Towards a permanent ACN solution for 6-wheel landing gear aircraft

Utilizing historical full-scale airfield pavement test data (that has been collected from the 1940's to the mid-1970's), and updating the historical record with test-to-failure data from the FAA National Airport Pavement Test Program, the pavement life cycle relationship to aircraft loading as indexed by landing gear type (dual, dual tandem, tri-tandem, etc.) has been investigated. The resulting collection of pavement failure data was analyzed for applicability to the existing S-77-1 methodology (using what is commonly referred to as the CBR equation). The investigation and analysis establishes that the CBR equation retains its usefulness for predicting pavement thickness requirements and pavement life for airfield pavements. It is concluded that the unique solution of the CBR equation at the 10,000 coverage level for four precisely defined subgrade support conditions (as defined by ICAO ACN guidelines) continues to be well suited to the use for which it was intended. A parallel study of the FAA test results via multi-layer elastic system solutions is included, which renders a similar conclusion.