Caproni Ca.60
The Caproni Ca.60, also known as the Noviplano or Capronissimo, was an experimental large flying boat prototype designed by Italian aviation pioneer Giovanni Battista Caproni and built by Società Italiana Caproni in the early 1920s for transatlantic passenger transport.[1][2] This ambitious aircraft featured a radical nine-wing configuration arranged in three staggered triplanes, with a wingspan of approximately 30 meters (98 feet 5 inches) and a height of about 9 meters (29 feet 6 inches), creating a massive structure intended to provide exceptional lift for long-distance flights.[1][2] Powered by eight 400-horsepower Liberty L-12 piston engines mounted in tandem pairs on the forward and aft wings, it had an empty weight of 14,000 kg (30,865 lb) and a maximum takeoff weight of 26,000 kg (57,320 lb), enabling a theoretical capacity for up to 100 passengers in enclosed cabins with panoramic windows and wooden benches arranged in compartments.[1][2][3][4] Developed in the post-World War I era to leverage Caproni's bomber expertise—such as from the Ca.3 biplane and Ca.4 triplane—the Ca.60 incorporated a triple-fuselage layout with a central main hull for the flying boat and stabilizing pontoons, an open cockpit, and in-flight engine servicing capabilities, aiming to make ocean crossings affordable and comfortable for civilians across the Atlantic or Mediterranean routes.[1][5][2] Completed by late January 1921 near Lake Maggiore, the sole prototype conducted its brief test flights, culminating in a crash on March 4, 1921, shortly after takeoff due to structural failure, rendering it a total loss and halting further development.[1][2][4] Remnants of the wreckage, including structural components, are preserved today at the Gianni Caproni Museum of Aeronautics in Trento, Italy, serving as a testament to early 20th-century aviation innovation and the risks of oversized aircraft design.[1]Development
Conception and Patent
Gianni Caproni, an Italian aviation pioneer renowned for his innovative multi-engine aircraft designs during World War I, sought to transition his expertise to civilian aviation in the postwar era. Having successfully developed the Caproni Ca.3, a three-engine biplane bomber introduced in 1913, and the Ca.4, a triplane bomber from 1917, Caproni envisioned a large-scale airliner that could safely transport approximately 100 passengers across the Atlantic Ocean, addressing the growing demand for reliable long-distance travel amid the collapse of military contracts and a surplus of surplus aircraft flooding the market.[5][2] On February 6, 1919, Caproni filed a patent for his "Noviplano" concept, an ambitious multi-engined seaplane design initially featuring a six-wing configuration that emphasized enhanced stability and lift through a triplane arrangement, principles drawn from his earlier triplane experiments. This patent laid the groundwork for what would evolve into the Ca.60, prioritizing redundancy via multiple engines to mitigate single-point failures and ensure safer operations over vast oceanic distances. The design's focus on a triplane setup was intended to provide superior low-speed handling and structural integrity for heavy loads, reflecting Caproni's belief in scaled-up wing surfaces for commercial viability.[5][6] Conceived as a flying boat, the Noviplano was tailored to exploit water-based operations, circumventing the limitations of rudimentary postwar land infrastructure in Europe and enabling direct routes from coastal hubs without reliance on underdeveloped airfields. Caproni's motivations were rooted in making transatlantic air travel accessible and economical, aiming to enable non-stop transatlantic flights to bridge continents like Europe and North America. Passenger comfort was a core emphasis, incorporating features such as panoramic windows and spacious accommodations to evoke a sense of luxury, transforming the aircraft into a veritable flying ocean liner.[2][5]Construction and Initial Testing
