The ACS-1 Citadel, or Citadel-class aerial battleship is a mobile, gargantuan aircraft class in service of the American military and very select few foreign militaries and other organizations around the globe.

First introduced in 1989, the Citadel-class air battleship has become a valuable vehicle for purposes of power projection, intelligence operations, covert operations and fire support. Some newer variants of this class have Red Matter systems and require magic and magically-powered individuals present to operate some of its energy and / or weapon systems.

The modern Generation-II and III Citadel-class air battleship performs a more expanded role than its predecessors, acting as a mobile aerial military base. At least a dozen are in the service of the United Liberators Coalition, which uses them frequently on international missions and for defensive purposes.

History Edit

Origins in the Cold War Edit

The first preliminary designs for the Citadel were drafted in the late 1970s and originally envisioned the ACS-1 as an aircraft capable of indefinite high-altitude flight for the purposes of research and, if need be, military applications in launching nuclear warheads and conventional missiles. As plans were refined, however, the Citadel-class was then refined with the intent that it would also become the successor class to the 'fortress' type aircraft (B-17 Flying Fortress, B-30 Superfortress, B-52 Stratofortress) which had similarly powered magical variants during World War II, Korean War, Vietnam War and Cold War.


Concept art proposal for the first Citadel series aircraft by Xaikon.

However, unlike its predecessors the Citadel was explicitly designed from the beginning to take advantage of the United States's population of Type-II individuals who could channel magic in order to build and operate a mobile air base that would aid the United States Air Force in military interests during the later stages of the Cold War. When the Type-III Awakening Incident began in 1985, production on the prototype was accelerated, with fears that the sudden surge in supernatural abilities would possibly change the face of warfare even more than magic already had. The United States government reasoned that in order to combat potential supernatural metahuman soldiers used by the Soviets, a solution must involve the use of magic on a scale never before seen in the arsenal of the United States Armed Forces. In reality, the Soviets were as fearful of the same thing, developing their Antonov Katyusha around the same time. Both would end up being used against metahumans, though ironically enough rampaging metahumans in their own borders who had no intention of serving any state.

To that end, the American company Xaikon Heavy Industries was contracted to aid in the design and development of the nation's first aerial battleship, receiving government assistance to greatly expand their facilities and to supply resources to the project.

The first Citadel-class aerial battleship, the USS Citadel was built and put into service in 1989, hurriedly pressed into action after completion of construction at a protected facility. Though arguably ultimately successful, the prototype suffered severe issues and had to be redesigned multiple times in order to allow the experimental magic-technology systems to be refined to a point where they were functional enough for actual military service.

First Generation Edit

In addition to experimenting with magi-tek reactors, the originally canceled Aircraft Nuclear Propulsion program, which previously developed the conceptual nuclear powered Convair NB-36H, was brought back into service for the Citadel Project and continued testing the feasibility of nuclear reactors powering aircraft, eventually culminating in the successful construction of a second Citadel-class battleship powered by nuclear power. Later Citadel-class aerial battleships produced afterwards utilized conventional non-magical technology such as nuclear fission, and later, fusion reactors.

Citadels were one of the most crucial instruments the United States government and military used to restore control over their territory; the aerial battleships were versatile and well-protected due to their flight altitude, long term deployment and ability to be used as command bases that could coordinate neutralization of remaining parahuman holdouts and re-stabilization of regions affected by the parahuman uprising. Throughout the 1990, the first twelve Citadels contributed greatly to restoring order to major American cities, and were extremely effective in dealing with metahuans, often with their long-range magi-tek cannons and railguns. In tandem with the C-20 Phoenix, these ships proved to be a valuable asset.

According to Helena Wolfe, the original Generation-I Citadels did not have onboard waste processing and required dedicate tanker planes to deal with waste from long deployments of weeks or more. Air Force personnel that were assigned to these waste management aircraft tended to be there because of disciplinary issues or other cases of less-than-stellar performance.

Citadels built after the first twelve ships boasted extended capabilities such as better weapon systems, more reliable energy efficiency, greater independence and flight capabilities, and onboard waste processing,

These ships, considered Generation-II Citadels, would come standard with billiard tables as furnishings in their lounges, for the purpose of bragging rights by the American military to show how exemplary the vessel's stability was, even in unfavorable conditions, by showing that the balls wouldn't move around while the aircraft was in flight.

