Statement I: The tyres of an aircraft are slightly conducting.
Statement II: If a conductor is grounded, the extra charge induced on the conductor will flow to the ground.

Explanation

Due to rubbing of body or vehicle with air or rubbing of tyres on the roads, friction makes them charged. Conduction of these charges through the vehicle body may produce heat and subsequently the fuel tank of the vehicle may catch fire. Conducting tyres keep returning charges to the ground and hence, fire hazards are avoided.