| Answer | Crossword Clue |
|---|---|
| SPRUCEGOOSE | Aircraft that flew only once, in California |
| SPRUCEGOOSE | Plane that flew only once |
| ROSEBOWL | It was held outside of California only once, in 1942 |
| HAPAX | ... legomenon (word that appears only once in a manuscript) |
| flashbulb | A light bulb that flashes in order to illuminate a photographic subject, of a type that is used only once |
| flashbulbs | A light bulb that flashes in order to illuminate a photographic subject, of a type that is used only once |
