Viper 289 was a Mk. II Viper spacefighter scrapped by CPO Galen Tyrol at the beginning of the episode "Flight of the Phoenix".
Note
This was not Viper 591, which Louanne "Kat" Katraine crashed in the previous episode. However, the damage observed on "Viper 289" in "Flight of the Phoenix" is almost identical to the damaged observed on Viper 591 (damaged wing, etc), plus given that it was scrapped by Tyrol in the episode immediately following "Final Cut", seems to imply that it was just a number goof in the script.