Macchi Castoldi MC 72 by SBS

1/72 scale
Kit No. 7015
Cost: $39.99
Decals: One version – Regia Aeronautica (Italian Air Force)
Comments: Cast and injection molded resin, crisp detail, engraved panel lines and flush rivet detail, stressed fabric-over-frame effects, photo-etch details

History

The Macchi-Castoldi M.C.72 was designed by Mario Castoldi for Aeronautica Macchi. It was a single-seat, single-engine, low-wing monoplane float plane constructed of wood and metal. It was 8.32 meters (27 feet, 3.5 inches) long with a wingspan of 9.48 meters (31 feet, 1.25 inches) and height of 3.30 meters (10.83 feet). The M.C.72 had an empty weight of 2,505 kilograms (5,512 pounds), loaded weight of 2,907 kilograms (6,409 pounds) and maximum takeoff weight of 3,031 kilograms (6,669 pounds). It was powered by a 50.256 liter (3,067 cubic inch) liquid-cooled, supercharged Fiat S.p.A. AS.6 24-cylinder 60° dual overhead cam (DOHC) V-24 engine with 4 valves per cylinder. Reports vary as to the engine’s output: it has alternately been cited as 2,850hp or 3,100hp, but regardless it was likely the most powerful aircraft engine of its day.

First flown on July 16, 1931, the Macchi Castoldi M.C. 72 was specifically designed to beat the British Supermarine S.6B in the 1931 Schneider Cup race. But the new thoroughbred engine had bugs to be worked out; it ran perfectly on the testing stand, but had a tendency to backfire and explode in flight, killing two test pilots and forcing Italy to withdraw from the 1931 race, ceding the Schneider Cup to Britain for all time. In the wake of this loss, the Italians redoubled their efforts to break the world speed record set by the S.6B. If it couldn’t be beaten in a race, it could still be bested in terms of pure speed.

On October 23, 1934 , piloted by Francesco Agello, an MC 72 set the absolute world speed record for a piston-powered seaplane of 440 mph just over three years later — a record which still stands over 80 years later. The M.C.72 was built by Macchi Aeronautica and operated mainly by the Regia Aeronautica (Royal (Italian) Air Force). The “MC” model designation reflects the fact that Macchi built the design by Mario Castoldi. Five M.C.72’s were built, with two being destroyed during test flights. For two years prior to Agello’s success with the M.C. 72, it suffered from many mechanical defects, and two test pilots had died trying to coax world class speed out of it (first Captain Giovanni Monti, and then Lt. Stansislao Bellini). The final design of M.C. 72 used contra-rotating propellers powered by a modified FIAT AS.6 supercharged V24 engine generating some 1,900-2,300 kW (2,500-3,100 hp), and wooden floats in place of metal ones fitted to earlier designs. The counter-rotating blades cancelled the engine’s torque effect.

In the years after the First World War, the “Golden Age of Aviation,” the Italian aviation industry experienced exceptional growth, beginning the in the second half of the 1920’s. The was due partly to the leadership of Italo Balbo, nominated as Secretary of State for Aviation on November 26th, 1926. He managed to promote and demonstrate the high level of Italian aeronautical achievements through a series of aviation exploits of global impact. Key among these were the Rome-to-Tokyo flight, and a world record flight on a closed circuit (Montecelio-to-Tours), both by Arturo Ferrarin in 1921 and 1928 respectively; the two long distance flights by Francesco De Pinedo, who in 1925 left Sesto Calende to arrive in Tokyo in a SIAI S.16, and in 1927 departed from Cagliari Elmas for the two Americas, later returning to Rome; and the Arctic exploits of Umberto Nobile, who in 1926 and again in 1928 reached and explored the North Pole in the airships “Italia” and “Norge.”
Balbo himself led two trans-Atlantic flights of the large, Savoia-Marchetti S.55 flying boats: 12 such aircraft in December 1930 from Rome to Rio de Janeiro, Brazil; and in 1933, 24 S.55’s on a round-trip flight from Rome to the Century of Progress in Chicago, Illinois.

But the effort that resonated the most in the minds of the Italian public was the Regia Aeronautica’s participation in the Schneider Cup races. The desire to win this trophy drove the Aeronautica to spare no expense. The Italians took the Cup in 1926 when Mario de Bernardi, piloting a Macchi M.39, won with an average speed of 246.49 mph. However, for the remainder of the 1920’s, the British seized the Cup from the Italians with Supermarine S.6 series of racing seaplanes, winning three consecutive races in 1927, 1929, and again in 1931. Under Benito Mussolini, it became a matter of national prestige for the Italians to beat the British and win the Schneider Cup back; that was a key reason for the development of the Macchi-Castoldi M.C. 72, and the motivation for the intensified involvement of the Regia Aeronautica.

