Which statement best describes the relationship between friction measurement MU and braking action reports?

Which statement best describes the relationship between friction measurement MU and braking action reports?

• A. MU has no relation to braking action.
• B. A very high MU guarantees braking action reports.
• C. A low MU indicates reduced braking action and may trigger braking action reports and revisions to procedures.
• D. MU only affects tire wear and is not used in operations.

Answer: (C)

Friction measurement MU quantifies the available tire–runway friction and is a direct indicator of braking effectiveness. When MU is low, the surface offers less grip, so braking action is reduced. That reduced braking action can trigger braking action reports and lead to revisions of procedures to maintain safe operations. A very high MU does not guarantee braking action reports, since other factors like contamination, temperature, and braking technique can still affect braking performance. MU is used to inform operational decisions about braking capability, not just tire wear.

Friction measurement MU quantifies the available tire–runway friction and is a direct indicator of braking effectiveness. When MU is low, the surface offers less grip, so braking action is reduced. That reduced braking action can trigger braking action reports and lead to revisions of procedures to maintain safe operations. A very high MU does not guarantee braking action reports, since other factors like contamination, temperature, and braking technique can still affect braking performance. MU is used to inform operational decisions about braking capability, not just tire wear.