DONE @p.4 +++ 1:72 РТАК-30 vintoplan (NATO: Hemlock), "33 Yellow", 1987

Old Wombat · March 28, 2019, 05:28:24 PM

Yup!

Dizzyfugu · March 29, 2019, 12:51:19 AM

Thank, you, glad you like it so far. Final assembly yesterday evening with the complete ordnance in place, and for the first time with all nacelles and props in place, too. It's a HUGE beast!

Still looks a little awkward, and I found another design flaw: in vertical position the rotors come very close to each other, something I did not consider - but dry-fitting the wings and the nacelles was simply not possible when I tried to stick the parts together.

zenrat · March 29, 2019, 02:01:43 AM

Fuselage and wings look right together which is just as well as I have an Italeri Ka-50 in the stash slated to one day become a fixed wing CoIn aircraft.

Dizzyfugu · March 29, 2019, 06:44:09 AM

I heavily suggest a Ka-52 for such a stunt - the single seater's nose is very narrow and the fuselage widens considerably in the engine section. The Ka-52 is much easier to "convert" into something aircraft-like, that's why my vintoplan became a two-seater...

zenrat · March 29, 2019, 11:14:09 PM

Thanks DIzz for the advice.

Dizzyfugu · March 30, 2019, 01:49:20 AM

Just a suggestion. It's certainly not impossible to use a Ka-50, but it involves IMHO a serious amount of body work between the cockpit and the engines. I have a Ka-50 in my stash which I had originally planned to use for the vintoplan build, but rather decided to get a Ka-52 instead. Still some work, but the body lines are much more streamlined.

Besides, final WiP pics from the ordnance mounting phase:

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) - WiP by dizzyfugu, on Flickr

NARSES2 · March 30, 2019, 04:16:14 AM

This is looking good

zenrat · March 30, 2019, 05:08:51 AM

Quote from: Dizzyfugu on March 30, 2019, 01:49:20 AM
Just a suggestion. It's certainly not impossible to use a Ka-50, but it involves IMHO a serious amount of body work between the cockpit and the engines. I have a Ka-50 in my stash which I had originally planned to use for the vintoplan build, but rather decided to get a Ka-52 instead. Still some work, but the body lines are much more streamlined.

TBH I haven't done more than open the box and peer at it then put it in a cupboard. It was an impulse purchase at Model Expo right at the end when everything was being knocked down rather than be taken back to the shop/warehouse/lock up.

Dizzyfugu · March 30, 2019, 06:30:22 AM

Secret footage from Western secret agents, taken at Zhukovsky AB near Moscow in 1987...

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

Tophe · March 30, 2019, 10:41:57 AM

Quote from: Dizzyfugu on March 30, 2019, 06:30:22 AM
Secret footage from Western secret agents, taken at Zhukovsky AB near Moscow in 1987...

Great, and this is secret, I will tell nobody I have seen it!

rickshaw · March 30, 2019, 06:02:23 PM

Footage? What footage? I have seen no footage of anything! I know nothing! Absolutely nothing!

Dizzyfugu · April 01, 2019, 01:19:33 AM

Photo session has been finished, but esp. the flight scenes will need some major editing (due to the four rotors...), so it will take a while until this one is "finished".

Stay tuned.

Dizzyfugu · April 04, 2019, 12:30:27 AM

Further delays with the pics and the background story, sorry... $:-\$

NARSES2 · April 04, 2019, 06:21:05 AM

Tease

No, seriously, don't rush it Dizzy we can wait

Dizzyfugu · April 08, 2019, 12:02:45 AM

Here we are, finally. Lack of photo mojo and the complexity of editing four propellers in different depth levels took some time (during which I built 3 other models, pics pending, too...

), but now the РТАК-30 can soar the skies:

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

Some background:
The РТАК-30 attack vintoplan (also known as vintokryl) owed its existence to the Mil Mi-30 plane/helicopter project that originated in 1972. The Mil Mi-30 was conceived as a transport aircraft that could hold up to 19 passengers or two tons of cargo, and its purpose was to replace the Mi-8 and Mi-17 Helicopters in both civil and military roles. With vertical takeoff through a pair of tiltrotor engine pods on the wing tips (similar in layout to the later V-22 Osprey) and the ability to fly like a normal plane, the Mil Mi-30 had a clear advantage over the older models.

