GRASSTAM – An Idea of a Notice on Grassy Runway Condition

The paper presents an idea of a new navigational notice to airmen on friction and bearing capacity conditions of grassy runways. The notice, tentatively named GRASSTAM, similar to NOTAM, will be issued for ICAO coded aerodromes with natural grass, unprepared runways. A great number of such aerodromes still exists in the European Union countries as well as in the other part of the world. Their utilization within the exiting air transport system could be improved by the knowledge of surface condition what would help the airmen in deciding to operate or not, depending on the actual meteorological situation. Therefore, the input data to create a GRASSTAM notice comes from a simulation program that becomes input data from an online weather service to have past, current, and future meteorological conditions to predict the mechanical strength of turf on a given airfield and to provide that in a readable, coded form. Another important input for the GRASSTAM algorithm is the measure of soil moisture and grass high, which will be delivered by a field sensor. The paper contains general information on the proposed notice with its structure and basic elements as well as the coding/de-coding methodology.