https://www.pcgamer.com/fortnite-reinstates-guided-missiles-adds-fly-explosives-jetpack-mode/

As expected, Fortnite's guided missiles are back. Part of its v5.10 Content Update—which is "all about jetpacks, explosives, and complete cartoon chaos"—the weapon joins its new Fly Explosives limited time mode.

From back to front, Fly Explosives is an "explosives only" outing that equips players with Jetpacks—before blasting their foes from above. Floor Loot spawners will occasionally offer Jetpacks, explains the update's patch notes, which have increased fuel regen and decreased burn rates against their default counterparts. Likewise, Rocket Ammunition is capped at 120, while between-storm wait times have been reduced as players require time less scavenging time.