Couzinet 70 Arc en Ciel (rainbow)

leaded50

Legendary member
i feel like having a record setting airplane "spree" at moments 😁

Next build up..... The worlds first plane to take a direct flight between Europa and Soth America ( Paris - Buenos Aires, Jan-1933 ) Started a
regular mail run to South America in May 1934. From 24 July that year there was a regular monthly crossing with mail or/and passengers.

Its design posed numerous challenges and pushed the bounds of aeronautical understanding at that time. It had a relatively
high level of fineness, which was a somewhat controversial design choice at that time; the resulting aircraft being
relatively difficult and expensive to fabricate. One positive result of the high fineness rate was the aircraft's ability to
climb with only two of its three engines operational; or maintain horizontal flight with only one running engine.
The two wing mounted engines could be accessed in flight through tunnels in the wing, who had a quite thick airfoil style. (1m high tunnel inside)
The tapered rear of fuselage gave its distinct tailstyle, more like a whale, a style only the Couzinet´s airplane had.

My version is built with two motors and the center one fake. 1400mm wingspan and 1050mm long.

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leaded50

Legendary member
Start of the front main fuselage. Space for battery planned in second part? also in that section where the wing starts......therefor not making any skin on lower part.
Neither is the motor firewall in place yet. ( the front former will later be removed and is just tacked at place).
The rear section here is the most conformed & widest one of the fuselage.

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leaded50

Legendary member
Then the frontal part/cowling is made, together with the cockpit/cabin part rearward. Here its also show my main horizontal internals rearward


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leaded50

Legendary member
one of the "nice" thing with this planes fuselage, is that its quite flat in bottom, and with just a very small curb in top , and sides mainly most curbed at front & rear. That gives possibillity to make panels slightly curbed at sides, pretty flat in bottom, and minor curbed at top.
More easy to shape, and eg. with some more similarity to the original earlyer Flite Test planes.
More easy seen at the picture here. Some panels adjusted in size instead of using full length to make the curbed sides , at side "up & down", but also curbed lengthwise.
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leaded50

Legendary member
then the wing is up for build... 1430mm wingspan, and as what who was typical for the Couzinets air liners, a very thick wing.
At the original plane, it had a 1meter height internal tunnel to the wing attached motors for maintenance/repair in flight, if necessary. (yeah, it also had access to the fuselage front motor from inside cockpit) This thickness also gave a good lift preference, and that the plane could take-off or land with just two motors, and do the cruiseflight at only one engine.
The wing was "flat" in sigth on the top, just bottom was slanted upward to the tip.

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Here its easier see, that the top of wing is going to be horizontal, just bottom slants upward to the tips. The bottom part is slightly curbshaped also, that gace some extra work to tension the upper panel correct, to get some of the bottom skin curbed a little when glued. If just pressed against flat surface and the top skin bendt back, its front bottom skin (and the frontal leading edge bend) would not be more adjusted to get in approx. the middle of wing. It needed tension to the bottom skin forward to get correct style when glued. I also "scavenged" away foam at the tips, and on the trailing endge, to get top/bottom meet each other to a "tip", not just a blunt end.
On the picture its also easier see that "midsection" got a CF-tube for more strength.

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leaded50

Legendary member
here is how the wing are fastned to the fuselage. : two of the "special" nuts is put underside of a plywoodplate glued in at bottom. Two black 5mm plasticbolts are used to press the wing to the fuselage bottom in this nuts.

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leaded50

Legendary member
Wing motorcelles is in work, together with the landing gear brace strut.

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The wing also needs get a 10 approx wind-deflectors on top and bottom .....
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leaded50

Legendary member
The fuselage got its big wing fillets shaped & glued on (still used of a pizzabox ;) ) Just glued to fuselage, not the wing, to get the necessary removal of wing in transport. Fillets treated with woodglue, to get stronger.
Here you also can se easier how the rear is shaped...
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leaded50

Legendary member
as on the picture here, you can see its quite ready for paintwork. A layer paint to get all the wing-deflectors shure to get the intended color here. Building is ready done, on fuselage and wing.
Even rudder and undercarriage with teardrop-styled wheelspants is on. And do you know..... a couple of plastic spoons together with foamboard and a little lightweight wallfiller, did the shape on all wheelpant-sides.... ;)

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