Presentation on theme: "ASFT Surface Friction Tester, and Weather Systems Presentation"— Presentation transcript:
1 ASFT Surface Friction Tester, and Weather Systems Presentation
2 Agenda Why Measure Friction? Operational Measurement in Winter conditionCalibration/maintenance measurement in non-winter conditionParameters that will influence the friction testingASFT in Focus?ASFT Continuous Friction Measuring Equipment (CFME)ASFT Mk IV rear-axle system, and New Generation ComputerWeather Monitoring EquipmentQ&A
3 Why Measure Friction? -Operational measurement in winter condition To control and guide the snow removal, and decing effortsObjective is to achieve acceptable landing and take-off conditions for airplanes, but also at, high speed exit area, taxi-way and apron.Freqvency on test is correlated to change in weather conditions.
4 Why Measure Friction? -Operational measurement in winter condition Friction classification in Winter-OpsMeasured Friction ValueBraking action to be reported0.40 or higherGood0.39 to 0.36Good to medium0.35 to 0.30Medium0.29 to 0.26Medium to Poor0.25 or lowerPoorThis table was created after Scandinavian Airlines System (SAS) sent out a questionnaire asking pilots how they experienced information on braking action, i.e. friction, and also on controllability in crosswind answers were collected
5 Why Measure Friction? -Calibration/maintenance measurement in non-winter condition
6 Why Measure Friction? -Calibration/maintenance measurement in non-winter condition Friction DeteriorationThe skid-resistance of runway pavement deteriorates due to a number of factors, the primary once being mechanical wear and polishing from aircraft tires rolling or braking on the pavement.Accumulation of contaminants, mostly rubber, but also 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 deposits of rubber from tires of landing jet aircraft.Rubber deposits occur at the touchdown, take-off and high speed exit areas on runways.The effects of these factors is directly dependent upon the volume and type of aircraft traffic.
7 Why Measure Friction? -Calibration/maintenance measurement in non-winter condition
8 Why Measure Friction? Directional Control and Braking Power Crosswind The wind tries to push the aircraft towards the sides of the runwayThe aircraft needs friction to stay on the runwayLess friction = less crosswind capability CrosswindReduced chance of reporting a “biased” braking power for runway surface
9 Rubber deposits Primary rubber deposit area Main problems caused Loss of braking actionLoss of directional controlThermal up windsThese problems will increase exponentially during rain. Measurements are therefore alwaysdone with water system to simulate rain for worst case scenario.Take off4000 m25 mHigh speed exit area500 m300 mTouchdown
10 Why Measure Friction? FAA AC C (Operational/Winter Measuring)C (Maintenance Measuring)Accident investigationDocuments for Civil LitigationICAO Annex 14 (Operational and Maintenance)UK CAA Cap 683Maintenance
11 Why Measure Friction? -Calibration/maintenance measurement in non-winter condition Number of Daily Minimum Turbojet Aircraft Landings Per Runway EndMinimum Friction Survey FrequencyLess Than 151 Year16 To 306 Months31 To 903 Months91 To 1501 Months151 To 2102 WeeksGreater Than 2101 WeekSource FAA AC 150/ C. Section 1, Table 3-1.
12 Why Measure Friction? -Calibration/maintenance measurement in non-winter condition Friction classification for Runway pavement surfaces:At 65 km/h or 40 mph0.50 Minimum0.60 Maintenance Planning0.82 New Design/ConstructionAt 96 km/h or 60 mph0.34 Minimum0.47 Maintenance Planning0.74 New Design/Construction
13 Why Measure Friction? -Calibration/maintenance measurement in non-winter condition
14 Average friction values Changi Airport, Runway 2, Direction 20L
15 Rubber Removal in Argentina for AA2000 Performed at night when air traffic volume typically is lessBlack area (Rubber deposits) have friction of 0.4 and white cleaned area have friction of 0.8
16 Parameters that will influence the friction testing Weather conditions, i.e. wet/dry/iceTyre pressure, contact area, tread patternMeasuring SpeedMicro and macro texture of the tested surfaceFrictional characteristics of the tested surface% braking slip on the test wheel (ASFT CFME has 13%)If using one type of friction testing equipment then this will not be issueType of friction testing equipmentMake sure it has participated in the JWRFMP and has a IFI
17 ASFT in FocusASFT is a small company, but we are the largest, and leading CFME Manufacturer in the WorldHead office and factory in Ystad, Sweden17 years experience with develop and manufacture different kinds of CFME300 units worldwide in more then 35 countries
18 ASFT in Focus ASFT & Saab Automobile AB The owners of ASFT acquired May 20th 1991 the Saab CFME division from Saab Automobile ABThis since General Motors had acquired Saab Automobile AB, and did not want to keep any special vehiclesManufacture 95% of all parts our selves
29 ASFT Measuring System ASFT Vehicle based CFME Advantages: Unmatched repeatability140 kilos absolutely constant vertical ground pressure on test wheelFord Galaxy and VW Sharan has high seating level which makes it ideal as inspection vehicleCan be used as a Follow Me VehicleGuaranteed constant ground contact pressure of test wheel at 140 kilosCan measure at 160 kph, and recommended maximum speed is 96 kphHigh-speed refilling of water tankliter water tank capacitySaab available with 580 liter1000 liter water tank capacity but with speed restrictions (Only available with Ford Galaxy)
30 ASFT Flow Chart for Vehicle Based CFME ProductionOf Mk IV rear-Axle andComputerSystem4 WeeksOrder VehicleFromCar dealer12 WeeksDeliverytimeAssembleInstall ElectricalsystemInstall Mk IV rearaxleInstallNG ComputerInstall roof bar,Yellow painting,etc.3 weeksProject startsTesting &Trimming2-3 daysDelivery3 weeks oceanfreightSite Training& Acceptance3 daysReview ofProject2 daysProject time approximately 19 weeks
31 ASFT Trailer Measuring Systems Trailer Advantages:Unmatched repeatability140 kilos absolutely constant vertical ground pressure on test wheel (T-10)100 kilos absolutely constant vertical ground pressure on test wheel (T-5)Very stable in all speeds due to coil suspension system, weigh distribution, load cell and hydraulic systemHeight adjustable towing barFree wheel-hub allows trailer to measure accurately even when turning. No change in slip ratioNo rotation on test wheel when not measuring, so no wear and tear when not in operating modeCan measure at 160 kph, but recommended maximum speed is 96 kphRotating light beacon
32 ASFT Flow Chart for Trailer CFME ProductionOf Mk IV rear-Axle andComputerSystem3 WeeksProduction ofChassisYellow Painting,etcAssembleInstall ElectricalsystemInstall Mk IV rearaxleInstall NGComputer1 weekProject startsTesting &Trimming2-3 daysDelivery5 days air-freightSite Training& Acceptance3 daysReview ofProject2 daysProject time approximately 6 weeks
33 ASFT Production, Computer and Mk IV rear-axle system. What makes the repeatability and reproducibility so high with ASFT CFME?Repeatability=When measurements are performed by a single operator using the same equipment and within a short time.Reproducibility=When measurements are performed by different operators using different equipments of same type, and with some lapse of time between them.Answer: Our in-house production of all parts, and installation. The ASFT computer and rear-axle system.
