F-47 "Chimaokin"

F-47 Chimaokin
A wing of Chimaokin leaving for combat.
Role	Fighter
National origin	Kāichrén Democratic State
Manufacturer	Akira Air Works
Designer	Akira-Mamatsuhita Design Group
First flight	April 2nd, 1944
Introduction	January 2nd, 1947
Retired	1961
Primary users	Kāichrén Democratic State Airforce Civil War Factions
Produced	1946-1950
Number built	5,125
Program cost	c. 13 Million MSD
Unit cost	c. 102 thousand MSD

The F-47 Chimaokin was a Kāichrén Democratic State twinjet swept-wing fighter aircraft, designed and first flown during the later years of the Great War. It was the first non-mixed propulsion jet fighter adopted by the KDSAF, and showed notable effectiveness against the late-war Marquesan fighters it was placed in opposition to. It would be succeeded for a limited time by the F-50 "Meimu" during the Great War itself, but owing to lacking production numbers for the former the Chimaokin would see greater utilization during the Kāichrén Civil War.

It was additionally the only plane designed by the ill-fated Akira-Mamatsuhita Design Group, whose attempts to create a uniform platform both delayed the development of the F-47 and let to their splitting in the wake of its completion despite the effort which had been placed into the merger by the state.

Development

Background

The Chimaokin was a descendent of previous Mamatsuhita jet designs, spurred by Kiyabu Aki's development of the Kakukijin Turbojet in 1942. Mamatsuhita's F-42 "Tethasu" mixed-power fighter would see massive adoption, owing to the distinct advantage it brought to the KDS. The massive sales they made during the course of the procurement of the Tethasu would allow them to remain functioning during the later stages of the war. This was not something which could be said of Akira Heavy Industries, who had been unable to profit to the same extent off their work on engines and plane-based armaments, leading to the Iminchebol taking a desperate action. Under the auspice of Ogata Katsu, shortly before his ascension to the role of Kantoku, the two Iminchebol were merged into Akira-Mamatsuhita.

This new company would attempt to secure their place through the development of the Chimaokin, which at the time was configured to be a straight-winged jet interceptor with limited dogfighting capacity, in line with the earlier F-41 "Maboroshi" prototype. This proposal would, however, immediately be opposed by the then-leader of Akira's flight research grouping, Sakaguchi Saburo. Saburo, known then for his eccentricity and personal innovation on several engines, insisted that the design should have swept wings and that it would be better utilized as a fighter instead of an interceptor, owing to its lower service ceiling than several then-emerging Marquesan planes. While he would initially be ignored, he gathered the support of several notable technicians from both parent companies - who threatened to strike if the design was not, at the very least, tested. This strike action drew the ire of both corporate higher-ups and Ogata himself, but tests eventually occurred which tended to show Saburo's theories right.

Testing

The plane would have its first powered flight in 1944, with its wings positioned in a 45% sweep, which - to the shock of many observers at the time, worked exactly as Saburo had predicted. Despite this, he and his supporters would see continued pushback on the nature of design - with industrial capacity to produce such and concerns about changing the nature of the design being raised. He firmly ignored this, leading to increasing tensions in the design team which he similarly ignored in the hopes of reaching a finished design, something hampered by Kiyabu's refusal to provide his team her most modern engine. This refusal was rooted in a number of interpersonal disagreements between the two, and as such was unable to be resolved until the Kantoku himself was forced to interfere in 1946. Demanding the engine be given over, it was - allowing the plan to successfully enter production rapidly.

Design

Philosophy

Saburo, despite his eccentricity, was a firm supporter of Industrial Sukoism on a larger-scale, and as such endeavored to reduce the number of separate parts involved in the creation of the plane. This was primarily accomplished through the utilization of combined brackets incorporating key engine components and landing gear into the same system, in comparison to more traditional utilization of mounting load-bearing systems on differing parts of the body. Additional attempts to ensure low (relative) cost included allowing the utilization of coal-derived oil despite the damages such caused to the engines, an sacrifice which limited them to a maximum of 60 flight hours before replacement and servicing became necessary.

