Vertibird (Fallout 4)

Characteristics
The Vertibirds utilized on the East Coast have transparent cockpits, sliding doors on the cabin, a minigun on the lefthand side, dual fixed forward machineguns on the fuselage nose, folding wings and rotors. The Vertibird also has a docking hook along the top near the tail, that links with the docking hook/arm on the flight deck of the Prydwen. Different from previous models is the model's retractable landing gear, in a different configuration with one along the centerline at the front of the aircraft and the other three in a tricycle layout at the rear of the fuselage.

There is one known model used by the pre-War United States Armed Forces and Arthur Maxson's Brotherhood of Steel, a bulkier transport model with a glass cockpit, retractable side doors, collapsible wings, and two additional jet engines behind the main cabin.

The Vertibird's VTOL flight mechanics allow it to approach landing zones, transiting into a hovering mode of flight, by tilting its rotors vertically upwards 90 degrees. Vertibirds lack the large armament package seen in the Capital Wasteland. When dropping the Sole Survivor off in an area inhabited with hostiles, a Vertibird transporting the player will sometimes support them by firing on the hostiles with its dual machine guns. Other Vertibirds may also engage hostiles with an NPC operating the minigun.

Vertibirds are easily destroyed by ranged weapons and can be targeted in V.A.T.S. When a Vertibird is airborne and takes enough damage, it starts spinning on its Y axis, similar to how helicopters spin when they lose their tail rotor, before crashing into the ground and exploding, similar to a mini nuke explosion. The Vertibird usually breaks up into four large pieces upon crashing, releasing small amounts of radiation for a short while. However, if the Vertibird takes an immense amount of damage the Vertibird will slowly fall to the ground and pass through it. Marking with a recon scope can show its progress under the terrain.

Although the Brotherhood of Steel operate nearly all functional Vertibirds seen in Fallout 4, the Gunners also possess one functional Vertibird, which can be encountered in the southwestern portion of the map. They at one point possessed at least one more, which crashed into the Mass Bay Medical Center. The Minutemen and the Railroad may also come into possession of a single Vertibird. The Good Fighters have also managed to repair two Vertibirds and make them flightworthy.

Travel
In order to travel by Vertibird, the Sole Survivor can throw a Vertibird signal grenade in a suitable location. The aircraft will then attempt to land as close as possible to the colored smoke signal, however, it may not be possible for it to land in highly congested terrain, in which case a message will appear and the used signal grenade will still be expended.

After a short amount of time, the aircraft will land nearby, it can then be approached and the option to Ride can be selected, upon which the player character will always board the aircraft by entering the left door and taking up a position at the minigun. Once on board 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.

It is generally not possible to request landings on the roofs of buildings, not even on designated helipads. However, in landing to drop off at the destination, the Vertibird will attempt to land as close as possible to the fast travel target, including if this is placed on a roof or similar surface, provided the surface is large enough and a clear glide path exists.

In moderately congested terrain, the Vertibird may need to land some distance away, potentially out of sight. 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.

Traveling over radioactive areas is less dangerous than walking through them. The vertical distance from the surface of the ground (or other radiation source) reduces the radiation effect, meaning that for example, in the Glowing Sea radiation effects will be experienced only while crossing very high places (such as the ridges of the Crater of Atom) or during the take-off ascent or landing descent.

Encountering creatures while on board a vertibird may result in these creatures chasing the vertibird. Burrowing creatures such as Radscorpions and mole rats (which ignore normal limitations on movement speed) may then burst from the ground upon landing, even a considerable distance (several game world cells) from where they were originally encountered.

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 in the normal way.

Combat
Combat on a Vertibird revolves around the usage of the door-mounted minigun. It utilizes a special 5mm round, similar to companion special ammo, which cannot be obtained or retained by the Sole Survivor. In a normal game, the ammo will not deplete.

The weapon functions differently, depending on if the player or a non-player character operates it. Player-operated miniguns profit from perks such as Heavy Gunner and Lone Wanderer, but the Sole Survivor may not utilize V.A.T.S. or other weaponry while on board. Miniguns operated by non-player characters suffer from a 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 and the dual fixed forward 5mm machineguns.

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. Note that the bonus damage of this perk is applied additively, not multiplicatively, after any other perks affecting the minigun.

The minigun may be fired when the aircraft is on the ground (after boarding and before take off, but not after landing) as well as while airborne. The aim point crosshair for the minigun is very wide when hip-firing, and disappears when aiming in first person view. In third person view, there is no aimpoint dot. It is only possible to aim down the door gun's barrel "by eye" in first person view.

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.

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.
 * The first Vertibird seen in the post-War Commonwealth if following the main story is one crashed on the roof of the Museum of Freedom.
 * 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 at around eighteen locations 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 like it should.
 * The Vertibird can suffer from Wounding Legendary weapon effect (bleed). With enough sequential hits and using enough powerful weapon, 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.
 * In the event of the minigun disappearing, it is then possible to select other weapons from inventory and - for automatic weapons and melee weapons only - attack with them.
 * The Vertibird and player character can glitch through the Prydwen while maneuvering to dock with the player character on board.
 * The Vertibird and player character can glitch under the ground or under water while maneuvering to land with the player character on board. This is rectified by the time the player character is ready to disembark the aircraft. It seems to be more common at the waters edge, for example outside The Castle or at Nordhagen Beach.
 * While aboard a Vertibird, energy damage (DMG) of personal weapons (excluding mines and throwables, and radiation damage) is reported by the Pip-Boy as 6x times normal. It is unclear whether the weapons would actually do this damage, since they cannot normally be used when aboard a Vertibird.
 * The additional reported damage is driven by the crRangedDmg actor value (AV) of the Vertibird, which is the input to the crRangedDmg perk. In the case of energy damage, the AV is used as a multiplier rather than being used additively. In turn this is because damage other than standard (ballistic) damage uses a different entry in the perk, Mod Typed Weapon Attack Damage as opposed to Mod Weapon Attack Damage.