Referring to the frail wood lattice covered with tissue.

This is another possibility and is all I can think of considering the lack of context.

Ribs make me think of corsets and petticoats on rib panniers.

It all depends on what the 'haute couture' bit is really referring to.

How about "finely tailored" for the "haute couture"?

with lattice or spars ....

Though I think much will depend whether we are talking old, fabric-winged planes or more modern ones.
membrure n.f. 1. Ensembles des poutres et pièces maîtresses constituant un châssis de véhicule, une poutre de pont, etc.
[Larousse Lexis]

spar any of the main structural beams attached to the fuselage of an airplane to support the wings
[Webster's]

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Note added at 6 hrs (2009-07-06 12:55:18 GMT)
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I really think we need to know the period. At what time was this adolescence?

"haute couture" makes one think of old fashioned aeroplanes made of wood and canvas, which were certainly fragile, while "argentée" makes one think of the great silver birds of more modern times, generally appreciated as being rather less so. At the same time, maybe the structure of modern planes could be said to be "haute couture" from a technological standpoint ...