Additional aspects of this philosophy included the refusal of upgunning the main guns located upon the plane, the continued utilization of the Kiri despite recently-developed early-implementation wire-guided missiles, and the removal of certain comforts which had been present in the Iron Lotus - despite the harm this did to pilot comfort. These efforts reduced the plane's construction cost from 172,000 to 102,000 Meridonian Dollars (2,422,630 MSD to 1,436,676 MSD, accounting for inflation c. 2034), additionally reducing necessary man-hours for construction from 6,800 hours to 4,400 hours.

Overview

The F-47 was an all-metal monoplane, incorporating a bubble cockpit and retractable landing gear. Where it diverged was primarily in its wing design - being one of the first craft to have swept wings of any noticeable degree. These wings allowed the craft to reach its (at the time) impressive speed of Mach 1.12, being one of the first transsonic aircraft ever produced, and the first to be so rapidly adopted. It was additionally one of the first jet fighters to use two engines, a necessity to allow the heavy plane to fly. It mounted one 20mm Kaiten-Taihō on each wing, and could additionally carry two anti-air rockets per wing alongside such.

Later variants would incorporate additional fuel tanks in an attempt to allow the craft to maintain combat tempo for longer periods.

Flying Characteristics

The Chimaokin was uncomfortable to utilize for long periods of time owing to the stripping of pilot comfort features from the craft, and it possessed a notable learning curve in comparison to the Iron Lotus. This was somewhat made up for by the superb handling for an early jet fighter it possessed, and the general reliability of the engine as long as it was under 80 hours of utilization. It would also have surprisingly decent low-altitude performance, which contributed to its utilization as a ground attack craft during the Kāichrén Civil War.

Armaments

As mentioned above, the Chimaokin mounted two 20mm Kaiten-Taihō cannons on each wing, with a 30mm variant rejected for the period of the war it was active. These 20mm would also function surprisingly well in the ground attack role it was adapted for during the KCW, being combined with small anti-ground rockets to create a formidable strikecraft. The two cannons and their ammunition were contained in "packs" on the plane, which could be removed easily for maintenance and repair.

The Chimaokin also incorporated the Karasu I910 following its testing on later variants of the Iron Lotus, an early air-to-air radar with lock-follow technology, which allowed it to have a far greater chance of functionally utilizing its air-to-air rockets. It had a range of 15.24km, 360 rotations per minute, and operated on a 3.3 GHz S-band Frequency.

Operators

• Kāichrén Democratic State

Specifications

General Specifications

• Crew: 1
• Length: 11.6m (36ft 23in)
• Wingspan: 14m (45ft)
• Wing Area: 25.578m^2 (275sqft)
• Height: 4.15m (13ft 5in)

• Empty Weight: 5,600kg (12,345lbs)
• Fuel Weight: 2,185kg (4,817lbs)
• Gross Weight: 7,785kg (17,162lbs)
• Armaments Weight: 400kg (881lbs)
• MTOW: 8,185kg (18,044lbs)
• Powerplant: 2x Akira-Mamatsuhita Suisen PV-1 Turbojets.

Performance

• Maximum Speed: 859mph (1,382km/h, 746kn) at Service Ceiling
  • Maximum Speed: Mach 1.12
• Stall Speed: 120mph (193km/h, 104kn)
• Ferry Range: 1,960km (1,220mi, 1,060nmi)
• Internal Range: 980km (610mi, 530nmi)
• Combat Rage: 660km (410mi, 360nmi)

• Service Ceiling: 15,000m (49,000ft)
• Rate of Climb: 24,85m/s (81.5f/s)
• Time to Ceiling: 10 Minutes and 6 Seconds
• Wing Loading: 320kg/m^2 (65.54lbs/sqft)
• Thrust/Weight: 0.66

Armaments

• Guns:
  • 2x Wing-Mounted 20mm Kaiten-Taihō Revolving Cannons
• Missiles:
  • 4x 50kg Kiri Unguided Air-to-Air Rockets