ADVISORY       CAUTIONARY       NON-DIRECTIVE
FOR INFORMATION, CONTACT:  Bruce Landry, AAS-300  (202) 267-8729

DATE: 	1/14/2005	No. 05-01	
TO: 	Airport Operators, FAA Airport Certification Safety Inspectors	
TOPIC: 	Airport Winter Operations (Friction Measurement Issues)	
Reference:	Aeronautical Information Manual (AIM), Paragraphs 4-3-8 and 4-3-9;
AC 150/5200-30A, Airport Winter Safety and Operations;
AC 150/5320-12C, Measurement, Construction, and Maintenance of Skid Resistant Airport Pavement Surfaces	

Questions have again risen regarding the collection and reporting of runway friction values during winter airport operations.  While the FAA does not require this action, the FAA has issued guidance in the form of Advisory Circular (AC) 150/5200-30A, Airport Winter Safety and Operation.  Airport Operators are encouraged to review and become familiar with AC 150/5200-30A and the Changes 1 through 7.
Although the International Civil Aviation Organization (ICAO) has published a comparison table for “MU” readings and braking action, the FAA is not in harmony with ICAO on this determination and publication.  The FAA has no approved publication that provides a comparable assessment rating between “MU” readings and braking action.  Further, the FAA feels that there is currently no conclusive correlation between braking action and MU value.  Braking action is subjective and dependent on many factors, whereas MU value is  an objective measurement.
Either MU values or braking action reports are acceptable for reporting pavement conditions to the Notice to Airman (NOTAM) system.  However, there is no correlation between the two.  THEY ARE NOT INTERCHANGABLE!  See the AIM, paragraphs 4-3-8 and 4-3-9.
A list of FAA approved Decelerometers for friction measurement is contained in AC 150/5200-30A, Appendix 4.  AC 150/5320-12, Appendix 5, contains a list of approved Continuous Friction Measuring Equipment.  The FAA highly recommends that Airport Operators closely review this list of friction measurement equipment prior to purchase.  Particular attention should be directed to the compatibility of vehicles that may be used to employ these friction measurement devices.  In particular, note that the decelerometer is not recommended for use on a vehicle equipped with an ABS braking system.
If Airport Operators have questions about the FAA approved friction-measuring equipment, please contact your Regional Airport Certification Safety Inspector.  
	January 14, 2005	
Ben Castellano, Manager 
Airport Safety & Operations Division	Date	

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