Exceedance

A region is considered "nonattainment" of an air quality standard (NAAQS) if its estimated exceedance rate of the NAAQS is more than once per year over three years. Exceedances are counted in terms of days.

1997 December, US General Accounting Office, Aviation Safety: Efforts to Implement Flight Operational Quality Assurance Programs, GAO/RCED-98-10, Report to Congressional Requesters, page 24, On a periodic basis, airlines aggregate and analyze exceedances over time—for example, the number of unstabilized approaches at a particular airport per month, over the last 12 months.

As defined in Chapter 2, an exceedance probability curve is a graphical representation of the probability that a certain level of loss will be exceeded over a future time period.

"Exceedances are decommissioned while they undergo remediation," Ms Hammat said.