Construction of the Caproni Ca.60 prototype commenced in the second half of 1919, shortly after the patent for its multi-wing design was filed, and spanned approximately 18 months until completion in late January 1921. Final assembly occurred in a large hangar specially erected on the shores of Lake Maggiore to accommodate the aircraft's enormous dimensions and complexity. The project demanded innovative techniques to manage the scale, drawing on Caproni's experience from wartime bomber production at their Taliedo facility near Milan, where initial components were likely fabricated.[1][5] The airframe featured a primarily wooden structure covered in linen fabric, consistent with early 20th-century aviation standards for large flying boats, while metal struts provided essential bracing to the nine-wing configuration and limited structural flexing. Aluminum elements were employed for the engine mounts to handle the vibration and weight of the powerplants, and steel reinforcements strengthened the hulls for water operations. Post-World War I supply shortages, particularly for the eight 400 hp American Liberty L-12 engines, caused significant delays in procurement and integration, extending the build timeline into early 1921.[2][5] Pre-flight preparations included rigorous ground testing phases to validate the prototype's stability and systems. Taxi trials on Lake Maggiore's waters began shortly after completion in February 1921, lasting nearly a month under test pilot Federico Semprini to fine-tune hydrodynamic balance and handling. Additional efforts encompassed structural load tests to assess the airframe's integrity under weight and engine run-ups to confirm the propulsion system's synchronization and reliability. These tests highlighted minor issues resolved through on-site modifications before attempting powered flight.[1][2]Design
Airframe and Hull
The Caproni Ca.60 featured a distinctive triple-fuselage configuration optimized for stability and buoyancy in its role as a large flying boat. The central fuselage formed the primary boat-like hull, measuring 23.45 meters in length, which provided the main hydrodynamic support for water landings and takeoffs.[7] Flanking this central hull were two smaller outrigger fuselages, which enhanced lateral stability and contributed to the overall structural balance during marine operations. The total height of the airframe, from the keel of the hull to the upper wing surfaces, stood at 9.15 meters.[7] The central hull incorporated a spacious, enclosed passenger compartment designed for luxury transatlantic travel, accommodating up to 100 passengers in two wide rows of seats arranged along the sides.[2] Large panoramic windows lined the length of the hull on both sides, offering expansive views and natural light to enhance the onboard experience, while including areas for lounges and galleys to support extended flights.[2] The rounded nose and integral flight deck integrated seamlessly into the streamlined hull shape, resembling aspects of modern wide-body jet fuselages.[2] Structurally, the airframe had an empty weight of 14,000 kg and a maximum takeoff weight of 26,000 kg, with provisions for ballast to adjust trim and ensure proper weight distribution across the triple-fuselage layout.[7] This design emphasized robust support for the passenger load and operational demands of water-based aviation.[5]Wings and Control Surfaces
The Caproni Ca.60 employed a distinctive nine-wing configuration, comprising three vertically stacked triplane sets arranged in tandem along the fuselage, with each wing spanning approximately 30 meters to distribute lift across the aircraft's length and provide inherent redundancy in the lifting surfaces.[4][1] These wings were built with wooden spars and a fabric covering, following the lightweight construction techniques prevalent in early 1920s aviation to support the large total wing area of 750 m² while maintaining structural integrity for heavy loads.[8] Ailerons were fitted to the outer panels of all three wing sets, enabling roll control, while the rear set incorporated twin booms supporting elevators and rudders for additional stability and directional control.[5] The multiplane arrangement stemmed from designer Gianni Caproni's experience with triplane bombers like the Ca.4, emphasizing enhanced low-speed lift and stability to facilitate safe operations as a seaplane over water bodies such as the Mediterranean or Atlantic.[2][8] Flight controls were cable-linked to a central open cockpit, allowing the pilot to operate the ailerons differentially across fore and aft sets for both lateral and longitudinal adjustments, with the rudder on the tail booms handling yaw inputs.[5][9]Propulsion System
