Much improved Me 109K?

[tomo pauk]

You can streamline the 109 but unless a few other things are fixed (and some are not easily fixable) you don't gain a whole lot.

Aleron response was already getting poor in the upper speed ranges, adding 30-50kph just makes things worse, you have a straight line fighter.

I don't know about rudder response/control, they were fitting rudder tabs near the end?

The 109 was too lightly armed to be a good bomber interceptor (3 gun versions) going faster really doesn't change that.

While a more streamlined plane may increase the range a bit it doesn't do much for endurance. You fly further in the same amount of time.

Streamlining gave 20+ km/h to the 109K-4 vs. 109G-10, on same engine and same level of fit & finish, so it was certainly a plus. When a 30mm cannon was installed, a Bf 109 was a very good bomber interceptor.

I am assuming the aerodynamic improvements only. I also believe that the later 1800-2000hp DB605 engines only ran at those power levels for a few minutes at a time and that max continuous power (non combat climb) was the same as the 1425-1475hp engines, endurance wouldn't change that much. I could be wrong.

The main advantage of the DB 605AS and D engines over the DB 605A was that they gave much better at higher altitudes, allowing the Bf 109s with these engines to negate much of performance advantage the Merlin Mustangs and P-47s possesed above 20000 ft.

 

[Milosh]

Is there an English translation?

Type 'translate' into Google. Basically it says why increase engine power when that increase in power is negated by crappy manufacturing.

 

[Milosh]

A bit more than just "some", I count ~1.8K AS versions vs ~2.9K non-AS

If it makes you feel better, I should have said some versions of the G-14...…..
My count, 2689 G-14 of which 854 were U4s, 1377 G-14/AS.

 

[Denniss]

1306 G-14/AS up to 11/44 + roughly 500 more to the end

 

[Milosh]

Not according to Post #26, Bf109 Neubau 1/44 to 3/45 - Page 3 - Luftwaffe and Allied Air Forces Discussion Forum

 

[dedalos]

You can streamline the 109 but unless a few other things are fixed (and some are not easily fixable) you don't gain a whole lot.
An aerodynamic improvement that would result 60km/h speed increase would give a noticeable improvement in sustained turned rate . Also marginally better acceleration at high speeds

Aleron response was already getting poor in the upper speed ranges, adding 30-50kph just makes things worse, you have a straight line fighter.
You exaggerate the problem. Operational pilots reported the problem and the Bf 109 was demanding physical strength at speed but did fight at those speeds.
50km/h would be a huge improvement . On the eastern front would be able to engage and disengage at will the russian fighters even at low altitude. On the western front would match the speed of the latest fighters
Anyway, by that stage of the war , all that Luftwaffe could do was hit and run attacks ,in which straight line speed was most important. Dog fighting was suicidal against the huge numbers of the allied forces

I don't know about rudder response/control, they were fitting rudder tabs near the end?
Occasionally yes, when supplies permitted but that was not a major flaw in the Bf 109

The 109 was too lightly armed to be a good bomber interceptor (3 gun versions) going faster really doesn't change that.
A better ability to avoid the escorts through greater speed would be invaluable
Klaus Mietusch, CO of III/JG26 until his death, claimed that the Mk108 did deserve his weight penalty because gave the Bf109 a good ability to destroy heavy bombers.
I would say that Bf109 s main mission was/should be air superiority .

While a more streamlined plane may increase the range a bit it doesn't do much for endurance. You fly further in the same amount of time.

Could you explain why? For a given cruising speed a more streamlined air frame requires lower power setting and thus lower fuel consumption. Am i wrong?

 

[Mike Williams]

Basically it says why increase engine power when that increase in power is negated by crappy manufacturing.

Likewise, the performance boost hoped for as a result of the measures listed in the opening post would not be obtained with exceptionally bad airframes as reported in Niederschrift Nr. 6730 .

 

[Shortround6]

Could you explain why? For a given cruising speed a more streamlined air frame requires lower power setting and thus lower fuel consumption. Am i wrong?

You are not wrong but then I am not sure you are really right. It depends so much on the speed chosen, by that I mean if the speed desired was, say 500kph and the throttle/s of the fighter group were adjusted to give that speed then both range and endurance would be increased. So you are right.
On the other hand if the pilots are told to cruise at say, 2000rpm and 1.15 Ata (or other power setting consistent with continuous power) then the increased speed due to better streamlining would give better range (more ground covered per minute of flight) but the endurance would be the same ( same fuel burned per minute of flight). I am not making any claims about the Germans but the British often flew at max weak mixture (2650rpm and 7lbs boost) on most Merlins or another rpm/boost setting , this simplified piloting as they knew the fuel burn at such a setting and they let the speed vary with whatever altitude they were at. Adjusting throttles as the altitude changed to give a constant speed is a bit more work.

