Best Messerschmitt Bf109 subtype

[claidemore]

Originally Posted by Fokker D21

Was an early Spitfire MK9 really better than a Me 109 G2?

Topspeed of the 109 G2 at combat rating (30 minutes) is 649 km/h.
Topspeed of the Spitfire Mk9 F at emergency rating (5 minutes) is 656 km/h.

That makes the 109 relative the much faster plane.

Those are top speed figures for one altitude, and not the same altitude at that. At 33,000 feet the Mk IX is 45 mph/72 kmh faster, at 15/16000 feet they are exactly the same speed. Thats at 15lb boost combat rating for the Spit IX Merlin 61.

Better performing Merlin 66 and 70 Mk IXs in early 1943 would have squared off against G4's, which had exact same performance as G2.

Of course top speed doesn't make a plane better, we have to look at all of its capabilites. Mk IX had twice the firepower of the 'clean' G2, had higher ceiling, smaller turn radius and shorter turn times (by about 2 seconds, which ain't much). Climb rate was very similar, and the 109G2 had quicker initial dive. MkIX had better visibility form the cockpit and lighter controls during high speed pullouts.

I think the G2 was as close a match for the Mk IX as the 109E was for the Mk1, but to say it was better would be ignoring too many factors.

[Fokker D21]

I didn't say the 109 G2 is better, merely that the Spit might not have been so superior as often assumed. Most Spitfire Mk9's were Low Flying variants though. (4010 LF, 1255 F and only 400 HF = 5665 Spit MK9).

The three Spit versions have very different top speeds at different altitudes. For an honest comparison the Spit Mk9 HF (Merlin 70) should be compared with a 109 G1 with GM 1 installation (not a 109 G2).

On paper the Spit has twice the firepower, the central placed guns on the 109 compensate this at least partially. The ammo load for the 109 is not that far behind, 200 versus 240 cannon rounds and 1000 versus 1400 machine gun rounds. And if the cannons were depleted you better consider going home.

At 33000 feet the speed of a 109 G2 at combat rating is 398 mph. Add 45 mph and you get a Spit Mk9's top speed to be 443 mph. No Spit Mk 9 version was that fast. With Merlin 66 at 25 lbs boost the top speed at 25000 feet is 394 mph, any higher altitude results in a lower top speed.

At around 15000 feet the 109 G2 does 386 mph at combat rating, the merlin 66 engined Spit does 373 mph at 18 lbs boost. Only the later use of 25 lbs boost brought the Spit up to 397 mph in 1943.

[Glider]

Persoanlly I went for the Emil. The reason being it dominated the opposition in the first year of the war and ruled the skies over France.
Only over the UK in the BOB did it meet a plane that was its equal and even here it had two priceless advantages
1) Its cannons.
2) The Fuel injected engine

The first gave it a punch that totally outclassed the 8 x LMG, which in itself, was at least as good if not better than any other non German fighter in the air.
The second gave it an evasion tactic that was both effective and very simple to use by any German pilot, of almost any level of experience.

We can (and have) debated the later versions against the opposition but in its time the Emil was the one to beat.

[kool kitty89]

Twice the number of guns doesn't mean twice as good an armament, especially in a Fighter vs Fighter sense. The 'clean' 109G-2 had all its armament nose mounted making it much more accurate with no convergence zone and simpler aiming. That said the Spit still had a slight edge with better spread and more round out there making a hit more likely at least near the convergence zone. And the single MG 151/20 was certainly better than the 2x MG FF of the 109E, particularly in a dogfight. (due to the poor velocity and RoF of the FF gun, and the wing mounting)

That changed once the 109 got the 13mm guns though. (I'd say it had the edge, even with the Spit's 2x 20mm 2x .50 cal armament)



But we're getting off topic. The best true "dogfighter" 109 would probably be the F-2/4 with the best agility. The Armament was better than the Emil's, except maybe the (relatively) weak 15mm gun, though in a dogfight it would probably be superior and it had excellent velocity and decent RoF and ballistics as well.

I'm still wondering about the performance of the G-10 though...

[claidemore]

I guess I should clarify my argument about the Spitfire weapon advantage.

The Spitfire with 2 x 20mm Hispano II and 4 x .303 Brownings was putting out 133.2 lbs of projectiles per second.

The 109G2, with 1 x 20mm Mg151 and 2 x 7.92 Mg17, put out 64.4 lbs of projectile/second.

Thats better than double the weight of projectiles per second. Add to that a 2 x 25% greater explosive charge of the twin 130 gram Hispano cannon shells vs the 105 gram Mg151 shell, and the 880mps velocity of the 20x110 Hispano vs the 725 mps of the Mg 151 20x 82 and you see quite a marked advantage to the Spitfire. All those numbers from this website:

The WWII Fighter Gun Debate: Gun Tables


But, KK makes a good point about the 13mm armed G6 onwards, that gave the plane 94lbs/second, with the E wing Spit at 130.8lbs/sec and B wing at 133.2lbs/sec.
Better, but still not equal. (the l/s figures for the.50 mg on that site are incorrect)
The .50 is 880m/s, (130m/s faster than Mg131) same as the Hispano, so that would make aiming simple for the first couple hundred meters.

Stick two wing cannon gondolas on the 109 and you get 124 lb/s for G2 and 154 lb/s for G6> with subsequent loss in other performance areas.

Nobody is voting for the ABCD 109, those models were the absolute best monoplane fighters in the world during their time weren't they?

