Presentation By: Timothy W. Neubert, MBA, A.A.E. 2010 FAA Worldwide Airport Technology Transfer Conference April 20-22, 2010 FRICTION: Science or Fiction Presentation By: Timothy W. Neubert, MBA, A.A.E. NAC President GIS in Aviation

Why do airports perform Runway Condition Assessments? Why is Friction & Contamination Important? Friction Measurement Survey TALPA – Aviation Rulemaking Committee, Takeoff and Landing Performance Assessment TALPA Recommendations GIS in Aviation

Why do we measure Friction ? DC-9 Aircraft Wet Runway Landing Veer-off Accident Reynosa, Mexico; October 6, 2000 GIS in Aviation

Why do we measure Contaminates? Aircraft Wet Runway Landing with Heavy Rubber Deposits, Tegucigalpa Airport , Honduras; May 30, 2008 GIS in Aviation

What is Mu? MU is a “non-dimensional number” that relates horizontal force to vertical load. CFME equipment measures the ratio of Horizontal force divided by the Vertical force, which would give a value between 0 to 1.0 GIS in Aviation

CFME Pavement Operation-Wet Test GIS in Aviation

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How Accurate is Mu using CFME? This method of calculating Mu value does not allow for Test Speed Tire Design Tire Pressure Slip Ratio Rolling Resistance – Surface Contamination Changing any of these factors will result in change in Mu Value. GIS in Aviation

Why do we measure Contaminates? Contamination Effects with Roll Resistance Aircraft Wet Runway Landing with Heavy Rubber Deposits, Tegucigalpa Airport , Honduras; May 30, 2008 GIS in Aviation

EMAS GIS in Aviation

Why do we measure Friction ? Over time, the skid-resistance of runway pavement deteriorates due to a number of factors: 1. Mechanical wear and polishing action from aircraft tires rolling or braking on the runway surface 2. Accumulation of contaminants The effect of these two factors are directly dependent upon the volume and type of aircraft traffic. GIS in Aviation

What is a Contaminant? Runway Contaminants, such as, rubber deposits, dust particles, jet fuel, oil spillage, water, snow, ice, and slush, all cause friction loss on runway pavement surfaces. The most persistent contaminant problem is rubber deposit from tires of landing jet aircraft. Rubber deposits occur at the runway touchdown areas and is expensive to remove. NOTE: Friction testing is required before and after rubber removal. Heavy rubber deposits can completely cover the pavement surface texture causing loss of aircraft braking capability and directional control, particularly when runways are wet. GIS in Aviation

Makes Mu Value Higher by 7% Contamination Drag Wheel Load 1000N – 224 Pounds Standing water of 3mm 47 / 688 = 7% error ! Makes Mu Value Higher by 7%

Why do we measure Friction ? During a heavy downpour, the conditions on the length of a runway can vary and may be deep enough to cause hydroplaning. A layer of water between the tires and the runway surface reduces the friction level to NIL braking action. When a runway is contaminated with water, the information passed to the pilot is reported as “wet”. GIS in Aviation

Why do we measure Friction ? “Traditional Information given to the Pilot GIS in Aviation

Pavement Runway TESTING AC150/5320-12C Measurement, Construction and Maintenance of Skid-Resistant Airport Pavement Surfaces GIS in Aviation

When is Friction Testing Required by the FAA? TABLE 3-1 MINIMUM FRICTION SURVEY FREQUENCY Ref : FAA 150/5320-12C Page 19 GIS in Aviation

Pavement Testing Friction Evaluations with CFME’s are required by the FAA Water is pumped directly in front of the friction measuring wheel at a controlled rate. This gives standard repeatable conditions This is an ideal test for monitoring rubber build up and the runways micro and macro texture Wet Friction Tests are critical to evaluating new surfaces material in meeting Friction Classification Levels Pavement Testing can only be performed using a FAA Approved CFME GIS in Aviation Info : FAA 150/5320-12C

Why Does Speed Matter? 40mph Testing determines the overall Macrotexture / Contaminant / Drainage condition of the Pavement Surface. 60mph Testing determines the overall Micro-texture of the Pavement Surface Tests give a good indication of the runway drainage ability during rain conditions GIS in Aviation

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Engineering Brief No. 44B Revised Coal-Tar SealeriRejuvenator Specification 3.5 TEST SECTION FOR FRICTION SURVEYS. Prior to full application on any runway or high speed taxiway exit, the Contractor must apply the material to a test section for friction survey testing at the application rate approved by the Engineer. The area to be tested will be designated and tested by the Engineer and located on the existing runway or high speed taxiway exit pavement. Application rates that result in an average Mu value on the wet runway pavement surface less than the Maintenance Planning Friction Level contained in Federal Aviation Advisory Circular 150/5320-12, “Measurement, Construction, and Maintenance of Skid Resistant Airport Pavement Surfaces,” must not be approved for full application. *********************************************************************************** NOTE TO ENGINEER. A friction survey test is mandatory for applications to runways and high speed taxiway exits. The Engineer may require friction survey tests on other pavement, as deemed necessary. ************************************************************************************* GIS in Aviation

Reasons for Addressing Contaminated Runway Takeoff Performance Safety Historically, about 9 percent of rejected takeoff accidents have occurred on contaminated runways. We estimate less than 1 percent of takeoffs in the U.S. are from contaminated runways. Therefore, the risk of a rejected takeoff accident on a contaminated runway is an order of magnitude greater than that for a dry runway. Runway contamination (slush, snow, ice, standing water) can significantly degrade deceleration capability Snow, slush, standing water can also seriously degrade acceleration capability

TALPA ARC Airport/Part 139 Working Group Recommendation Instructions to Airport Operators: Whenever a runway is not dry the airport operator is responsible for providing current runway surface condition reports. Report runway surface conditions using the runway condition and contamination terms, percentage of runway coverage, contaminant depth, and procedures provided in this document. During rapidly changing conditions airport operators are required to maintain a vigilant runway inspection process to ensure accurate reports. GIS in Aviation

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TALPA ARC Airport/Part 139 Working Group Recommendation GIS in Aviation

TALPA ARC Airport/Part 139 Working Group Recommendation NOTAM SAMPLE Scenario 1: Tampa International Airport observed the following conditions for runway 9: Average surface temperature -30C Mu 39/41/35 The entire runway was covered with 1/8 in water Operations vehicle experienced reduced directional control slightly reduced braking action and no downgrade in condition was recommended. TPA RWY 9 4/5/3 100% 1/8 INCH WET SMOOTH 1512Z 15 JUN 2009 GIS in Aviation

TALPA ARC Airport/Part 139 Working Group Recommendation RATIONALE Contaminant terms were harmonized to the maximum extent possible with ICAO. The few differences are due to the ARC’s desire to limit terms to those for which aircraft manufactures can provide performance data. Runway surface descriptions such as SMOOTH, GROOVED and PFC were added to WET conditions to allow manufactures to gain improved performance capability when providing such data (as a few currently provide). This descriptor technique made also made it easier to deal with and report when the SLIPPERY condition exists. GIS in Aviation

GIS in Aviation

Copy of this presentation is available upon request THANK YOU Copy of this presentation is available upon request Ph: 727.538.8744 www.airportnac.com GIS in Aviation