The Caproni Ca.60 was powered by eight Liberty L-12 water-cooled V-12 engines, each rated at 400 hp (298 kW), for a combined output of 3,200 hp. These American-built engines, the most powerful available from World War I production, were acquired from U.S. military surplus to capitalize on their proven reliability and availability.[1][8][10] The engines were arranged in two distinct groups of four to optimize thrust distribution and maintenance access. Four tractor-configured engines were mounted in nacelles on the lower wing set, with two positioned on each side of the fuselage; the remaining four were configured as pushers on the upper wing set in a similar bilateral layout. This setup allowed crew members to access and service all engines in mid-flight via walkways and platforms integrated into the wing structure.[5][2] Fuel was stored in main tanks located in the upper sections of the hulls, aligned with the central fuselage for balance. From these, fuel was pumped to auxiliary feeder tanks in the wing roots, enabling gravity feed to the engines for reliable delivery during operation. The system supported an estimated range of 610 km under typical loads.[5][1] To enhance safety on long overwater routes, the propulsion layout incorporated redundancy features, including independent throttles for each engine that permitted continued flight on as few as four engines in the event of failures. This multi-engine approach ensured the aircraft could maintain control and progress despite partial power loss.[11]Operational History
Maiden Flight
The Caproni Ca.60 prototype underwent initial taxi tests on Lake Maggiore in early 1921, conducted by test pilot Federico Semprini, a former military flight instructor employed by Caproni.[12][2] These tests, lasting nearly a month, focused on balancing the hydroplane and assessing stability on the water, revealing high drag from the extensive wing surfaces and sensitivity in the control surfaces during maneuvers.[2] Some historical accounts report a brief short hop at low altitude prior to the official maiden flight, confirming basic takeoff capability and the multi-wing arrangement's ability to generate lift.[13][7] Post-hop evaluations highlighted the prototype's basic airworthiness, with engineers noting effective initial performance despite the observed drag and control challenges from taxiing. Minor rigging adjustments were implemented to refine handling and stability ahead of further testing.[13]Crash and Investigation
The maiden flight of the Caproni Ca.60 took place on March 4, 1921, over Lake Maggiore in northern Italy, with the aim of achieving sustained airborne duration.[14] Piloted by Federico Semprini with two engineers aboard, the aircraft became airborne using all eight engines, but stalled approximately 20 seconds after takeoff while climbing at an excessive angle of attack, reaching only about 18 meters (60 feet) in altitude.[15][1] The ensuing crash saw the flying boat nose-over into the lake, breaching the hull and causing the aircraft to partially submerge with severe structural damage, though the pilot escaped with slight injuries and there were no fatalities.[15][1] The prototype was subsequently salvaged from the water, but additional damage occurred during recovery efforts, rendering it unrepairable.[2] Investigation into the accident pointed to several possible causes, including a shift in the sandbag ballast simulating passenger weight, which may have destabilized the aircraft; failure in control linkages; or inherent instability related to the high wing loading and unconventional nine-wing configuration.[1][9] Designer Gianni Caproni attributed the stall primarily to pilot error, claiming Semprini had pulled up too abruptly.[2] In the aftermath, the Ca.60 project was abandoned, with no further prototypes constructed due to the extensive damage and financial implications.[1] The failure negatively influenced subsequent flying boat designs by highlighting the risks of extreme multiplane layouts, contributing to a shift toward more conventional biplane or monoplane configurations in large seaplanes.[2]Legacy
Surviving Components
Following the crash of the Caproni Ca.60 on March 4, 1921, during its maiden flight over Lake Maggiore, salvage operations were promptly initiated under the direction of designer Gianni Caproni. The wreckage, consisting of hull sections, wing elements, and engines, was dragged to shore using ropes and horses, but this process exacerbated the damage to the fragile wood-and-canvas airframe, causing much of it to disintegrate. The remaining components were stored in Caproni's lakeside hangar near Vizzola Ticino for assessment, though plans to rebuild the aircraft were ultimately abandoned due to the extent of destruction and high costs.