Messerschmitt Bf-109E-2?

[nuuumannn]

Hi Again, more questions about the Messerschmitt Bf 109, this time the E-2. Wikipedia has this to say: "Only very limited numbers of the E-2 variant were built, for which the V20 prototype served as basis. It was armed with two wing mounted, and one engine mounted Motorkanone MG FF cannon, which gave considerable trouble in service, as well as two synchronized MG 17s cowl machine guns. In August 1940, II./JG 27 was operating this type.[16][17]"

The two references are 16, Mason, Francis K. Messerschmitt Bf 109B, C, D, E in Luftwaffe Foreign service. London, UK: Osprey Publishing Limited, 1973. ISBN 0-85045-152-3 and 17, Hitchcock, Thomas H. Messerschmitt 'O-Nine' Gallery. Chicago: Monogram Aviation Publications, 1973. ISBN 978-0-914144-00-7.

Here: https://en.wikipedia.org/wiki/Messerschmitt_Bf_109_variants

I'm dubious about the Emil ever being fitted with a centre machine gun, many sources state that the E-3 was but it couldn't have been; the space aft of the engine was taken up by an oil tank vent tube and ammo boxes for the cowl mounted guns, which took up a lot of space behind the engine in Emils. The difference between the E-3 and previous variants was the fitting of 20 mm cannon in the wings in place of the MG 17s. My understanding is that the Friedrich was the first production Bf 109 with the centre mounted gun fitted.

Can anyone elaborate on the E-2 and confirm or deny the Wikipedia entry?

 

[GrauGeist]

the info I have, is from "German Aircraft of the Second World War" by J. Smith/A. Kay and they state that the E-2 had two MG17 MG and two MG FF for armament. It was the E-3 that reached service by late spring, armed with four MG17 MGs and an engine mounted MG FF/M cannon.

 

[Denniss]

No production/acceptance af an E-2 was recorded by RLM (available in German Bundesarchive) so most likely experimental conversions done at some time from unknown source aircraft.

 

[stona]

Agree with Denniss.

"It was the E-3 that reached service by late spring, armed with four MG17 MGs and an engine mounted MG FF/M cannon." Surely a typo! The E-3 was armed with two cowl MG 17s and two wing mounted MG FF. The E series did not feature a centreline cannon.

Cheers

Steve

 

[Airframes]

Correct. It was intended to mount a motorkanone, but vibration and feed problems lead to this being shelved until the 'F' series.
Unfortunately, the myth has continued since at least 1940, at least in terms of 'popular' understanding, probably/possibly helped along the way by the blunt spinner with the 'hole' in its center, and certainly by 1950's and 1960's comic books and fiction.

 

[Denniss]

Another myth is the use of DB 601E in later E-marks of the 109.

 

[Vincenzo]

later E used DB 601N

 

[Denniss]

later E used DB 601N

To a limited extend yes, majority of E-7s were equipped with 601A/Aa.

 

[Vincenzo]

yes i would write that a minority of later E used the N engine

 

[nuuumannn]

Thanks everyone.

No production/acceptance af an E-2 was recorded by RLM (available in German Bundesarchive)

Thank you Denniss, the kind of evidence needed. I was under the impression the E-2 was not built, so seeing that it equipped JG 27 left me a little surprised. This is like the similar myth that the Clara-2 was also built and entered service in Spain - it also was a paper project only.

Surely a typo! The E-3 was armed with two cowl MG 17s and two wing mounted MG FF. The E series did not feature a centreline cannon.

My understanding of the Emil's armament, too.

Correct. It was intended to mount a motorkanone, but vibration and feed problems lead to this being shelved until the 'F' series.

Also agree, Terry. Like I wrote to begin with, there was no space in the Emil for a motorkanone. Some sources state that early models of the E-3 were fitted as such and were removed once in service, but that would entail reducing the MG 17's rounds containers in the nose to hold approximately half of what they did, so some would have a different configuration inside the nose than others. Is there anything on record that this situation arose? The Friedrich's top cowl guns had a reduction in rounds as a result of the fitting of the centre gun, so the Emil's would too.

 

[Airframes]

I'm not sure if I still have it, but I think Uwe Feist covered at least part of the ammo load, feed problems etc in a book he either wrote or contributed to.
It might be in the old (1962) Harleyford 'Messerschmitt- Story of a famous fighter', which I have, so I'll dig it out and have a look in the next day or so.

 

[nuuumannn]

Thanks Terry. I'm finding variations in the story in publications prior to 2000. WSubsequently, some of the myths have been erased, like the mistaking of the Bf 109V3 for the V4, but the Emil being fitted with a centreline gun continues. Confirmation of that would be ideal.

