Flying High.

I was the getting the washing  in off the line, when suddenly  i could hear the sound of an aeroplane in the distance. It was a surprise to see this rather old bi-plane, flying over our home. I rushed back into the house to grab my camera, and managed to trip over the step,( there followed some choice words ) but i managed to capture a few shots before it disappeared into the sun. I wonder if anyone knows what it is?