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Author Topic: Junkers EFo designations  (Read 9204 times)

Offline Jemiba

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Junkers EFo designations
« on: March 21, 2012, 01:47:37 am »
As proposed by Artie , I'll start to list the "EFo" designations, found in Wolfgang Wagners book "Hugo Junkers. Pionier der Luftfahrt - seine Flugzeuge". They all are belonging to models for the windtunnel, or for towed tests and as said before,
cannot always be regarded as "projects". All pictures (in low res only) are from the mentioned book.

EFo-08                   high-altitude bomber, 2 jet engines
EFo-09                  single-seat fighter, 10 jet engines, prone pilot
EFo-11                  single-seat fighter, 2 jet engines
EFo-12              bomber, 4  jet engines
« Last Edit: March 21, 2012, 01:50:44 am by Jemiba »
It takes a long time, before all mistakes are made ...

Offline Jemiba

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Re: Junkers EFo designations
« Reply #1 on: March 21, 2012, 01:50:23 am »
EFo-15                   improved EFo 012
EFo-17                   single-seat fighter, 2 jet engines, similar to Me 262
EFo-18                   single-seat short range fighter, 4 jet engines
EFo-19                   single-seat fighter, 2 jet engines
It takes a long time, before all mistakes are made ...

Offline Jemiba

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Re: Junkers EFo designations
« Reply #2 on: March 21, 2012, 01:52:31 am »
EFo-21-3                six-engined trans-atlantic passenger aircraft (coupled engines)
EFo-22                   record aircraft, 2 jet engines
EFo-43                   towed model. probably for a guided glidebomb
It takes a long time, before all mistakes are made ...

Offline blackkite

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Re: Junkers EFo designations
« Reply #3 on: March 21, 2012, 02:18:41 am »
Wow! Super. You made my day.

Offline richard

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Re: Junkers EFo designations
« Reply #4 on: March 21, 2012, 02:59:52 am »
The EFo 22 is sometimes refered as EFo 10 ...



Heinkel He343 (reply #31 )

Offline Alcides

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Re: Junkers EFo designations
« Reply #5 on: March 21, 2012, 03:17:26 am »
Fantastic Work Jemiba. Thanks a lot!!!  :D :D :D

I wonder which was the idea behind the efo-11. Why the engines in that position?

Offline Skyblazer

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Re: Junkers EFo designations
« Reply #6 on: March 21, 2012, 04:19:48 am »
Great topic. Thanks for sharing!

Offline Jemiba

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Re: Junkers EFo designations
« Reply #7 on: March 21, 2012, 04:21:05 am »
I wonder which was the idea behind the efo-11. Why the engines in that position?

Judging the quite similar profiles of the fuselages of those twin-engined fighter designs, I think,
it was just to test the pros and cons of different engine installations. There still were very few
real experiences with jet aircraft, so it was a phase of trial-and-error.
Reasons that made this layout interesting could have been the unobstructed wing and fuselage,
that allowed for a quite small aircraft.
It takes a long time, before all mistakes are made ...

Offline toura

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Re: Junkers EFo designations
« Reply #8 on: March 21, 2012, 06:10:48 am »
Hi Jens
Thanks for the job ! Beautiful !
         but
I've read that the EFo 22 come from the EFo18
and this EFo 22 is like the EFo 10 ?
(See my drawing)
 
And more, could you tell us what is the signification
of "EFo"  and "EF"

Offline toura

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Re: Junkers EFo designations
« Reply #9 on: March 21, 2012, 08:34:16 am »
I've found :
" Entwicklungs--flugzeug"
in French : avion en cours de developpement
in English ( perhaps) development aircraft

Offline Jemiba

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Re: Junkers EFo designations
« Reply #10 on: March 21, 2012, 11:35:26 am »
I've found :
" Entwicklungs--flugzeug"
in French : avion en cours de developpement
in English ( perhaps) development aircraft

Yes, that's what I've found, too ! But honestly, I don't believe it, apart from the fact,that it wouldn't
fit for the "EFo" designations. But still yet, I've found no better explanation, but asked in the German
Flugzeugforum. Let's wait, perhaps we'll get a plausible answer.
BTW: I've found a list, which might be helpful, too:
http://www.lwag.org/forums/archive/index.php/t-2329.html
It takes a long time, before all mistakes are made ...

Offline Jemiba

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Re: Junkers EFo designations
« Reply #11 on: March 22, 2012, 12:37:35 am »
Got an answer from Peter Achs, aka "Junkers-Peter" in the Flugzeugforum, a specialist for Junkers
aircraft. Paul, you're right, "EF" stould for "Entwicklungsflugzeug" (aircraft design). In the abbreviation
"EFo", "E" stands for "Entwicklung", too, and "Fo" for "Forschungsvorhaben" (researchproject).
That means, that at least the EFo-numbers weren't all assigned to aircraft designs, but to engines, or
general aerodynamic researches. So, we should be aware, that not every number can be supplemented
with a 3-view. And, btw, Peter quoted from a letter to the editor he sent to the Jet & Prop magazine
in March 2004 just about this theme, were he warned about putting too much faith in Wolfgang Wagners
statements about the EFo/EF designations, although he mainly meant the general history and not explicitly
the list. 
Seems, there's still a lot of work left for us !
It takes a long time, before all mistakes are made ...

Offline Skyblazer

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Re: Junkers EFo designations
« Reply #12 on: March 22, 2012, 02:07:33 am »
Got an answer from Peter Achs, aka "Junkers-Peter" in the Flugzeugforum, a specialist for Junkers
aircraft. Paul, you're right, "EF" stould for "Entwicklungsflugzeug" (aircraft design). In the abbreviation
"EFo", "E" stands for "Entwicklung", too, and "Fo" for "Forschungsvorhaben" (researchproject).

What is still unclear to me is whether the EF and EFo lists are one and the same or if they were separate...

Offline Jemiba

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Re: Junkers EFo designations
« Reply #13 on: March 22, 2012, 03:15:02 am »
They were two separate lists. The EF designations were used by the "Konstruktionsbüro - KoBü",
probably best translated as "design office". Those numbers actually should have been used for
aircraft designs, whereas the EFo designations came from the "Forschungsabteilung" (Research
department) and were used for all objects of research, Peter Achs brought as an example a report
about a "Luftschraube mit veränderlichem Durchmesser" (propeller with variable diameter), which had
an EFo-designation, too. And he added, that numbering of projects of the research departments
was completely independent from that of the design offices.
Just my thought, but here we could have a reason for those strange duplicates, when over the years
EFo- and EF-designations were mixed up.
It takes a long time, before all mistakes are made ...

Offline Michel Van

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Re: Junkers EFo designations
« Reply #14 on: March 22, 2012, 04:07:57 am »
and to make things even more complicated


according the Book "Hugo Junkers Pionier Der Luftfahrt - seine Flugzeuge" by Wolfgang Wagner
once a EFo project got a windcannel model,  the designation change to EF !


The List are not great help because the project explanation are in Telegram style


sorry, but we german have this pesky habit to abbr. and "to be brief" in documents  :-[

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