Head to the back of Shal Korva at /setwaypoint 10264 5552
Here you will find 3 quest givers that give quests for the airship!
You can pick them all up, or just do the one required for the cheevo.
Once you have picked up your quests, head over to the back of the platform and wait for the next airship!
The airships take a full tour around Planetouched Wilds so it may be a couple of minutes before the next one arrives.
To complete the Soaring Over Shal Korva quest you will need to walk onto the airship when it arrives and then just stay on it for the whole trip.
The other quests require you to use quest items (moths or fireworks) at certain points or get off the ship onto one of the floating islands and then jump down.
You can find a full guide to the Planetouched Wilds quests here.