Airbus is trying to stem the flow of sales going to Boeing, by bashing the B787's all-composite airframe. Not literally, by driving a catering truck into it, but by questioning what would happen if someone did drive a catering truck into it--and maybe even didn't report it. Aluminum (or "aluminium" as my British readers insist on calling it) dents and tears on impact, while a composite could potentially accumulate invisible damage until it shatters, like an Airbus rudder.
I'm thinking of the plastic or composite components on airplanes I have flown. Many use plastic for cosmetic details in the interior, and those are prone to cracking and embrittlement. The main structural elements of all the airplanes I have flown have been aluminum (or wood and steel wires if you want to count some of the sketchier non-commercial aircraft I've decided to pilot), but many have exterior fairings made out of plastic. And I can't think of a single plastic component that I haven't flown around knowing was cracked. I remember being questioned by a Transport Canada safety inspector who wanted to know why our wing strut was wrapped in duct tape. We were able to show him a properly formatted, signed and stamped logbook entry documenting the "temporary fairing repair" effected by our maintenance department. And this was a commercial passenger airplane.
It's not really duct tape, it's speed tape a similar silvery-grey sticky tape that I'm sure costs at least ten times as much. I've done a field repair myself, using speed tape for temporary damage control.
Comparing the plastic components on airplanes as old as I am to the all-composite airframe of the new 787s is a bit like saying "Metal? They make airplanes out of metal? My car is made out of metal and it fell apart after five years of winter driving!"
Looks like duct tape, but isn't. Sounds like plastic, but isn't. Different kinds of metals ... I'm a pilot, not a materials scientist. But if you're looking for a career in aviation maintenance, I'm thinking that experienced non-destructive testing technicians are going to be in high demand before too long. Also you don't have to wield a rivet gun.