| Item | 20511 |
| Country | Liberia |
| Year | 2003 |
| Face Value | 10 Dollars |
| Metal | Silver .925 |
| Weight | 25 g |
| Size | 38.61 mm |
| Quality | Proof |
| Mintage | 5000 pcs |
The American Pilot Charles E. Yaeger was the first human who reached beyond the sonic speed i.e. the speed of 1200 km/hour with the aerodynamic enhanced Bell -X1 airplane. In the following years – during the cold war – mostly for military application, airplanes reached the supersonic speed of 2000 km/hour („Starfighter“).
