Which of these DB 601 powered fighters was the best? Bf 109F-2, Ki-61-I or C.202

[Juha]

Nice theory but Radinger Otto said that G-6/R3 was a FR plane with RB 50/30 based on datasheet dated 8 March 43, and because it had upper cowling mgs (but MG17s) it could not have same kind of extra oil thank than G-4/R3 had. It also had the MG 151/20.

Prien et noticed that G-6/R3 had RB 75/30. They also noticed that there was allegedly another version with the designation G-6/R3 Fl. Presumably a further recon version like G-4/R3 with 2x300l dts but proof is lacking that such a plane was in fact built.

Now Prien et al is 20years old and IMHO Radinger's and Otto's book is not as good as their 109 A-E book and it is also some 15 years old. So some new info on G-6/R3 might well have surfaced after the publiscation of those books. The other 2 books are more recent ones. And all authors are well aware of the difference between Rüstzustand and Rüstsatz.

BTW the photos you kindly posted showed why British thought that German aerial recon cameras were overengineered and unnecessarily heavy.

Juha

 

[Tante Ju]

Not theory, primary source.

G-6/R3 had the same + 15 liter extra oil capacity and of course G-4/R3, G-6/R3, G-6/R4 all retained their Mauser cannon, without the MGs. Now IIRC G-8 was simply the rename of some earlier G-6/Rx figher-recon variant (G-6/R5?), with small cameras for tactical recce.

BTW the photos you kindly posted showed why British thought that German aerial recon cameras were overengineered and unnecessarily heavy.

I think their opinion is irrelevant. List me 3 known British camera manufacturers please... Anyone into photography understand the adventages of large photographic material with large objectives. If the British were into taking scenic photography with smartphones and the Germans doing the same with full frame DSLR then its clear who is doing things right.. but I do not think so, probably different use.

The Germans had smaller camera types, and I am quite sure the British had more serious camera equipment as well. But even these large ones could be fitted to a small fighter like 109.

 

[Juha]

Not theory, primary source.

I meant the theory that the authors were not aware on the difference between Rüstzustand and Rüstsatz. Exactly what primary source? D-Luft-Ts? I just want to know the sources of info as usual.

G-6/R3 had the same + 15 liter extra oil capacity and of course G-4/R3, G-6/R3, G-6/R4 all retained their Mauser cannon, without the MGs. Now IIRC G-8 was simply the rename of some earlier G-6/Rx figher-recon variant (G-6/R5?), with small cameras for tactical recce.

So Radinger and Otto are in error on this?

I think their opinion is irrelevant. List me 3 known British camera manufacturers please... Anyone into photography understand the adventages of large photographic material with large objectives. If the British were into taking scenic photography with smartphones and the Germans doing the same with full frame DSLR then its clear who is doing things right.. but I do not think so, probably different use.

Vinten and Williamson Manufacturing Companyat least, during WWII. British had comparable cameras but they were lighter without those "nice to have" extras. And because they were lighter and smaller they were more suitably to aerial work but probably German cameras had better lenses, they were famous on those. British had F8, F24 and F52 cameras and got excellent photos on almost everything Germans had, ships, rockets a/c, mapped out their radar sites etc.

The Germans had smaller camera types, and I am quite sure the British had more serious camera equipment as well. But even these large ones could be fitted to a small fighter like 109.

Same in RAF, later PR Spits could carry cameras up to slip pair of vertical F52 36-in lens cameras.

Juha

 

[riacrato]

I like the Hien a lot, I think it's one of the most beautiful aircraft of the war. But at the end of the day, I'd want to be in the fighter that gives me the best chance at keeping the initiative. And that is the Bf 109 I think.

 

[krieghund]

I realize that this is for the F-4 but it should be in the ballpark for the 601N engine and should give a good approximation of what can be expected of the F-2. If one cruises at 0.65 ata at 7km you have about 265 liters of fuel available to you after warm-up and taxi/take-off, and fuel to climb and reserves for diverting. Which is 830km plus 40km in the climb for a range of 870km.