Since the vintoplan concept was a completely new field of research and engineering, a dedicated design bureau was installed in the mid-Seventies at the Rostov-na-Donu helicopter factory, where most helicopters from the Mil design bureau were produced, under the title Ростов Тилт Ротор Авиационная Компания (Rostov Tilt Rotor Aircraft Company), or РТАК (RTRA), for short.

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

The vintoplan project lingered for some time, with basic research being conducted concerning aerodynamics, rotor design and flight control systems. Many findings later found their way into conventional planes and helicopters. At the beginning of the 1980s, the project had progressed far enough that the vintoplan received official backing so that РТАК scientists and Mil helicopter engineers assembled and tested several layouts and components for this complicated aircraft type.
At that time the Mil Mi-30 vintoplan was expected to use a single TV3-117 Turbo Shaft Engine with a four-bladed propeller rotors on each of its two pairs of stub wings of almost equal span. The engine was still installed in the fuselage and the proprotors driven by long shafts.

However, while being a very clean design, this original layout revealed several problems concerning aeroelasticity, dynamics of construction, characteristics for the converter apparatuses, aerodynamics and flight dynamics. In the course of further development stages and attempts to rectify the technical issues, the vintoplan layout went through several revisions. The layout shifted consequently from having 4 smaller engines in rotating pods on two pairs of stub wings through three engines with rotating nacelles on the front wings and a fixed, horizontal rotor over the tail and finally back to only 2 engines (much like the initial concept), but this time mounted in rotating nacelles on the wing tips and a canard stabilizer layout.

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

In August 1981 the Commission of the Presidium of the USSR Council of Ministers on weapons eventually issued a decree on the development of a flyworthy Mil Mi-30 vintoplan prototype. Shortly afterwards the military approved of the vintoplan, too, but desired bigger, more powerful engines in order to improve performance and weight capacity. In the course of the ensuing project refinement, the weight capacity was raised to 3-5 tons and the passenger limit to 32. In parallel, the modified type was also foreseen for civil operations as a short range feederliner, potentially replacing Yak-40 and An-24 airliners in Aeroflot service.
In 1982, РТАК took the interest from the military and proposed a dedicated attack vintoplan, based on former research and existing components of the original transport variant. This project was accepted by MAP and received the separate designation РТАК-30. However, despite having some close technical relations to the Mi-30 transport (primarily the engine nacelles, their rotation mechanism and the flight control systems), the РТАК-30 was a completely different aircraft. The timing was good, though, and the proposal was met with much interest, since the innovative vintoplan concept was to compete against traditional helicopters: the design work on the dedicated Mi-28 and Ka-50 attack helicopters had just started at that time, too, so that РТАК received green lights for the construction of five prototypes: four flyworthy machines plus one more for static ground tests.

The РТАК-30 was based on one of the early Mi-30 layouts and it combined two pairs of mid-set wings with different wing spans with a tall tail fin that ensured directional stability. Each wing carried a rotating engine nacelle with a so-called proprotor on its tip, each with three high aspect ratio blades. The proprotors were handed (i.e. revolved in opposite directions) in order to minimize torque effects and improve handling, esp. in the hover. The front and back pair of engines were cross-linked among each other on a common driveshaft, eliminating engine-out asymmetric thrust problems during V/STOL operations. In the event of the failure of one engine, it would automatically disconnect through torque spring clutches and both propellers on a pair of wings would be driven by the remaining engine.
Four engines were chosen because, despite the weight and complexity penalty, this extra power was expected to be required in order to achieve a performance that was markedly superior to a conventional helicopter like the Mi-24, the primary Soviet attack helicopter of that era the РТАК-30 was supposed to replace. It was also expected that the rotating nacelles could also be used to improve agility in level flight through a mild form of vectored thrust.