In 1928 the Italian government created the Scuola Alta Velocità (High Speed School) at the seaplane base in Desenzano del Garda under the command of Colonnello Bernasconi. The Ministero dell’Aeronautica considered the creation of such a specialized unit absolutely necessary following the dismal Italian performance at the Schneider races in Venice during 1927. The scarlet-colored Italian seaplanes, the supposed favorites, had lost to the British Supermarine racers which proved more advanced and mechanically, far more reliable. In the Scuola Alta Velocità, the Regia Aeronautica had created an extremely specialized team, which would work in close cooperation with the Italian aviation industry, and produce highly skilled pilots and engineers dedicated to the singular goal of permanently winning the trophy; achieved only by the team which won at least three competitions over a five year period.

At the next Schneider Cup race at Calshot in 1929, the Italian aircraft again failed to win the competition due to technical problems with its engine. Macchi had built the majority of the nation’s attractive but under-performing seaplane racers, but the Aeronautica felt they were up to the job, and ordered Macchi to develop a new seaplane racer powered by the new FIAT AS 6 engine. From the pen of designer Mario Castoldi flowed a drawing of a beautiful and lithe floatplane, with clean aerodynamic lines, low drag and reduced weight. Castoldi designed the wing using duralumin with a symmetrical bi-convex profile, and tail stabilisers of wooden construction. The revolutionary liquid-cooled FIAT AS-6 24 cylinder V-engine could produce an extraordinary 2,850 hp and drove two large, coaxial, contra-rotating propellers. So much power generated large amounts of heat demanding the maximum available cooling area, so Castoldi integrated the radiators into the lines of the airframe so that they would lie flush with the wing and float surfaces, and the cooling tubes would run parallel with the airflow. Castoldi would go on to design the Macchi MC.202 Folgore during WWII.

The M.C. 72 was an amalgamation of all the latest technology, and it rode the ragged edge of what was possible. As powerful as it was, it was a delicate balance to get it all to work reliably. Unfortunately, the new engine suffered from serious problems caused by dangerous back fires, which led to two fatal accidents involving pilots Monti and Bellini in the run-up to the 1931 Schneider Cup race. On August 2, 1931, an engine backfire caused the fuel mixture in the intake manifold to ignite, and the engine exploded, killing test pilot Monti when the plane hit the water. On September 10, 1931, two days before the race, Lt. Bellini set a record of 394 mph, but near the end of the flight crashed into a hillside and was killed on impact. Subsequent investigation revealed another engine backfire which crippled the plane. These tragedies resulted in an Italian request to postpone the Schneider competition, but with permanent possession of the trophy at stake, the British refused to budge, so the Regia Aeronautica felt compelled to pull out of the 1931 races. With the American team having dropped out previously, only the British ended up flying the race with their Supermarine S.6As and S.6Bs.

At this point the Scuola Alta Velocità seemed to have outlived its usefulness, as the principal goal for its founding, winning the Schneider Trophy, was now irretrievably lost. Nevertheless Italo Balbo, conscious of the advanced level of technology and human performance reached, decided to entrust the unit, recently renamed the Reparto Alta Velocita or RAV (High Speed Unit), with the task of breaking the air speed record. A British pilot, Flight Lieutenant George Stainforth, had set the speed-to-beat of 655 kmh (407.5mph) in Supermarine S.6B S1596 just over two weeks after the 1931 Schneider races.

In reality, the RAV was charged with three primary objectives: i) break the speed record, ii) set the absolute record for speed over a 100 km distance (and therefore win the Coppa Bleriot created by the French pioneer for the first pilot to fly for 30 minutes at an average speed greater than 600 kmh), and iii) to participate in all the other international competitions of the period in which the speed element played an essential factor.

All RAV personnel set to work on the M.C. 72, believing the aircraft, once perfected, could easily achieve all these targets. Finally, by early 1933, the design team had mostly resolved the major engine problems, partly through the novel use of new, higher octane fuel mixtures, but principally by re-dimensioning the engine and adopting new carburetor tubes. With the serious flaws overcome, a newer spark plug design enabled the RAV engineers to boost the AS-6 engine’s power to over 3000 hp. The RAV chose Warrant Officer Maresciallo Francesco Agello, the last surviving pilot of the four originally tasked for the Schneider Trophy races, to fly the M.C.72 on its record attempts. He was the perfect man for the job, with exceptional experience and capability in regular flying duties and as a test pilot. Agello started with a series of “preparation flights”, and by early April, 1933 both plane and pilot were ready to challenge the records. April 10th, 1933 was the triumphant day. For almost a week the team had waited for the ideal weather conditions, and in the morning Colonel Bernasconi took to the air over Lake Garda to conduct a check on the weather and visibility. Upon his return, Bernasconi gave the go ahead for the flight.