 

[Tante Ju]

It seems the best the F-4 can make is 410 km/h TAS at 130 liter / hour at 7000m.

That would be 1261 km if the aircraft does not have to climb, taxi, have reserves etc, ie. the full 400 liter tank. Substracting 100 liter for that and leaving 300 for cruise, gives you 946 km, which is pretty much in line with other data. This essentially doubles with a 300 liter droptank and tripes with two - you do not need to warm up, taxi, climb etc. two or three times..

 

[Juha]

It seems the best the F-4 can make is 410 km/h TAS at 130 liter / hour at 7000m.

That would be 1261 km if the aircraft does not have to climb, taxi, have reserves etc, ie. the full 400 liter tank. Substracting 100 liter for that and leaving 300 for cruise, gives you 946 km, which is pretty much in line with other data. This essentially doubles with a 300 liter droptank and tripes with two - you do not need to warm up, taxi, climb etc. two or three times..

IIRC the 300l dt increased the max range 2/3 in British 109 tests, that because of the extra drag of the dt

 

[Tante Ju]

IIRC the 300l dt increased the max range 2/3 in British 109 tests, that because of the extra drag of the dt

Good point. According to kurfurst site droptank reduced speed by 39 kph, without weight into account, so say - 45 kph loss with weight. Drop tank attachment reduced speed by -4 kph.

So in above example, 300 liter flyable.

300 + 300 liter with droptank (100 liter reserve), 410 kph - 45 = 365 kph at 130 liter/h = 2.307 h cruise at 365 kph = 842 km, then after dropping tank
300 liter (100 liter reserve), 410 kph - 5 kph (drop tank attachment) = 405 kph at 130 liter/h = 2.307 h cruise at 405 kph = 934 km

934 + 842 = 1776 km (1103 miles) total covered in cruise.

Interestingly shown also is speed loss with 2 x 300 liter (streamlined) droptank, i.e. long range recce variants. In this case drag loss was only 26 km - two faired droptanks caused less loss then one unfaired! Say 35 km/h with weight drag into account. Then gives:

300 + 600 liter with droptank (100 liter reserve), 410 kph - 35 = 375 kph at 130 liter/h = 4.615 h cruise at 375 kph = 1730 km, then after dropping tanks
300 liter (100 liter reserve), 410 kph - 10 kph (drop tank attachments) = 400 kph at 130 liter/h = 2.307 h cruise at 400 kph = 922 km

1730 km + 922 km = 2652 km (1647 miles)

In both cases 100 liter flyable (probably used in climb, taxi, reserve etc). Distance covered in climb not counted. This is rather pushing this of course, more like theoretical maximum.

 

[davebender]

If one cruises at 0.65 ata at 7km you have about 265 liters of fuel available to you after warm-up and taxi/take-off, and fuel to climb and reserves for diverting.

Such calculations are fine for ferry range. Combat is a different matter. Internal fuel is all you have and 10 minutes @ WEP will consume fuel faster then beer at Oktoberfest.

 

[Tante Ju]

True. But its easy to make such calculations and, range is usually given without or with minimal allowances.

 

[Ivan1GFP]

And the first ot these conversions was made in late 1943 / early 1944, the last in july 1944.

Apparently there were a bunch of fighters from various -I but not KAI series converted starting just pas mid year 1943 but that wasn't all that long after the Ki-61-I first became operational. The conversions stopped after they ran out of the cannon but the Ki-61-I-KAI was changed in order that it could mount the Ho-5 cannon as a cowl gun.

I like the Hien a lot, I think it's one of the most beautiful aircraft of the war. But at the end of the day, I'd want to be in the fighter that gives me the best chance at keeping the initiative. And that is the Bf 109 I think.

I believe either of the two other fighters had better high speed maneuverability and the Macchi 202 wasn't all that much slower.

- Ivan.

 

[davebender]

Comparing internal fuel capacity is even easier and for most aircraft probably a better indication of relative combat radius.

