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Dornier Do-212 Experimental Seaplane

Dynoman

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I was looking for additional information on the Do-212 developed by the Germans and the Swiss during WWII.

The unique pusher configuration may have been an effort to move the thrust-line symetrically along the longitudinal axis and through the CG, minimizing pitch changes with power changes. Note small propeller for water clearance.

Also, does anyone know what the mission for this aircraft would have been. Developed under a German directive and developed during wartime I imagine that it would have been for SAR missions or maybe agent infiltrations. However, the range may have been greatly reduced due to fuel capacity. Just a guess.

Description:
"The Do 212 from the "A.G. für Dornierflugzeuge", the Swiss Dornier works at Altenrhein, was a design for a small 4-seat amphibian according to German requirements. It was of a modern all metal construction, fitted with a 450 hp Hirth HM 512-B-0 air-cooled engine just aft of the cabin, driving a four-bladed pusher propeller through an extension shaft. To protect the propeller against splash water during take-off, the shaft could be tilted upward through 12°. Construction started in 1941 and in late July 1942 the aircraft was ready for test flight. On August 3, Egon Fath made a few attempts to start from the water, but these failed. A Do 24 was used to tow the Do 212 and it finally flew, however instability forced the pilot to ditch just after take off. Further trials ended in the same way and development was terminated. It was scrapped in 1943."



 

Jemiba

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Development actually started in 1938 and the aim was to develop a civil
light transport, a kind of successor to the Do 12 Libelle III. Work was done
in Althenrhein/Rorschach, the swiss branch of Dornier. The RLM wasn't
too much interested, the first and only flight revealed, that the aircraft was
underpowered and in 1943 the project was axed.
(3-view from FlugRevue 3/74)
 

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Dynoman

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Thanks Jemiba...and great three view. Its and interesting configuration, I don't think I've ever seen pontoons like these before.
 

Jemiba

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I think, the wingtip floats were used aerodynamically as endplates.
 

blackkite

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Hi Aerodynamic engineers!
Please show us what wrong part is!
Dornier didn't do wind tunnel test?
I feel wing is small and horizontal tail stabilizer is large.
What is the effect of wing tip floats and variable angle propeller shaft for instability?
 

AeroFranz

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many things could be wrong, but usually these things are traced back to an unfavorable position of the cg with respect to the center of lift. I am surprised by the relative sizes on wing and tail, the latter being quite large, but usually that has a positive effect on longitudinal stability. Maybe it denotes an unsuccessful attempt to fight a rearward cg due to the engine placement in the tail, which is destabilizing.
I don't know about the tilt-shaft, but one thing is sure: if the thrust line does not pass through the cg, there will be pitch moment changes with power application.

Regarding the endplate effect of the floats, I wonder if their use was already known at that time. It strikes me as suspect, but maybe someone can clarify this :)
 

Steve Pace

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Aerodynamics working in concert with hydrodynamics...
 

Gannet

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My first impression is that maybe it is designed to be a forerunner to a Wing in Ground Effect aircraft and that the large horizontal stabilizer is for greater pitch authority.

But probably the design intent was shorter alighting run

Also the picture of the actual aircraft and the model do not appear to match the prop on the model is underneath the horizontal stabilizer
 

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blackkite

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AeroFranz said:
many things could be wrong, but usually these things are traced back to an unfavorable position of the cg with respect to the center of lift. I am surprised by the relative sizes on wing and tail, the latter being quite large, but usually that has a positive effect on longitudinal stability. Maybe it denotes an unsuccessful attempt to fight a rearward cg due to the engine placement in the tail, which is destabilizing.
I don't know about the tilt-shaft, but one thing is sure: if the thrust line does not pass through the cg, there will be pitch moment changes with power application.

Regarding the endplate effect of the floats, I wonder if their use was already known at that time. It strikes me as suspect, but maybe someone can clarify this :)
Many thanks AeroFranz!
Yes main wing position is little too forward.
 

blackkite

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Gannet said:
My first impression is that maybe it is designed to be a forerunner to a Wing in Ground Effect aircraft and that the large horizontal stabilizer is for greater pitch authority.

But probably the design intent was shorter alighting run

Also the picture of the actual aircraft and the model do not appear to match the prop on the model is underneath the horizontal stabilizer
Gannet! I surprised very much to hear your opinion. You are very sharp eyed,too,
 

Jemiba

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Today I had a look into "Dornier : die Chronik des ältesten deutschen Flugzeugwerks"
(Dornier - The chronicleof the oldest german aircraft manufacturer) exactly confirming
AeroFranz suggestion : The large tailplane was an attempt, to put the CG right, which
was positioned too far backwards due to the complicated and heavy engine installation.
In some way, Dornier had unintentionally realised a kind of Delanne design !
 

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borovik

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Pictures Do-212 model with a different conception (probably the initial version) /from Aero Revue/
With this form of horizontal tail stabilizer / fin, excluded problematic the possibility of using deflected up the shaft.
 

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richard B

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quote :

" With this form of horizontal tail stabilizer / fin, excluded the possibility of using deflected up the shaft. "

Maybe not ? :)

PATENT DORNIER 1939 :
 

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VictorXL188

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Further to the previous posts, here's the article from the Plane Facts section of Air Enthusiast's September 1973 issue regarding the Dornier Do 212
 

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hesham

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In my files,

and as I know there was more than one concept projected and developed from this beauty
design,can anyone light us ?.
 

Flitzer

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Thanks for this. Very interesting especially as it's a new one on me.
 

hesham

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Flitzer said:
Thanks for this. Very interesting especially as it's a new one on me.
Thank you my dear Flitzer,and I hope someone has a direct Info.
 

riggerrob

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Dornier 212's main wing looks too small and too far forward. The only it would balance is if the aft horizontal surface provided a substantial amount of lift ala. Delanne.
Also, those vertical fins look too small for yaw stability.

That pusher propeller configuration was based on the Dornier 26.
Dornier 26 had four Junkers Jumo 205 diesel engines pumping out 868 hp. Engine nacelles were mounted at the bend of the gull wings with two tractor and two pusher propellers. Driveshafts on the pusher engines titled up to keep props out of spray during takeoff a and landings. During cruise, they tilted down to horizontal to reduce drag. The Dornier 26 first flew in 1938 and hauled mail across the Atlantic (to South America) until the start of WW2 when most they were pressed into military service.
 

Kuno

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The Do 212 is an absolutely fascinating project - at least for me. Not only the unique pusher configuration but also the that they were using the Hirth HM 512 engine... as far as I know this engine was not used in any other aircraft (I would be happy if somebody could tell me something else).

Above Reply #11 on: December 12, 2009 of Borovik - would somebody know in which issue of "Aero Revue" this artists impression was shown?
 

Jemiba

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hesham said:
... as I know there was more than one concept projected and developed from this beauty
design ...
Rear mounted pusher engines, which were tilted upwards for take-off and landing were indeed
proposed by Dornier later in the P340 6-07 design, tendered for the NATO MR requirement (Shown
by Chris in his book "Nimrod's Genesis")
 

hesham

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Thank you my dear Jemiba,

and there was some of them before the end of the WWII.
 
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