Not everyone happy with so much dust

The Lidar data shows high concentrations between 4500 and 10000 ft, so we flew towards Aeolus track at 10 000 ft as the wind models predict less head wind than at 5000 ft. But they were wrong. 30 knots direct into nose. On the way back we went down to 5000 ft. Grisa is happy with so much dust his instruments are collecting, but I am not, as that much particles in the air could make huge problems to the engine. At sun set we safely land at windy Cesaria Evora airport.