Why was the BF109 so slow compared with the P51?

[Shortround6]

Not really new. B - C - D - E - F. Until the end (K), the adjustments were always small. The biggest change was E -> F, not a priority for performance but in more production-efficiency. (Blueprints for F are dated from mid-1940)

I am agreeing with Tomo. The B-D were one generation, differences were minor and often just a change in equipement.
I am not sure if you could turn a D into an E, to would take quite a bit of work and parts.
But an E is basically a D with a new engine, new radiator installation (and oil cooler) and larger fuel tank.

The F has a lot more changes to the basic airframe and no, it wasn't just for production reasons. An early F was 20-30mph faster than a late model E when using the same engine. Later Fs did get higher powered engines but the change from a 350mph airplane to a 390mph airplane was NOT due to the new engine alone. This is the major break between the 1935 109 and the 1944-45 109s. from the F on there was little or no aerodynamic refinement and performance increases came from fitting increasing more powerful engines. Which unfortunately for the Germans and fortunately for the rest of the world, often had teething troubles that lasted for months and prevent full use from being made of the hoped for power increase.
late 109s were a mad scramble to get something into the air and aerodynamic refinement went out the window. The wing bulges over the tires on the K series may have negated much of the gain from the auxiliary wheel well doors for example.

 

[nuuumannn]

The F has a lot more changes to the basic airframe and no, it wasn't just for production reasons

Yup, the 'F was arguably the peak of design development of the Bf 109 as a pure fighter. Yes, you could argue that the K and marks of the G were faster etc, but they were swiftly overtaken by events and by then, the Bf 109's basic design was a bit long in the tooth. At the time the Friedrich entered the fray the Bf 109 was at the top of its game; it was the best fighter in service in Western Europe; the aerodynamic changes over the Emil did pay off, but they came at a price; the removal of the tailplane bracing struts did cause early 'Fs to suffer structural failure owing to tail flutter at high speeds, leading to the aircraft being grounded, but strengthening was undertaken. The Friedrich also had a governed constant speed prop for the first time in a '109, previous iterations being variable pitch only.

AS SR stated, in the Gustav the aerodynamics suffered. Those bigger guns and wheels resulting in protrusions did nothing for the the aircraft aerodynamically or appearance wise; the Gustav wasn't nicknamed the 'Beule' for nothing!

 

[Schweik]

Maybe the obvious basis for.comparison is that they in fact competed directly in combat thousands of times. The Bf109G and K etc. variants that faced P-51B and C in 1943 were obviously not the same fighter as the 1935 design that saw action in the Spanish Civil War, nor was a Spit 21 the same bird as a Spit I from the BoB.

Whether using an earlier design for the basis of the latest front line fighter or coming up with something entirely new, the challenge was much the same. Changes radical enough to meet the harsher and harsher standards of each new year of the war were likely to pose a host of problems in implementation.

Getting new engines to work properly, or new wings better streamlining, a new fuselage etc. is going to take a while and break the hearts of a lot of good engineers and mechanics in the process. A brand new aiframe poses even more potential teething hazards than a major upgrade but also offers the potential of new design improvements that bypass old limitations. Either way its a gamble

This was the challenge faced by North American Aviation when asked to produce P-40s for England (or further extend the even older P-36, depending how you look at it). They took a risk and got lucky with their streamlining and exhaust system, but still had a lot of teething problems (like bad ailerons.) The fuel capacity seems to be almost a happy accident.

Orher more radical designs like the Do 335 and the 262 (or He 280) never got through their teething / implementation challenges quickly enough to make it into the field in sufficient numbers to make a difference in the war.

Even the 262, while it probably could have had a greater impact as a heavy bomber killer if political circumstances had been different, may not have been a mature enough design to change thimgs on the Russian Front for example, or over the Tactical Battlefield over Europe.

Ultimately the German designers and engineers for all their skill, also made mistakes and reached the limits of their abilities. They were way ahead of the game in 1936, and even still in 1940 to a large degree (the Spitfire being the one glaring exception), but by 1943 they had lost a step in the face of onrushing doom and annihilation in the zero sum game they themselves had instigated.

The designers of the Allied countries proved to be as resourceful- and more, in the long run.