 

[stona]

There were still ammunition feed problems with the cannon installation on the early F series. The ammunition was fed from the port wing root and I've read of expedient fixes involving wooden wedges and blocks to make it work.
I wouldn't want to be flying an F series Bf 109 with a jammed cannon as that would leave just a WW1 armament of two machine guns!
Cheers
Steve

 

[nuuumannn]

There were still ammunition feed problems with the cannon installation on the early F series. The ammunition was fed from the port wing root and I've read of expedient fixes involving wooden wedges and blocks to make it work.

The MG FF 20mm cannon gave all sorts of problems and the MG 151 seemed to be less troublesome, from what I've read. It had a greater muzzle velocity and rate of fire compared to the MG FF. One problem the Friedrichs had that I'd not heard of before was a few of the F-1s were lost in unexplained circumstances. Friedrichs were grounded as a result. Effectively, there was a high freqquency occilation in the tailplane spar that matched the engine, which resulted in structural failure, causing the tail to disintegrate. Part of this was less rigidity with the removal of the tailplane bracing struts. Plates were added to the rear fuselage to strengthen them.

The argument of the F's armament is well known, Molders and Marseille being supporters of the less is more philosophy, whereas Galland was critical, commenting on the Friedrich being a retrograde step. I guess if you're good enough, two MG 17s might just be enough!

 

[Milosh]

To a limited extend yes, majority of E-7s were equipped with 601A/Aa.

Denniss,

Can you put an approx. number for the number built with each engine for the ~900 E-7/Ns built?

Why was the A/Aa used?

Did this also apply (A/Aa instead of N) to the the Bf110s?

What are the differences between the A/Aa and the N?

 

[bobbysocks]

what works flawlessly on the ground is a different matter when G's and unusual attitudes are involved.

 

[nuuumannn]

What are the differences between the A/Aa and the N?

According the William Green in The Augsburg Eagle, the 'N had; "flattened instead of concave piston heads, the compression ratio being increased from 6.9 to 8.2 and, using 96 octane C3 fuel in place of 87 octane B4, provided 1,200 hp for take off at 2,600 rpm with full boost for one minute, and a maximum emergency output of 1,270 hp for a similar period at 16,400 ft (5,000 m)."

The 'Aa engine was used in the E-3 and E-4 models as well as the E-7, the E-4/N being the subject of Green's description above.

 

[Denniss]

The 601N was actually specified for 1175PS take-off power although it's unsure if this was ever available in the Bf 109 E-series. It was available in the F-series though (some modification to engine to permit this). The rated altitude was higher with 4.9 km vs 4.5 in 601A and 4.0km in 601Aa.
The 601Aa had a max output of 1175 PS via slightly more boost and revs but rated alt was lower than 601A.

 

[tomo pauk]

The DB-601N endured several modifications, the boost and RPM being increased through time. This chart shows 1175 PS for take off, on 2600 rpm and 1.35 ata. On same RPM and boost, it provided same power at 4.9 km.
The engine was up-rated for the Bf 109F1/F2, the max boost was increased to 1.42 ata. Not sure what was the power vs altitude; the Kennblatt for the 109F1/F2 notes that previous engines, that were rated on 1.35 ata max, have 6% less power. That works to around 1245 PS for engines operated at 1.42 ata? It is very much possible that rated height for that manifold pressure and power was lover, though.
Further, same source, dated 1941 (when in 1941??) allows for revving up the engine up to 2800 rpm at (or above? - my remark) rated height, that would give another 10% more power above rated height?

The 109F1/F2 were listed, by same source, to be capable for 615 km/h at 5.2 km (using 2600 rpm and 1.42 ata); the gain in speed when over-revved to 2800 was to be 10-15 km/h.

The early 601N seem to be limited to 1 min at highest setting, while the Kennblatt for the 109F1/F2 states that 2600 rpm and 1.42 ata can be used up to 3 minutes. The 'new' engine should also feature the new supercharger, at least it is so stated here.

The 601Aa have had the rated altitude of 3.7 km, where it was making 1100 PS (on 2400 rpm and 1.35 ata). Take off was at 2500 rpm and 1.45 ata. Looks like the Aa was a 'low-alt variation of the 601A, that one was making 1020 PS at 4.5 km (on 2400 rpm and 1.30 ata). Take off at 2400 rpm and 1.40 ata.
The 1st variant of the 601A was making 1020 PS, but at 4 km rated altitude; later versions received an upgraded supercharger.

 

[nuuumannn]

I'll take your word for it, Tomo! Not being an engine man I fell asleep by the time you introduced the first chart! My German's not too flash either. I'm not sure whether you answered Milosh's query or not.

Anyway. This researching the Bf 109 has been an interesting experience, particularly considering that many different sources have many different versions of the same events. Not being anywhere near the likes of the Bundesarchiv, which it doesn't help that I don't speak German, means I don't have access to anything other than second hand information. It does surprise me however that the most famous German aeroplane ever has so much misinformation surrounding it. I'm also surprised that I haven't had a greater response to my queries about this aircraft, considering the level of devotion people have toward German aircraft and the Luftwaffe in general on this forum.