The VF-31J, (used exclusively by Delta Squadron) was developed as a general-purpose support variable fighter exclusively for the Tactical Sound Unit 'Walkure'. Though the basic airframe and construction are descended from the VF-31 Kairos, internally the addition of a 'Fold Wave System' and different engine necessitated numerous internal changes and reinforcements in order to accommodate the improved engine performance. The VF-31 Siegfried currently has C, E, F, J, and S variants fielded, with the base specs being relatively similar, primarily differing in external appearance - such as the head section design and number of beam guns installed there. (The J model has one anti-air beam gun while E, F, and J have two, and the S model has four.) Though there are essentially no significant internal differences, each model has a number of software changes, with the fold wave system on each model being tuned to the individual parameters of each Walkure member, and matching the the ARIEL III onboard AI with the movement patterns of each member, in addition to minor avionics changes.
The S model, as the commander unit, has formation command systems as well as improved transmitters and datalink systems.
Basic design: Surya Aerospace (Surya Aerospace is a joint venture formed from four companies: Shinsei Industries at the core, along with LAI, Feifeng Aerospace Industries, Ltd., and Bharat)
Modifications: Kaos Walkure Works
Total Length: 19.31m
Total Width: 14.14m
Total Height: 3.85m
Battroid Mode Height: 15.33m (excluding laser cannons)
Empty Weight: 8,525kg (Multi Purpose Container Not Equipped)
Maximum Airframe Design Load: 29.5G
(With the Inertia Conversion system active, the entire airframe, including external stores, are protected from high G loads)
Engine: Shinsei Industries/P&W/RR
FF-3001/ FC2-StageIIC Thermonuclear Jet Turbine x2 (Maximum Thrust in Space is 1,875KN x2)
With Fold Wave System in operation, approximately 15% overthrust is possible.
Equipped with thrust reversers and three-dimensional vectored nozzles.
High Manueverability thrusters: P&W HMM-10A
Maximum Speed: M5.5+
(at altitude of 10,000m. Speed beyond this is possible, but in normal operation speed is limited for thermal buildup reasons, however orbital velocity can also be achieved at this velocity.)
The primary mode of a variable fighter, the aircraft mode. The most notable characteristic of the Siegfried are the modified forward swept main wings, which are also canted downwards. This change also changes the center of gravity to increase maneuverability, and allows them to augment the vertical stabilizers at extreme angles of attack.
The variable fighter mode perhaps most symbolic of the VF Variable Fighter series, the GERWALK mode. GERWALK is an abbreviation for 'Ground Effective Reinforcement of Winged Armament with Locomotive Knee joint, and is designed to reduce vulnerability during the transformation sequence by allowing high-maneuverability hovering flight and is called the 'Third Mode' of movement in a Variable Fighter.
This mode allows landing in rough terrain, low altitude penetration, air-to-surface attacks, and allows the Variable Fighter to be combat effective in all space, air, and ground missions.
The human form of the Variable Fighter is perhaps its greatest characteristic, originally developed after evidence of giant humanoid aliens was discovered. The Fighter and Gearwalk modes allow assaults into the interior of enemy ships, where the battroid mode allows close quarters Marine-type boarding actions. However, as colonization fleets began to spread across the galaxy, the battroid mode's capabilities were found to be highly useful against other life forms and weapons, not only hostile giant humanoids.
Arm Rail Gun (Minigun Pod)
The multipurpose container unit is another notable characteristic of the VF-31 series that must be mentioned. Developed from the unit used on the VF-30, the container unit was tested on the VF-31 as a cruical means to allow it to perform as a multirole fighter. Using space created after a careful redesign of the transformation mechanisms in the arm, containers could be installed in several areas to greatly expand the range of optional equipment used by the VF-31. While it is most common to mount micro missile pods in these areas, other types of missile pods, beam cannons, sensor units, Reconnasiance packs, ECM packs, Rescue Units, Fold Wave Booster connection units, and even personnel insertion pods are just some of the countless types that have been developed.
The gun pod is mounted on top of the fuselage while in GERWALK mode on a rotating turret.
The superalloys used in its construction allow a high degree of sharpness, and its damage potential can be augmented by utilizing the pinpoint barrier system.
This extremely effective shield, used in Battroid mode, is equipped with energy conversion armor, and dramatically increases defensive capabilities when used in concert with the pin point barrier. A hard point for the assault knife is located on the rear side.
In order to protect the wings from damage or from interfering with the range of arm movements, the wings fold into a compact form on the back of the fuselage.
Source: 1/72 VF-31J Siegfried (Hayate Immelmann) Model Manual, Bandai 2016.