One Citadel has been lost to non-combat accident and catastrophe, by flying into a mountain due to pilot error. Further upgrades were introduced to ensure that such collisions in the future would be unlikely to occur again.

Modern Day Edit


US Air Force Generation-II Citadel, the USS Montana.

Despite the end of the Cold War and their original intended purpose becoming moot, the Citadel-class aerial battleship has found service in United States Air Force and United States Navy, and to a lesser extent, in the United Liberators Coalition for use in international missions and combating large scale threats. Fully magically-powered variants were later successfully built and operated during early 2000s upon refinement and completion of superior magic-technology integrated systems.

Generation-III Citadels entered service in the late 2010s, almost all of them having enhanced magical capabilities of some sort.

In 2015, controversy over the British Commonwealth's assignment of the Super Bastion submarine, the HMS Leviathan, to the Xanjeran Navy resulted in the United States cancelling orders from Citadels from the Commonwealth, and ceasing export of the aircraft class entirely. Citadels denied to them, this would cause the British to eventually develop their own Rook-class airship.

By 2029, these represented some of the most highly advanced aviation technology produced by the Americans, and had features and capabilities their predecessors lacked, which included, for the first time, being able to land, take off, and for a brief period of time, hover unassisted without magic. They also introduced Mission Modules, which enabled specialized equipment to be quickly and temporarily installed and swapped in and out to suit certain missions.

In 2020, Charlie Lang watched a Citadel-class ship take off from the Phoenix Complex while with his father at San Francisco Aquatic Park Cove.

Citadel PNG closeup

The ULCS Golden Eagle, a Gen-III variant. Note the blue engine exhaust and Mission Module, characteristic traits of modern Citadels.

In 2029, a few Citadels were seen near the Phoenix Complex, one of them belonging to Liberators-830A. Instead of having to wait for a separate plane to deliver their cargo and personal vehicles, all of the A team's equipment was loaded onto the ship and was transported to Union Falls in one trip. This Citadel has its own docking bay hidden underneath Atlantes Center.

By March 2029, one of the United States Air Force's Citadel fleets had been moved to off the coast of the Korean peninsula due to the rising threat posed by North Korea, accompanied by dozens of squadrons of conventional aircraft and three aircraft carriers. They participated n the Korean War that followed en masse, downing significant numbers of metahumans in their first engagement against large numbers of powered individuals since the original Awakening Incident. No Citadels were lost, thanks to their famous (or infamous to some) ability to sustain massive amounts of damage and remain operational.

In late 2030, during the Langford cognitohazard attack, two Citadels were subjected to and compromised by the virus: The ULCS Golden Eagle, and the ULCS Stormbreaker. The Golden Eagle was saved due to the quick actions of its flight crew who initiated a computer core purge and restart, and the Stormbreaker was lost in an active combat situation when the virus compromised its ability to defend against the Order of Morgana's floating Landmass and its army of aerial Swarm drones. The Stormbreaker's loss is the only combat loss of a Citadel on record ever, but it set a historical precedent and a grave reminder that such an aerial battleship is not truly invincible.

In Coalition service, Citadels are supplemented and in cases of smaller Liberator chapters, supplanted by ACS-2 Aquila-class stealth command jets, which perform a similar role on a smaller, more covert scale.

With the loss the Stormbreaker, there are about 87 Citadels currently in service as of 2029. Of the original 12 Generation-I Citadels, 3 of them remain in active service with the rest of them mothballed or converted into museums, or scrapped.

Operators Edit

Variants Edit

Most Citadels utilize Red Matter systems to gain maximum performance from magically-enhanced weapon and energy systems. Very few Citadels are purely standardized, with almost all Gen II and all Gen-III vessels being the ACS-1R variant.

Standard Citadels (ACS-1) Edit

  • Main weaponry: Standard Citadel-class battleships are armed with sixteen electromagnetic dual cannon railgun turrets, eight mounted on the dorsal 'hump' of the ship and eight mounted underneath on its ventral side.
    • Citadels that are not magitek lack bow cannons entirely, so this feature is absent.
  • Power: Power production plants of all standard Citadels use four nuclear reactors. All Citadels built after 2013 use nuclear-fusion reactor technology, while Citadels constructed before utilize nuclear-fission reactors.
  • Defense: Gen-III Citadels have an electromagnetic shield array that mitigates kinetic and projectile damage.

