Go after Phoenix is a mission in The Lost Frontier. After beating the Danger Course, Jak, Daxter and Keira Hagai returned to Skyheed and Ruskin to receive the eco seeker. However, upon arrival they were attacked by the sky pirate Phoenix, who made off with both the eco seeker and Keira, prompting Jak to chase after him.
You must use the Hellcat to follow Phoenix' Sky Raider through a series of tunnels as you dodge large rocks being spewed forth from the magma below, large support pillars and other various machinery. Use both your boost () and airbrake () to avoid these obstacles while you follow Phoenix, who cannot be overtaken in any case. Periodically small drones will appear to attack you, shoot them down as you encounter them. Both the various obstacles and the drones pose little threat to your plane, though enough collisions and damage will cause you to fail once your extra repair patches run out. Note that Phoenix himself poses no threat and should be ignored as Keira is onboard, though damaging it does not actually cause the mission to fail.
At set intervals Phoenix will access the current tunnel you're traveling through and emerge out into the open, where after Jak prompts you to use your grappling tool () to launch Daxter and to start Daxterjacking Phoenix' ship. This will have to be done three times in total, slowly damaging his ship each time as well as stealing one air speed mod and two lock-on missile weapons. Eventually in the middle of the chase a cutscene begins, in which Jak and Daxter will run into an ambush from the sky pirates, causing them to crash on Brink Island.