Soon after throwing a vertibird signal grenade, a vertibird will appear on the horizon and track towards the Sole Survivor and land in the vicinity of the marked location, albeit not instantaneously. The player character can then board the aircraft to take control of its side-mounted minigun. Opening the Pip-Boy map and selecting a location to fast travel to will cause the vertibird to lift off and start flying to the selected location. When the vertibird has landed, the player character may exit or use the Pip-Boy map to select a different destination.
Alternatively, the player character can change the destination mid-flight. The vertibird signal grenade can only be used outside, and only by members of the Brotherhood of Steel, the Minutemen or the Railroad upon completion of the latter's main questline. The grenade produces orange smoke.
If the Sole Survivor completed the Railroad's main questline, Drummer Boy in the Railroad HQ will say that the vertibird is ready for use, giving the Sole Survivor three signal grenades. He then informs the player character that more can be purchased from Tinker Tom.
It also appears that the pilot of the vertibird does not take radiation damage.
- The Minutemen have two similar support items: flares and smoke grenades. The flare will signal for troops and the smoke grenades direct a strike from nearby artillery.
- The Institute has synth relay grenades to spawn synths.
- Eight are given by Elder Maxson as a reward for completing the quest Show No Mercy.
- Sold by Proctor Teagan aboard the Prydwen after completing Show No Mercy.
- Three are given by Drummer Boy upon completion of The Nuclear Option for the Railroad.
- Sold by Tinker Tom at the Railroad HQ after completing The Nuclear Option for the Railroad.
- Given by Preston Garvey after completing The Nuclear Option for the Minutemen, and upon destroying the Prydwen.
- The vertibird will still come even if one defeated the BoS in the main quest. However, factions such as the Minutemen and the Institute may be hostile.
- Temporary followers from BoS radiant quests, such as scribes and squires, won't use the vertibird.
- Shooting creatures in the Glowing Sea while on board of a vertibird may result in these creatures chasing the vertibird. Radscorpions and mole rats may then burst from the ground upon landing.
- Throwing the grenade at an NPC (such as a settler) will cause them to become hostile.
- Signal grenades do not work on the Far Harbor island or in Nuka-World.
- If the fast travel target to an area is cluttered or would be impossible to get to, the vertibird can land either time at a different area, ranging from 60+ feet to an entire cell.
- The hidden quest ID for calling in a vertibird is VFT. It can be manipulated in the console like any other quest.