Bf 109 H WNr.110073

[harrison987]

Thanks for the image...



Here is the problem though...

This was never implemented. Prototype only.

So, the H model would never have had this...

[Nick Beale]

Originally Posted by harrison987

Thanks for the image...



Here is the problem though...

This was never implemented. Prototype only.

So, the H model would never have had this...

But could you describe the Bf 109H that flew with 5.(F)/123 as anything more than a prototype or experimental model? It wasn’t in series production and it wasn’t a standard Umrüst Bausatz, was it?

[piero]

Given the content of post n. 1, I would be very interested.
Giampiero Piva

[Charles Bavarois]

The fotos of the pressurized Erlahaube were attached to a letter from Phänomen-Werke to Forschungsanstalt Oberammergau dated 28. Nov. 1944. They were to back up a not included report on testing the cabin 009.128-Z003/123-Z001. It is quite clear that the cabin was prototype only. IMHO a pressurized Erlahaube was not available for WNr. 110073 anyway.
One of the fotos has a handwritten note: "Windschutzaufbau 8-109.128-Z003 K3 - Z003 druckfest".

[harrison987]

Originally Posted by Charles Bavarois

The fotos of the pressurized Erlahaube were attached to a letter from Phänomen-Werke to Forschungsanstalt Oberammergau dated 28. Nov. 1944. They were to back up a not included report on testing the cabin 009.128-Z003/123-Z001. It is quite clear that the cabin was prototype only. IMHO a pressurized Erlahaube was not available for WNr. 110073 anyway.
One of the fotos has a handwritten note: "Windschutzaufbau 8-109.128-Z003 K3 - Z003 druckfest".

Correct...

Even the Me109K never had it in 44/45. Impossible for the H model to have it in 1943 when it was not even available (and probably still on the drawing board).

[pvanroy]

Originally Posted by piero

Given the content of post n. 1, I would be very interested.
Giampiero Piva

One more thing I thought about for your reconstruction: testing of the V54, and experience with the G-6/AS showed that the standard Fo 870 oil cooler provided insufficient cooling capacity. As a result, the V54 was to be refitted with the larger Fo 987 oil cooler, which was also introduced during G-14/AS production, and retrofitted to some G-6/AS. Therefore, 110073 possibly may have been equipped with the larger Fo 987 oil cooler. We really need to see the photographs that purportedly exist of that aircraft!

[ArtieBob]

I have not seen the photographs, but there is a 3-view drawing, which appears to be of Me origin on microfilm of the captured German documents at The US National Air and Space Museum. It is not a very good image, but it is pretty well dimensioned and shows some internal detail, i.e. location of the GM-1 tank, etc. Of course, the real aircraft may not appear exactly the same as the drawing, but the canopy on the drawing certainly does not appear to be the Erla type.
Best Regards,
ArtieBob

[pvanroy]

Originally Posted by ArtieBob

I have not seen the photographs, but there is a 3-view drawing, which appears to be of Me origin on microfilm of the captured German documents at The US National Air and Space Museum. It is not a very good image, but it is pretty well dimensioned and shows some internal detail, i.e. location of the GM-1 tank, etc. Of course, the real aircraft may not appear exactly the same as the drawing, but the canopy on the drawing certainly does not appear to be the Erla type.
Best Regards,
ArtieBob

Do you mean the schematic three-view drawing dated 21.7.1943? That one indeed shows the regular three-piece canopy. An overview schematic of the Baugruppen dated 24.2.44 also shows the regular three-piece canopy. There is also another schematic side-view drawing of the proposed production version of the H (using the K fuselage), which shows an Erla Haube, but unfortunately I don't know the date for that one.

[harrison987]

Yes, I already said that the standard Erla Haube could not be pressurized, due to the steels used.

The prototype H model was made at the end of 1943, which is why I referenced it...I was not referring to this specific aircraft, but rather the initial design (which was based on an F initially)...so that was not me misquoting anything. I was simply stating that when it was initially designed, the pressurized Erla Haube was not even on the drawing board.

Just because an Erla Haube was said to have been installed on a G5 airframe, does not mean that they kept the pressurization. It could started WITH a pressurized cockpit (and standard canopy)...and then adapted later to take the Erla (pilot preferred) with no pressurization.

