During taxiing engines of commercial aircraft generate jet blast. If at existing aircraft positions or taxiways new aircraft types are planned for authorization, it is to be examined whether existing safeguard measures are sufficient against the increased jet blast. Basis of such analyses is nowadays the so called "35 mph jet blast isotach", which is provided for each type of aircraft by its manufacturer. Due to the restrictive space situation in the terminal area it is often difficult to fulfill these requirements.
The Project Center Aviation Logistics developed for Fraport AG the operator of Frankfurt Main airport an appropriate measuring setup to assess the jet blast at defined points and preliminarily evaluated the current isotach based planning approach.
The core of the specially designed measuring setup constitutes a 2D sonic anemometer. As mass less test system, with a measurement rate of up to 200 Hz, it is particularly suited to cope with the dynamic wind conditions behind taxiing aircraft. The portable measuring setup records besides wind speed, also the jet blasts temperature and direction. It achieves a high accuracy and exact reproducibility of results. The initial measurements have shown that the actual wind velocities behind taxiing aircraft lie far below the values of the isotach based planning approach.