Externally visible differences between Bf 109E-3 and E-7?

[Dénes Bernád]

I would like to hear your input regarding the externally visible difference(s) between the Bf 109E-3 and E-7, as currently I have an ongoing debate regarding this issue.

Thanks,

[gogh]

Hello Dénes
The best is to visit Falcon site
http://www.messerschmitt-bf109.de/index-1024.php

or this site
http://www.xs4all.nl/~tozu/me109/index.htm

cheers Peter van Gogh

[Andreas Brekken]

Hi, Denes

In my opinion, You cannot state from a photo that has no visible date or WNr of the aircraft that it is an E-3 or E-7.

There are several reasons for this:

- Numerous E-3's were upgraded to E-7 standard, and thus in fact became E-7s

- A few E-7's (identified by works number) have been identified with the early type cockpit glazing.

- Also, I would suppose that E-3's did exist that had their engine changed and a N engine installed, and the cockpit hood exchanged with no official E-7 conversion data plate

So - it's an E!

Much of the reason for this is of course that repaired, converted and refurbished E-series aircraft were used to the end of the WWII

Regards,
Andreas

[lritger]

Andreas pretty much nailed it... if the cowling is off, you could look for the "saddle tanks" on either side of the engine, which appear to be a hallmark of the DB 601N and that would be one way to identify an E-7, as would an external fuel tank. But as Andreas points out, so many early models were rebuilt into later variants that it's often an exercise in futility to positively identify what a given aircraft is, even with the W.Nr! One can make an educated guess, but that's about it.

Lynn

[Kuba Plewka]

The easiest way is to check an octane trangle.
DB 601 A, which powered Emils since E-1, E-3 and E-4 used B4 low octane aviation fuel.
DB 601 N installed on E-7 burned high octane C3 fuel (96-100 oct.) due its higher fillin pressure and so on.

You have raised an extremally interesting point - the rebuilt ones.
One must keep in mind, that no W.Nr but equipment made a version.
So, if E-1 was given wings with MG-FF/m (or the cannons only were installed) it became E-4. If E-1 was given those cannons and also a better N engine it became E-7.


all the best
Kuba

[Dénes Bernád]

The whole story started with the cover of a model kit's box:


I argued that based on ARR documents I have copies of, No. 64 was not an E-3 (despite the appearance), but rather an E-7.

Somebody else argued that since it has the early type cockpit canopy, truncated spinner and no underbelly rack, it's an E-3.

I replied that these don't have any significance when identifying the proper sub-type, as there were older models (like the E-3) refurbished/upgraded to E-7 standards, even with the early type cockpit canopy and truncated spinner.

The other guy - a modeller - keeps insisting that to him it's an E-3, not an E-7, which must have newer style squared canopy and full spinner.

So I offered him a compromise solution: it's an E-7, which looks like and E-3. He did not accept it, either...

Here is a rather indifferent quality reproduction of the famous colour photo of the same airplane (bottom) , also featured on the rear cover of my book on the Rumanian air force, published by Squadron/Signal (photo by S. Tulea):

[olefebvre]

An E-7 did not necessarily have a DB601N installed actually the number of E-7/N and E-7/Z which were equipped with this engine was fairly low.
The saddle tanks were required not because of the DB601N but due to the introduction of the droptank, oil amount was insuficient using the standard oil tank given the extra 300l of fuel.
E-7/E-8 standards basically meant that, piping/wiring for the droptank and a few other changes (using the E/B as a basis). It should have had the DB601N as well but they gave so much troubles that the E-7 were built w/o except for the few E-7/N and E-7/Z.
The official designation for the type is E/B with modifications so as to carry a droptank, 4 MG-17s equipped a/c are to be know as E-8 and 2MG-17 and 2 MG-FFM a/c are to be known as E-7

So denes if your 109 could use a droptank it's an E-7...

btw Externally besides the octane triangle there is only one way to identify an DB601N equipped Emil...

[Rabe Anton]

Servus, Dénes!

