The Northrop F-20 evolved from the F-5G design study, which in turn evolved from the F-5E.
Northrop proposed the F-5G as an attempt to modernize the F-5E design by fitting it with state-of-the-art avionics and radar and with a more powerful engine.
The F-20 design went much further than the initial F-5G, including digital fly-by-wire and a state of the art digital multi mode radar set. It also incorporated unique aerodynamical features that were applied before to the YF-17 design.
Another change to the initial F-5G design was moving the tail fin assembly further back by about 9in, all of the actual F-20 airframes had the tail fin in this location.
As part of the FX program the F-20 was proposed as a lower-cost export alternative to the F-16A and Northrop made sure to prove that it could match or better the F-16A.
The F-20 development program ran from 1982 until 1986, when a political decision to allow F-16A to be exported to non-NATO countries ruined any chances of F-20 sales.
Three F-20 airframes were completed, with the first one (GG1001, 82-0062, N4416T) bearing a closer resemblance to the original F-5G design by using F-5E nose and cockpit sections and the second (GI1001, 82-0063, N3986B) and third (GI1002, 82-0064, N44671) airframes being built to full F-20 specs.
As with the YF-17, the F-20s were repainted in different liveries quite often.
Between 1983 and 1986 one or two F-20s would be present at about every major Air Show, including shows in Europe and Asia, showing off with spectacular flying displays.
In 1984 LS released a 1/144 scale kit of the F-20 that captures most of the design characteristics of the F-20 well.
A few things that can be improved are:
Back in 1985 I completed an LS F-20 kit and finished it as the second aircraft in two-tone gray camo scheme using the kits decals.
I also had started building a second kit and later I acquired an incomplete third kit, which I started converting into an F-5E (only to abandon it later when Dragon announced an 1/144 F-5E kit).
In 1989 Airfix added a 1/144 F-20 kit to its line-up, this kit came with decals for the 3rd aircraft in gloss metallic gray scheme so I bought one, but the kit itself turned out to be a rather poor chinese copy of the LS kit. The main sprue is marked 'F-1324', which matches the catalog number of the Trumpeter 1/144 F-20 kit, so the Airfix kit is in fact a reboxed Trumpeter kit.
Recently I looked into completing the kit I had already started and also made plans to turn my abandoned third kit into the nr.1 aircraft using bits from the Airfix kit.
As I need the fuselage halves of the complete LS kit as a reference for turning the abandoned kit back into an F-20, first thing to do is restoring the rear fuselage of the abandoned kit.
Once that fuselage is restored, its nose needs to be replaced by one cut from a Revell F-5E kit (cat.nr. 04018), again using the LS kits fuselage halves as a reference for getting the length of the nose right (base of windshield to rear edge of fuselage).
The nr.3 aircraft can be completed once the fuselage of the nr.1 aircraft is converted.
This page is split into two build reports:
Long ago I had started to convert the fuselage to an F-5 by cutting down the rear.
Now that I want to turn it back into an F-20 I need to undo the changes by grafting parts of the rear fuselage of the Airfix/Trumpeter kit onto the LS fuselage halves.
Apart from that some general changes need to be made:
The fuselage of the Nr.1 airframe differs from the others in a number of ways:
Before fitting the F-5E nose section the rear fuselage needs to be restored.
When I attempted to turn the F-20 kit into an F-5, I started by cutting down the rear fuselage and cutting back the wingroot leading edge extensions before abandoning the conversion.
It would be easier to use the rear fuselage of the Trumpeter kit than to restore the modified LS fuselage, however the Trumpeter plastic is thin and the shape of the rear fuselage is off, so that won't work.
Instead I cut some wedges out of sprue and inserted one in each of the fuselage sides. I left a 'T'-shaped ridge at the inside of each wedge to fit against the insides of the fuselage.
Before glueing the wedges in place I sanded the yellowed traces of glue off of the mating surfaces as these were not responding to glue, I also chipped off any old filler as that had turned brittle.