Magical Citadels (ACS-1R) Edit

  • Main weaponry: Magical Citadel-class battleships utilize, instead of conventional technology, sixteen magi-tek energy cannons, eight mounted on the dorsal side of the ship and eight mounted on its underside.These cannons are single-barreled weapons that fire extremely powerful bright orange discharges at long range, with a distinctive noise described as an 'electric gong'.
    • On magitek Citadels, the bow cannons underneath the bridge of the ship are larger, fixed versions of the main batteries that are used for head-on assaults.
  • Secondary weaponry: Magitek Citadels also feature 16 additional smaller socketed quad turrets capable of rapid firing rates of 400 discharges a minute and eliminating targets at medium range. They are mounted at tactical points throughout the ship's wings and fuselage. Unlike the main weapons, these do not retract for normal non-combat flight.
  • Power & Propulsion: Magitek Citadels utilize reactor cores that are enhanced by red matter systems. Generation-II Citadels possessed a single red matter energy core that required attention from a wizard at all times to keep energized, whereas Generation-III Citadels possess highly advanced fusion reactors that are merely enhanced to become even more powerful with the addition of wizard engineers.They are also redudant; though a single reactor core cannot match the power output of an Ilyushin-104 Airborne Guided Missile Battlecruiser's reactor, four of them easily outstrip its rival's power output and provide redundancy and more power than needed.
    • Magitek results in a greater energy output than their standard counterparts, allowing for longer flight time in the air, longer weapon operation and capability to perform in excess due to the high efficiency and power of their experimental magic-technology engines.
    • Engine augmentation particularly grants pilots a 'turbocharged' emergency mode in which the Red Matter systems alter the physical attributes of the entire airframe to allow for maneuvers otherwise difficult or impossible. This is activated with a protected red button on the throttle controls.
    • Gen-III magitek Citadels also have the capability hovering indefinitely with their VTOL systems using a similar method, in addition to their non-magical ability of takeoff and landing vertically and hovering for limited periods of time without magic.
  • Defense: In addition to having the standard electromagnetic shield, magitek Gen-III Citadels are capable of projecting a mana shield and runic arrays to defend itself in flight. This has proven to be especially useful against magical and metahuman threats.

Citadel Generations Edit

Citadel size comparison

Size comparison of a Gen-III Citadel with other contemporary aircraft considered large.

There have been three distinct generations of the Citadel-class battleship throughout the last 50 years since the first one was launched. They are Generation I, Generation II, and Generation III.

  • Generation I: From 1989 to 1999. The first 12 Citadels were constructed in secrecy after the success of the first vessel's launch. These ships were instrumental in expelling metahumans from the United States and safeguarding the country's recovery.
  • Generation II: 2005 to 2018: The majority of the Citadels were built during this period after the United States' recovery and substantial industrial growth following the turn of the millennium. 64 examples of the aircraft were built in this time frame.
  • Generation III: From 2020 to present. Generation III Citadels are the latest and most advanced version of the aerial battleship, and introduced new features such as direct VTOL and hovering capability, and Mission Modules. About 21 examples have been produced, including the ULCS Golden Eagle.

Armament and Technical Specifications Edit

The ACS designation denotes its purpose as an Airborne Command Station. Citadels are generally used as highly strategic mobile bases to perform effective reconnaissance, stealth deployment, or direct strike operations.Their immense size and weapons capacity means that in most cases, there are very few types of aircraft and weaponry that it is vulnerable against, due to its tendency to be able to soak up massive amounts of damage and keep functioning despite the fact.

Their size eclipses all preceding aircraft before them, and excluding spacecraft launch vehicles and gas airships, they are the largest aircraft in the world, with measurements clocking in with a wingspan of over 250 meters and a length of 130 meters.

