On this page of our guide to Batman: Arkham Knight you will find exact locations of destructible objects that can be found on board Stagg Airships. Destructible objects are one of secrets (collectibles) available in the game.
ON board both of the Stagg airships there are fifteen Insect Crates that you need to smash. Smashing all of them completes three new Riddler puzzles (the counter goes up every five objects that you smash).
There are two different ways, in which to destroy the insect crates. For some of them, you simply need to walk up to them and press the attack key/button. Some of the crates, however, are not as easy to access and in such a situation, you need to use the batclaw non the crate's a lach to rip it apart.