COMFAA 3.0 Beta. Acknowledgments. Gordon Hayhoe, Rodney Joel and Jeff Rapol, FAA. Ken DeBord and Mike Roginski, Boeing Commercial Airplane Co. Outline. Brief review of ACN/PCN system and ICAO definitions. FAA guidance on PCN calculation.
Annex 14 to the Convention on International Civil Aviation
ICAO Aerodrome Design ManualPart 3 – Pavements
“Support of a particularly heavy load, but only rarely, does not necessarily establish a capability to support equivalent loads on a regular repetitive basis.”
Where is the line between “regular” and overload operation?
Gross Weight data may transition.
PCN data request now part of all airport inspections
7 Basic Steps to Determine Pavement Classification Number in AC 150/5335-6B:
Flexible Layer Equivalency
COMFAA generates an aircraft ACN table. CBR 9 indicates B subgrade designation.COMFAA Output – Details (I)
COMFAA generates a table based on the CDF method. For each aircraft, allowable gross weight and corresponding PCN are identified.
CBR 9 indicates B subgrade designation.
Existing Pavement Data
Effective k at top of base = 323 psi/in
17″ PCC, R = 775 psi
k-value = 160 psi/in
The original design based on procedures in AC 150/5320-6D called for 16.3 inches of PCC. This value was rounded to 17.0 inches.
Pavement thickness requirements based on actual annual departures:
Airplanes can operate without restriction
ACN values for each airplane (from COMFAA)
Assuming the B737-700 as the design airplane per the procedures in 5335-5A
Calculated PCN 59.8/R/BPCN = (60/R/B)
Rigid Pavement k-Value
Copy and Paste Data into Support Spreadsheet