1:72 Sukhoi Su-18 (NATO 'Fitter N'), aircraft "24 Yellow" of the Soviet Naval Aviation Baltic Fleet's 66th OMShAP; Veshchovo AB, Vyborg District/Russia, 1991 (Whif/Smer kit conversion)

+++ DISCLAIMER +++

Nothing you see here is real, even though the conversion or the presented background story might be based historical facts. BEWARE!

 

 

Some background:

The Su-18 was the final evolutionary step in the long journey of the Su-7 fighter bomber. Seeking to improve low-speed and take-off/landing performance of the Su-7B fighter-bomber, in 1963 the Sukhoi OKB with input from TsAGI created a variable-sweep wing technology demonstrator. The Su-7IG (internal designation S-22I, NATO designation "Fitter-B"), converted from a production Su-7BM, had fixed inner portions of the wing with movable outer segments which could be swept to 28°, 45°, or 62°.

 

A fixed inner wing simplified construction, allowing the manufacturer to retain the Su-7 landing gear and avoiding the need for complex pivoting underwing hardpoints, and it minimized the shift in the center of pressure relative to the center of mass with change in wing sweep. The new wing also had extensive leading-edge slats and trailing-edge flaps. Su-7IG first flew on 2 August 1966 with V. S. Ilyushin at the controls, becoming the first Soviet variable geometry aircraft. Testing revealed that take-off and landing speeds had decreased by 50–60 km/h (31–37 mph) compared to the conventional Su-7.

 

The production aircraft was named Su-17 (NATO designation "Fitter-C", factory designation S-32) and was unofficially dubbed Strizh (Стриж, martlet) in service. Aside from the new wing, it differed from its predecessor Su-7 in having a new canopy and a dorsal fuselage spine for additional fuel and avionics. The Su-17 first flew on 1 July 1969.

The Su-17 saw several development steps, ending with the capable Su-17/22M3 and Su-17/22M4; the latter made its maiden flight in 1980 and the last variants were produced until 1990.

 

The Su-22M4 was also operated by the Soviet Naval Aviation (Авиация военно-морского флота in Russian, or Aviatsiya Voenno-Morskogo Flota, literally "aviation of the military maritime fleet") in the attack role, and from the beginning it was clear that the type had no sufficient capability for tactical strikes, esp. against sea targets. The Su-24 tactical bomber was an option, but it was complex and expensive, so that an upgrade of the Su-17 was considered. Primary requirement was a more capable radar/attack suite, tailored to a naval environment, and a better/more modern engine, esp. with a better fuel efficiency.

 

OKB Sukhoi started to take on the task in 1982. Effectively the design team tried to create a "Su-24 light" on the basis of as many proven Su-17/22 elements as possible. The project received the internal designation S-54D. Mission avionics were to comprise the ‘котёнок‘ (= ‘Kitten’) suite, a slimmed-down 'Puma' nav/attack system optimized for naval environment. This system complex consisted of two Orion-A superimposed radar scanners for nav/attack, a dedicated Relyef terrain clearance radar to provide automatic control of flights at low and extremely low altitudes, and an Orbita-10-58 onboard computer.

 

It soon became clear that the original Su-17/22 airframe with nose air intake and its central shock cone did not offer sufficient space for the radar scanners, so OKB Sukhoi had to modify the complete nose section in order to fit a large radome. This radically modified aircraft was designated T-54DM and presented as a mock-up in 1984.

 

To create sufficient room, the box-shaped air intakes were moved to the flanks and into the wing roots, what meant that the original NR-30 cannons were omitted. As a positive side effect, top speed at height and supersonic performance were reinstated since the Su-17M4's fixed nose cone was replaced by effective, adjustable splitter plates (not unlike the design on the Su-15 interceptor) in the new air intakes - getting the new aircraft's top speed back to more than 2.000 km/h at height. On the other side, the space for the original air duct around the cockpit could be used for avionics and other mission equipment, including a pair of more modern GSh-30-1 30 mm cannons in the lower front fuselage with a 150-round magazine each, which were more effective against ground and air targets alike.

