The safety of the rolling air traffic on the ground is largely achieved through the quality of airfield areas. At airports, the paved areas such as pistes, taxiways and aprons are dynamically loaded intensively by the high weights of the aircraft.
These dynamic loads are transferred into the subsoil. In addition to conventional methods such as drilling cores, etc., we use sensory systems which illuminate the areas and evaluate concealed damage based on their nature, location and extent in order to measure defective changes in the structure before they are detected on the surface areas.
In case of already occurring damages this technique allows us to describe these damages precisely according to type and extent.
Based on the findings of the examination we develop proposals for (preventive) damage repair in accordance with European Aviation Safety Agency EASA and International Civil Aviation Organisation ICAO and implement them after quality controls.
In addition to the paved airport areas the unpaved areas include areas such as the RESA Runway End Safety Area on the trail heads and the strip along the pistes within the graded portion.
High quality requirements are imposed on the load bearing capacity of the subsoil on these unpaved surfaces, which in the event of runway excursion, an overshoot or underrun must meet the following criteria:
1. Deceleration of the aircraft within RESA and stripes.
2. No structural damage to the aircraft, in particular no collapsing of the landing nose gear.
Three technical systems are mentioned by EASA and ICAO as detection methods for the bearing capacity of the surfaces of RESA and strips:
A: The CBR test California Bearing Ratio in accordance with ASTM.
B: The SWL test Single Wheel Load Test in accordance with EASA.
C: Rollover test in accordance with an aircraft in accordance with EASA.
We use A and B. If the required quality is not satisfied, we also develop proposals for suitable efficiency-boosting measures (ELOS Equal Level of Safety, or ALOS Acceptable Level of Safety) accompanying measures and document the quality achieved.
Unlike at airports with paved surfaces aircraft rolls in airfields mostly on unpaved grassy areas. The quality requirements of EASA and ICAO also apply in this case. To demonstrate the qualities we use here the SWL test with light loads or the Plate Impact Test PIT. The development of different geosynthetic systems allow for an economic improvement for many airfields in case of detected stability deficiencies.
