SNCAN (Nord) 1700 « Norélic » and 1710 helicopters

[hesham]

My dears,

I have a mystery aircraft to me,it was mention in old magazine I saw it from
many years,it was SNCASE SE-1710, a single seat gyrokite rotary wing aircraft of 1950,
look like Focke-Achgelis Fa-330 or it was developed from it.do you know information
about it ?.

 

[Jemiba]

Hi Hesham,
the "1710" you mentiones was probably the Nord N.1710, the smaller and
lighter follow-on design to the N.1700, which was abandoned after two
accidents. Both used a unique rotor system and a shrouded pusher prop
for anti torque control. And both were helicopters, not autogyros.
The N.1710 was later modified and flew again as the Bruel-Durand-Molinari
BDM 01 (the name was longer, than the whole machine ! )
And in FLIEGER, 1950, I've found a drawing, designated Nord 1700,
which shows a helicopter with a pusher prop, instead of a conventional
tail rotor. So far, it's principally identical to the N.1700 prototype from 1947,
but this drawings shows a completely faired fuselage.
Can somebody confirm, that this was a later or even proposed series version ?

 

[dan_inbox]

Well, the Nord 1710 looks very much like your drawing, only with an open cockpit.

 

[Jos Heyman]

Picked this picture up somewhere sometime ago.
Other info:
The engine directly powered a rear axial helix which blew on two flap shutter systems, some horizontal, some vertical, to control pitch and yaw. The aircraft was damaged at first, due to violent vibrations of transmission, induced by brutal clutching. After repairing it, they resumed power checks but, in the hands of an inexperienced pilot, it hit an obstacle. It was then decided to abandon further development. It has been suggested that the first flight did take place on 17 November 1947.

 

[richard]

From " Science&Vie " ,end of 40'

 

[Jemiba]

Thank you very much, for your comments and especially for the
pictures. Seems to me , that the "proof-of-concept demonstastor"
would have been developed into this nice looking heli, if the concept
wouldn't have failed.
The N.1710 was a second attempt on the same basis, but much smaller.
It was abandoned, too, after at least two accidents, but modified and
test flown in 1959 by the Nord engineers Bruel, Durand and Molinari,
designated BDM 01.Nevertheless, the results don't seem to have been
encouraging.
BTW, I just came across today, that we saw pictures of two
different series or production versions of the N.1700. The one
from Aviation Magazine seems more related to the prototype,
whereas the drawings shown in Science & Vie and Flieger could
be a very early artist's impression, I think. Did SNCAN really
propose this version ?

 

[richard]

Just found this scrap from " Aviation Magazine "
For no French speaking readers :
The first heli Nord 1700 "Norélic" was too late ,development was stopped .

 

[richard]

The B.D.M-01 F-WEPH used some stuctural parts of the Nord-1710 ,including rotor .
( From "Les Ailes " early 60' )

 

[Stargazer]

Adapted from Jean Boulet's Histoire de l'hélicoptère racontée par ses pionniers – 1907-1956:


The N 1700 was a two-seater machine with a two-blade rotor fitted with a stabilizer bar. Engineer André Bruel wanted to get over and done with cyclic pitch control, which he considered too complex. The rotor head was mounted onto an articulated parallelogram which enabled it to move sideways. In this manner, lateral control was obtained by offsetting the rotor head more or less from the center of gravity.

The 160 hp Mathis GR7 engine directly drove the axial tail propeller which blew over two sets of flaps, one horizontal and the other vertical , so as to control pitch and yaw respectively. The helicopter was first damaged after a rough clutch caused some violent vibrations in the drive shaft. Once repaired, it was able to resume tethered testing, but left in the hands of some unexperienced mechanic, it moved and hit an obstacle.

The SNCAN board thus decided to cancel the N 1700 and to focus on the small, single-seat N 1710, built along the same principles. SNCAN requested from SNCASE that they let go of test pilot Jean Boulet to test the machine. The first flight took place on July 1, 1950. After a few difficult flights in hover mode, the first translational flight took place on July 22. The longitudinal control proved quite inefficient, and modifications had to be made. This included increasing the flexibility of the horizontal flaps. On September 29, a new translational flight was attempted , but the modifications proved to have the opposite effect of what was expected. Boulet quickly lost control of the machine, which flipped over and projected him to the ground.

The aircraft was repaired and its tail was lengthened so as to improve the efficiency of the rudders. In Spring 1951, more flights took place. Boulet was sent to work in Marignane and was therefore replaced by André Onde, who took over and performed more flights in hover mode between June 18 and July 2. Translationary flights ensued to distances between 30 and 40 kms. On July 19, when Onde tried a closed circuit flight for the first time, he lost altitude in a bend, touched the ground and flipped over. The program was cancelled after that.




Attached photos:

• The N 1700 frame on a test rig. André Bruel is the one with the cigarette in his mouth.
• The N 1710 and the team that worked on it. Bruel is now the one that is seated.
• The N 1710 in hover at Montesson airfield.
• The N 1710 after its accident.

 

[toura]

from "Le FANA" AND "AVIATION MAGAZINE"

 

[Stargazer]

Topics merged.