 

Concerning the engine, the Su-17's Lyulka AL-21F-3 afterburning turbojet was to be replaced by the new and promising Soyuz R-79F-100 turbofan that yielded about 15% more thrust than the original AL-21F, even though fuel consumption was not much better and reliability remained a serious problem throughout the Su-18's career, how the type was officially called in service when it was delivered in early 1987 to the Baltic and Black Sea fleet.

 

When the aircraft was discovered on NATO’s satellite pictures, it was erroneously interpreted as a Su-22 export version for China (since the new nose arrangement reminded a lot of the Q-5 modification of the MiG-19 fighter), and some ‘experts’ even considered the Su-18 to be an interceptor version of the swing-wing fighter bomber. Anyway, since the Su-18 was still seen as part of the huge Su-7 family it kept its ‘Fitter’ ASCC code, with the ‘N’ suffix.

 

The Su-18’s service was short and ambivalent, though. The type was only introduced to the Soviet Naval Aviation, since its котёнок avionics suite was rather limited in scope and could not match up with the Su-24’s ‘Puma’ system. Additionally, the Su-27 multi-role fighter had become a more versatile option for the Soviet Air Force, which had begun to face a severe re-structuring program.

 

Positive asset was the fact that the Su-18 did not require much flight training – no trainer version was ever built and training was done on Su-17M3 two-seaters. On the other side the single crew layout coupled with the complex weapon system made flying and weapon operations at the same time rather demanding, so that the Su-18 could hardly play out its full potential.

 

Only about 120 Su-18s were produced until 1990, and in a move to eliminate single engine strike aircraft from its inventory the Russian Air Force already retired its last Su-17M4 along with its fleet of MiG-23/27s in 1998, while the Su-18 in Naval Aviation service soldiered on until 2000. Some countries like Peru and Indonesia showed interest in these aircraft, but all were destroyed in the course of the bilateral START (Strategic Arms Reduction Treaty) treaty.

 

 

General characteristics:

Crew: 1

Length: 19.02 m (62 ft 5 in)

Wingspan:

Spread: 13.68 m (44 ft 11 in)

Swept: 10.02 m (32 ft 10 in)

Height: 5.12 m (16 ft 10 in)

Wing area: 38.5 m² (415 ft²) spread, 34.5 m² (370 ft²) swept

Empty weight: 12,160 kg(12.2t) (26,810 lb)

Loaded weight: 16,400 kg(16.5t) (36,155 lb)

Fuel capacity: 3,770 kg (8,310 lb)

 

Powerplant:

1× Soyuz R-79F-100 turbofan, rated at 99 kN (22.275 lbf) dry thrust and 130 kN (29.250 lbf) with afterburner

 

Performance:

Maximum speed:

1.400 km/h (755 knots, 870 mph) at sea level, 1,860 km/h (1,005 knots, 1,156 mph, Mach 1.7) at altitude

Range:

1,150 km (620 nmi, 715 mi) combat range in hi-lo-hi attack with 2.000 kg (4.409 lb) warload; ferry range: 2.300 km (1.240 nmi, 1.430 mi)

Service ceiling: 14,200 m (46,590 ft)

Rate of climb: 230 m/s (45,275 ft/min)

Wing loading: 443 kg/m² (90.77 lb/ft²

Thrust/weight: 0.68

G-force limit: 7

Airframe lifespan: 2,000 flying hours, 20 years

 

Armament:

2 × 30 mm GSh-30-1 cannons, 150 RPG in the lower forward fuselage

Up to 4000 kg (8,820 lb) on ten hardpoints (three under the fixed portion of each wing, four on the fuselage sides), including Kh-23 (AS-7 'Kerry'), Kh-25 (AS-10 'Karen'), Kh-29 (AS-14 'Kedge'), Kh-31A & P (AS-17 ‘Krypton) anti-shipping/anti-radiation missiles and Kh-58 (AS-11 'Kilter') guided missiles, as well as electro-optical and laser-guided bombs, free-fall bombs, rocket pods, cluster bombs, SPPU-22-01 cannon pods with traversable barrels, ECM pods, napalm tanks, and nuclear weapons.