 

[fubar57]

Maybe the obvious basis for.comparison is that they in fact competed directly in combat thousands of times. The Bf109G and K etc. variants that faced P-51B and C in 1943 were obviously not the same fighter as the 1935 design that saw action in the Spanish Civil War, nor was a Spit 21 the same bird as a Spit I from the BoB.

The Bf 109K faced the P-51 in '43?

 

[GrauGeist]

The shortcomings of the Germans was their approach to production and manpower.

*IF* they had started the war on a wartime footing AND not made questionable decisions regarding where to launch new fronts, then perhaps they might have had a chance.

Waiting until 1944 to peak aircraft production five years AFTER starting the war is not going to lead to any measure of success.

 

[Schweik]

The Bf 109K faced the P-51 in '43?

Grouping all variants that faced it from 43 to the end. Sorry I was typing on a phone.

 

[michael rauls]

Speaking of the 109k I read once that about 2000 were made but only about 200 ever saw combat. Other than this one statement in one article I've never run across anything else pertaining to numbers of k's built or deployed.
Would be interested if anyone could confirm or dispell this.

 

[swampyankee]

One thing to remember is that the NACA was formed to advance aeronautics and directly improve aircraft performance, construction, and design methods, with the information being made widely available. To a great extent, it was the world's source for this information, with, for example, NACA airfoils being used by German aircraft, such as the Bf109.

I don't know how mobile German aeronautical engineers were, but US ones have long been notorious job hoppers, which means that there is quite a lot of inter-company intellectual cross-fertilization.

 

[fubar57]

Speaking of the 109k I read once that about 2000 were made but only about 200 ever saw combat. Other than this one statement in one article I've never run across anything else pertaining to numbers of k's built or deployed.
Would be interested if anyone could confirm or dispell this.

Wiki cites these books as sources for the production numbers so I think it might be safe to quote Wiki in this case, "...Deliveries began in mid-October 1944 and 534 examples had been delivered by the Messerschmitt A.G., Regensburg by the end of November and 856 by the end of the year.[105][106] Regensburg delivered a total of 1,593 by the end of March 1945, after which production figures are missing.[citation needed] With such a high rate of production, despite continuous heavy fighting, by the end of January 1945, 314 K-4s – about every fourth 109 – were listed on hand with the first line Luftwaffe units..."

 

[michael rauls]

Wiki cites these books as sources for the production numbers so I think it might be safe to quote Wiki in this case, "...Deliveries began in mid-October 1944 and 534 examples had been delivered by the Messerschmitt A.G., Regensburg by the end of November and 856 by the end of the year.[105][106] Regensburg delivered a total of 1,593 by the end of March 1945, after which production figures are missing.[citation needed] With such a high rate of production, despite continuous heavy fighting, by the end of January 1945, 314 K-4s – about every fourth 109 – were listed on hand with the first line Luftwaffe units..."

View attachment 526332View attachment 526333​

Thanks George. Looks like a good adition to my prospective reading list. I tried to rate your post as useful but at least on my screen the ratings aren't working right now.
Might just be a problem with my phone.
Thanks again.

 

[stona]

Yup, the 'F was arguably the peak of design development of the Bf 109 as a pure fighter.

I don't disagree from an aerodynamic point of view, but it was badly under armed for a1941/42 fighter.

An MG-FF cannon (admittedly later upgraded to the faster firing MG 151/15) and a couple of 7.92mm MG 17s is nothing to shout about. It was fine for shooting down P-40s and Hurricanes in the MTO I suppose.

Cheers

Steve

 

[Schweik]

I think they're mainly talking about speed here.

But I also think the armament on a 109F was sufficient for shooting down Spitfires and Yak ones and sevens and P-38s and Pe 2s and Blenheims & Bostons & Baltimores and B 25s and pretty much anything else they needed to shoot down while they were in action.

When more heavy bombers and better-armed Il-2's hit the battlefield the need for heavier armament was addressed in the G series if perhaps in a less than ideal manner.

 

[nuuumannn]

An MG-FF cannon (admittedly later upgraded to the faster firing MG 151/15) and a couple of 7.92mm MG 17s is nothing to shout about.