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

The РТАК-30's streamlined fuselage provided ample space for avionics, fuel, a fully retractable tricycle landing gear and a two man crew in an armored side-by-side cockpit with ejection seats. The windshield was able to withstand 12.7–14.5 mm caliber bullets, the titanium cockpit tub could take hits from 20 mm cannon. An autonomous power unit (APU) was housed in the fuselage, too, making operations of the aircraft independent from ground support.
While the РТАК-30 was not intended for use as a transport, the fuselage was spacious enough to have a small compartment between the front wings spars, capable of carrying up to three people. The purpose of this was the rescue of downed helicopter crews, as a cargo hold esp. for transfer flights and as additional space for future mission equipment or extra fuel.
In vertical flight, the РТАК-30's tiltrotor system used controls very similar to a twin or tandem-rotor helicopter. Yaw was controlled by tilting its rotors in opposite directions. Roll was provided through differential power or thrust, supported by ailerons on the rear wings. Pitch was provided through rotor cyclic or nacelle tilt and further aerodynamic surfaces on both pairs of wings. Vertical motion was controlled with conventional rotor blade pitch and a control similar to a fixed-wing engine control called a thrust control lever (TCL). The rotor heads had elastomeric bearings and the proprotor blades were made from composite materials, which could sustain 30 mm shells.

The РТАК-30 featured a helmet-mounted display for the pilot, a very modern development at its time. The pilot designated targets for the navigator/weapons officer, who proceeded to fire the weapons required to fulfill that particular task. The integrated surveillance and fire control system had two optical channels providing wide and narrow fields of view, a narrow-field-of-view optical television channel, and a laser rangefinder. The system could move within 110 degrees in azimuth and from +13 to −40 degrees in elevation and was placed in a spherical dome on top of the fuselage, just behind the cockpit.

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

The aircraft carried one automatic 2A42 30 mm internal gun, mounted semi-rigidly fixed near the center of the fuselage, movable only slightly in elevation and azimuth. The arrangement was also regarded as being more practical than a classic free-turning turret mount for the aircraft's considerably higher flight speed than a normal helicopter. As a side effect, the semi-rigid mounting improved the cannon's accuracy, giving the 30 mm a longer practical range and better hit ratio at medium ranges. Ammunition supply was 460 rounds, with separate compartments for high-fragmentation, explosive incendiary, or armor-piercing rounds. The type of ammunition could be selected by the pilot during flight.
The gunner can select one of two rates of full automatic fire, low at 200 to 300 rds/min and high at 550 to 800 rds/min. The effective range when engaging ground targets such as light armored vehicles is 1,500 m, while soft-skinned targets can be engaged out to 4,000 m. Air targets can be engaged flying at low altitudes of up to 2,000 m and up to a slant range of 2,500 m.

A substantial range of weapons could be carried on four hardpoints under the front wings, plus three more under the fuselage, for a total ordnance of up to 2,500 kg (with reduced internal fuel). The РТАК-30's main armament comprised up to 24 laser-guided Vikhr missiles with a maximum range of some 8 km. These tube-launched missiles could be used against ground and aerial targets. A search and tracking radar was housed in a thimble radome on the РТАК-30's nose and their laser guidance system (mounted in a separate turret under the radome) was reported to be virtually jam-proof. The system furthermore featured automatic guidance to the target, enabling evasive action immediately after missile launch. Alternatively, the system was also compatible with Ataka laser-guided anti-tank missiles.
Other weapon options included laser- or TV-guided Kh-25 missiles as well as iron bombs and napalm tanks of up to 500 kg (1.100 lb) caliber and several rocket pods, including the S-13 and S-8 rockets. The "dumb" rocket pods could be upgraded to laser guidance with the proposed Ugroza system. Against helicopters and aircraft the РТАК-30 could carry up to four R-60 and/or R-73 IR-guided AAMs. Drop tanks and gun pods could be carried, too.

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

When the РТАК-30's proprotors were perpendicular to the motion in the high-speed portions of the flight regime, the aircraft demonstrated a relatively high maximum speed: over 300 knots/560 km/h top speed were achieved during state acceptance trials in 1987, as well as sustained cruise speeds of 250 knots/460 km/h, which was almost twice as fast as a conventional helicopter. Furthermore, the РТАК-30's tiltrotors and stub wings provided the aircraft with a substantially greater cruise altitude capability than conventional helicopters: during the prototypes' tests the machines easily reached 6,000 m / 20,000 ft or more, whereas helicopters typically do not exceed 3,000 m / 10,000 ft altitude.

