to replace the under nose oil cooler with a cooler similar to that of D9
Study the usefulnes of a different attachement of the wing for higher speeds
Ensure good building quality
Use slipper fuel tanks to boost range
Introduce as soon as possinle MW50 ,wide propellers and 603 supercharger

OR
Simply replace it with an easier to produce version of the Fiat G55

 

[Juha]

Hello Jim
I agree with the first part and the need for a better canopy, the more aerodynamical fuselage, Flettner tabs if possible and better quality control. And if easily possible the movement of GC somewhat nearer to the main u/c legs and some more fuel. But because of the reasons you gave in the first part of your message, that's all.

 

[Juha]

Well, that kinda knocked me off my feet. Because I distinctly remember this well known website about Finnish experiences with the Bf 109:
virtualpilots.fi: 109myths

And I am talking about empty weight, based on official German test report sheets. Of course the G-6 gained more weigth.

Kris

Hello, if you read the comments of the most experienced, you see what I meant, for. ex Karhunen never flew 109 in combat, all his kills were achieved while flying Fokker and B-239.

Juha

 

[Tante Ju]

I do not get why the wing needs to be redesigned with two spars... for one the current one was plenty strong with a box spar and good torsion resistance, and had some space in it for fuel if one really wanted that... one could place tanks in the gondola bay for example.

But why would anyone want that btw? The main L-shaped fuel tank was in the rear of the fuselage, right behind the pilot, and could be easily enlarged backwards a bit for a larger capacity one - as was done before, the original Bf 109 had a much smaller tank, something like 250 liters - the was both space and it would be close to the CoG. In fact they could slam a 100-110 kg MW 50 tank, GM 1 tank with no problem much further back in the fuselage.

So why tinker with the wing when you have space in the fuselage I wonder. The Mustang held fuel in the wings, because the fuselage space was already occupied by the radiator. The Spitfire could not enlarge the fuselage tank without some difficulty and redesign of the fuselage, since the volume around it was already non-existent, being slammed between the pilot and the engine.

 

[Tante Ju]

Anyway, if the answers to the above questions were YES
The logical next step after the F4 would be the aerodynamic airframe of the K4, even with DB605A. Could be available middle /late 43 . Would be 25-30 km/h faster than G6 on same engine.

I agree. Even better, introduce those fixes like wheel well cover on the first 109G, as was originally intended (did anyone notice the straight sides wheel wells vs the rounded ones on the 109F?) And why those bulky HMG bulges were used when it must have been quite obvious to anyone that a elongated, streamlined cowling (as on the 109K proto) could be much better is beyond me.

A new ,under fuselage radiator could give some additional speed . The freed space at wings perhaps could accept small fuel tanks

Possibly doable, but would need a major redesign of the aircraft, since the fuel tank was already where a Mustang-style ducting would be. The Italian design had such, but the Germans criticized those for a) being too small capacity b) making it impossible to mount heavier bombs under the fuselage hardpoint. Note the size of italian wing bombs.. and droptanks.

Or introduce some type of combat flaps.

Already present, just manual.

Standart main wheels , not the enlarged of the K4. Long tail wheel. Accept the fact that it was a small air superiority fighter. Not use it as multi purpose fighter, with heavy equipment. Its structure and landing gear should be only strong enough to support the standart configuration (with the 605 engine) and a 300lt drop tank. No 30mm cannons,no rockets ,no bombs , no presurized cocpits, no fancy radios . All these required additional structural strength (=additional weight)

But tactically all these were very very useful. Also the larger main wheels were needed to cope with increased weight and added stability. BTW the larger main wheels were not a problem, but they were mounted in more right angles, which more or less fixed the looping tendency.

Improve its armament by introducing better guns I have read about the proposals and studies of a faster firing and lighter 20mm gun, and more powerful but little heavier 13mm HMG

IMHO the guns were all fine. The 13mm weak HMGs were light, fast firing and could penetrate any aircraft armor. That was all asked for.

Introduce flettner tabs IF the wing can handle the forces

Agree. It was a mistake that these were only introduced on certain batches.

Study the possibility for a sliding canopy similar to that of Ania S199. It seems to offer even better visibility than Erla canopy
Study the possibility to replace the under nose oil cooler with a cooler similar to that of D9
Study the usefulnes of a different attachement of the wing for higher speeds

Probably studied though and though not worth it.. I doubt the sliding canopy would have been any better, but one interesting (and unexplainable) thing was that the 109K proto featured a bulged-top canopy. The 109 canopy was fine, except for tall people. A small bulge would have easily fixed that, and ti was only one plexi panel to be changed. Perhaps they worried about canopy distortions.

Ensure good building quality
Use slipper fuel tanks to boost range

That would probably add a few km range and kph speed with a droptank - and would also mean that 109s would need a special droptank and could not use the standard droptank used by all other aircraft from fw190 through ju 87 to destoyers. A simply aerodynamic fairing between the tank and the fuselage was tried and was very effective in reducing drag, but probably not worth it. Increasing speed for cruise by 20 km/h in a four hour cruise adds what, 80 km to range?

Introduce as soon as possinle MW50 ,wide propellers and 603 supercharger

The problem is that the engine bearings/lubrication can't even handle 1500 HP until the autumn of 1943, much less 1800-1900.. though a 603 supercharger could be probably still used.

