A Mighty Dragon

Subject

The Chengdu J-20 is the third 5th generation aircraft to enter service after the Lockheed Martin F-22 Raptor and Lockheed Martin F-35 Lightning II. Christened “Mighty Dragon” by the Chinese, it has been assigned the NATO reporting name “Fagin”.

The prototype made its maiden flight on 11 January 2011 and the first production aircraft were delivered to the PLAAF in December 2016. Since then, estimates are that 200-300 J-20s have been produced as at June 2024, making it the second most produced 5th generation fighter after the F-35 (1000+) and ahead of the F-22 (195) and Su-57 (~32).

It is an unusual looking aircraft, with a large delta wing featuring leading-edge extensions, canards with significant dihedral, twin outwardly canted, all-moving vertical tails and two large, outwardly canted, strakes below. Early J-20 were powered by a pair of closely-spaced Russian AL-31FN engines, with later aircraft powered by the Chinese WS-10 (indicated by serrated engine exhaust nozzles).

The J-20 is a large aircraft with an impressive combat range of 2000 km (1080 n miles) and includes the typical 5th generation configuration features of internal weapon carriage, radio frequency (RF) signature reduction measures such as edge alignment for the flying surfaces, serrated panel joins and access door edges, plus diverterless supersonic intakes (DSI) leading to serpentine intake trunks that obscure the engine faces. The engine exhausts are also well shielded from all but a rear aspect, no doubt as a means of minimising the forward aspect Infra-Red (IR) signature.

The sensor suite includes an Active Electronically Scanned Array (AESA) radar, an IR targeting system under the nose, the usual array of conformal antennae associated with Electronic Support Measures (ESM) and a distributed Electro Optic (EO) detection system with apertures in front and behind the cockpit, aft of the main weapon bay (forward and aft facing) and either side of the nose.

The main weapon bay is in the lower fuselage between the intake ducts and is divided in two, housing the long-range PL-15 air-to-air missiles (200-300 km / 108-162 n miles), and two smaller weapon bays, housing the short-range PL-10 (20 km / 11 n mile). The latter have the unusual deployment function where the bay door opens and the missile and its launch rail rotate out into the airstream and the by door closes again to preserve the LO signature. The missile is then free to acquire its target prior to launch, after which the launch rail is retracted back into the weapon bay.

The Kit

Trumpeter was first to produce a 1/48 kit of the J-20, with kit number 05811 launching in 2020. That kit builds into the basic aircraft with the option of four external ferry tanks. This version, kit 05821 and released in 2022, adds new serrated engine exhaust nozzles and extra weapons with twin launch rails to build the J-20 in 'Beast Mode' with external weapons.

Meng released their own kit of the J-20 in 2023 that appears, from a brief examination, to be more accurate than the Trumpeter kit in a number of respects. However, it does feature raised serrations along panel lines and control surfaces, much the same as every F-22 and F-35 kit, that are annoyingly inaccurate. 5th generation aircraft take great care to present as smooth a surface as is possible and the Trumpeter kit features more traditional engraved lines to distinguish panels and other features.

Construction

Unusually, construction starts with the main undercarriage and their bays. The sides of the bays are solidly connected using dove tail joins and the gear legs themselves can be assembled and inserted, with a small amount of difficulty, at the end.

Next are the intake trunks, which are of rectangular cross-section, and the two L-shaped halves of each duct join seamlessly, again using dove-tail joins, and attached to a bulkhead. There is no representation of the engine face on the bulkhead, but then these are hard to see anyway. The main weapon bay is a similarly solid construction and the side weapon bays are single pieces with the aft wall being provided by the bulkhead that the intakes attach to.

These sub-assemblies fit neatly together into the lower fuselage half, which is one piece including the lower wings, and result in a very solid structure. The front of the intake assemblies stop short of the intake lips and fit neatly, allowing the intakes to be painted white and the intake lips to be painted the fuselage colour.

The lower nose up to the intakes is moulded separate from the main fuselage and the nose wheel bay is built and attached to this before it is attached to the lower rear fuselage assembly. The nosewheel bay is made up of four parts that capture the nose gear leg. I should have avoided that because the forks that hold the nose wheel did both break off during construction and I almost lost them. I ended up drilling and pinning the nose wheel in place for strength and gluing the fork pieces in place as one of the final steps in the build.

The cockpit is built next and then attached to the upper fuselage half (which also includes the upper wings). At first glance, Trumpeter provides a reasonable representation of the cockpit with raised detail on the side consoles and a detailed instrument panel. The latter has five flat screens - two large ones side-by-side below two smaller ones and the fifth large screen between the pilot's legs. The Meng kit has a single wide screen and a narrow one between the pilot's legs. Photos I have found online show a range of configurations and I suspect that the Trumpeter is an early version.

It was only once I'd assembled the cockpit and closed up the fuselage halves that I realised something was not right. I began to assemble the seat and realised that it was a little narrow and the cockpit was nearly twice as wide. In fact, the width scaled out to around 600 mm. Add that to the strangely tall throttle and very wide lower flat screen and the pilot would be sitting in the aircraft as if he was sitting on a chopper motor bike. I ended up losing the throttle after it broke off for the 'n'th time and replaced it with a scratch-built throttle of more conventional shape.

The cockpit walls go straight down from the edge of the cockpit opening and I realised that Trumpeter's failure to include a cockpit sill resulted in the cockpit being too wide. That also meant that, when I attached the canopy in the closed position, the contact was between two sharp angles and therefore providing minimal scope to glue them together. Had I realised all this earlier, I could have reworked the cockpit with a bit of surgery and scratch building.

My solution to the narrow seat was to scratch a new seat using parts from both an unused F-16 seat and the kit parts, including the kit supplied etched set belts.