After fitting the wedges I heat-stretched some sprue and used that to fill any gaps.
First step in restoring the rear fuselage is adding a missing piece to the gap in the top.
I used half of a Hasegawa 1/24 F-104G (cat.nr.1002) wing fuel tank (part nr.B19) as its center section has the exact same diameter as the rear F-20 fuselage.
I trimmed both the cutout in the F-20 fuselage and the replacement part until an exact fit was achieved. I left a small section of the tank protruding behind the fuselage to help with alignment.
The forward section of this fuel tank has about the right amount of taper to be used for replacing the F-20 spine, I already cut out the section that matches the shape of the spine best.
The shape of the nose section of the Airfix kit is just too far off for either an F-20 or an F-5E and its plastic is not thick enough to sand the nose down to a proper F-5E shape either, so I decided to fit the nose section of a Revell F-5E kit (cat.nr.04018). I planned to steal the Revell kits canopy anyway.
For first F-20 the spectacular red/white roll-out scheme is an obvious choice.
Fortunately I managed to find a nice set of 1/144 scale F-20 decals made by TripleNuts ("F-20/F-5E/F Vol.1", cat.nr.TN-004) which includes a set of stripes for the red/white color scheme of the nr.1 aircraft.
The red used for this scheme appears to be Insignia Red, I could not find any details on the exact paint color used.
|Paints (to be) used|
|fuselage, overall||White||Tamiya Acrylic XF-2 Flat White|
|Red||Pactra Acrylic A-7 Insignia Red|
|cockpit interior and seat frame||FS.26321||Pactra Acrylic A38 Dark Gull Gray|
|seat cushions||Red||Humbrol H-60 Matt Scarlet|
Construction of this kit is straightforward, no additional changes need to be made, aside from:
I am considering fitting two or three auxilary 330gal fuel tanks, as that is how I saw the aircraft arrive at the Paris Salon and Farnborough Air Show. The LS F-20 kit only contains a single fuel tank but fortunately I have stores of three kits.
'Plan B' would be to fit a pair of scratch-built 'Smoke-winders' to the wing tip rails instead.
As I had already finished one kit in the two-tone gray camo scheme, I planned to finish the number 3 aircraft in the gloss metallic gray scheme.
The gloss metallic gray paint used was an automotive laquer but sources disagree on the exact color used: one option is "1983 Mercedes Benz Anthrazitgrau Metallic 172" , others (including the painting guide in the 1/48 Monogram F-20 kit) mention "1981 BMW Ascotgrau Metallic 151" , in either case a true gray gun-metal shade. It could well be that the aircraft were first painted in one shade, then repainted in the other as automotive paint usually fades and weathers quickly under high-UV conditions.
For the gloss metallic gray scheme the civilian registration numbers and tail fin tip appear to have been painted in FS.36270, the radome was FS.36320 but at the time of the 1985 Paris Salon air show a gloss black radome was fitted.
|Paints (to be) used|
|fuselage, overall||MB Anthrazitgrau 172||Tamiya mix LP-19/LP-20 Gloss (Light) Gun Metal|
|tail fin tip||FS.36270|
|cockpit interior and seat||FS.26321||Pactra Acrylic A38 Dark Gull Gray|
|seat cushions||Red||Humbrol H-60 Matt Scarlet|
Some pictures of the main parts of both kits compared show why I consider the Airfix/Trumpeter kit to be a poor LS copy.
The sprue layout and the way the Trumpeter model is split into separate parts is almost identical to the LS kit, too close to be an original design IMHO.
The white model in the pictures is the Trumpeter kit, the gray one is the original LS kit. I did not bother adding the intakes to the Trumpeter kit as those only make it look worse.
The most obvious faults of the Trumpeter kit summarized:
The Trumpeter kits canopy (at top and left in the picture) deserves a special mention as it is too large in all dimensions and the rake of the windshield is too steep, making it look more like a WW2 fighter canopy.