The crew's jolly roger is a cartoon-like depiction of a traditional skull with the upper teeth being replaced by a long set of piano keys (reminiscent of Apoo's own upper teeth) forming a wave, as well as Apoo's trademark braided hair tail. Instead of the usual crossbones in the background there is what seems to be a lightning bolt which might here again be a reference to Apoo's hairstyle (his roots having a lightning pattern).
They made it to Saboady Archipelego, where they were met by other strong crews. Their captain, Scratchmen Apoo witnessed the many different powers of three Supernovas including X Drake's ancient Zoan fruit, Urouge's ability to grow larger, and Basil Hawkins' straw ability. Apoo attempted to take on AdmiralKizaru himself, but was defeated.
After the reading the news about Doflamingo's defeat, Kid and Killer dined with Hawkins and Apoo. They learned that Luffy and Law's target is Kaido and were glad as their intended Yonko target is Shanks. Some time later, they were alerted by what seemed to be an earthquake. They quickly investigated the source of the commotion, which was a large crater on the ground in the shape of a human. The alliance then came face-to-face with the Yonko, Kaido.
After Jack's defeat, Apoo contacted Kaido and informed him that communications with Jack had been lost. Referring to the Yonko as "Kaido-san" and reporting this news to him via a Den Den Mushi, it indicated that Apoo was now assisting him on some level.
The captain is Scratchmen Apoo, one of the Eleven Supernovas. All confirmed crew members of the On Air Pirates bear a resemblance to their captain in regard to Chinese dress and theme, with all of them wearing the same style of Chinese gown as Apoo, though in different colors. One wears an oriental styled cap and a short Fu Manchu mustache while the other has his hair tied back in an (almost) oriental manner.
It can be presumed that they are strong because of their captain's high bounty and the fact that they made it all the way to Sabaody Archipelago and the New World. Another example of their strength is that they were able to escape Kizaru's raid despite their captain being beaten by Kizaru's attack. They have also formed an alliance with the Hawkins and Kid Pirates.
The term "on air" is normally used for when a radio studio's microphone is activated and its listeners can hear the DJ speaking on the broadcast from the radio station. Coincidentally, Scratchmen Apoo himself resembles a DJ both in appearance and fighting stance.
The On Air Pirates arrived on an island in the New World where they ended up running "on the air" to escape some giant boars.