Caproni Ca.60

Caproni

Industry	Aviation, Aircraft manufacturing
Founded	1908 in Italy
Founder	Gianni Caproni
Headquarters	Italy
Key people	Gianni Caproni (founder)
Products	Aircraft, including the Caproni Ca.60 Transaereo

Template:Infobox aircraft

The Caproni Ca.60 Transaereo, also known as the Noviplano (meaning nine-wing) or occasionally called Capronissimo, was a pioneering prototype of a massive nine-wing flying boat designed to serve as a transatlantic airliner with a capacity for 100 passengers. The design incorporated eight engines and three sets of triple wings.

Constructed solely once by the Caproni firm under the guidance of Italian aviation pioneer Gianni Caproni, it underwent testing on Lake Maggiore in 1921. Its initial flight occurred on either February 12 or March 2. The second attempt took place on March 4; shortly after lift-off, the aircraft crashed into the water and disintegrated upon impact. Additional damage occurred during retrieval efforts. Although Caproni intended to reconstruct the plane, the project was discontinued due to prohibitive expenses. Remaining fragments are exhibited at the Gianni Caproni Museum of Aeronautics and at Italy’s Volandia aviation museum.

Development

Gianni Caproni earned renown as an aircraft designer and manufacturer throughout First World War, with his company producing successful heavy multi-engine bombers such as the Ca.32, Ca.33, Ca.36, and Ca.40. However, postwar demand for military bombers sharply declined in Italy, prompting Caproni, like many contemporaries, to pivot toward civil aviation markets.

As early as 1913, at age 27, Caproni predicted in an interview with La Gazzetta dello Sport that aircraft capable of carrying one hundred or more passengers would soon be realized. Following the war, beyond converting some large wartime bombers into passenger planes, he embarked on designing an enormous and ambitious passenger flying boat; he secured a patent for this concept on February 6, 1919.

At that time, envisioning a large multi-engine flying boat for extended passenger flights was regarded as unconventional. Nonetheless, Caproni believed such an aircraft could provide faster transportation to remote regions compared to land or sea routes and considered investment in innovative air travel more cost-effective than upgrading traditional infrastructure. He proposed its use both domestically and internationally, particularly in vast countries with underdeveloped transport systems like China.

Caproni argued that merely modifying wartime aircraft would not suffice to meet these goals; instead, a new generation of airliners with greater range and payload—thereby reducing per-passenger costs—was essential. He illustrated this by comparing communication times between New York and Buenos Aires: while letters took about a month each way via existing means, his triple-wing seaplane could complete the journey in three or four days.

Despite criticism from prominent Italian aviation figures including aerial warfare theorist Giulio Douhet, Caproni proceeded with his innovative design, patented in 1919.

Aware of safety concerns inherent to passenger aviation—which fueled Douhet’s objections—Caproni focused on enhancing reliability and mitigating accident risks. He designed his large seaplane as a multi-engine craft capable of maintaining flight even if one or more engines failed. He also contemplated (though ultimately rejected) backup engines that could be deactivated during cruise altitude and reactivated if necessary. The seaplane configuration allowed relatively safe emergency water landings on any sufficiently calm body of water. Furthermore, Caproni aimed to improve passenger comfort by increasing cruising altitude through technologies such as turbochargers and variable-pitch propellers, which compensate for engine power loss at higher elevations.

File:Ca.60 under costruction.jpg

The Transaereo during assembly in Sesto Calende. Gianni Caproni is seated on the left outrigger.

Construction of the model 3000, later known as Transaereo, commenced in late 1919. The earliest documented mention appears in a French newspaper dated August 10, 1919; initial components were likely fabricated at Caproni’s Vizzola Ticino factory. In September, an air fair held near Milan at the Taliedo factory extensively showcased this ambitious project. Later that month, Caproni conducted experiments using a Ca.4 seaplane to refine calculations for the Transaereo design. In 1920, a large hangar was erected in Sesto Calende on Lake Maggiore’s shore where most assembly took place; parts produced by subcontractors—many veterans from wartime collaborations—were integrated here.

