WW1 Italian Prototypes WW1 US Patent Designs

Longobardi’s Combination Vehicle

United States of America/Kingdom of Italy (1918)
Flying Submarine Car – None Built

In the centuries of the patent system, a veritable pantheon of good and bad ideas have come and gone and, in the wake of World War One, this tradition continued with some truly awful ideas. One of these ideas was quite rightly consigned to the dustbin of history. The idea of a wonder weapon capable of fighting both on the seas as a warship, in the air as a combat aircraft, and on land as a tank. This is Mister Longobardi’s improbable armored car-plane-submarine-warship of 1918.

The Man

Felix Longobardi is anything but a household name, but there are clues to this man from his patent application in the United States on 12th June 1918. Mr. Longobardi provided a city residency as Chicago, Illinois and was clear that he was a subject of the King of Italy i.e. had not yet adopted US citizenship.

Felix Longobardi arrived at Ellis Island, New York on the SS Patria from Naples, Italy on 23rd September 1915 (the ship left Naples on the 8th) with his brother Domenico (and his brother’s wife), a baker by profession. As Felix was an “additional person” on that record to his 53 year old elder brother, it is fair to assume that Felix was born after Domenico although no actual date of birth or age is listed for him.

Ellis Island immigration register
Felix Longobardi’s name in the Ellis Island immigration register 23/9/15.

Felix is only recorded as submitting a single patent in the US – this one for the combination vehicle, although it should be noted that a ‘Felice Longobardi’ with an address in Chicago did submit a patent application in 1929 for a pneumatic vehicle wheel and used the same firm of attorneys to do so, namely Messers. Glenn and Noble. Whether this patent applicant is the same person as ‘Felice’ rather than ‘Felix’ cannot be determined.

To add to the unknowns about the designer, Felix is not listed on the 1920 or 1930 US census nor in the rolls of the US Expeditionary Force War dead from 1917-1919. What happened to him is unclear. He may have changed his name, returned to Italy, or been one of the numerous casualties of the flu which swept across the US at the end of the decade.

The Vehicle

The outline of the shape of the vehicle is very distinctive and, as can be imagined for a vehicle capable of operating in 4 domains, is impractical in all of them although it is really the break-down of trying to make a vehicle suitable to travel in each medium which requires some analysis.


As a land-based vehicle, the Longobardi Combination Vehicle is utterly hopeless. Four small wheels lie astride the central third of the vehicle along its length. None of the wheels appear to be fitted with any kind of suspension and the patent explains they are on common axles and can be steered somehow. The ground clearance for the vehicle is woefully inadequate for anything other than the smoothest possible road with the three propellers underneath in each third of the length reducing this even further. This terrible clearance is compounded by enormous overhangs at both the front and rear, meaning that the bow and stern of this vehicle would be guaranteed to strike the ground on even the most rudimentary upwards or downwards slope. Add to this the exceedingly narrow track width (the distance between the centre-line of the tyres of wheels on a common axle) and this ungainly machine is seriously overbalanced laterally. Should it attempt to negotiate even a modest side slope it would likely topple over.

The idea that this vehicle could be used as a land-based weapon of war is frankly therefore laughable and creates probably one of, if not the worst designs for an armored car imaginable.


When this design was submitted in 1918, the basics of flight had been known for many years and armies had already deployed aircraft in combat. As a result, there is little excuse for such an inadequately designed machine as an aircraft. Firstly, there is the problem of the wings. Two relatively short rectangular wings protrude from the front third of the machine, each of which is barely wider than the hull of the machine itself.

Longobardi’s Combination Vehicle
Digitally cleaned front views of Longobardi’s Combination Vehicle with wings out (left) and stowed (right). The extremely narrow track width is apparent. Source: US Patent US1286679

The main wings were to be supported by cables and were also hinged at the body. When not in use, these wings could be raised and stowed in the vertical position, ensuring that this already enormous vehicle was even more visible when used on land.

Propulsion in the air was the same as in the sea – propellers – lots of propellers. In fact, two large propellers at the front provide pull in the air and in the water. Likewise, the three propellers underneath were to provide uplift in the water and (according to Longobardi) in the air as well. Thus, these horizontal propellers could provide vertical trim and additional lift.

Control of the horizontal and vertical attitude of the craft was to be provided by means of the small tail rudder working in combination with a small set of wings at the back when operating in the air or water.

ongobardi’s Combination Vehicle
Digitally cleaned plan-view of Longobardi’s Combination Vehicle shown facing to the right. At the front a pair of propellers were to provide propulsion. Of note is the very small wing surface on the rectangular wings at the front. A small rudder is positioned at the back. Source: US Patent US128667
Longobardi’s Combination Vehicle shown facing to the left
Digitally cleaned side view of Longobardi’s Combination Vehicle shown facing to the left. Source: US Patent US1286679


All of the propulsion for the vehicle via wheels and propellers (save for the rearmost propeller) was provided by a pair of large batteries in the bottom central portion of the hull. No means appears to have been provided by which these batteries could be charged up in the manner of an electric or hybrid-drive system, so once the vehicle set off, it would continually be reducing the available charge in the batteries. Unlike a conventional liquid or even solid-fuel vehicle, no combustion takes place, which means that the Longobardi’s vehicle is the same weight when the batteries are half or fully discharged as they are when full. With a conventional vehicle, as it consumes fuel it gets progressively lighter, which assists in extending the range. No such advantage exists here with a purely battery-driven system.