Weaponry and Defenses Edit

  • Gun batteries: Citadels are equipped with sixteen heavy electromagnetic dual-railgun batteries, with eight mounted on its ventral side and eight mounted on its dorsal side. Magically-enhanced Citadels possess single gun magical energy cannons mounted in their position instead. In both cases, the weapon batteries in their dormant state are retracted and protected by metal covers, which quickly retract in the event weapon systems are ordered to be fired up.
  • Missiles: Some Citadels are equipped with vertical launch systems to deliver missile salvos. US Navy variants have VLS block located in the space that would normally be a landing platform elevator shaft for planes in US Air Force and United Liberators Coalition variants.
  • Defensive intercept systems: For defense, the Citadel relies on its ability to launch its auxiliary craft to intercept incoming threats, as well as eight Phalanx Close-In Weapon System mounts and five Mark.55 Guided Missile Launch system mounts.
  • Shielding: Should the incoming attack fail to be deflected, Citadels are equipped with a technological electromagnetic energy field generator, or additional magical mana defense barrier, and can additionally sustain heavy damage to its armor plating and internal systems and remain operating. Generation-III Citadels are capable of forming rune matricies in midair to magically defend against attacks.

Internal layout Edit

  • Designed as a military vessel, Citadels have few windows but have several lookout and observation stations throughout the ship in the event of radar and sensor systems failure. The nose-cone forming the aircraft's bow is made of reinforced transparasteel and provides a sweeping view of the ship's surroundings. Generation-III Citadels feature gondolas underneath the wings and a rear-facing landing control gondola at the aft of the ship to facilitate docking of smaller aircraft.
  • Hangar: Citadels have the capability to hold up to four F-35 Trident-II jet fighters, or alternately six V-25 Valkyrie gunships, enabling this class of aircraft to partially act as an airborne aircraft carrier.
    • Some ships are able to dock in flight with the Citadel-class, and are guided into the large hangar at the rear of its fuselage. Only VTOL aircraft are capable of doing this, and must match speed with the aerial battleship in order to be brought in by mechanical retrieval arms onto the primary hangar's flight deck.
    • This hangar is connected to the aircraft's two cargo bays, which spread out into the wings and and often act as expanded hangar space to give the ship its maximum capacity.
  • Decks: Citadels vary in their configuration of decks depending on service branch and even individual vessels. There are some constants however, such as all variants having a lounge on Deck 6 in the aft, the commanding officer's quarters located inside the dorsal 'hump' of the ship, their hangar spaces, the location of the reactor cores, and the command bridge / flight deck being located within the aircraft's transparent nose. See the ULCS Golden Eagle page for its specific configuration.
  • Evacuation systems: In the event of an emergency, the Citadel-class is equipped with two escape pod bays with downward-firing ejection capsules to evacuate its crew if need be.Generation-III Citadels can use their Mission Modules as additional escape vehicles.


Flight Systems Edit


A Gen-III Citadel exhibiting its VTOL capability. Note how the ventral main engine pods open and redirect thrust downwards.

  • Power generation is carried out at the heart of the ship in a contained, reinforced chamber that either houses a single magi-tec Rm reactor (Generation-II versions), or four nuclear fission or fusion reactors (Generation-III). This reactor compartment is reinforced by heavy bulkheads and pressure doors, granting access only to authorized personnel.
    • In emergencies, the Citadel-class is capable of ejecting their reactor cores.This ability was present on the Generation-I and II Citadels but was lost on Generation-III vessels.
  • For main propulsion, the Citadel-class relies on four gargantuan fusial thrust nozzles acting as the ship's primary engines. They are located in nacelles blisters that protrude out of the aircraft's stern, with two pods on both starboard and port; one pod being mounted above the wing and one pod mounted underneath.
    • Generation-III Citadels include additional nozzles and red-matter mana turbochargers and injection systems, visibly changing the engine's shape and structure.
  • Five secondary thrust nozzles are located between the wing rudders on both sides of the ship, giving the Citadel an impressive total count of 14 engines.
    • Generation-III Citadels once again have significant design changes, possessing saw tooth edges on its thruster nozzles and cleaner burning fusial thrust systems to reduce vibration and noise. These Citadels, unlike the previous two generations, have a distinctive bright blue glow from their engines as opposed to the firey orange thrust found on previous versions.
  • Ventral thruster clusters aid the ship in landing and takeoff, slowing descent speed for landing and assisting liftoff for takeoff. These are not present on the original 12 Citadels.
    • These were first introduced on Generation II Citadels, granting it the ability to make extremely short takeoffs compared to the original ships. This however was not true VTOL, which would not come until decades later.These nozzles were chemical rockets which had to be recharged for every flight.
    • Generation-III Citadels introduced direct vertical takeoffs and landings as well as magically-assisted indefinite hovering abilities, making dedicated landing docks (dubbed 'Citadocks') preferable for their storage and maintenance. Citadocks are found at a few US military facilities and at installations like Atlantes Center Base, The Bunker and the Phoenix Complex. The VTOL systems on these aircraft are fed by air intakes and make use of fusial thrust propulsion.
  • Two massive air intakes, one on each side of the ship's bow, feed the four fusial thrust engines while the other ten engines are fed by intake banks in the leading edge of the ship's wings directly ahead of them.
    • On Generation-III Citadels, the VTOL lift fans close to the center of the ship are fed by the main intakes, while the ones out on the wings open up intakes atop the wing instead.

