The original WB-19 (Sabre) started in 1954 and was an attempt to replicate certain features of the Super Sabre, and fuse it with the famous Mig-17's abilites. The project was top secret and did well in the early stages. However, this replication process faced issues. The new revolutionary soviet rotary cannon, the Gs-9, often failed when jammed leading to catastrophic accidents. It featured a new afterburner called Sputnik-AF Mk.1. With the afterburner it could achieve high speeds, but it couldn't match the maneuverability of the Super Sabre due to wing design issues. It carried a new kind of missile, the K-6, hinting at advancements in airborne missile technology, even though it had early problems. However the plane was promising so they started the production of a few prototypes. Later in 1957 they added an ejection seat into the plane making it the WB-19E. It was one of the few planes at the time to feature this kind of technology. The WB-19 also featured a new kind of HUD technology which was top secret soviet development.