Simply replace it with an easier to produce version of the Fiat G55

They would end up with much fewer fighters with different set of problems.. the G55 was a good fighter, but costly and far from perfect IMHO. The Germans considered it seriously, even tested it, but declined in the end.

 

[Milosh]

Both the P-51 and Spitfire got fuselage fuel tanks mounted behind the pilot Tante Ju.

 

[Tante Ju]

As far as volume went, its possible on any plane, but the original placement of the tanks will limit its practicality.

both spit/109 of them had stability problems until the tanks were emptied (as exhaustively discussed in the another threard), for a simply result, CoG is usually located near the main tanks for obvious reasons, and placing aux. tanks far from the CoG (forward in case of the Spit, I am not sure about the 51).

 

[OldSkeptic]

Forgotten which one said it, but a famous German fighter ace said, "it just needed a bigger wing'.

Basically needed a 190D or Tempest like conversion. Stretch the fuselage, bigger wing, bubble cockpit, bit more fuel, some more guns.
Crash program, start (say) mid 41, production in late 42.

 

[GregP]

Agree OldSkeptic, wholeheartedly.

Thye 109F was very good. Later models could have been better but weren't.

 

[stona]

That's EASY. Change the requirements so the landing gear track was wider.

I thought we were talking about improvements to the extant Bf 109, not starting with a completely different aeroplane
Cheers
Steve

 

[Dogwalker]

Possibly doable, but would need a major redesign of the aircraft, since the fuel tank was already where a Mustang-style ducting would be. The Italian design had such, but the Germans criticized those for a) being too small capacity b) making it impossible to mount heavier bombs under the fuselage hardpoint. Note the size of italian wing bombs.. and droptanks.

And the solution was...

You need more than a (or two, with two hardpoints, you have only to have enough power to lift it) 640 kg bomb? The Re.2005 made several tests with the asymmetrical hardpoint, with good results (even the landing of the MM495 prototype with a 640kg bomb still attached to the rack due to a failure in the hydraulic system can be considered a success), and it still had the wing hardpoints.
Note thet this solution was possible only with the outward retracting wheels.

 

[Civettone]

Hello, if you read the comments of the most experienced, you see what I meant, for. ex Karhunen never flew 109 in combat, all his kills were achieved while flying Fokker and B-239.

Juha

True, but he was the commander of a Bf 109 unit. I am sure he knew what he was talking about.

Agree. It was a mistake that these were only introduced on certain batches.

Interesting. On which batches is that? And why was it not generally introduced? My gut feeling tells me there was no need for it.

They would end up with much fewer fighters with different set of problems.. the G55 was a good fighter, but costly and far from perfect IMHO. The Germans considered it seriously, even tested it, but declined in the end.

Declined? I believe the Italian surrender came in between. Would you happen to have a source which states that the Germans declined?
Also, I am very curious and sceptical about the Kurt Tank link. I do not see why he would be interested in the licence production. In fact, he would be least likely candidate, as he had the Dora lined up.

Basically needed a 190D or Tempest like conversion. Stretch the fuselage, bigger wing, bubble cockpit, bit more fuel, some more guns.
Crash program, start (say) mid 41, production in late 42.

They already tried modifying an existing Bf 109. Every change led to another required change, eventually becoming the Me 209, a totally different ship.

Kris

 

[silence]

And the solution was...

You need more than a (or two, with two hardpoints, you have only to have enough power to lift it) 640 kg bomb? The Re.2005 made several tests with the asymmetrical hardpoint, with good results (even the landing of the MM495 prototype with a 640kg bomb still attached to the rack due to a failure in the hydraulic system can be considered a success), and it still had the wing hardpoints.
Note thet this solution was possible only with the outward retracting wheels.

But you could have several 109s produced for every 2005. Can one 2005 make up for, say, three 109s? Even switching to the G55 you'd only get one of G55 for every two 109s. I think Germany needed numbers and the 109 was at least more than good enough considering its production advantages.

 

[Dogwalker]

I'm not saying that Germans had to produce Re.2005s. I'm saying that's possible to carry a bomb, or two, or even a torpedo (the Re.2005 had the same loading capability of the Re.2001/2002, that included a W125/450/3.63 600kg torpedo), under the fuselage with a ventral radiator, and incidentally it requires the same undercarriage disposition the Bf109 already had.

Even switching to the G55 you'd only get one of G55 for every two 109s.

That's producing it in Italy. Even producing a Bf109 in Italy would require much more hour of work than producing it in Germany. Were the industrial conditions more than the projects that made the difference.
However, to switch production from the Bf109 to another rather similar piston engined aircraft sometimes in 1944 was simply not convenient for Germans.

 

[stona]

Also, I am very curious and sceptical about the Kurt Tank link. I do not see why he would be interested in the licence production. In fact, he would be least likely candidate, as he had the Dora lined up.

Any license agreement would have gone through the RLM, neither Tank/Focke-Wulf nor any other manufacturer had freedom to make such deals. This would make it even less likely. The RLM was more interested in licensing German aircraft technology for production abroad. I too would be very sceptical.

Oh, I think you meant that Focke-Wulf had the Ta 152 lined up. The "Dora" was just a stop gap

Cheers

Steve