A400m Blowing Snow Testing

Israel López Herreros, Photogrammetry Responsible Team / Flight Test Analysis, Airbus Defense and Space, Getafe-Madrid, SPAIN
Iago Abuin Álvarez, Photogrammetry Team / Flight Test Analysis, ATOS
Gabriel Velasco Velasco, Photogrammetry Team / Flight Test Analysis, Altran

Abstract

The A400M engine operation must comply with EASA requirements for operation under falling and blowing snow conditions. After natural ice campaign in Kiruna/2011 and Grenoble/2012, clearance for operation under snow conditions with 1000m of visibility was obtained. To achieve A400M falling and blowing snow clearance with 400 meters visibility, new tests were necessary. Since the needed weather conditions for testing are uncontrollable and not predictable, it was proposed to EASA to use artificial snow.

One option was to use the McKinley Climatic Laboratory but this option was rejected because of lack of compatibility and availability and high price. Therefore, Airbus DS considered developing a new testing methodology involving artificial snow produced by snow guns in order to reproduce natural snow conditions. EASA establishes as a means of compliance for taxi at 15-25kt with 1g/m3 of snow density, and for A/C stopped 3g/m3 of snow density. The aim of this new methodology is to assure the snow density and velocity upstream the propeller during tests. This methodology is based on photogrammetry techniques to calculate a representative value of snow speed and on the application of continuity equation to estimate snow density.

Three test campaigns (Teruel/2016, Bolzano/2017 and Kiruna/2017) were carried out to develop this methodology and to demonstrate to EASA that A400M can operate under snow conditions equivalent to 400 meters visibility. This new methodology has demonstrated to be a good option to develop this kind of tests. Though error is still around 10%, path is clear and future research can be developed to reduce errors and make this methodology even more accurate.