From Macross Compendium
- Manufacturer: Shinsei Industry/General Galaxy
High-performance fighter which introduced various new technology.
At the end of the 2050s, the VF-25 Messiah and the VF-27 Lucifer were developed under the slogan "Last manned VF" exceeded even the VF-19 Excalibur and the VF-22 Sturmvogel II, VF's known for their super high performance (additionally, the VF-25 is formally called VF-25/MF25 and since the design information of the VF-27 was not disclosed, it is treated as the YF-27 as of 2059). The VF-25 adopted a swing-wing, twin-engine aircraft and the VF-27 adopted a variable retracting 4-wing type, but with respect to their appearance, both machines were developed on emigrant fleets teams using the same trial production VF as a basis. The prototype unit was a trial production VF and the YF-24 Evolution, which incorporated a variety of innovative mechanisms.
The biggest feature of the "YF-24 family" including the YF-24 and the modified units, VF-25 and the VF-27, was the mounting of ISC. ISC is device that eases the gravitational acceleration (G) which the airframe and pilot suffer.
The necessity of ISC is directly related to the improved output of the thermonuclear turbine engine. The main engine of a VF, the thermonuclear engine, after the VF-1's FF-2001, advanced in higher output with the VF-19, with the thrust-to-weight ratio exceeding 10:1 (the propulsion force amounts to 10t or more to the fuselage weight 1t). Although the maneuverability of a VF improved remarkably by increasing thrust, a problem occurred. It became intolerable to the pilot to match the large engine output.
The pilot of a VF-19 or a VF-22 would sometimes be forced to operate under a high-G environment beyond 10G. It resulted in lost of control during simulated air combat maneuvering training, where accidental crashes occurred frequently. Although various measures were attempted, it did not result in a fundamental solution and it became a cause where extensive deployment of the VF-19 and VF-22 was shelved.
But with the YF-24 family, it was compatible to combine high-output engine and reducing burden on the pilot with the introduction of ISC. Through this, the manned aircraft with performance exceeding unmanned aircraft was born.
In 2040, Shinsei Industries and General Galaxy Corporation began research on the next generation VF through the YF-24 project. During this period, various problems surrounding the main fighter were erupted. The first problem was the adoption of the VF-19 as well as the VF-22. The VF-19 and the VF-22 were difficult to operate and neither were fit for extensive deployment at high costs. During the "Sharon Apple Incident", it is said that super high performance was proven because YF-19 broke through the Earth defensive sphere independently, therefore the senior military officials were reluctant to deploy to the immigration fleets. The second problem is unmanned aircraft. The experimental unmanned aircraft Ghost X-9's combat efficiency exceeded the YF-19 and YF-21. But since the military authorities had borne a distrust to AI, the main fighter did not become an unmanned aircraft.
Three YF-24s were manufactured as an actual proof test demonstration. One crashed due to a malfunction of the linear actuator during transformation. Although ISC was packaged with one of the remaining two, ISC ran recklessly during the experiment and the pilot was seriously injured. Afterward, development of the YF-24 was halted. The VF-171, developed as an alternative unit of the manned main VF, had been successful beyond anticipation and this also became a factor which obstructed the conversion to the YF-24.
Delta-wing design. In the YF-24 plan, further improvement to fuselage performance and research on new aircraft control were performed. Importance was place especially on research of new fuselage control mechanism and technology which increases the simple improvement in output; not only by enhancing the fuselage structure but maneuverability control, and the the pilot's safety was issued in the YF-24. In addition to the below, most of the inner frame structure is made unecessary, converting stress on the skin structure was planned and succeeded in maintaining strength and lightweight-ness. ISC (Inertia Store Converter), a kind of inertia control system. G is stored and eases G's as a result by slowly returning it. The effect affects not only the airframe but also the increase equipment of a pilot, super parts, etc. The ISC prototype of the YF-24 was a large-sized model and the system's gross weight reached as high as 18t that it could not be accommodated in the fuselage. It apparently stored up to 2G of acceleration for a 5-second interval as the limit. EX-Gear serves as an escape mechanism with a G-proof seat equipped with a transformation mechanism to a self-powered flight-type powered suit. The angle of the seat has a function of being optimized automatically to Gs. Linear Actuator, a contact-less, electromagnetic-powered type actuator. Since there are few mechanical parts, it is lightweight, has a low failure rate and excels in maintenance. It is said that transformation speed is shortened 2/3rds or less than that of older VF models. Stage II Thermonuclear engine which possess output greater than the FF-2500/2550 series of the VF-19. It is considered that the engine that became the VF-25's FF-3001A is the same or prototype was installed in the YF-24.