Zone of Endless

"A red aircraft? I've never seen a paintjob like that before."

Zone of Endless^[14] (abbreviated as Z.O.E.) is an artificial intelligence developed by Gründer Industries for use in fighter aircraft. The AI's machine learning improves its combat data with each battle to become more advanced in future battles. Later developments provided the ability for multiple Z.O.E.-equipped aircraft to network with each other.

Zone of Endless was first deployed secretly during the Usean coup d'état against the Usean Allied Forces. Despite being equipped with next-generation technology and aircraft, including the ADF-01 FALKEN, Phoenix defeated all of the Z.O.E. units. Gründer continued improving the AI's flight patterns over the next two decades, including using data from ace pilot Mihaly A. Shilage. Z.O.E. versions using Mihaly's flight data were installed onto drones during the Lighthouse War, including an ADFX-10 and two ADF-11F Ravens that were later destroyed by Trigger.

History[edit | edit source]

Development[edit | edit source]

Gründer Industries launched the Zone of Endless project in complete secrecy just after the Belkan War ended in 1995. The Belkan Air Force was crippled after losing so many of its skilled fighter pilots in the war. Due to its low population, Belka found these pilots to be a very precious resource. Thus, the country was forced to adopt unmanned technology while training new pilots for the future.^[15] Theodor Sander, a Belkan War veteran who joined Gründer's UAV development program, is believed to have contributed to the Zone of Endless project.^[16]

Z.O.E.'s purpose as a pilot replacement AI was realized in one key feature: the ability to learn through consecutive battles. Z.O.E. can collect information from battles it participates in, analyze the data, and evolve to overcome its own weaknesses.^[15] In practice, Z.O.E. will usually continue to fight until it is shot down, but it can optionally retreat after sustaining damage.^[2]^[4]

By 1998, Gründer installed the Z.O.E. program onto five separate aircraft, including their newly-developed ADF-01 FALKEN.^[9]^[10] All of these aircraft were painted in a distinctive crimson finish with no nationality markings, making them appear rogue to the Allied Forces^[2] and the rebels, who only determined they were friendly via IFF.^[4]

Usean coup d'état[edit | edit source]

Through unknown circumstances, the five Z.O.E. aircraft arrived on the Usean continent by May 1998. Phoenix first engaged a Z.O.E.-equipped F-14^[1]^[2] followed by an F/A-18E.^[3]^[4] Phoenix later engaged and shot down an experimental aircraft equipped with Z.O.E.^[5]^[6] When the Usean Allied Forces moved to recapture Saint Ark in September 1998, an advanced Z.O.E. F-15 engaged Phoenix over the capital before Phoenix shot it down.^[7]^[8] The final Z.O.E. aircraft, the ADF-01, attempted to defend Fortress Intolerance during the rebels' last stand. Phoenix shot down the ADF-01, opening a path to attack the fortress.^[9]^[10]

Lighthouse War[edit | edit source]

At some point before the war, the Z.O.E. project continued development under the lead of Doctor Schroeder. The drones initially flew similarly to the drones seen in the Usean coup d'état, but they were deployed in much greater numbers and lacked the trademark crimson livery of the original drones. In addition, Schroeder utilized the skills of Mihaly A. Shilage and an experimental Su-30SM to gather advanced flight data to strengthen the drones.

One advanced UCAV prototype, the ADFX-10, was developed in small numbers and served to obtain flight data from both mobility and functionality tests, namely detaching from a RAW-F.^[12] One particular ADFX-10 unit in the midst of a test flight was pursued by Cyclops Squadron. Trigger destroyed this drone during Operation Full House, but development continued.^[11]

The ADFX-10 was finalized as the ADF-11, which was designed to work inside the body of the ADF-11F Raven. Two Raven aircraft—codenamed Hugin and Munin—were the only aircraft produced at the International Space Elevator to receive the final Z.O.E. data Schroeder gathered.^[17] Mihaly's granddaughter, Ionela, destroyed the drive containing the data.^[18] Avril Mead, Tabloid, Georg, Ionela, Ionela's sister Alma, and Schroeder destroyed the rest of the drone production facility^[18] while Princess Rosa Cossette D'Elise sabotaged the space elevator's power production.^[17]

To circumvent the loss of the data drive, the drones attempted to transmit their Z.O.E. data through the space elevator, attempting to send the information to all drone factories across the continent. Before they could succeed, a coalition of Osean and Erusean forces launched a desperate assault on the aircraft. Trigger destroyed both of the Ravens and both of the cockpit ADF-11s controlling them before any data was transmitted.^[13]

Gameplay[edit | edit source]

Ace Combat 2[edit | edit source]

Z.O.E. originally appears as a recurring group of secret named aircraft in Ace Combat 2. The player receives medals for shooting down each Z.O.E. aircraft. The full list of Z.O.E. aircraft, and their ranks, is as follows:

