New runway pavement strength rating operational requirements

Effectivity: Learjet series aircraft 

ATA: 04 - Airworthiness 

By: Chris Hyde – Technical Services  

The methods to determine aircraft classifications and runway pavement strength ratings have been updated to reflect new runway materials/construction methods and current aircraft landing gear configurations.  

The previous calculation methods included the aircraft classification number (ACN) and pavement classification number (PCN). They were developed decades ago and were overly conservative, did not consider complex landing gear configurations, and were inconsistent with modern pavement designs. 

This new method of calculating aircraft classification rating (ACR) and pavement classification rating (PCR) will be fully applicable in November 2024, with the following benefits: 

• Overcomes the deficiencies of the ACN-PCN system and allows consistency and alignment between pavement design and pavement rating systems 

• Enables an optimized usage (in terms of allowable aircraft weights and  

frequencies) of existing and future pavements, without excessive conservatism 

• For aircraft operators, it should lead to fewer pavement-induced weight restrictions (local exceptions are possible)   

FAA Advisory Circular 150-5335-5D was re-issued in December 2022 to introduce the ACR/PCR method. The new PCR values are to be published by the individual airport, with ACR values computed based on the combined result of aircraft weight, wheel loads, tire pressures and landing gear geometry. Specific Learjet aircraft calculated ACR values are available through the Technical Services Group, as a chargeable service, and may be obtained by emailing ac.ict@aero.bombardier.com. 

For additional information or questions, please contact your regional Field Service Representative.