Could the experience of inflatable structures in boats be applied to large aircraft design?
We now have experimental use of inflatables in space as well as for boats.

If an aircraft's engines are responsible for the inflation of any aerodynamic or structural part of the aircraft, however, one would have to answer what happens if the engines stop. A conventional aircraft whose engines fail at a sufficiently high altitude can glide for some time, giving the crew a chance to restart the engines; it may even be landed without engine power if necessary. This is a very bad time for the aircraft to lose aerodynamic performance or structural strength--for example, for the winglets to deflate just when the crew need the best possible glide slope.

Unlike boats or spacecraft, moreover, most conventional aircraft are intended to descend from altitudes of low pressure to altitudes of high pressure. If the amount of gas in an inflatable structure is held constant, one has to balance structural rigidity at low altitudes against the stress on the fabric from the much greater pressure difference at high altitudes. If the amount is not constant, it has to be replenished during descent. The engines cannot be relied on to do this, since the reason for descent may be engine failure. Gas could be supplied from high-pressure cylinders, but those can be heavy.

For an aircraft not intended to climb very high, these concerns are less severe.