By year-end, U.S. Ambassador to Italy Robert Underwood Johnson visited the site and expressed admiration for Caproni’s extraordinary aircraft. Press reports anticipated test flights starting January 1921 and suggested that successful trials would position Italy as a leader in civil aviation worldwide.

On January 10, 1921, tests were conducted on forward engines and their nacelles without detecting harmful vibrations; two aft engines passed tests on January 12. On January 15, Caproni formally requested authorization for test flights from General Omodeo De Siebert, Inspector General of Aeronautics.

Design

The Transaereo was a massive flying boat featuring a primary hull that housed the cabin, suspended beneath three tandem sets of wings. Each set consisted of three vertically stacked aerodynamic surfaces, forming a triplane arrangement: one set was positioned in front of the hull, another behind it, and the third centrally located slightly lower than the other two. Each of the nine wings measured 30 m (98 ft 5 in) in wingspan, with a combined wing area totaling 750.00 m² (8073 ft²). The fuselage extended 23.45 m (77 ft) in length, while the overall height from the hull’s base to the uppermost wing reached 9.15 m (30 ft). The aircraft’s empty weight was recorded at 14,000 kg (30,865 lb), with a maximum takeoff weight of 26,000 kg (57,320 lb).

File:Caproni Ca.60 modeli in Volandia Museum.jpg

Scale model of the Transaereo displayed at the Volandia museum. Note the central push-pull engine nacelle flanked by pull-only nacelles on each side, along with open pilot cockpits atop the main cabin and a flight engineer station within the central nacelle.

Lifting and control surfaces

The three-wing sets were directly adapted from the lifting surfaces originally designed for the triplane bomber Caproni Ca.4; after World War I, multiple Ca.4 aircraft were dismantled to provide components for constructing the Transaereo.

The aircraft’s flight control system incorporated ailerons on every wing and rudders for directional control, despite lacking a conventional tail assembly, particularly no horizontal stabilizer. Control over roll, or rotation about the longitudinal axis, was achieved through differential movement of the port and starboard ailerons in a standard manner. For pitch, which involves rotation around the transverse axis, control was managed via differential action between fore and aft ailerons since no elevators were present. Yaw control—rotation about the vertical axis—was provided by four articulated vertical surfaces situated between the wings of the rearmost set, functioning as both vertical stabilizers and rudders. The wings were designed with a positive dihedral angle, enhancing stability around the roll axis. Caproni anticipated excellent pitch stability due to the tandem-triplane layout, with the rear wing set serving as an extensive and effective stabilizing surface; he claimed that this immense aircraft could be "operated with just one hand on the controls." This distinctive control system was patented by Caproni on September 25, 1918.

Propulsion

File:Caproni Ca.60 Liberty engine.JPG

Displayed here at the Caproni Museum is the sole remaining example of the eight Liberty L-12 engines used on the Transaereo.

The aircraft's powerplant consisted of eight Liberty L-12 V12 engines manufactured in the United States. Each engine delivered 400 hp (294 kW), ranking among the most potent engines produced during the First World War.

These engines were organized into two clusters of four: one positioned on the front wing assembly and the other on the rear wing assembly. Each cluster incorporated a central nacelle housing a pair of engines arranged in a push-pull configuration, all driving four-blade propellers. Flanking these central nacelles were single-engine pods equipped with two-blade propellers. In the forward cluster, these side engines operated in a pulling manner, whereas in the rear cluster, they functioned in a pushing mode.

Every nacelle was equipped with radiators to cool the cooling liquid. The two front side engines were structurally connected to both the central wing section and their corresponding rear engines via truss booms with triangular cross-sections.

Within each central nacelle was an open cockpit designated for a flight engineer. These engineers managed engine power output based on pilot instructions transmitted through a sophisticated system of illuminated signals and gauges mounted on electrical control panels.

File:Caproni Ca.60 engine control panel.JPG

An engine control panel from the Transaereo, exhibited at the Caproni Museum. The panel’s switches and indicator lights facilitated communication between pilots and flight engineers.

Fuel tanks were installed in the cabin roof near the central wing structure. Fuel delivery to the engines was achieved using wind-driven fuel pumps.