Depends on who you're talking to. Galland thought the same thing as you, but both Molders and Maseille said that was all they needed to shoot down the enemy. Yes, other fighters had heavier armament, but that didn't stop the Friedrich out performing the Spitfire V - the frontline RAF interceptor in almost every respect, with the exception of the turn and as one RAF pilot said when this was pointed out to him, "Turning doesn't win battles!" It's record speaks for itself; the 'F was a very potent fighter.

 

[stona]

Depends on who you're talking to. Galland thought the same thing as you, but both Molders and Maseille said that was all they needed to shoot down the enemy.

It was all they needed to shoot down enemy fighters, which were the target at the time. Once the Luftwaffe was forced onto the defensive it became completely inadequate. There was a good reason that the early G-series had a commonly used option for two MG 151/20s under the wings. By early 1943, when the G-6 started reaching front line units much heavier armament came as standard ( two heavy MG 131s and an MG 151/20 or MK 108 cannon) with the option for underwing cannon retained.

I'd also point out that what Molders and Marseilles thought they needed might not apply to many other Luftwaffe pilots Didn't Bader persevere with 8 pop guns after cannon were introduced? He was good enough to make them count at very short range and he was confident that they wouldn't let him down. Most of his contemporaries couldn't fly like him, however much of an a-hole he may have been!

Cheers

Steve

 

[tomo pauk]

I think they're mainly talking about speed here.

But I also think the armament on a 109F was sufficient for shooting down Spitfires and Yak ones and sevens and P-38s and Pe 2s and Blenheims & Bostons & Baltimores and B 25s and pretty much anything else they needed to shoot down while they were in action.

When more heavy bombers and better-armed Il-2's hit the battlefield the need for heavier armament was addressed in the G series if perhaps in a less than ideal manner.

Depends on who you're talking to. Galland thought the same thing as you, but both Molders and Maseille said that was all they needed to shoot down the enemy. Yes, other fighters had heavier armament, but that didn't stop the Friedrich out performing the Spitfire V - the frontline RAF interceptor in almost every respect, with the exception of the turn and as one RAF pilot said when this was pointed out to him, "Turning doesn't win battles!" It's record speaks for itself; the 'F was a very potent fighter.

Agree with Steve here - Germans introduced gondola cannons as an option already for the F series, and G2 with gondolas were used by 1942 and early 1943 both in East and MTO. They certainly didn't felt that every pilot is a world-class marksman.

Perhaps the Germans failed to pick the low-hanging fruit until too late - the belt-fed MG FFM, available from some time 1943 and used on night-fighter Do 217s with 200 rpg. A Bf 109F with 3 internally-mounted, belt-fed MG FFMs, anyone?

 

[DarrenW]

From reading the discussion so far, I'm under the impression that the only way the BF 109 could ever compete on anything like equal terms with Allied aircraft such as the P-51D it needed vastly more horsepower. The air frame refinements found on the the later G and K models did very little in the way of overcoming its relatively inferior aerodynamics. The performance gap seems to have been closed somewhat by the implementation of over-boosting, using water-methanol injection and/or higher octane fuels, but 109 pilots were still left wanting.

I haven't seen any discussion here concerning the rather poor manufacture quality of late-war 109s, which must have also played some role in its apparent inferiority to the Allied fighters that it faced by 1944.

From Spitfire Mk XIV versus Me 109 G/K:

Conditions in Germany during the last year of the war, however, were not conducive to aircraft achieving maximum theoretical performance levels. Hans Knickrehm of I/JG 3 recalled the condition of new Me 109 G-14/AS's received by his group in October, 1944:

The machines that were delivered were technically obsolete and of considerably lowered quality. The engines proved prone to trouble after much too short a time, because the factories had had to sharply curtail test runs for lack of fuel. The surface finish of the outer skin also left much to be desired. The sprayed-on camouflage finish was rough and uneven. The result was a further reduction in speed. We often discovered clear cases of sabotage during our acceptance checks. Cables or wires were not secured, were improperly attached, scratched or had even been visibly cut...​

And I know it's a gaming forum but there's actually some intelligent conversation going on here, intermixed with both snippy and childish remarks too I'm afraid....

