Dewoitine D.700 to D.721

Hi,

from the list of Dewoitine which my dear Deltafan gave it
to us,both of the D.700 and D.710 were three seat twin-
engined aircraft,the D.700 was unfinished prototype and
the D.710 was a project,and may be the two projects
related to each other,from Flightglobal there was an artist
drawing to D.700,I don't know they were a fighters or
what ?.

http://www.flightglobal.com/pdfarchive/view/1939/1939%20-%200976.html

HI hesham
look at
1000aircraftphotos.com/contributions/KleinBernhard/8003.htm
Bye

That should be: http://1000aircraftphotos.com/Contributions/KleinBernhard/8003.htm

BTW: that photo was lifted directly (and 1000aircraftphotos' text verbatum) from Vol.8 of William Green's War Planes of the Second World War (Dewoitine D.720, p.20).

In my files I have recorded that the D.700 designation was used for:
1. HD.700, a 1934 project for a South Atlantic crossing seaplane;
2. A three seat twin engined aircraft of 1937 which was not completed (and obviously the one we are discussing here);
3. The Pulqui I interceptor jet for Argentina (1945/46); and
4. A 1945 twin engines transport project for Spain.

Just for your information.

Hi, the link about Dewoitine :

http://www.secretprojects.co.uk/forum/index.php/topic,4652.0.html

In Les avions Dewoitine (Raymond Danel and Jean Cuny, Collection Docavia, Editions Larivière, sept. 1983, there is this page 171 :
(...)
HD.700 : 1934 : seaplane, to cross South Atlantic (project)
D.700 : 1937 : 3 seats, two engines (unfinished prototype)
D.700 : 1945-46 : Pulqui I : interceptor jet for Argentina
D.700-T2 : 1945 : transport, two engines (project studied in Spain)
D.710 : 1938 : 3 seats, two engines (project)
D.710 : 1947 : transport, two engines (project studied in Argentina)
D.720 : 1938 : 3 seats, two engines, derivative of the first D.700
D.720 : 1948 : interceptor jet (project studied in Argentina)
D.721 : 1938 : derivative of the first D.720 (unfinished prototype)
(...)

On pages 250 to 255 :
D-700, D-710, D-720 and D-721 are called : "triplaces de travail" (three seats for "work" ?) in the chapter "Les appareils de renseignement" (recon planes). They were not fighters.

A link for a FS2009 Dewoitine D.700.

http://www.jrlucariny.com/Site2008/d700t2/d700t2Imagens/004D700T2.jpg

and noww Dewoitine
always " aviation magazine"

The great site Maquettes de souffleries (devoted to wind tunnel models) presents a design for a twin-engined ASW aircraft that is believed to be a post-war Bréguet study with an underbelly radome:

That's really a discovery, although I don't see the relationship to the Br.690.
Neither wing planform, nor the tail seem to match. The eliptical wing looks
a bit old fashioned for a post-war type, I think, and why change the simple straight
leading and trailing edges of the Br.690 ? Perhaps it's not a radome under the
fuselage, but a ventral station for an observer, as we know it, for example,
from the Dewoitine D.700 ?
( http://www.secretprojects.co.uk/forum/index.php/topic,10572.msg99619.html#msg99619 )
Looks more similar to my opinion, but let's see.

Did some further searching with regards to the „twin engined ASW“ aircraft and, though I’m still not
sure about it, I think, it’s not a Breguet design, but a „missing link“ between the Dewoitine D.700 and 720:

- Shape of the fuselage, tail and especially the gondola are very similar to the D.700
- Shape of the wing is more elliptical for both, the D.700 and 720, than for the Br.690
- Attachement to the wing and profile of the engine nacelles match those of the D.720
quite well, I think.
- Not sure about the shape of the nacelles when viewed from the underside, but that
asymmetrical shape of the rear portions cannot be found on the Br.690 either. Anyone
to point me to a trustable 3-view of the D.720 showing the underside ?

(Dewoitine D.720 : http://www.myhobbylinks.com/images/3V-D39-D720..jpg )

Very interesting, Sherlock Jens, keep at it! I think you're about to solve the mystery...

Elementary, my dear Watson-Beaumont ! ;D

Think, I will start to make a provisional 3-view ...

Ok, let's have a try ! Have combined the D.720 (wings, tail, rear fuselage) with what we have about the D.700.
Judging our designations list (http://www.secretprojects.co.uk/forum/index.php/topic,4652.0.html) , and several
other sources the 700 to 720 were closely related, the main change was moving the observer from the ventral
gondola to the nose station, fitting a retractable landing gear and more powerful engines. So, to my opinion, the
model shows either the design prior to the change of the observers station, or a design in between. Don't want
to make reckless assumptions, but I think, the designation would have been > 700 to <= 720 !
Waiting for your verdict, if we can say with a reasonable probability, that this model isn't a Breguet ASW design
and, if so, move it to an appropriate thread.
To the jury, please ponder the arguments and pleadings, and decide to the best of your believe !

Beautiful work, Jens!

I think the designation bit might be a little over-speculative for this part of the forum... otherwise it's great.

Again my argumentation:

- This wind tunnel model bears no resemblance to the the known Breguet types with that task (ASM and
"Alizé bi-moteur"

- Wings, engines, empenage and rear fuselage are very similar to the Dewoitine D.720.

- Nose and ventral gondola are very similar to what I know of the D.700. Here's a weak point in my argumentation,
as still yet, I can only rely to the single sketch from the Flight magazine.

- From what we know about the development history of the D.700 series (D.700 to 720) of the late '30s (and regarding
the D.700 as authentic), we can at least trace back the repositioning of the observer from the ventral gondola to the
nose and the change from fixed to retractable landing gear.

IF (and I still know, it's just an assumption), the wind tunnel model from that site was just wrongly labelled as a Breguet
type, probability for the "Dewoitine solution" should be rather high, and again IF, then the types designation would be
between 700 and 720 with a high probability, I think, but this maybe just a kind of "wishful thinking" from my side, of course.

I tried to reach the owners of the site, maybe I'll get more information about the origin.

So, I just would like to get a feedback from other members here.

Not sure, that this can be regarded as the final answer to that question, nevertheless here's
the answer to question to "Le Comptoir de l'Aviation":
"Dear Jens, Thank you very much for your email. Unfortunately this model has been sold, but I remember that the model did not
have any kind of marking.
You are absolutely right, many visitors told me this error but I did not modify the page yet. This a test model of the
Dewoitine !
Thanks again for you message and your help. [font=arial, helvetica, sans-serif]Kind Regards,[/font]
[font=arial, helvetica, sans-serif]Philippe Agulhon"[/font]

Thanks very much for sharing this reply, and congratulations on correctly identifying the design as Dewoitine.

Now that I've split the topic, I still wonder if this shouldn't be filed under "Early projects" considering the general layout of the aircraft (and the fact that Dewoitine had ceased all activities after the war).

Absolutely right, so I moved it to this section and changed the title. As it certainly
is from the late '30s, the ventral thing could hardly have been a radome.

Hi! Dewoitine D.720. Only one prototype completed. Crew :3.

http://www.airwar.ru/enc/spyww2/d720.html
https://twitter.com/armeedelairbot/status/848286426726662148
http://www.cyberaerobreton.esy.es/france/d_720.htm

https://fr.wikipedia.org/wiki/Dewoitine_D.720
"It's in December 1936 the french Air Ministry established a specification intended for delivery to theair force of an aircraft of class T33. This category of very particular aircraft should be able to perform missions of recognition,Advanced training, and operations support as well in the colonies."