Hulls

Extending beneath most of the wing framework, the main fuselage spanned the entire length of the aircraft. The passenger compartment was enclosed and featured expansive panoramic windows. Seating arrangements consisted of wooden benches designed for paired seating, with passengers facing each other—two seats oriented forward and two backward. A lavatory was situated at the aft section of this fuselage.

Above and slightly behind the forward cabin windows sat an open cockpit accommodating both a pilot in command and a co-pilot seated side-by-side. This flight deck floor was elevated relative to the passenger cabin, allowing pilots’ shoulders and heads to protrude through an opening in the roof. Access to this cockpit from inside the fuselage was provided by a ladder.

In addition to the primary hull, two side floats were mounted beneath the central wing assembly serving as outriggers that stabilized the aircraft during stationary floating, takeoff, and landing. Renowned seaplane designer Alessandro Guidoni was commissioned by Caproni to develop these hull components—the floats, their hydrodynamic connectors, and two small hydrofoils near the aircraft’s nose. Guidoni’s innovative float designs aimed to minimize both size and weight for enhanced performance.

Test flights

On January 20, 1921, the Transaereo was removed from its hangar for the first time and extensively photographed that same day. The following day, January 21, plans were made to place the aircraft on the water for its initial flotation, with a cameraman hired to capture footage of the flying boat on the lake. However, due to the lake's low water level and complications involving the slipway connecting the hangar to the lake surface, the aircraft was unable to reach the water. After obtaining authorization from De Siebert, the slipway was extended on January 24 and then lengthened again on January 28. Efforts continued amid various difficulties until February 6, when Caproni was informed that 30 wing ribs had broken and required repair before flight testing could commence. This news angered him, prompting him to keep his team working overnight so that testing could begin on February 7. Although the ribs were repaired, a broken engine starter was subsequently discovered, causing further delays in starting the trials.

Finally, on February 9, the Transaereo was placed on the water with its engines running smoothly and began taxiing across the lake's surface. The pilot for this and all subsequent tests was Federico Semprini, a former military flight instructor notable for having performed a loop with a Caproni Ca.3 heavy bomber. No flights were conducted with more than one pilot aboard.

File:The Caproni Ca.60 on Lake Maggiore, 1921.png

The Transaereo afloat on Lake Maggiore.

While remaining on the water’s surface, the aircraft executed several turns before accelerating as if preparing for takeoff and performing additional maneuvers in front of Gianni Caproni and other prominent figures in Italian aviation during the 1920s: Giulio Macchi and Alessandro Tonini from Nieuport-Macchi, and Raffaele Conflenti of SIAI. The tests were cut short due to deteriorating weather conditions but yielded positive results. The aircraft responded well to controls, demonstrated stability and maneuverability; however, it appeared somewhat light at the front. By day's end, some water had leaked into the fuselage, though Caproni remained satisfied.

File:Caproni Ca.60 Transaereo scale model.JPG

A period scale model of the Transaereo displayed at the Gianni Caproni Museum of Aeronautics reveals details such as the left outrigger position and hull shape.

The next day, after reevaluating his calculations, Caproni opted to add ballast to the bow of the Transaereo before conducting further tests to prevent excessive nose pitching.

Additional taxiing trials were successfully completed on February 11. On either February 12 or March 2, 1921, with approximately 300 kg (660 lb) of ballast loaded in the bow, the Transaereo reached a speed of about 80 km/h (50 mph) and achieved its first takeoff. During this brief flight, it remained stable and maneuverable despite a continuing tendency to climb steeply.

The second flight occurred on March 4. According to Semprini’s later account, he accelerated to between 100 and 110 km/h (62–68 mph), then pulled back sharply on the yoke causing the aircraft to lift off with a steep nose-up angle. He reduced throttle but soon lost control as the tail began dropping sharply; this led to a rapid loss of altitude. The tail struck the water first followed by the nose crashing into the surface, breaking apart the forward section of the hull. The fore wing collapsed into the water along with the nose section while both central and rear wing assemblies and tail remained afloat. The pilot and flight engineers escaped unharmed.

File:Il Caproni Ca.60 dopo l'incidente, 4 marzo 1921.png

The damaged Transaereo being towed ashore after its crash on March 4, 1921. The boat visible may be linked to interference during takeoff contributing to the accident.