F-14A Tomcat (Captain) - "Sledgehammer"^[1]
F/A-18E Super Hornet (Major) - "Seagull"^[3]
YF-22 Lightning II (Colonel) - "Power Play"^[5]
F-15S (General) - "Kingpin"^[7]
ADF-01 FALKEN (Commander) - "Fighter's Honor"^[9]

The Z.O.E. aircraft are entirely optional and appear in order; if the player happens to miss one, it will take the place of the next one. For example, if the player doesn't shoot down the Z.O.E. F-14A in "Sledgehammer", the F-14A will then spawn again in "Seagull" instead of the F/A-18E. Therefore, the ADF-01 will only spawn in "Fighter's Honor" if the player shoots down all of the Z.O.E. aircraft in their first appearances.

In addition, the only way the player can advance to the final two missions, "Last Resort" and "Fighter's Honor", is by shooting down the Z.O.E. aircraft that appears in "Kingpin" regardless of which one it is. If the player fails to shoot down the Z.O.E. aircraft in "Kingpin", they will receive the game's "normal ending".

Ace Combat: Assault Horizon Legacy[edit | edit source]

Campaign[edit | edit source]

Instead of acting as hidden named aircraft (which the game still features), Ace Combat: Assault Horizon Legacy changed the Z.O.E. aircraft to be integral components of the story and necessary TGTs for the player to shoot down. This makes it impossible for the player to miss any of them, but they will still earn a Z.O.E.-related medal for completing the campaign.

All five Z.O.E. aircraft are capable of performing advanced maneuvers. The F-15 S/MTD and ADF-01 units are also capable of radar jamming that disrupts the player's HUD, creating false targeting boxes like those seen in "Blind Spot" and "8492" in Ace Combat 5: The Unsung War. The ADF-01 is also capable of firing missiles and machine guns backwards until it is severely damaged.

The full list of Z.O.E. aircraft in Legacy is as follows:

F-14D Super Tomcat - "Midnight Assassin"^[2]
F/A-18E Super Hornet - "Seagull"^[4]
YF-23 Black Widow II - "Green Bird"^[6]
F-15 S/MTD - "Kingpin"^[8]
ADF-01 FALKEN - "Fighter's Honor"^[10]

The F-14D features Phoenix's emblem on the nose and vertical stabilizer, likely due to a model reuse. In addition, the F-14D, F/A-18E, YF-23, and F-15 S/MTD appear to use the Color Customization skins painted in red (Colors 5, 5, 5, and 6, respectively).

The unused Z.O.E. F-35 as it appeared in a trailer

A Japanese trailer for Assault Horizon Legacy features a Z.O.E. F-35C Lightning II during "Green Bird". This was changed to the YF-23 in the final release of the game.^[19]

Extra Missions[edit | edit source]

Z.O.E. makes two appearances in the game's Extra Missions, which are considered non-canon to the main story.

In "Extra Mission 02", the player must shoot down a Z.O.E. ADF-01 that is flying fast through Seals Bridge Ravine. This ADF-01 uses the game's Color 1 for the aircraft instead of Z.O.E.'s crimson red livery. While its main purpose is to escape the ravine, the ADF-01 will still fire missiles and machine guns backwards towards the player.

At first, "Extra Mission 04" is identical to "Fighter's Honor", including the fight against the Z.O.E. ADF-01 without any changes. However, after destroying the ICBM in Fortress Intolerance, the player is ordered to perform a U-turn and escape from the entrance. Once outside, four Z.O.E. ADF-01s engage the player. These aircraft do not have radar jamming or backwards fire, but they are all equipped with Tactical Laser Systems and their models more closely resemble the ADF-01 in Ace Combat 5: The Unsung War. One of the ADF-01s uses the plane's Color 6, while the other three use Color 5; any player customization to those colors will be reflected in the mission.

Other games[edit | edit source]

Z.O.E.'s "Ace of Aces" appearance in Ace Combat: Joint Assault

Z.O.E.'s crimson red livery has been featured in other Ace Combat games as an unlockable livery, usually for the ADF-01 FALKEN.

Ace Combat Infinity featured the Z.O.E. livery on multiple Special Aircraft:

Infinity also held a "Z.O.E. PROJECT" Online Co-Op Missions Ranking Tournament where players could earn the Z.O.E. livery as skins for the F-15 S/MTD, the F-14D, and for the first time, the F/A-18F Super Hornet and F-22A Raptor (replacing the F/A-18E and YF-22 from Ace Combat 2). The tournament also featured related emblems and nicknames for players to use, including "Evolving Combat AI" and "Self - Propagating".

In addition, Z.O.E. appears as an enemy unit in the bonus missions for Ace Combat X: Skies of Deception ("Operation X") and Ace Combat: Joint Assault ("Operation X" and "Ace of Aces").