The development aircraft of the FSWS project focused on how to tactically operate the RX-78's attack capability at a higher level, but the emerging new type of military use and control is that. There is no widespread talk about what was going on behind the scenes. However, in any case, the demand for powerful mobile suits with excellent striking power is naturally high in the general army, and the realization of advanced development of such existing aircraft was urgently required in parallel with FSWS. Of the RX-78s that had undergone final adjustments at Jaburo Base, Units 1 to 3 were lifted into space in line with Operation V, but the remaining Units 4 to 8 were designated as target mother units at the request of the FSWS mentioned above. The operation was decided. Among them, Unit 4 was manufactured as the initial structural design machine of RX-78-1, and since it was designed in consideration of sharing with the production line of RX-77, it was made the same 78-1 type and especially the main body. Compared to the other types 1 and 2, the B part of the frame has a total volume that is nearly 25% larger, including the armor (the A part also has a slightly looser structure). It reflected the strength design prior to the purification of Luna-Titanium. Since it was indispensable to change to the Type 2 specification in order to operate as the FSWS planned mother machine, it was decided to divert this Unit 4 to another development machine. That is the heavy armor type RX-78 = FA-78-2 type prepared as a sub-proposal of FSWS. Whereas the FA-78-1 type plan was a multiple outer shell type attack mechanism concept that utilized the core block system, in this FA-78-2 the aircraft itself is the standard of FA-78-1 from the beginning. The specifications are taken to be implemented in the same way as the equipped state, and the state of the RX-78 specification, which will eventually enable hand-to-hand combat, has been rounded down and redesigned. Therefore, the pet name is also given the name of Heavy Gundam. Since the prototype machine has been remodeled from RX-78-1, the core block of the C part is directly connected to the A and B parts, the function of the escape recovery system is omitted, and the outer armor material is reinforced as many times as both parts. Has been done. Since the RX-78's armor state is omitted in this aircraft, which also serves as a prototype for production purposes, the balance of the composite armor thickness can be adjusted with a margin, and the volume of the integral tank is greatly improved. Although the mobility (followability) that can withstand the use of the new type pilot has been lost, the field motor has been replaced with a larger and stronger one (78-3 type magnet coating processed). The rocket cannon is left as a fixed armament, the built-in beam saber is abolished, and the one with the same specifications as the RX-78 is equipped on the left shoulder. The layout of the exterior of the A part has been revised for the reason mentioned above, and the appearance is different from the FA-78-1. In addition, the face shield prepared in the initial plan of the RX-78-1 series was added to the head dual camera system. The most important feature of this aircraft was that it was designed to exterior a large compound weapon pack = frame launcher that combines a Gatling gun that uses real ammunition and a rocket missile launcher. Both the left and right arms can be integrated into the frame (there is also a plan to attach it to both arms), and it is also possible to use a special beam rifle that has been redesigned accordingly. As for the development weapons used in combination with this machine, a prototype of a mobile bust liner (8 aircraft can be operated in the North Pole class) as an anti-ship attack weapon remains in the material, and the design of the dedicated transport bomber gun carry has been completed. Or, it seems that the operation assuming a ground battle was also included in the tentative plan. Although the details of the operation outline have not been disclosed yet, a special information gathering unit under the command of Colonel Den Bazaar conducted an infiltration operation (actually developed into a capture operation) on the asteroid Pezun, which is one of the Zeon weapons development arsenal. It has been announced that this aircraft was introduced from time to time, and the North Pole-class amphibious assault ship is still in operation as the mother ship.