And in any case we may be arguing over 10% or less in range/endurance. Or a 50 minute combat flight vs a 55 minute combat flight.
Some of the later DB 605s could burn 425 liters an hour at 2600rpm and 1.45 ata and and 610 liters an hour at 2800rpm and 1.80 ata (1600PS at 6000 meters)
5 minutes at the high rating and 15 minutes at the max continuous rating is 157 liters, without a drop tank that leaves 243 liters to start, warm up, take-off and climb to 6,000 meters or better and then find the fight and get back home, maybe I have overestimated the time spent at the high throttle conditions but a more streamlined 109 is only going to pick up a few minutes of endurance on an intercept mission.

 

[BiffF15]

An aerodynamic improvement that would result 60km/h speed increase would give a noticeable improvement in sustained turned rate . Also marginally better acceleration at high speeds

Dedalos,

Cleaning up an airframe will give you an increase in speed, or an improvement in fuel burn / mileage but I don't think it will give as much of an improvement in rate. To turn you roll and pull, deflecting the elevator up, creating drag. The drag rise or bleed rate will go down but not enough in my opinion to give you a noticeable change in rate. Hopefully Bill will chime in here to explain it better.

Also roll is important even at high speed. An example would be during a high speed attack on the bomber stream. The ability to roll will increase the number of aircraft you can attack per pass as well as the accuracy (lateral corrections during the pass).

Cheers,
Biff

 

[Denniss]

Not according to Post #26, Bf109 Neubau 1/44 to 3/45 - Page 3 - Luftwaffe and Allied Air Forces Discussion Forum

I know this list but it seems incomplete, especially if you look at the single Bf 109G-6/AS in it

 

[Milosh]

There was only one (1) G-6/AS built. All others were conversions.

 

[XBe02Drvr]

Cleaning up an airframe will give you an incre upase in speed, or an improvement in fuel burn / mileage but I don't think it will give as much of an improvement in rate. To turn you roll and pull, deflecting the elevator up, creating drag. The drag rise or bleed rate will go down but not enough in my opinion to give you a noticeable change in rate.

Dedalos, there you have it, straight from a combat pilot.
Cleaning up the parasite drag for top speed (straight and level flight) is not going to have that much effect on your energy bleed in a high G, high AOA turning fight, as the relative wind isn't striking the parasite drag features from the angle they were streamlined for, and the huge increase in induced drag from the AOA and G load is going to far outweigh the minor reductions in parasite drag from the aerodynamic cleanup.
Cheers,
Wes

 

[Denniss]

There was only one (1) G-6/AS built. All others were conversions.

No, G-5/AS were conversions (Erla Antwerpen), the 325 G-6/AS were new-built

 

[ktank]

The 109 had reached the max it's design could really allow. You can only squeak more performance out so much.

That does not take anything away from it. It was a solid design. It was a mid 1930s design though. I think that says a lot (same for the Spitfire) that it was able to remain competative and dangerous right up to the end.

The difference was that the Spitfire was still flyable by the average pilot. The later Me109s were still lethal weapons in the hands of the Experten but deathtraps for new pilots.

 

[DerAdlerIstGelandet]

The difference was that the Spitfire was still flyable by the average pilot. The later Me109s were still lethal weapons in the hands of the Experten but deathtraps for new pilots.

I think you are over exaggerating a bit here...

 

[Milosh]

No, G-5/AS were conversions (Erla Antwerpen), the 325 G-6/AS were new-built

My apologies Denniss. Don't know why that was in my head. Anyways Prien has 225 new builds total and the rest of the 686 were conversions.

 

[P-39 Expert]

I think you are over exaggerating a bit here...

Some sources say that the Luftwaffe lost one third of all 109s to accidents.

 

[DerAdlerIstGelandet]

Some sources say that the Luftwaffe lost one third of all 109s to accidents.

And that has been thoroughly discussed, and if I recall found to be not entirely accurate, as the numbers didn't match up.

 

[P-39 Expert]

And that has been thoroughly discussed, and if I recall found to be not entirely accurate, as the numbers didn't match up.

Can you direct me to that discussion? Thanks.

 

[DerAdlerIstGelandet]

Can you direct me to that discussion? Thanks.

I'm not sure where it is, but it's here, and I might be confusing it with a different conversation that was about soneone saying that 2/3rds of all 109 losses were landing accidents which is not true.