 

 

The kit and its assembly:

This whif creation was triggered by a discussion at whatifmodelers.com, circling around an updated/improved Su-17/22. I remembered a photoshop creation of a Su-17 with side air intakes (from an A-4) and a nose radome (probably from an F-14) in USAF-markings – a potential way to go, even though the graphic design had some flaws like the subsonic air intake design or the guns’ position right in front of the intakes. Well, “Let’s tackle that, and do it better”, and the Su-18 is my interpretation of that idea.

 

The kit the Su-17M4 from Smer, a kit that has nice proportions and good detail, but nothing really fits together – expect lots of putty work! From that basis only few things were actually changed or added:

• Nose intake replaced by a F-15 radome

• Side air intakes with splitter plates come from a PM Model Su-15

• The following ducts are a halved part from an Art Model Bv 155 underwing radiator

• A new seat had to be used in the cockpit

• Main wheels from a Me 262 replace the OOB parts

• New twin front wheel which retracts backwards now

• For the anti-shipping role, a pair of Kh-31 missiles and the launch rails from an ICM weapon set

 

My biggest concern were the air intakes and the wide ducts, since these had to be blended into the round Su-17 fuselage. For the intakes, the wing roots were cut open and the Su-15 parts inserted. The Bv 155 parts were a lucky find, as they matched perfectly in size and shape – otherwise I had had to sculpt the ducts from 2c Putty. The arrangement still looks a little brutal, but the side intakes look plausible.

The nose radome posed little problems, even though I worried for a long time that the nose section could look too bulbous for the rest of the aircraft. But finally, when the stabilizers were in place, everything looked more balanced than expected.

 

Changing the front wheel from the original, forward-retracting single-wheel arrangement to a rearward-retracting twin wheel creation also helped selling the new proportions.

 

Painting and markings:

Very early I had the idea to keep the Su-18 in Soviet/Russian service, but it should feature an unusual, yet plausible paint scheme. The Soviet/Russian Navy actually used the Su-17, but only in tactical camouflage, with green and brown upper surfaces and light blue undersides. While browsing for alternatives I came across the Su-24 (also flown by the Navy regiments), and their typical light grey/white livery was what perfectly fit my story for the aircraft.

 

Said and done, the model was painted in Humbrol 167 (RAF Barley Grey) from above and painted with the rattle can in a vintage VW car tone called “Grauweiß”, a very dull white. Later, panels were emphasized through dry-brushing (Humbrol 127 and 130), plus a light black ink wash and more overall dry-brushing with light grey tones. Also, some panels were painted all over the fuselage, as well as an overpainted Red Star on the fin which was replaced by a Russian Flag decal – a common experimental practice in the early 90ies, but the idea did not catch on.

 

Speaking of decals, these mostly come from the very complete Smer decal sheet. Personal additions are only the flags on the fin and the Russian Navy emblem on the nose.

The cockpit was painted in typical psychedelic cockpit interior turquoise, while the landing gear and the wells were painted in blue-grey (Humbrol 87); the wheel discs were kept in bright green (Humbrol 2) – a nice contrast to the rest.

The drop tanks were painted in Aluminum, for some overall contrast, and the Kh-31 missiles according to real-life pics; the launch rails were painted in Russian Underside Blue, again for variety and contrast.

 

While the finish of the model is far from perfect, I am satisfied with the convincing result. You could certainly place this aircraft in line with other, typical Suchoj types like the Su-7, -15, -17 and -24, and it would not look out of place! A highly effective whif, IMHO. ^^

 

Done