The M.C. 72 took off from the lake with Agello at the controls. Agello flew the five required laps over a 3 km course, identified on the surface of Lake Garda by red and white buoys. Along the course, intermediate stations housed the official Fédération Aéronautique Internationale time keepers, who recorded the lap times. At the conclusion of the five laps, the commissioners calculated the average lap time, with the possibility of excluding the slowest lap. After having been aloft for 20 minutes and 32 seconds, Agello landed back at the seaplane base, where the base personnel at Desenzano greeted him with rapturous applause, certain he’d smashed the records.

The FAI officials agreed, recording that he’d beaten the previous absolute world speed record by some 27 km/h, with an audited average lap speed of 682.403 km/h (425mph). Despite the euphoria of the moment, in the following days Col. Bernasconi and all the RAV personnel were convinced that this limit could be extended further to perhaps 700 km/h or even 750 km/h. The RAV had achieved their first target of attaining the world speed record, but there were still other records to overcome.

In the coming months the engineers worked furiously to further increase the performance of the Macchi M.C. 72 and its engine, but the attempts on the record were foiled by additional technical problems. Finally, on October 23rd, 1934 Agello was ready to try again. Taking off smoothly, Agello completed the four laps over Lake Garda at an average of 709.202 km/h (440mph). The FAI team recorded the lap speeds as follows: 1st lap 705.882 km/h (438mph)—2nd lap 710.433 km/h (440mph)—3rd lap 711.426 km/h (441mph) and the 4th lap 709.034 km/h (440mph). The record was subsequently verified by the FAI for the seaplane with internal combustion engine category (subclass C-2, Group 1).

Despite this, neither Col. Bernasconi nor Agello were completely satisfied, as they were convinced that with better weather conditions, it would be possible to achieve an even better result. In fact, in the course of an earlier, unofficial flight, the M.C. 72 had recorded speeds greater than 730 km/h (453mph). Unfortunately, the arrival of winter and the high costs involved with hosting an eleventh record attempt, the two men decided to accept their already excellent result with good grace.

The Kit

The SBS Macchi Castoldi MC 72 is cast in grey resin and consists of 30 resin parts along with 16 photo-etch parts, most of which will be used to detail the cockpit (instrument panel, seat straps, and rudder pedals). The fuselage is painstakingly recreated in every detail, from the engraved panel lines, to the flush rivets, to the flush exhaust ports over the engine – even the myriad of vents in the forward fuselage to address the tendency of the FIAT AS 6 V-24 powerplant to overheat.

The MC 72’s two floats are solid cast resin pieces, and are also meticulously detailed with recessed panel lines, flush rivets, and also delicate engraved detail representing the extensive radiators which helped disperse the engine’s heat. The wings are also solid cast resin, featuring recessed detail for the ailerons, and also bearing an abundance of engraved detail for the radiators to be found there, which appear to occupy almost 90% of the wings’ upper and lower surfaces.

In terms of internal cockpit detail, there is a simple two-part seat, a control yoke, a photo-etched instrument panel with a film insert, and a forward bulkhead with an instrument panel hood. Photo-etched parts provide additional detail in the form of instrument levers, rudder pedals and seat straps. The fuselage interior bears raised sidewall detail illustrating the cockpit framing.  The ailerons as well as the elevators and rudder for the tail section are well-detailed with a nice stressed fabric effect. There are individually mounted blades for the kit’s contra-rotating propellers, and separate parts for the dorsal and ventral vertical tail surfaces. A separately mounted two-piece spinner and a clear windshield round out the kit’s resin parts.

The kit instructions have little text but are clear and very well illustrated. They even provide a guide on the placing of the bracing wires (not provided, but sold separately and also manufactured by SBS, Product No. 72042). There is a separate folded sheet that is the Painting Guide – a color plate providing profile and top views of the MC 72. However, it simply refers to colors by their names (gloss red, brass, gloss black) and does not identify any manufacturer, so the modeler is left to his own ingenuity and preferences in this department — you are on your own if you are manic about “accurate” colors.

Markings

Decals are provided not only for the Italian tri-color on the tail, but also for stencils as well as what appears to be the seal for the House of Macchi. Noticeably absent are markings depicting the Italian fascist symbol, which is seen on some models of this kit as well as artist’s renditions, but is not substantiated either by the photographic records of the plane itself, or the restored example currently on display in the Italian Air Force Historical Museum in Rome.

Conclusion

This is a beautifully rendered kit that appears to be painstakingly accurate, and is a radical improvement over the Delta 2 kit, the only other manufacturer known to have produced the MC 72 in 1/72 scale. Highly recommended.

References

• warbirdnews.com ~ “Macchi Castoldi MC 72, The World’s Fastest Piston-Powered Seaplane,” by Luigino Caliaro
• fly.historicwings.com ~ “Agello and the MC 72”
• forums.x-plane.org ~ “Macchi-Castoldi M.C.72 Fastest SeaPlane (1934)”
• wikipedia.org