Question: new BF109E4: when were the modifications first time used?

[kraut1]

Hi All,

For historical mission generation I would like to know:

-When was the armoured wind screen first time used?

-When was the DB601N first time used?

Already known for me:

Bombs: August 1940

And the Mirror and the removed head rest are of course field modifications.

Many thanks in advance!

[LukeFF]

July 1940 for the 601N. 

 

Additionally, the Romanians apparently had some of these planes in their inventory. 

[kraut1]

11 hours ago, LukeFF said:

July 1940 for the 601N. 

 

Additionally,the Romanians apparently had some of these planes in their inventory. 

Thank you very much for the information, very importent for Battle of Britain missions.

(It seems to me that due to the priority for the DB601/N engine for BF110 destroyers (and maybe bombers)

only 1 Jagdgruppe of JG26 + JG26 Commander Galland was using this engine in the BF109. Is this correct?)

Wikipedia:

 

Concerning the Armoured wind screen:

Has maybe anyone historical Battle of Britain BF109-E4, E7 photos with date that show the Armoured Wind Screen?

Edited October 13 by kraut1

[Heart0ne]

On 10/12/2025 at 3:35 PM, kraut1 said:

 

-When was the armoured wind screen first time used?

 

The TL;DR-answer is: "Unknown, that is lost to history."

I've looked into my Osprey books about the Battle of Britain and books about the Bf-109E around that time, and I couldn't find a single image or reference to the armoured wind screen.

According to Baumgartl, the first documented mention of ANY armour on a production-109 stem from 13 and 15 september 1940, and the mentioned weights are what one would expect from head armour, seat armour, and fuel tank armour. British testing documents from that same month about a captured 109E, mention the armoured wind shield with roughly correct dimensions and weight, and apparently there are pictures of this aircraft in Mombeeck's book about JG2 (Vol.1).

AFAIK those are the only 100% properly dated references from glass armour in that time period.

 

However, in January 1940 the first tests were carried out for head and seat armour at the flight testing squadron, and they deferred the decision to Messerschmitt. The next known document talking about armour for the 109E is an aircraft modification document dated 15 june 1940. According to Prien, there are also "british documents" from that time period that speak of armour on the 109E, so he came to the conclusion "from July 1940 onwards..."

So, making a mission with JG2 aircraft in september 1940 could be accurate, making a mission in July 1940 could also be accurate.

In any case, the armoured wind shield shouldn't have been very common if the supply chain couldn't even deliver them to the factories in bulk in late 1940, and the armoured wind shield was omitted as a standard feature for the F-model, contrary to the other armour added to the Bf-109 through the course of 1940.
 

[kraut1]

1 hour ago, Heart0ne said:

The TL;DR-answer is: "Unknown, that is lost to history."

I've looked into my Osprey books about the Battle of Britain and books about the Bf-109E around that time, and I couldn't find a single image or reference to the armoured wind screen.

According to Baumgartl, the first documented mention of ANY armour on a production-109 stem from 13 and 15 september 1940, and the mentioned weights are what one would expect from head armour, seat armour, and fuel tank armour. British testing documents from that same month about a captured 109E, mention the armoured wind shield with roughly correct dimensions and weight, and apparently there are pictures of this aircraft in Mombeeck's book about JG2 (Vol.1).

AFAIK those are the only 100% properly dated references from glass armour in that time period.

 

However, in January 1940 the first tests were carried out for head and seat armour at the flight testing squadron, and they deferred the decision to Messerschmitt. The next known document talking about armour for the 109E is an aircraft modification document dated 15 june 1940. According to Prien, there are also "british documents" from that time period that speak of armour on the 109E, so he came to the conclusion "from July 1940 onwards..."

So, making a mission with JG2 aircraft in september 1940 could be accurate, making a mission in July 1940 could also be accurate.

In any case, the armoured wind shield shouldn't have been very common if the supply chain couldn't even deliver them to the factories in bulk in late 1940, and the armoured wind shield was omitted as a standard feature for the F-model, contrary to the other armour added to the Bf-109 through the course of 1940.
 

Thank you very much for your detailed answer!

[YR-AndreiTomescu]

On 10/12/2025 at 10:19 PM, LukeFF said:

Additionally, the Romanians apparently had some of these planes in their inventory. 

Royal Romanian air force bought 50 Bf 109 E4 in dec 1939. First 11 came in spring 1940, 39 spring 1941, E3 and E4 variants. All composed Gr 7 Vt (fighter group). In 1942 bought 19 more, E7 variant.

in 22 june 1941 Gr 7 Vt started the Basarabia campaign with 109 E 30 machines, with 10 more added later .  Gr 7 Vt ended the 1941 year with 61 confirmed aerial victories, 1 probable and 7 aircraft destroyed on the ground, lossing 6 aircrafts and 2 damaged. 

regarding the improved engine: it used the 100 high octane fuel, which we did NOT have. so i guess those romanian aircrafts didn't have the "N" variant. 

Mirror: dictated by the british and french doctrine still liked by romanain pilots, despite the rigurous german doctrine implemented since 1939-1940, they (the pilots) loved mirriors, put those on planes. They were ordered to take them off in 1943, once the remains of Gr7, escaped from Karpova , were given G-s and included for a while in the Udet flotilla.

 

[LukeFF]

2 minutes ago, YR-AndreiTomescu said:

regarding the improved engine: it used the 100 high octane fuel, which we did NOT have. so i guess those romanian aircrafts didn't have the "N" variant. 

 

Thanks - it was something Oleg Maddox told me a long, long time ago when I emailed him and asked about the usage of the N engine on the Eastern Front. 

[YR-AndreiTomescu]

near Ploiesti, Romania,  the first rafinery in the world was opened at Râfov, in 1857, by brothers Teodor and Marin Mehedințeanu. it produced...  LPG. !!!

still, the large complex of oil rafinery found at Ploiesti in the '40 was outdated, and didn't have the technology of producing anything higher that 85 octane. (70 octane was the norm)

the germans needed the romanian oil badly, until they could get their hand on the russian one. so they used romanian produced fuel for engines with lower demands, and took oil/fuel in germany for further processing to obtain the 100 octane needed for more performant engines.

it is to be noted that that technology was top notch, top secret and the german ally refused to implement it in romania at the beginning. 

also it is to observe that the deal including acqisition of 69 109 E's and 120 + 209 109 G's later on, and the training by the german military expedition corps of the romanian pilots was conditioned by the oil supplies, and paid such.