Question: what is the out side of an aeroplane made of?

Stephen Curry answered on 17 Jun 2010:

Taking my cue from James Cameron (have you see Avatar?) I am tempted to say ‘outsidium’.

But in actual fact, modern planes are usually made of some or other kind of aluminium alloy. I think pure aluminium is too brittle to cope with the stresses and strains of flight – alloys are preferred because they are more ‘stretchy’ – or ductile (to use the jargon).

Use of ductile alloys also helps to avoid metal fatigue – a phenomenon that was only discovered unfortunately when the Comet airliner started to crash in the 1950s.

Have you ever looked out the window of an airliner and watched the wing tips wobble up and down? Thank goodness for ductile metals…!