Today's topics answered by Peter Cox, who is a 737-800 Captain for a major UK leisure airline are: Is the air recirculated on a plane, where does the air come from? Am I more likely to get ill on a plane from the air? How dirty are planes? Should I drink the water/tea/coffee on a plane? Do the pilots eat the same food? Do the pilots sleep during flight? What happens if one pilot/both pilots are taken ill?