When in The Commodore Club, Peralta introduces himself as "Spike Marsters" This may be a nod to James Marsters who played Spike in Buffy the Vampire Slayer (1997)
First appearance of Jake's dad.
The puzzle given by Captain Holt in reality has multiple (similar) solutions. It is even possible to determine not just which person is different, but whether they are heavier or lighter.
The "tribute air"airplane that Jake's dad is flying is actually an Emirates A340-600