Airport Runway Surface Friction Testers
| Company | ASFT |
|---|---|
| Date | 01.03.2010 |
Ford Taurus – Runway Friction Tester –
1. The computer system
The ASFT computer system includes measurement computer, main computer with printer and an operator's panel with only six keys to simplify the handling of the system. The computer is pre-programmed for measurement and presentation in accordance with ICAO, FAA, and CAP 683. The computer system controls the measuring procedure and presents the results on the computer display and/or on paper printout.
2. The self-watering system
The ICAO and FAA clearly state that a CFME must have a self-watering system. The ASFT self-watering system sprays a water layer on the runway surface in front of the measuring wheel. The tank volume is sufficient for measuring more than 6.000 meters runway with a water layer depth of 1 mm (0,04").
3. The electricity service box
Relays and fuses for all the measurement system are centralized to a service box which is very easy to reach.
4.The torque transferrer
When the measuring wheel slips on the runwy surface, the friction creates a torque which is transferred to the chain system and measured by a load sensor.
5. The measuring wheel
A special high pressure tyre, the Friction Tester "Aero" tyre has been developed for operational measurement purposes. Measuring results with this tire have been shown to correlate well with aircraft braking characteristics. For calibration purposes a low pressure tyre can be used. The slip ratio of the measuring wheel is about 12%, the exact value depending on the wear of the measuring tire and the car tyres
6. The hydraulic unit
The unit provides constant pressure for the wheel retraction mechanics and for the vertical load on the measuring wheel.
7. Vertical Load Sensor
This monitors the vertical down pressure created by the hydraulic system, and makes any necessary adjustments to it. It ensures that an absolute constant ground contact pressure is kept.
