The Swissmint Patterns. 20 francs 2025 B, Bern. Pioneers of Swiss aviation. SILVER PATTERS. Propeller blade with "E" symbol for ESSAI. Value below / Hot-air balloons. 20,00g. NGC PF69 ULTRA CAMEO. (8806430-003). Extremely rare, only three species struck. Technical information from Swissmint: This Pattern was realized with three strokes of 104 tons pressure. Aviation in Switzerland began with pioneering balloonists at the end of the 19th century. In 1897, the Federal Council decided to set up a Swiss airship company, ten years after military airships had become established in Europe. Before that, pioneers like Eduard Spelterini and the Piccard brothers had made the first balloon test flights for the army. With the outbreak of the First World War and the development of modern air forces, the importance of balloons wanted; in 1937, the balloon corps was dissolved. This coin is the first in a series of three commemorating Swiss achievements in aviation.,