The comparison fails when you add flying bricks with massive fuel capacity such as P-47 as fuel consumption is much worse then normal.

 

[Civettone]

It is still remarkable how only the DB 601Aa was cleared for licence production. As Dave once said, putting a DB 601E in the C.202 would have made it a top notch fighter aircraft.

However, the DB 601Aa also had some advantages. This I got from Vanir, an unfortunately banned member:

ndeed the smaller blower in the Aa, which other than the blower is a 601A-1 engine, actually let the motor spin to its maximum emergency rating more easily and for longer.
The normal maximum rating of the 601A-1 is actually 1.3ata/2400rpm for 5min. During take off only (under 1000m) you could press it to 1.4ata at the same rpm but it rattled a lot and was under blower effiency height which is about 2000 metres.
The Aa blower lowers this to about 1500 metres maximum efficiency and helps it spin easier in thick air. Under 1000m the Aa will spin the 601 to 2500rpm/1.4ata instead of 2400rpm which is worth about 100hp.
But the lower throttle height is actually a reduction in performance. At 3800 metres the Aa puts out 1100PS military which is a little over 100hp more than the A-1, but at 4500m the A-1 puts out 1020PS military with good pressure and the Aa motor is dropping below 900hp and definitely out of breath. Maximum performance height for the airframe then rates at about 4200m for the Aa/Emil and about 5500m for the A-1/Emil, consider that typical frei-jäger in BoB is 7000m (because Spits lost climb rate at 6000).

Very loosely speaking comparing the A-1 to the Aa is very much like comparing a Merlin 45 to a 50. You do get higher maximums at low alt with a smaller blower that has a better efficiency down lower, but it really doesn't help you at fighter vs fighter combat heights, mostly for close ground support operations or escorts.
An exaggerated comparison is the 605A vs 605AS. Only difference is the blower diameter, but it's worth 1-2000m throttle height for a slight sacrifice in low alt power.

Given aerial combat height in the early-mid war in western Europe (particularly vs England) is rated at 5000-7000 metres (later goes upwards), it's really only coastal units, point defence interception and unlucky patrols that are running around at 3500 metres where the 601Aa is better. Even in the Med combat is 3000-6000 metres for the most part (typical transport sortie w/escort in 42 would have transports at 3-4000 and escorts at 5500).
Throughout the war it was noted fighter aircraft needed good performance at around 5000 metres, a lot of very good planes have their throttle heights here. Tempest, all the FWs, etc. And they're considered low alt fighters.

In short, the DB 601Aa had more power at take-off and low altitude, but suffered at medium altitude, where most combat took place.

Kris

 

[Juha]

Good point. According to kurfurst site droptank reduced speed by 39 kph, without weight into account, so say - 45 kph loss with weight. Drop tank attachment reduced speed by -4 kph.

So in above example, 300 liter flyable.

300 + 300 liter with droptank (100 liter reserve), 410 kph - 45 = 365 kph at 130 liter/h = 2.307 h cruise at 365 kph = 842 km, then after dropping tank
300 liter (100 liter reserve), 410 kph - 5 kph (drop tank attachment) = 405 kph at 130 liter/h = 2.307 h cruise at 405 kph = 934 km

934 + 842 = 1776 km (1103 miles) total covered in cruise.

Interestingly shown also is speed loss with 2 x 300 liter (streamlined) droptank, i.e. long range recce variants. In this case drag loss was only 26 km - two faired droptanks caused less loss then one unfaired! Say 35 km/h with weight drag into account. Then gives:

300 + 600 liter with droptank (100 liter reserve), 410 kph - 35 = 375 kph at 130 liter/h = 4.615 h cruise at 375 kph = 1730 km, then after dropping tanks
300 liter (100 liter reserve), 410 kph - 10 kph (drop tank attachments) = 400 kph at 130 liter/h = 2.307 h cruise at 400 kph = 922 km

1730 km + 922 km = 2652 km (1647 miles)

In both cases 100 liter flyable (probably used in climb, taxi, reserve etc). Distance covered in climb not counted. This is rather pushing this of course, more like theoretical maximum.

