After using a whole dual tube of Expoy, I have fixed my Fusion and flew it this morning.
I originally crashed because I was stupidly performing dive/climb manoeuvres that made the wings bend far too much. The whole thing nearly fell apart in mid air. On my last dive, I couldn't pull up enough, so the plane ate dirt.
As you can see, I have added carbon strips to the wings to make them more rigid. They really made a great difference this morning.
Now it's time to test fly with 100g of weight on the front for training before I buy a camera and stick it on.