The K-4 Isn't Special

Some comments made in this thread:

.....All DB 605D and ASB-ASC engines were cleared for 1,98 ata at that time (i.e. the month before and after Bodenplatte)


"Chin bulges on the lower cowling - this was present only on aircraft with uprated DB 605 ASB/ASC engine (same engine, designated differently depending on fuel/boost used). These engines could operate on either B-4 / 87 octane fuel up to 1.8ata (ASB), or 1.98ata with C-3 fuel (designated as ASC). This particular aircraft has a C-3 fuel triangle, pointing towards that it uses the latter ASC rating.

I was under the impression that 1.8 ata was the highest boost setting ever approved for field use. Anyone have data to refute this notion?

And surely C3 fuel must have been used to a greater extent than most realize. I happen to see far too many photos to believe otherwise. But on the other hand maybe it was normal practice for B4 fuel to be used in place of the seemingly rarer C3, so these markings didn't necessarily denote the actual fuel used????

From a Wiki article on the DB 605 engine ( Daimler-Benz DB 605 - Wikipedia ):

The DB 605AM, running initially on C3 and MW-50, saw power improved to 1,800 PS (1775 hp) for takeoff. In mid-1944, the requirement for C3 was dropped and standard B4 fuel with MW-50 was used.

As early as 1942 Daimler had also been working on an upgraded D-series engine that could run on either C2 or C3 fuel. The first of these, which appeared in late 1944, were a small series of DB 605DM, followed by the main production series, the DB 605DB/DC. These engines were fitted with an adjustable screw stop which allowed the use of either B4 fuel with MW-50, or C-3 fuel without MW-50, in which case the engine was designated DB 605DB, or the use of C-3 fuel with MW-50, in which case the engine was given the -DC suffix instead...

 

[tomo pauk]

From reading the discussion so far, I'm under the impression that the only way the BF 109 could ever compete on anything like equal terms with Allied aircraft such as the P-51D it needed vastly more horsepower. The air frame refinements found on the the later G and K models did very little in the way of overcoming its relatively inferior aerodynamics. The performance gap seems to have been closed somewhat by the implementation of over-boosting, using water-methanol injection and/or higher octane fuels, but 109 pilots were still left wanting.

I haven't seen any discussion here concerning the rather poor manufacture quality of late-war 109s, which must have also played some role in its apparent inferiority to the Allied fighters that it faced by 1944.
...

Aerodynamic refinements do count. The K-4 introduced the more stremlined HMG installation, wheel well covers, and reintroduced retractable tailwheel - all of that accounted for 20+ km/h more than 109Gs with DB 605ASM and 605D engines. The K-4 was upposed to do 710 km/h at 7.5 km with 1565 PS (441 mph at 24600 ft with 1543 HP), that is a ballpark with P-51D that used ~1500 HP to do the same.

This also shows at least two things:
- size matters (smaller size can get you fly fast)
- P-51 was one very, very sleek fighter

 

[swampyankee]

Every report I've seen has shown the P-51 had, by far, the lowest zero-lift drag coefficient reported for any piston-engined aircraft of the era, at about 0.016 to 0.018. The Bf109 was quite high, at 0.027 to 0.029. All the other monoplane fighters were in the band of about 0.020 to 0.025, regardless of type of piston engine: radial, V-12, or H-24, with most aircraft between, if I recall, between 0.021 and 0.024.

To a great extent, the BF109 was at the opposite end of the bell curve as the P-51. This is one reason (there are others....) why I claim that the US had, on average, better aircraft designers than did the nazis.

 

[nuuumannn]

Most of his contemporaries couldn't fly like him, however much of an a-hole he may have been!

Ha ha! Funny!

They certainly didn't felt that every pilot is a world-class marksman.

True. The fact that the three guns alone still enabled it to be a potent fighter is not in dispute, though. The canoe guns did affect handling and manoeuvrability, however; virtues that the F maintained, but were lost on subsequent variants.

 

[Schweik]

Does the zero lift drag coefficient take into consideration the size of the object (like the wingspan) or is it just like a per meter kind of thing?

Is there a list of the drag coefficients for different aircraft by type?

The 109 had a lot of protrusions, tail wheel and open wheel wells and everything but it was such a small aircraft. That is why it had relatively low drag.

Wasn't until the ultra streamlined P-51 showed up that they arguably needed to focus more on reducing drag further.

The low drag wing of the P51 seems to have lost a little bit and lift because it doesn't turn all that well despite being pretty big, or maybe that's just a factor of weight