Vertibird (Fallout 4)

Characteristics
Vertibirds have offensive capabilities such as Gatling lasers, miniguns, and missile launchers. They can take damage and crash, the subsequent explosion causing damage to nearby individuals. The Brotherhood of Steel, Gunners, and Minutemen and the Railroad utilize the vehicles. There are four named vertibirds, including the Claymore, Scimitar, Spatha, and Vorpal. During flight, the vertibird's wings will change position as it turns or changes altitude.

Signal grenade
In order to travel by vertibird, the Sole Survivor can throw a vertibird signal grenade. The aircraft will then attempt to land as close as possible to the colored smoke signal. The player character can interact with the object, selecting the option to "Ride." Once onboard the vertibird, the Pip-Boy's map tab can be opened and a destination selected. The destination can be changed mid-flight, at any time prior to final descent at the currently selected destination. A landed vertibird will always add a quest to the Pip-Boy's miscellaneous section, which initially is not active. Once activated, the quest marker can be used to locate the vertibird, and it will be automatically activated for landed vertibirds in the future.

Encountering creatures while onboard a vertibird may result in these creatures chasing the vertibird. In Survival mode, periodic damage from over-encumbrance does not occur while traveling in a vertibird. Thirst and hunger effects, and periodic damage from disease, occur normally.

Statistics
The craft's minigun can be used by the player character, and the ammo will not deplete. Perks such as Heavy Gunner and Lone Wanderer impact the use of the minigun, but the Sole Survivor can't utilize V.A.T.S. or other weaponry while on board. A popup message warns the player character when a vertibird they are traveling in falls below 25% Health.

Miniguns operated by non-player characters suffer from much lower base damage have only half the ammo capacity, and their operators receive a 10% accuracy penalty per 100 range, for targets within 500-1000 range, resulting in a 50% penalty for targets at 1000 range. However, non-player characters may also utilize weapons other than the minigun, including personal weapons.

Damage
A hidden perk (crRangedDmgPerk) grants bonus damage for all vertibird-mounted weapons, typically +5, higher for high-level NPC vertibirds - see table below. This increases the base damage of the wing-mounted fuselage guns as well as the minigun and affects both the Sole Survivor and non-player characters. The bonus damage of this perk is applied additively, not multiplicatively, after any other perks affecting the minigun.

Vertibirds operated by NPCs are leveled in a similar way to monsters and other hostile non-player characters. Their level range reaches from 20 to 50, with their stats varying for each level range. Vertibirds used by the player for fast travel are the lowest tier types, identical to the level 20 NPC types. Brotherhood of Steel personnel, operating on randomly encountered vertibirds, have a perk that reduces explosion damage they suffer by 50%.

Locations

 * The first vertibird appears in the opening sequence of the game, flying over Sanctuary Hills and landing next to the entrance of Vault 111. Another vertibird hovers over the Old North Bridge.
 * Operational vertibirds are seen after the quest Reunions when a Brotherhood of Steel force shows up with the Prydwen. Afterward Brotherhood of Steel vertibirds are seen flying, sometimes in pairs, throughout the Commonwealth deploying squads or firing on hostiles.
 * After the quest Show No Mercy, the player character gains the ability to call in a Brotherhood of Steel transport vertibird by using a vertibird signal grenade. Alternatively, it is possible to gain this ability in the end-game when siding with the Railroad (after completing The Nuclear Option) or with the Minutemen (after completing With Our Powers Combined).
 * Crashed vertibirds are found in the Commonwealth, including Coast Guard pier, the Glowing Sea, Mass Bay Medical, Boston Airport, the National Guard Training Yard, as well as at various wilderness locations and military checkpoints.

Behind the scenes
In The Art of Fallout 4, the Fallout 4 vertibird is described as the "result of a goldfish meeting a Hind helicopter."

Bugs

 * The wreckage from a destroyed vertibird may continue to move long after it has crashed, sending (harmless) fuselage spinning over and over around the crash site.
 * Boarding a signaled vertibird that has landed in Boston Common Pond will cause you to remain irradiated, even after landing.
 * Idling long enough inside the vertibird to where the camera pans around the character in third person, then moving the camera after landing, may cause the player to become stuck inside, and the vertibird will take off with the player unable to move. After a few moments, the player will fall out of the vertibird.
 * When a vertibird runs out of health, it is supposed to spin wildly out of the air and crash into the ground. However, sometimes a glitch occurs where it gets staggered while this is happening, causing the vertibird to become 'zombified'. It will hover in the air and slowly drift towards the ground, sometimes even sinking into it rather than exploding as it should.
 * The vertibird can suffer from Wounding Legendary weapon effect (bleed). With enough sequential hits and using enough powerful weapons, like Pickman's Blade, the vertibird's life can be seen diminishing from bleeding through V.A.T.S.
 * The vertibird can suffer from having the minigun disappear after the player has taken off, essentially making it defenseless for the remainder of the journey. there seems to be no set trigger. moving or not moving, panning the camera or not. zoomed in or out.