34 ASFT Skiddometer principle Two reference wheelsOne test wheel.MK IV have slip ratio of 13%Friction wheel is breaked by 13% against both reference wheelsThis principle only needs one test tire. It will thereby only consume half the amount tire and water compared to systems that have two test tires
35 ASFT Mk IV Rear-axle Relay box Water pump Spring Arm Loadcell Hydraulic systemMeasuring -computerHydraulic blockPulse TransmitterT-transducerWater nozzelHydraulic cylinder
36 ASFT Mk IV Rear-axleSolid tube design can’t collapse as a split rear-axle can when heavy loaded (water-system)Not attached to the body of the host vehicle, or trailerOnly attached to the rear axle via a springThis unique design prevents the friction wheel to pick-up any disturbance from moments in the host vehicleThis design allows the friction wheel to have an absolute constant ground contact pressure at 140 kilos. Which is ensured by the vertical load sensor, and hydraulic system
37 ASFT Mk IV Rear-axleMk IV is retracting friction wheel when not in use, and is also equipped with free wheel hub, so all rotation stops when wheel is in elevated position. This will lead to less maintenance and wear and tear.Test wheel is automatically retracted when going in reverse.Mk IV is built with differentials, so it can measure accurately when turning. This since the slip ratio will not change.High speed exit areasApronTaxiwayTwo reference wheels. Test wheel is attached to both rear-wheels which results in better control of the slip ratio (13%).
38 ASFT New Generation Computer system This is a completely new method of Receiving, Presenting and Storing friction dataEmbedded Windows gives ”unlimted” capability to integrated with other systems on airport.”Unlimited” capability to store dataOne platform for all data, friction, position, air and ground temperature, etc.Real time viewing of data on digital map of airport in car and on the InternetFriction and temperature is painted in color (red, yellow and green) for quick glance which makes it possible for stake holders to take rapid action.Each operator has a unique id and password which has to be used in order to operate the tester. This information is permenantly stored with test results for complete traceability
39 ASFT New Generation Computer system Ground and ambient temperature is automaticaly recorded and stored.Remote support via Internet via secure session.The position of each measuring result is automatically recorded by a built in GPS.Friction test can be viewed in real-time from any internet connection.Full pdf and XML report can be downloaded to USB stick.
42 Presentation Computer The driver of the CFME is controlling and monitoring the system through a 10,5’ rugged Touch screen computer. The GPS and GPRS gives the ability to see the friction values as well as the temperature values in the map view of the screen in real time on its accurate positionTouch screen
43 ASFT New Generation Computer system Tabel & Graph Views
44 ASFT New Generation Computer system Quick glance Mu-Views
45 ASFT New Generation Computer system Quick glance Temperature-Views
46 Weather Monitoring Equipment Weather Monitoring Equipment - A Cooperation between ASFT and Saab SecurityFreezing Point Detection (Frensor)Precipitation Monitoring (Optic Eye)Ground Frost MeasuringIce Warnings (Advicy)Ice Deposit GrowthColour/IR Camera SystemsThis technology is purpose built for stationary or mobile useOpen systemCan be integrated with other Weather Systems
48 OpticEye™ Precipitation sensor Classifies rain, sleet and snow IntensityAmount
49 Frensor – Freezing point (Active sensor) Independent to which Anti-icing agent used - by measuring the actual freezing point temperatureActive sensor only needs to be factory calibrated.It’s constantly taking sample and cooling it down until freezing point is reached. Sensor is then heating up again.Three or more sensors are installed in a cluster at three location on runway (take-off, middle, and touchdown).Exceptional MTBF and MTTR
51 How to use and interpret the RWIS data - table Precipitation – Type and amount (Actual snowdepth, not melted form) Need for snow clearence resources?Wind conditions Risk of snow drift? Dangerous wind gusts?Runway condition – Wet / Dry / Frost Need for friction enhancement resources?Arrows shows trend for each parameterThreshold parameters can be set to generate alarms