[2] Among the key artifacts recovered are a forward fuselage fragment, a control and communication panel, a propeller, and parts from one of the Liberty engines, which have been preserved since the 1920s. These items, along with sections of the outriggers and lower hull, reflect Caproni's foresight in retaining historical elements despite the project's failure. At the Volandia Museum of Flight near Milan, visitors can view displayed fragments including a fuselage bracket, a wing strut brace, a section of the triangular truss-boom that connected the wings to the floats, and a portion of the lower hull, all salvaged directly from Lake Maggiore.[2][1][16] The majority of the Ca.60's structure was scrapped shortly after salvage owing to irreparable crash damage, leaving only these scattered fragments. Further losses occurred during World War II, when Caproni's facilities in the Lake Maggiore area were disrupted by military activities and bombing, scattering or destroying additional remnants. At the Gianni Caproni Museum of Aeronautics in Trento, surviving pieces such as engine components are on display.[2][1] As of 2025, no significant new discoveries of Ca.60 components have emerged from Lake Maggiore or related sites. Conservation efforts at Italian aviation museums continue to focus on stabilizing the existing artifacts against deterioration from age and environmental factors, including non-invasive treatments for wood and metal elements to maintain their integrity for future study and display.[1]Cultural Depictions
The surviving components of the Caproni Ca.60 are preserved and displayed in Italian aviation museums, serving as focal points for exhibits on early 20th-century experimental aircraft design. At the Gianni Caproni Museum of Aeronautics in Trento, artifacts including a propeller and engine elements from the prototype are showcased, highlighting the engineering innovations of the 1920s interwar period.[17] A section of the hull, along with fuselage brackets and wing struts recovered from Lake Maggiore, is exhibited at the Volandia Museum near Milan, accompanied by blueprints, photographs, and a large-scale model that contextualizes the aircraft's ambitious transatlantic aspirations within the era's aviation advancements.[2] In popular media, the Ca.60 appears as a fictionalized element in Hayao Miyazaki's 2013 animated film The Wind Rises, where it represents the perils of bold yet imperfect aeronautical engineering during the protagonist's dream sequences.[18] The aircraft's depiction draws from its real historical failure, symbolizing the creative risks taken by designers like Gianni Caproni. The Ca.60 is frequently cited in aviation histories as a quintessential example of overambitious interwar experimentation, illustrating the challenges of scaling up flying boat technology for passenger transport before aerodynamic and structural refinements were mature.[2] It receives occasional coverage in documentaries on early aviation pioneers and unconventional aircraft, such as those exploring 1920s prototypes and their role in shaping modern airliners.[19] As of 2025, interest in the Ca.60 has seen renewal through scale model kits available from specialty manufacturers, enabling enthusiasts to replicate its distinctive nine-wing configuration, alongside online aviation communities discussing its historical significance.[20] However, no major new films or dedicated exhibits have emerged in recent years.Technical Specifications
General Characteristics
The Caproni Ca.60 Noviplano, a pioneering prototype for large-capacity transatlantic air travel, featured massive dimensions to support its nine-wing configuration and flying boat hull. Its overall length measured 23.45 meters, with a wingspan of 30 meters and a height of 9.15 meters; the total wing area spanned 750 square meters, enabling substantial lift for heavy loads.[21][7] In terms of mass, the aircraft had an empty weight of 14,000 kilograms and a maximum gross weight of 26,000 kilograms, yielding a useful load capacity of 12,000 kilograms that encompassed fuel, baggage, and accommodations for up to 100 passengers along with a crew of 8, including pilots and onboard mechanics.[21][7] The passenger configuration utilized multi-level seating within the central hull, emphasizing comfort for long-haul civilian operations, while the design incorporated no armament as it was intended solely as a commercial airliner.[21]| Characteristic | Specification |
|---|---|
| Wingspan | 30 m (98 ft 5 in) |
| Length | 23.45 m (77 ft) |
| Height | 9.15 m (30 ft) |
| Wing area | 750 m² (8,073 sq ft) |
| Empty weight | 14,000 kg (30,865 lb) |
| Gross weight | 26,000 kg (57,320 lb) |
| Useful load | 12,000 kg |
| Passenger capacity | 100 |
| Crew | 8 (pilots and mechanics) |
| Powerplant | 8 × Liberty L-12 V-12 engines, 400 hp (300 kW) each |
| Propellers | 4-bladed fixed-pitch |
| Armament | None |