Canada: A number expressing the bearing strength of a pavement for unrestricted aircraft operations. PLRs are expressed on a scale from 1 (weakest pavements) to 12 (strongest pavements). Aircraft tyre pressure restrictions, where applicable, are given in megapascals (MPa). The PLR system for reporting airport pavement bearing strength is used exclusively in Canada. For international reporting purposes, the PLR chart for each airport also reports bearing strength using the ICAO PCN code.