Caproni was delayed arriving at Lake Maggiore by car from Vizzola Ticino and reached only after the crash had occurred. Reflecting later he said: "Years of work ended in an instant—an aircraft intended as a foundation for future aviation lost so quickly. Yet one must not despair if progress is desired; advancement is paved with hardship."

At that time, two primary factors were identified as causes of the accident. First was believed to be interference from wake waves created by a steamboat operating near where Transaereo was accelerating for takeoff. Second was pilot Semprini’s error in persistently pulling back on the yoke instead of performing corrective actions such as lowering the nose to gain speed before climbing. Another theory suggests that since Semprini had intended only taxiing trials—not actual takeoff prior to Caproni’s arrival—he may have been forced into taking off prematurely at insufficient speed to avoid colliding with a ferry carrying passengers nearby. More recent analyses propose that unsecured sandbags used as passenger weight simulators shifted backward when the aircraft pitched up suddenly during takeoff; this rearward shift altered center of gravity unfavorably causing loss of control and stall followed by tail-first impact with water.

File:Museo dell'Aeronautica Gianni Caproni Ca.60 (2).JPG

Remnant pieces of outriggers and lower front section of main hull exhibited at Gianni Caproni Museum of Aeronautics.

File:Caproni Ca.60 fragments in the Volandia aviation museum.JPG

Additional surviving fragments including part of a truss boom and one hydrofoil displayed at Volandia museum.

Since both Caproni and photographer traveled together by car, no images exist capturing takeoff or crash events; however many photographs document wreckage aftermath.

Though severely damaged by impact, roughly two-thirds of rear fuselage plus central and aft wings remained intact but required towing ashore. During this transfer—possibly aboard same boat implicated in takeoff disturbance—the aircraft suffered further harm: significant water ingress submerged part of fuselage while central and rear wings partially collapsed.

Repair prospects appeared slim as only metal components and engines remained serviceable; nearly all wooden structures needed replacement. Caproni estimated restoration costs would equal about one-third of original prototype expense but doubted company resources could support such outlay. Despite initial discouragement, by March 6 he was already contemplating design changes aimed at continuing development toward a transatlantic flying boat capable of carrying 100 passengers; he resolved to construct a quarter-scale model for ongoing testing.

Following consultations with De Siebert and Ivanoe Bonomi (former Minister of War), Caproni believed building a one-third scale model feasible; Bonomi pledged full financial backing should he win upcoming elections. Although Bonomi became Prime Minister in July, shifting political priorities ultimately led to abandonment of further Transaereo development.

While never achieving success operationally, the Caproni Ca.60 remains regarded as "one of history’s most extraordinary aircraft."

Aircraft exhibited

Following the eventual discontinuation of the Transaereo project, most of the damaged airframe was lost. Nonetheless, Caproni recognized the significance of safeguarding and commemorating the historical legacy tied to the origins and early progress of Italian aviation overall, and specifically to the Caproni company. Due to his historical awareness, several components of the Transaereo—later designated as the Caproni Ca.60—were preserved: these included the two outrigger structures, the lower front portion of the main hull, a control and communication panel, and one Liberty engine. These elements accompanied the Caproni Museum through its various relocations from its establishment in 1927 until its transfer to Trento in 1992. In 2010, they were exhibited alongside other permanent collection items within the museum's principal gallery.

Additionally, a segment of one of the two triangular truss-booms survived, as did one hydrofoil that linked the main hull to an outrigger. These remnants are currently presented at the Volandia aviation museum located in the Province of Varese, housed within former Caproni industrial facilities at Vizzola Ticino.

Technical data (Ca.60)

File:Caproni Ca.60 3-view.svg

In popular culture

The Caproni Ca.60 appears in the 2013 semi-fictional film The Wind Rises, directed by the renowned Japanese filmmaker Hayao Miyazaki. The film also includes a portrayal of Caproni himself.

See also

• Gianni Caproni Museum of Aeronautics
• List of experimental aircraft
• List of flying boats and floatplanes

External links

• Period documentary about the Transaereo (static display)