[Fokker D21]

The Hispano II HE round has 8% HEI * 130 gram projectile = 10,4 grams of high explosive.

The MG 151/20 HEM round has 21,7% HEI * 92 gram projectile = 19,964 grams of high explosive.

That gives the MG 151/20 the advantage in HE of almost 2 to 1 (the numbers come from Tony Williams website who wrote a book about the subject together with the writer of the gun debate website).

Muzzle velocity for HE rounds is not very important (according to the same website).

Also see my website below about this subject. The Hispano wins the kinetic contest but the MG 151/20 wins the chemical (HE) contest.

I agree that the MG 151/20 API and HET rounds are not very strong but the HEM round more than compensates for this. The Hispano SAPI and HE round are more equally matched. Add to that a higher rate of fire (700 versus 600 rpm) for the Mg 151/20 and both guns turn out to be pretty equal in power.

[Fokker D21]

The strongest opponent for the 109 B, C, D variants was the Polikarpov I-16. It had about the same speed but was more agile and had a much better armament with 4 ShKas fast firing machine guns (2 x 1800 rpm unsynchronized and 2 x 1400 rpm synchronized).

The 109 was however at the beginning of its development stage, the I-16 at its end.

[Juha]

And French AF Curtiss Hawk 75As seemed to have been more than match to 109Ds in early 1940.

Juha

[HoHun]

Hi Claidemore,

>The Spitfire with 2 x 20mm Hispano II and 4 x .303 Brownings was putting out 133.2 lbs of projectiles per second.

>The 109G2, with 1 x 20mm Mg151 and 2 x 7.92 Mg17, put out 64.4 lbs of projectile/second.

Hm, let's have a look at the actual firepower instead of mere projectile mass (using international decimal separators):

Spitfire:

2x Hispano II: 2x 1,06 MW
4x Browning ,303: 4x 0,09 MW

Total 2,48 MW

Me 109G-2:

1x MG 151/20: 1,27 MW
2x MG 17: 2x 0,09 MW

Total 1,45 MW or 58% of the Spitfires.

However, with the centreline position of the Messerschmitt's armament and the extreme outboard position of the Spitfire's machine guns, I'd still consider both weapons systems as about equal.

The Me 109's hub cannon has about half the dispersion (four times the fire concentration) of the Spitfire's wing cannon, and there no problems with wing flex shifting the aim point during turns. Besides, there is no need to compensate for convergence/divergence of wing guns in relation to range, so aiming is considerably simpler for the Me 109 pilot.

Regards,

Henning (HoHun)

[Fokker D21]

The French Hawks were delivered first in December 1938. The first Me 109 E were also completed at the end of 1938. Providing that it took the same time to get the aircraft into service the rival of the Hawk is the 109 E (not the D).

My country also ordered these aircraft, unfortunately they arrived too late.

[HoHun]

Hi Fokker,

>Providing that it took the same time to get the aircraft into service the rival of the Hawk is the 109 E (not the D).

It seems that the Bf 109D met the Hawk 75 in combat, as Osprey's "Bf 109 D/E Aces of the Blitzkrieg" mentions an engagement between 27 Doras of JGr 102 and 9 Hawks guarding a Potez 63 reconnaissance aircraft.

The score was 4 Me 109s shot down and another 5 crash-landed against just 1 Hawk shot down. (It appears that the Messerschmitts tried to bounce the Hawks, so it's not like they were caught unaware.)

The Me 109E certainly was a tough opponent for the Hawk, but I'd say the Me 109D was outperformed due to its much less powerful engine.

Regards,

Henning (HoHun)

[claidemore]

Bookmarked your site Fokker, will read it as I get time, theres a lot there. Good info in your post too!

Questions,(which i might answer myself as I read further)
-Why did the 130 gram Hispano HEI (that's High Explosive Incendiary? right?) round have so much less explosive material?
-Did the Hispano rounds have heavier jackets, thereby making them less frangible?
-Did they use a different explosive material than the Germans?
-Did that 130 gram round have more incendiary material if it had less explosive stuff (I'm using the technical form of the word "stuff") ?

BTW, the longer heavier Hispano round would have a much higher ballistic coeffficient, making it more accurate.

Post war investigation of downed planes showed that it was incendiary rounds that contributed the most, so agree that AP was not as important.

[lesofprimus]

I voted for the F series... I think it was the most superior vs. its opponent than any other version... The 4-5 Vets I talked to concerning the 109 all said the same thing....

Thats good enough for me...

[claidemore]

Hi Fokker;

After a bit of perusal of your website, which is excellent BTW:

Mg 151 HEM (thin walled shell) had 19 grams of explosive, while the HET had only 3.68 grams.
The Hispano had 10.4 grams in the HEI round.

I think that answered some of my questions!

Anybody know the usual mix of API, HET and HEM in the 109? and the mix of API and HEI in the Spitfire?

[HoHun]

Hi Claidemore,

>Anybody know the usual mix of API, HET and HEM in the 109?

According to the Schießfibel manual, 1:1:3 was found to be the best combination against fighters.

>and the mix of API and HEI in the Spitfire?

As they have virtually the same total energy, it doesn't really matter. I think Tony once pointed out that early on, there were actually ordinary steel "ball" rounds were used in the mix, substituting for one of the shell types, but I'm not certain that he was able to pin down the exact time ball was abandoned.

(My above calculations are based on an even API/HEI mix without ball. If it's used, Hispano II firepower drops below the figure I gave.)

Regards,

Henning (HoHun)