Here are my Top Five occurrences of this, presented in no particular order.
Order of the Stick:
Captain Scoundrell trains Elan. Set on the pirate's airship, this is a glowing homage to fast-track training needed by would-be heroes. The hows and whys of training are highlighted best here. [Part I] [Part 2]
Star Wars:A New Hope: Obi-Wan trains Luke. On a different kind of pirate's airship, the novice Luke learns to wield his sword of light. More importantly it is another opportunity to describe the nature of the force to the audience.
Heroes episode "Landslide" : Kaito trains Hiro. No airships this time, but the plucky Hiro must learn the way of the sword, and more importantly the way of the warrior.
Lord of the Rings:Fellowship of the Ring: Boromir trains the Hobbits. A tall mountain stands in for the airship here, as Boromir give the little ones a refresher in dodge, turn, parry and thrust.
Stardust: Captain Shakespeare trains Tristan. The pirate's airship again becomes the centre for training, as shopkeep Trisan learns swordwork, dancing and fashion sense.