The Hurricane was a steady gun platform, and had demonstrated its ruggedness as several were badly damaged yet returned to base. But the Hurricane's construction made it dangerous if it caught fire; the wood frames and fabric covering of the rear fuselage allowed fire to spread through the rear fuselage structure easily. In addition, the gravity fuel tank in the forward fuselage sat right in front of the instrument panel, without any form of protection for the pilot. Many Hurricane pilots were seriously burned as a consequence of a jet of flame which could burn through the instrument panel. This became of such concern to Hugh Dowding that he had Hawker retrofit the fuselage tanks of the Hurricanes with Linatex, a self-expanding rubber coating. If the tank happened to be punctured by a bullet, the Linatex coating would expand when soaked with petrol and seal it. However, some Hurricane pilots felt that the fuel tanks in the wings, although they were also protected with a layer of Linatex, were vulnerable from behind, and it was thought that those, and not the fuselage tank, were the main fire risk.