After all...none of these aircraft NEEDED pressurization. The B-17 was at mega high altitudes and was unpressurized. Though it was "convenient" for the German pilots to have this...they were already flying at high enough altitudes without it.

If it was something they "had" to have...they would have made the G3 and G5 in mass numbers.

I suspect it originally had the standard canopy, but was later changed out to the Erla...and they dropped the pressurization as it was not needed, really not that great to begin with, and had its problems.

[pvanroy]

Originally Posted by harrison987

Yes, I already said that the standard Erla Haube could not be pressurized, due to the steels used.

The prototype H model was made at the end of 1943, which is why I referenced it...I was not referring to this specific aircraft, but rather the initial design (which was based on an F initially)...so that was not me misquoting anything. I was simply stating that when it was initially designed, the pressurized Erla Haube was not even on the drawing board.

Just because an Erla Haube was said to have been installed on a G5 airframe, does not mean that they kept the pressurization. It could started WITH a pressurized cockpit (and standard canopy)...and then adapted later to take the Erla (pilot preferred) with no pressurization.

After all...none of these aircraft NEEDED pressurization. The B-17 was at mega high altitudes and was unpressurized. Though it was "convenient" for the German pilots to have this...they were already flying at high enough altitudes without it.

If it was something they "had" to have...they would have made the G3 and G5 in mass numbers.

I suspect it originally had the standard canopy, but was later changed out to the Erla...and they dropped the pressurization as it was not needed, really not that great to begin with, and had its problems.

Actually, I think we are mostly in agreement. My comment about the standard Erla Haube was in reply to Graham Boak’s suggestion that it might have been modified for pressurization – something I agree with you would have been impossible because of its construction.

I took your 1943 reference to be with regard to 110073 at Guyancourt, hence the misunderstanding. While, strangely, the 1942 Sofort-Programm to produce a high-altitude fighter was based on the 109 F (which had ceased production in April 1942, with the G-1 entering production in February of that year), the Schnellösung of 1943 which gave rise to the 109 H was based on the G-5/U2 from the outset, with projected production versions being derived from the 109 K. Two drawings of the production 109 H based on the K fuselage both show an Erla Haube. Unfortunately, I do not have a date for those drawings, but I would assume they are from early 1944, given that the 109 H was essentially shelved by the middle of that year.

I agree that the V49 may have lost its pressurization – see my reply to Graham Boak. However, both the DB 628 and the Bf 109 H had design altitudes of 14 000 – 15 000 m. So, for testing the full envelope of both this engine, and the airframe, a functioning pressure cabin would have been indispensable. The V54 was tested extensively, also at high altitudes, and the Guyancourt W.Nr. 110073 was used for high-altitude reconnaissance. So, at least both these two airframes would have required functioning pressure cabins.

I also agree that for combating bombers over Europe, pressurized fighters were not required – which is also a reason why pressurized versions of the 109 were abandoned after the G-5 (of which about 550 were built, not an insignificant number). However, cabin pressurization is indispensable for high-altitude reconnaissance aircraft, which was one of the main roles envisaged for the 109 H besides that of extreme altitude fighter (where it could have been used to combat allied high-altitude reconnaissance machines). Remember, the 109 H was intended to operate at altitudes around 14 000 m, where cabin pressurization is a necessity.

In any case, to get back to the Guyancourt machine W.Nr. 110073: this aircraft definitely had a functioning pressure cabin, given its intended role and the quoted altitude of 14 200 m it achieved (Nick Beale's Ghostbombers website). Planning for the conversion dates at least to January 1944 (see the Bauzustand posted by piero, with a date of 24.1.44). The machine was converted at Guyancourt in Spring 1944, with Fritz Wendel making the first test flights on 5-6 April 1944 (test report by Wendel). In May it was transferred to 5.(F)/123 for operational testing, and on 12 July it was shot down by friendly FlaK (Ghostbombers website, courtesy of Nick Beale). So, while I consider it most likely that this aircraft was fitted all the time with a standard three-piece pressurized canopy, in my opinion, this timeline does not entirely exclude the possibility that it *might* have been equipped at some point with a pressurized Erla Haube. The same also goes for the V54, which made its first flight on 2 November 1943, and was damaged in a forced landing on 29 June 1944, marking its final flight (it was intended to be repaired and slated to undergo further modifications, but it seems this was never finished – see Nick Beale’s Ghostbombers page).