| Answer | Crossword Clue |
|---|---|
| SUBSONIC | Slower than Mach 1 |
| SPEEDOFSOUND | Mach 1 |
| SST | Mach 1 breaker |
| SSTS | Mach 1 toppers |
| SSTS | Mach 1 breakers |
| SST | Mach 1 beater |
| SST | Mach 1 flyer |
| SST | Mach 1 passer |
| SST | Mach-1 surpasser |
| SSTS | Mach 1 fliers |
| SSTS | Mach-1 exceeders |
| SONIC | Mach 1 barrier. |
| SUBSONIC | Below Mach 1 |
| SST | Mach 1 exceeder |
| SST | Mach-1 exceeder |
| SONIC | At Mach 1 |
| SST | Retired mach 1 breaker |
| SST | Mach 1 breaker, once |
| AVIATED | Went Mach 1, maybe |
| SST | Mach 1 breaker, briefly |
| SOUND | It travels at Mach-1 |
| YEAGER | First person to break Mach 1 |
| YEAGER | First pilot to exceed Mach 1 |
| SONICBROOM | Hag's transportation that passes Mach 1? |
