The Ridgebacks were formed in the 21st century by the United Nations following the Ulysses Disaster, with the aim of having elite pilots put a quick end to terrorist threats around the world. The unit, led by a man named Slash, pilots a special variant of the ASF-X Shinden II as its primary aircraft. They became known through mercenary networks such as Arrows Air Defense and Security, and were commonly referred to as the "Single Lines" due to the single white stripes running down the back of their aircraft.
In May 2019, the Ridgebacks were tasked to work with the Bone Arrow Squadron to rescue the Greymen from a terrorist cell in Iyuli, and later fought with them during Operation Crusher to destroy Stonehenge Type-3 in Turkey. They later assisted Bone Arrow in ending the threat to Tokyo during Operation Override.. They were later merged with Bone Arrow Squadron to form Task Force 118 "Arrowblades".
- The Ridgebacks allude to different aspects of the Ace Combat series:
- The squadron's name and emblem are based on the Rhodesian Ridgeback, a dog breed. This may reference Wardog Squadron from Ace Combat 5: The Unsung War, as their emblem and name were based on their Labrador Retriever, Kirk.
- The "19th" designation refers to the 19th Squadron from Ace Combat: Ikaros in the Sky, a fictional squadron that tested ASF-X Shinden IIs.
- The callsigns "Slash" and "Edge" reference the wingmen, Slash and Edge respectively, from Ace Combat 2 and Ace Combat: Assault Horizon Legacy.
- The callsigns of the members of Ridgeback Squadron all reference bladed weaponry in some fashion.
- "Slash" is a word commonly associated with a cutting attack. "Slashing" is also used to refer to the motion of laser attacks such as those from the MQ-90Ls that killed Slash.
- "Edge" refers to the edge of a blade.
- "Lance" is itself a weapon.
- "Fencer" is the term used for one who participates in fencing.
- "Axeman" refers to an axe.
- In Ace Combat 7: Skies Unknown, the Ridgebacks' livery was included for the ASF-X Shinden II as part of the game's 2nd Anniversary Free Update.