Advanced Plastics Lighten Solar-Powered Manned Aircraft

There are eight thermoplastic parts already developed for a solar-powered airplane under development with at least seven more coming.

The Solar Impulse is a long-range aircraft currently under study at the Swiss Federal Institute of Technology (EPFL) in Lausanne, Switzerland.  The aircraft is intended to be a one-seater. The wingspan of the Solar Impulse will be 262.5 ft, slightly wider than the wingspan of an Airbus A380. The structure is made from carbon fibers.

A prototype with a 200-ft wingspan is under construction in Switzerland and initial test flights are expected in one year. Construction of the final plane is still two to three years off. It’s hoped an around-the-world flight, in stages, will begin in 2011.

The purpose of the prototype is to validate mechanical engineering concepts being developed for the plane. These include new lightweight plastic parts from Solvay, one of the principle sponsors of the project.

The newly developed parts include:

• Battery binder: Solef polyvinylidene fluoride/Solvay Solexis

• Hinges (inserts): Ixef polyarylamide/Solvay Advanced Polymers

• Throttle housing: Radel polyphenylsulfone/Solvay Advanced Polymers

• Bushings: Torlon polyamide-imide and KetaSpire polyetheretherketone/Solvay

Advanced Polymers

• Foam cockpit eggshell: Solkane foam/Solvay Chemicals

• Circuit board spacers: PrimoSpire self-reinforced polyphenylene (SRP)/Solvay Advanced Polymers

• Bolts and screws: PrimoSpire SRP/Solvay Advanced Polymers

• Lubricant: Fomblin perfluoropolyether/Solvay Solexis

In the most recent development, two Solar Impulse pilots flew a virtual flight in a cockpit identical to the one in the first prototype. The flight simulator was assembled by the EPFL, enabling them to pilot the aircraft for the first time, equipped and harnessed as they will be during their first flights with helmet, safety harness, parachute, oxygen mask and with food supplies and the accessories adapted for their natural needs.

Pilot André Borschberg practiced circling in the sky, descending and landing and testing the behavior of the Solar Impulse in windy and turbulent conditions. “The airplane seemed very safe to me, but let’s not forget it is only a simulator. Piloting the prototype will be even more demanding and will involve much more of the unknown.”