Control Surfaces Edit

  • Citadels have nine rudders; eight wing-mounted rudders, four on each wing with two atop and two underneath, and a massive ventral rudder mounted underneath the stern of the ship, with its leading edge trailing from a chine leading to the bow of the ship. Two massive flaperons are present on both wings as well as elevators and airbrake panels, aiding in adjusting the roll and speed of the aircraft as well as assisting in turns and banking maneuvers.
  • For landing, seven landing gear clusters deploy from the ship's underside, one from the underside of the bow, two from the amidship undercarriage (one on both port and starboard sides), and two additional clusters from the center of both wings (one on both port and starboard). Each wheel is taller than a typical human being, with a diameter of 3 meters. During landing procedure, the five ventral rudders (four wing-mounted ones and the large central rudder) retract, swinging backwards and locking into a stowed-away position to avoid scraping the ground upon touchdown.
    • Generation III Citadels typically carry out direct vertical landings and takeoffs by touching down in docking cradles at Citadocks with their fins still extended, but are capable of conventional landings on runways as they are still equipped with conventional landing gear. Due to the fuselage chine dipping down more steeply and deeply than previous versions to the point of going underneath the gear wheels, the bottom of the fuselage is designed to split open to regain ground clearance and has the side effect of acting as stabilizers during landing.
  • Citadels are capable of maintaining indefinite flight thanks to their reactors. Citadels are capable of landing at most international airports and airports rated to accommodate 'superheavy' classifications of aircraft.
  • The Citadel can operate with a minimum crew of 30 (Generation-I), 25 (Generation-II) or 10 (Generation-III). This number has been reduced due to increasing computer automation.
    • Typical Generation-Ill Citadel Flight Crew: 5
      • 1 pilot
      • 1 co-pilot
      • 2 flight engineers
      • 1 communications officer
    • Additional bridge crew
      • 1 commanding flight officer
      • 2 weapons operators
      • 1 logistics officer / loadmaster / flight deck coordinator

Other features Edit

  • Citadels are typically painted gray and have little to no stealth capabilities due to their enormous size making it impractical / ineffective.
  • Citadels posses formation lights and floodlights for use in communicating to other aircraft and to ensure visibility for both in flight and on the ground, as well as a loudspeaker system to blare messages down at ground targets.
  • All versions are capable of in-flight water, fuel and coolant replenishment by tanker aircraft.
  • In the case of the ULC Golden Eagle, its chapter designation number is prominently displayed on its side in bright white letters, on both sides of its nose and on both sides of its belly. The ventral tail fin displays the American flag and the ULC eagle, as well as the ship's registry code. All are lit by bright flood lamps during flight for visibility.

Trivia Edit

  • The Citadel-class battleship was largely inspired by the Valkyrie bomber from Captain America: The First Avenger, which also used mystical energies as a power source. The original Citadel design had forward windows much like the Valkyrie, but it was deemed too close in appearance and thus changed to a transparent nose-cone.
  • The Citadel-class battleship, along with the United Liberators Coalition, is one of the few concepts and designs to be kept and reused from the former Liberators RP. In its previous incarnation, it was the sole ship of its class and was instead powered by another mystical energy source known as the "Orb of Eternity'.
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