User blog comment:Miskos3/Fairy Tail 531: Pegasus vs. Black Dragon/@comment-5894890-20170414235951/@comment-30462872-20170416100924

To be fair, he's ancient and they didn't have airships like Christina when he was still being sociable/in the world and not being a recluse.

Plus, even if he did know, Wendy was on it and wasn't affected until the Lacrima was destroyed, so he was probably like "Okay, the small child Dragon Slayer is on that boat without a problem, I'm good to land on that thing and start ripping its engine out."