How are the tires thermally protected from blowout?

• A. Heat shields around tires
• B. 4 Thermal Fuse Plugs in each Wheel
• C. Insulated wheel rims
• D. Cooling fans in wheel wells

Answer: (B)

Tires on aircraft rely on a built-in thermal relief to prevent a blowout. Each wheel contains fusible plugs that melt at a predefined high temperature, acting as a simple venting mechanism. When the tire overheats—from heavy braking, hot brakes, or other heat sources—the plugs open and air escapes, reducing the tire’s internal pressure and lowering the risk of a catastrophic failure. Having multiple fuse plugs per wheel provides redundancy, ensuring venting occurs even if one plug isn’t responding in a given overheated scenario. Other ideas like heat shields, insulated rims, or wheel-well cooling fans don’t provide this automatic pressure-relief function, so they don’t achieve the same protective effect.