|“I want that!”|
|— Kai spotting the Kai Fighter|
The Kai Fighter was a small surveillance aircraft created by Borg Industries to protect the citizens of New Ninjago City from threats. During the Nindroid Conflict, all of the fighter jets were corrupted by the Digital Overlord expect for one, which was hacked into by Kai and flown by him on numerous occasions. Kai flew the fighter to Garmadon's Monastery and even tried using it while in the Digiverse, though he was unsuccessful in doing so. After returning to Ninjago from Arcturus, the Ninja arrived at the city in their vehicles. Kai flew the fighter into the city, but the vehicle was obstructed by the Golden Master. Using Golden Spinjitzu, the Golden Master destroyed the Ninjas' vehicles, including the Kai Fighter.
It is unknown what happened to the other fighters following the fall of the Golden Master and his Nindroids. It is likely they were either scrapped or stored away for future use.
While deciding on a vehicle to hack with his Techno Blade, Kai settled on an incoming Aircraft and hacked it, boarding the vehicle. Whilst piloting it and being pursued by other enemy aircraft, Kai learned from Cyrus Borg's message the nature of the Techno Blades and the incident at hand. After regrouping with the others, the Ninja made a plan to smuggle the Techno Blades out of the city by using the Kai Fighter to pick up the fallen weapons as Master Wu leaped over an alley, and succeeded.
Kai landed the Kai Fighter outside Garmadon's Monastery and covered it with tree branches to hide it. Following the Nindroid attack, Kai activated the fighter's autopilot, causing it to fly around in zigzags until it was shot down by the Destructoid.
While in the Digiverse, Kai was briefly able to summon his jet, though due to his inexperience, he quickly lost control over it and the fighter vanished.
As the Ninja fell from the sky following their makeshift rocket burning up, P.I.X.A.L. coordinated a hacked Kai Fighter to safely catch the Red Ninja. Kai then used it during the Ninja's attack on the Golden Master, but the Kai Fighter was quickly shot down by the Overlord, and before it could be saved was promptly destroyed in the ensuing Spinjitzu tornado summoned by the Golden Master.
In LEGO Ninjago: Shadow of Ronin (non-canon)
On route from Kryptarium Prison to Ed & Edna's Scrap N Junk, Kai briefly used the Kai Fighter to fight off several Rattlecopters.