Two motors are provided inside the vehicle, one in the front third which could drive propellers as well as a cable drum for winching in-or letting out the cable which controlled the position of the wings, and a second motor at the very rear which drove the primary propeller at the back.

No sizes or motor capacities were described in the patent. Nor is there any detail as to the power source for these motors. No estimates as to the weight of the batteries is provided or the available storage.

The primary advantage of electing this electric-drive system is that it obviates the need to burn fuel so the vehicle does not need an exhaust or funnel to vent out gases. This is an advantage for a vehicle planned for potentially going underwater, as it allows for the hull to be kept watertight more easily. The large funnel-shaped object on the vehicle is not, in fact, a funnel, but is the conning tower for observation and access, although when in use on land or flying, observations were to be carried out from the small compartment in the front roof of the vehicle marked as ‘38’ on Longobardi’s cut-away drawing.

 Longobardi’s Combination Vehicle shown facing to the right
Digitally cleaned cut-away side view of Longobardi’s Combination Vehicle shown facing to the right. Source: US Patent US1286679


No weapon of delivering war to your enemies is much use without some form of offensive firepower and Longobardi’s vehicle is no different. Clearly shown on the drawings in the patent as a trio of cannons. Looking at the foremost of these weapons, it is also clear that it is intended for firing out of a split rectangular hatch in the side of the hull and, as the left view of the vehicle also shows, such a door strongly suggests a fourth gun as a single gun to fire out of both sides would be extremely limited in what it could fire at, as it would be set back too far from both of those side hatches.
The rearmost of the guns are both shown pointing upwards through hatches in the roof of the vehicle and were intended for protection against aircraft. No details of what type of guns these may be is explained by Longobardi but the most notable part of his plan for armament is the lack of forward-facing weaponry.

Although the hull is air-tight, there is no mention of any thickness of it or what material it would be made from. If steel, even lightweight and all welded steel is considered it would have to be thin to keep that weight down but also strong enough to withstand the pressure of being submerged even a small distance under the water. It could only be concluded that no meaningful protection to even bullets could be provided for this vehicle.


The only mention of crew was the single operator/driver of the machine. Considering the potential for 3 to 4 guns, however, this would mean a crew complement of at least 5 to be of any possible use.


Considering the year of the design was 1918, Longobardi certainly took inventiveness to a new level. In his design, he was picturing an electrically powered vehicle capable of independent flight as well as what would have been one of the largest wheeled vehicles on the roads of the day. The design is frankly a poor one. Far too boat-like and almost certainly incapable of any form of flight short of driving off a cliff. Ungainly and hopeless on the road, the vehicle was an enormous target as a ground-based vehicle, too big and too heavy for any realistic flight and added nothing to the issue of sea power that a conventional and far smaller, less technically complex ship could already accomplish. The whole machine is far too big to be able to have any kind of meaningful protection. There is, after all, a good reason why there are no flying submarines and despite Longobardi’s intentions to try and create an all-encompassing vehicle capable of operating anywhere, what he created instead was a design for a vehicle incapable of operating anywhere in any way better than vehicles, ships, and planes which already existed.

Longobardi’s Combination Vehicle in all of its glory, showing its wings, wheels and propellers to move on all sorts of terrain. Or, more physically accurate, sink, fall and break down on all terrains. An illustration by Yuvnashva Sharma, funded by our Patreon campaign.


Crew at least 5
Propulsion Electric batteries and motors
Speed little or none
Armament 3 – 4 guns
Armor little or none
Total production None built


US Patent US1286679 ‘Combination Vehicle’, filed 12th June 1918, granted 3rd December 1918.
US Patent US1796952 ‘Vehicle Wheel’, filed 15th June 1929, granted 17th March 1931.
New York Passenger Arrival Lists (Ellis Island) 1892-1924. Page 99, Line 9. US National Archives.

7 replies on “Longobardi’s Combination Vehicle”

The fundamental error of Longobardi was that he tried to sell his idea to the army. He should have targeted the toy market. This would have been a nice tin toy. The wheels and propellers could have been driven by clockwork. Just imagine holding it in your hand moving it through the air making motor sounds or having it swimming in your bathtub!
The idea of a giant flying submarine was used in at least one Japanese movie: Kaitei Gunkan. That shows the fascination of the concept.

Some ideas are ahead of their time to be truly effective. One man tanks, underwater aircraft carriers. These ideas were all tested and thought about many times, but it is not until 21’st century we finally have technological capacity to make these weapons efficient (robots and submarines launching drones).

You know the guy that doesn’t know how to min-max in a game? This is the vehicle equivalent.

here is a theory about the Longobardi vehicle, what if they made the vehicle secretly and maybe they did not want the public to find out and they secretly tested the vehicle if it will do anywhere at a secret location off of America or my other theory they made it and they been doing secret operations of it on sea air? or land and they manage to succeed in being the first vehicle to go on air-sea and land?

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