The cockpit is one area where the Meng kit beats Trumpeter.

The general shape of the kit looks good, but one area that is not quite right is around of the EO window just ahead of the cockpit which should have been slightly built up with bulges either side. Meng appears to have got this right, but I decided not to worry about it.

The top and bottom halves of the aircraft are then joined together, capturing the canards in the process. These later broke off and I drilled and pinned them in place at the end of the build.

I decided to close the starboard side weapon bay but have the port PL-10 hanging out in the ready to launch position. I made the mistake of gluing the three arms that hang the launch rail out which broke off while I was handling the kit during painting. Fortunately, I was able to glue them back on later without too much difficulty.

At this point the canopy, IR windows under the nose and open bays were masked and stuffed with tissue paper ready for painting.

Colours and Markings

Trumpeter offers two schemes - the first in three greys with angular demarcation and the second in the same three greys but with curved demarcation between the two main colours. Both have low-viz national insignia but no aircraft serial numbers or other identifying markings. The decal sheet does provide a full set of digits to make up the serial number, carried on the vertical tails, but it is up to the builder to decide what that will be.

So, I began trawling the internet and magazines for pictures of J-20s with the serrated engine exhausts and came upon a series of photos featuring a pair of J-20s with serials 78130 and 78131. I chose the former. I have no other information on these aircraft in terms of unit or location.

I started off painting the flying surface edges with Gunze H308 FS36375 and masking it off when dry. The radome was painted H53 Neutral Grey and likewise masked off while the fin tips were painted Gunze H307 FS 36320 before also masking them. The darker camouflage colour, Gunze H305 FS36118, was sprayed over the appropriate areas next.

I scanned the paint instructions and loaded them into my vector graphics package and scaled them up to 1/48 so that I could create masks using my wife's Cricut cutting machine using their specialist masking material.

I applied the resulting very large masks and sprayed the main body colour, Gunze H306 FS 36270.

Unfortunately, the mask material was a bit to tacky and I hadn't primed the kit, so parts of the darker grey lifted off when I removed the masks, so there was a bit of masking (using the mask ‘negatives') and respraying required.

Photos of the aircraft show that the main gear doors and main and side weapon bay doors are outlined in black. This is probably because the panel edge LO treatment either hasn't been applied or has been applied but not painted. Either way, I first painted the area around the closed bays black and then masked the outline before applying the main grey colour. For the open doors, I painted the grey and then masked and sprayed the black edges.

The windows for the distributed EO system were painted a dark green and then overpainted with Gunze H95 Smoke Grey.

After a coat of SMS Clear Gloss, I started decaling. The first thing I did was the serial numbers on the fins and that went well. Next, I added the national insignia, starting with the upper port wing. I managed to get the decal all twisted and folded upon itself and almost threw it away in despair, but managed to get it untangled, don't ask me how, and got it in place. I was more carful with how I slid the remaining decals off their backing sheet and had no further problems.

Annoyingly, the decals silvered in spite of the gloss surface, but I managed to fix most of them with a second application of Mr Mark Setter.

Disaster struck while I was spraying the matt clear coat. I managed to spill the thinned clear matt on the upper surface near the port intake which then took a large section of the underlying paint with it when I wiped it off. Fortunately, it was only on the main grey area and no decals were harmed and, after some vigorous sanding and a respray, the area was restored.

Looking at photos, the visible parts of the engine are a light metallic colour while the exhaust petals are much darker. So, I painted the external parts of the engine and petals Gunze SM204 Super Stainless 2 and then used Tamiya Weathering Master Set D (Burnt Blue, Burnt Red and Oil Stain) to colour and darken the petals. Perhaps not particularly accurate, but this was my first attempt to simulate burnt metal effects and I was happy with how it turned out.

Once the painting and decaling was done, I installed the main gear legs without too much difficulty and then attached the main gear bay covers. This construction is reassuringly solid, so there is no danger of one of the main gear collapsing.

The last things I painted were the missiles. I hate painting gloss white and particularly on missiles which required multiple passes before I was happy with them. The IR seeker on the PL-10 was first painted silver and then clear smoke. Curiously, Trumpeter doesn't supply enough decals for all the PL-15 missiles in this boxing, but I was OK given I was only using six them. Photos show the J-20 armed with four PL-15s across the two main bays, but I followed the kit instructions and inserted three PL-15 in each bay. The PL-10 and its launch rail were mounted in place on the port side.

The third major error by Trumpeter is to do with the main weapon bay doors. A close look at photos shows that there should be three doors each side. A thin section on the outer edge seems to rotate in place while the large middle section is hinged to open outward and the narrow inner section folds back in on itself. Trumpeter missed the outer section and instead provides a larger hinged middle section and the narrow inner section. They also missed the actuator arms that attach between the fuselage structure and the inner sections causing them to fold over as the main doors open. This means that the doors probably hang a little lower than they should.

I may go back and see if I can rectify this one day, but for now I'm OK with it as it is.

Meng appear to have got the doors right, having moulded the closed doors option as a single piece and the open doors with the outer and middle doors moulded as single overlapping pieces.

The last thing that Trumpeter missed was the pitot-static sensors either side of the nose. I scratched these from the fins for the unused drop thanks.

Conclusion.

Trumpeter have gotten some things wrong with this kit, but these could have been fixed with a bit of work had I not realised too late. Meng, on the other hand appear to have got thing pretty right but they have marked all the LO treatment with raised serrations along panel lines and control surfaces that I find inaccurate and annoying.

So, given the choice, I would build the Trumpeter kit again because fixing its errors would be so much easier than erasing the Meng surface treatment.

I'm happy with the result and it looks great sitting next to my Su-57 Fellon.

Now, on to fixing the surface of my Meng F-35A…