Basically Aircraft tyres perform the following functions,
- They provide a gripping surface
- Absorb some of the initial loads on landing
- Provide an easily replaceable wearing surface
- Discharge electricity on landing
- Multiple wheels spread the aircraft weight
- Provide a means of anti-fire action on the brakes by discharging the Nitrogen in the tyres through FUSIBLE plugs.
And incase you dont know what a Fusible plug is, its basically a piece of solder which melts at a pre-set temperature, the colour of the plug dictates what temperature it melts at, these plugs you can find on the wheel and look for a bolt head, the fusible insert is inside. The fusible plugs reduce the possiblity of explosion due to thermal pressure build up.
Red plug- melts at 155 degs/c
Green- 177 degs/c
Yellow- 199 degs/c