2 dts weight more than one, so one needed more fuel to achieve the optimal flight altitude and IMHO the 600l external vs 400l intenal wasn't a coincidence but the idea was that in optimal case after using the fuel in the dts it was still possible to return with the internal fuel when one remember that return was "downhill". The 2/3 rule of thumb.

And the odd thing still is that LW seemed not to utilise the theoretical ferry range capacity of the 109G but the all the ferry flights i'm aware were made using rather short stages.

Juha

Juha

 

[GregP]

Just to throw something in here, we are restoring an Hispano Ha.1112, which is esentially a Bf 109G from the firewall backward, with a Merlin in the nose. Since the Merlin was not an iverted V-12, there was no possibility for it to have a cannon through the spinner. Don't know about the REST of them, but OUR Hispano has wing armament and wing tanks. The wing armament was two Hispano HS-404 20 mm cannons ... IN the wing. I have seen the inside of the wing structure and the mounts are not only possible, they are there. It also had outboard wing tanks that we have removed since ours will be an airshow aircraft and doesn't need the extra fuel.

So, if the Germans had wanted to install wing cannons, they certainly could have, since the Spanish, with no other alternative, DID.

 

[wuzak]

Just to throw something in here, we are restoring an Hispano Ha.1112, which is esentially a Bf 109G from the firewall backward, with a Merlin in the nose. Since the Merlin was not an iverted V-12, there was no possibility for it to have a cannon through the spinner. Don't know about the REST of them, but OUR Hispano has wing armament and wing tanks. The wing armament was two Hispano HS-404 20 mm cannons ... IN the wing. I have seen the inside of the wing structure and the mounts are not only possible, they are there. It also had outboard wing tanks that we have removed since ours will be an airshow aircraft and doesn't need the extra fuel.

So, if the Germans had wanted to install wing cannons, they certainly could have, since the Spanish, with no other alternative, DID.

Just for reference Greg, the reason that a motor cannon could not be fitted to the Merlin was not that it was upright, but that its induction system (supercharger, intake pipe) got in the way.

 

[GregP]

The induction system of ALL upright WWII V-12's gets in the way, so it IS because it is upright. If they had fuel injection, maybe not ... but they didn't until very late on the war in the Allied side at least (without major modification to the induction systems), and the Axis side used inverted V-12's.

I submit the "upright" part required the induction to get in the way of a cannon through the spinner unless specifically designed to go around it, and the Merlin, Allison, Hispano-Suiza, Griffon, Sabre, etc. didn't do that.

Or am I mistaken?

The P-39 did, but that was a remote engine with a driveshaft that allowed a cannon. Maybe they could have done that with a Merlin or Griffin, but did they?

 

[Dogwalker]

In short, the DB 601Aa had more power at take-off and low altitude, but suffered at medium altitude, where most combat took place.

Kris

It's worth to note however than a C.202 had his maximum speed at 5900m. Higher than a Bf109 F1/2 with the DB601N (5200m) and similar to a F4 with the DB601E (6000/6200m)

 

[GregP]

Good point, DW!

 

[Juha]

The induction system of ALL upright WWII V-12's gets in the way, so it IS because it is upright. If they had fuel injection, maybe not ... but they didn't until very late on the war in the Allied side at least (without major modification to the induction systems), and the Axis side used inverted V-12's.

I submit the "upright" part required the induction to get in the way of a cannon through the spinner unless specifically designed to go around it, and the Merlin, Allison, Hispano-Suiza, Griffon, Sabre, etc. didn't do that.

Or am I mistaken?

The P-39 did, but that was a remote engine with a driveshaft that allowed a cannon. Maybe they could have done that with a Merlin or Griffin, but did they?

Hisso was the original motor-cannon engine, look MS 406 or Dewointine D.520