Flight tests in general and flight control system refinement in specific lasted until late 1988, and while the vintoplan concept proved to be sound, the technical and practical problems persisted. The aircraft was complex and heavy, and pilots found the machine to be hazardous to land, due to its low ground clearance. Due to structural limits the machine could also never be brought to its expected agility limits
During that time the Soviet Union's internal tensions rose and more and more hampered the РТАК-30's development. During this time, two of the prototypes were lost (the 1st and 4th machine) in accidents, and in 1989 only two machines were left in flightworthy condition (the 5th airframe had been set aside for structural ground tests). Nevertheless, the РТАК-30 made its public debut at the Paris Air Show in June 1989 (the 3rd prototype, coded "33 Yellow"), together with the Mi-28A, but was only shown in static display and did not take part in any flight show. After that, the aircraft received the NATO ASCC code "Hemlock" and caused serious concern in Western military headquarters, since the РТАК-30 had the potential to dominate the European battlefield.

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

And this was just about to happen: Despite the РТАК-30's development problems, the innovative attack vintoplan was included in the Soviet Union's 5-year plan for 1989-1995, and the vehicle was eventually expected to enter service in 1996. However, due to the collapse of the Soviet Union and the dwindling economics, neither the РТАК-30 nor its civil Mil Mi-30 sister did soar out in the new age of technology. In 1990 the whole program was stopped and both surviving РТАК-30 prototypes were mothballed – one (the 3rd prototype) was disassembled and its components brought to the Rostov-na-Donu Mil plant, while the other, prototype No. 1, is rumored to be stored at the Central Russian Air Force Museum in Monino, to be restored to a public exhibition piece some day.

General characteristics:
Crew: Two (pilot, copilot/WSO) plus space for up to three passengers or cargo
Length: 45 ft 7 1/2 in (13,93 m)
Rotor diameter: 20 ft 9 in (6,33 m)
Wingspan incl. engine nacelles: 42 ft 8 1/4 in (13,03 m)
Total width with rotors: 58 ft 8 1/2 in (17,93 m)
Height: 17 ft (5,18 m) at top of tailfin
Disc area: 4x 297 ft² (27,65 m²)
Wing area: 342.2 ft² (36,72 m²)
Empty weight: 8,500 kg (18,740 lb)
Max. takeoff weight: 12,000 kg (26,500 lb)

Powerplant:
4× Klimov VK-2500PS-03 turboshaft turbines, 2,400 hp (1.765 kW) each

Performance:
Maximum speed: 275 knots (509 km/h, 316 mph) at sea level
305 kn (565 km/h; 351 mph) at 15,000 ft (4,600 m)
Cruise speed: 241 kn (277 mph, 446 km/h) at sea level
Stall speed: 110 kn (126 mph, 204 km/h) in airplane mode
Range: 879 nmi (1,011 mi, 1,627 km)
Combat radius: 390 nmi (426 mi, 722 km)
Ferry range: 1,940 nmi (2,230 mi, 3,590 km) with auxiliary external fuel tanks
Service ceiling: 25,000 ft (7,620 m)
Rate of climb: 2,320–4,000 ft/min (11.8 m/s)
Glide ratio: 4.5:1
Disc loading: 20.9 lb/ft² at 47,500 lb GW (102.23 kg/m²)
Power/mass: 0.259 hp/lb (427 W/kg)

Armament:
1× 30 mm (1.18 in) 2A42 multi-purpose autocannon with 450 rounds
7 external hardpoints for a maximum ordnance of 2.500 kg (5.500 lb)

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

1:72 Rostov Tilt Rotor Aircraft Company РТАК-30 (NATO ASCC code "Hemlock"); 3rd prototype "33 Yellow" during state acceptance trials; Zhukovsky (Moscow Oblast), 1987 (Whif/kitbashing) by dizzyfugu, on Flickr

Technical data to follow

A complex kitbashing project, and it revealed some pitfalls in the course of making. However, the result looks menacing and still convincing, esp. in flight – even though the picture editing, with four artificially rotating proprotors, was probably more tedious than building the model itself!