Concerning the Roumanian Bf 109E-3 that became an E-7, there's just no explaining the obstinancy of some folks, is there?!

I just checked an official wartime RLM document stating that the Messerschmitt Bf 109E carried by the Roumanian AF as No. 64 was an E-7 subtype, just as you have indicated. Werknummer was 704. Obviously an older E-3 that became an E-7.


My own research indicates that the Luftwaffe and the RLM pursued a universal program to convert all airworthy E-1s, E-3s, and E-4s into E-7s after 1940. I further suspect that there was not one comprehensive technical change order which included all mods necessary for conversion to an E-7 but that there might have been phases or stages of modification. Naturally, also, the conversions were not accomplished overnight, but by 1942-1943 it is unusual to find a "live" E-1, E-3, or E-4 carried in loss records or unit inventories. The preponderance of E-7s in training school reports is especially interesting.

Could still be much debate over the Emil canopy configuration. I sort of suspect that the "square" or "flat top" canopy style was prescribed as part of the conversion to an E-7, but for whatever reason was not universally carried out. Another explanation for "round head E-7s" might be that a mandated changeover to the "flat top" canopy came along later after the first E-7 mod orders were issued. On the other hand, I have never seen an E-7 assigned to either 7./JG 26 or I./JG 27 in the MTO that had a "round top" canopy, yet we know with certainty that many, if not most, of these same E-7s were updated E-1s, E-3s, and E-4s that must have originally had them. Something to chew on, perhaps.

RA

[olefebvre]

In fact there were a lot upgrades which were introduced in the 109 life which were designed to be retrofitted to earlier batches of produced a/c. While some introduced a change in designation like the equipment for droptanks some did not, the canopy for instance. There were hundreds of such modifications which should have been applied whenever possible.

Conversion to E-7 standard was indeed a must as it provided the Emil with a much needed extra endurance, and it was a definite high priority upgrade.
The WkNr 704 is typical of E-3s which went through the main upgrades, as it appears at a point as an E-4 and then as an E-7.

AFAIK only newly produced E-7 got the squared canopy and those earlier a/c which had them fitted at some point. The earlier a/c kept their canopy or they may have got a new squared one if time/spares where available or repairs needed.

[Kjetil Aakra]

I also think Andreas got it right.

The old notion that the "square" canopy signifies an E-4 while the older "rounded" was a feature of the E-1 and E-3 has been abandoned now, as far as I know. At least it should be.

These two types were readily interchangeable which is proved by the fact that there are even some Bf 109Fs with the "rounded" canopy. Rather than being early examples of Bf 109Fs as some sources have stated I think these are in-the-field modifications. The best know examples are the Fs flown by Horst Carganico. On his F-4s you can easily see these old canopies and as they were also a feature of his Emils (which is otherwise in E-7 configuration, with capped spinners), it is likely Carganico simply preferred these older versions, probably feeling they provided him with a better view from the cockpit.

Rabe Anton's ideas of the Emil modification program is also in line with my findings. I agree fully that there was probably no single standard set down for this upgrade, except to upgrade armament. In all likelyhood the main modifcation to be carried out was the fitment of droptank piping, MG FF cannon (on E-1s) and, in most cases it would seem, the capped spinner. The external armoured windscreen glazing was also fitted to most of these older models.

The attached photos are indicative of this practice. They show what was originally W.Nr 6274, an E-1 built by Fieseler at Kassel (note the black exhaust shrouds which is a feature of Fieseler-built Bf 109Es & Ts) and later modified into an E-7 with capped spinner, windscreen armour and MG FFs (and probably droptank piping). The photos show it in service with 5./JG 5 as Red 19 in 1942. Note the round metal sheet covering the original MG 17 port.

This one still retains the "round" canopy and this must have been the least important feature of the modification so I am not surprised that it was ignored for quite a few conversions. At least there are several examples to be seen in the JG 5 invetory of 1941-42.

Kjetil Aakra