The iconic display boards are representative of a nostalgic bygone era of air travel.

Once regular features at airports worldwide, split-flap departure and arrivals boards have all but disappeared as LED and digital screens have taken over. Yet their legacy lives on as the sight and sound of excited trepidation for millions of travelers as they embarked on their first-ever journey by air. Let's take a trip down Memory Lane and look at these iconic features of commercial aviation history.

The typical modern-day airport terminal is fast becoming a monolith of polished stone floors, with copious amounts of glass providing an abundance of light to its users.

However, it was not long ago that terminals echoed with the familiar 'clack-clack-clack' sound and the gentle breeze created as cogs whirred, wheels turned, and hundreds of characters on huge flight information displays would miraculously and regularly re-invent themselves

The visual spectacle as numerous lines of flight information transformed themselves as the flights gradually moved up the display would often gather crowds. Many passengers would stand and stare, marveling at this technological masterpiece as it underwent this procedure hundreds if not thousands of times each day. Others would simply obtain the information they required and head on their way.

The split-flap display, otherwise known as Solari boards, eponymously named after their inventor, was once a cornerstone of airport terminals worldwide. Yet, regardless of their technological genius and ability to display vast amounts of information that could be changed every few minutes, such boards have sadly been all but confined to aviation folklore.

Split-flap displays are electro-mechanical digital display devices that present changeable alphanumeric graphics to convey information in dynamic settings like airports or other transportation hubs. The signs also later developed the capability to display graphics and logos. The device, just like clocks, changed the information it displayed via motors and electrical current.

In split-flap devices, such as early digital clocks, each character or graphic position has a collection of flaps on which the various characters or graphics are printed. These flaps are precisely rotated via the internal mechanics to show the desired character or graphic.

Having the ability to display information clearly and change automatically, just like a clock, meant that these devices found a vast array of applications, such as railway stations and airport terminals from the 1960s onwards, typically to display departure or arrival information.

The split-flap displays of this era were complex and required specialist knowledge if they required maintenance. When installed, split-flap displays appear sleek and simple. However, over 5 million individual pieces contribute to the display's functionality and sound.

Yet, in an age before LED and digital displays, their ability to constantly refresh the information was invaluable to transport hubs such as airports while also offering the following additional benefits -

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The story of these displays goes back to 1725 when the Italian clockmaking company, Solari di Udine, opened for business in a small town in northern Italy. The company specialized in the manufacture of clocks for the towers of churches and other municipal buildings.

In the post-Second World War era and following a long history of successful trading, the family-owned firm (run at this stage by Remigio Solari) collaborated with an Italian designer, Gino Valle. Together they designed a moving sign created initially to display the time to users of railway stations.

These early signs were simple but brilliant, using four flaps, each split horizontally across the middle, containing ten digits. With white numbers set against the black flap backgrounds, the groundbreaking design won the prestigious Compasso D'Oro award in 1956. Later that same year, Solari di Udine sold its first moving sign to Liege railway station in Belgium.

With further collaboration and input from a Belgian inventor, John Meyer, the basic design evolved into the more complex arrangement we are now familiar with, increasing from four to 40 flaps.

With this increase in size, along with the enhanced capability to display letters and numbers, the Solari board transformed from a simple time-telling device into something with a far greater number of applications.

Thanks to their versatility in such environments, the company has reportedly sold thousands of boards to airports and railway stations worldwide. The company even shifted units to many far-flung corners of the world and even to many remote markets, given their international recognition and as their appeal spread across the globe.

Although Solari was not the only manufacturer, and copy-cat manufacturers sprang upon the groundbreaking technology, it's the Italian company that became forever linked to the technology, which along with companies such as Hoover, Jeep, or Jacuzzi, has become synonymous with its unique design.

Solari di Udine remains an industry leader in dynamic signage and still sells products to airports and railway stations. However, the signs are now fully electronic, reducing the maintenance required with the resulting increase in reliability. Sadly, the company that invented the split-flap display no longer markets or sells the products it is most well-known for to airports.

That said, many Solari boards do still exist. Some airports still do retain them, albeit in a non-operational state. They're often kept as nostalgia pieces, protected behind glass and retained for historical reasons, or increasingly to provide exciting subject matter for this Instagram age.

In Australia, for example, there are three working boards in the Qantas first class lounges at Sydney and Melbourne airports. Additionally, there are two retained in the remarkable TWA Hotel located at New York's JFK International Airport.

However, you are more likely to find Solari boards away from airports rather than inside them these days. The hospitality industry, in particular, has adopted the iconic retro appearance of the boards. Indeed, Solari di Udine continues to sell its boards to shops, restaurants, museums, and hotels. In recent years, other sectors have also been embracing them as a nod to the sepia-tinted age of nostalgia.

With the introduction of wireless technology, cloud-based applications can assist users in controlling their modern-day split-flap displays with ease. Many of the new displays run on Linux, which means that users can control messaging either manually or autonomously from anywhere in the world. And no longer are complex electronics required either. A standard 110-220V power supply is all that is needed for a split-flap display to operate.

Although essentially now extinct from airport departure concourses and arrivals halls alike, the split-flap display will long be remembered as a key part of the visual experience of air travel. The sight of them and the sounds they created will be retained in the memories of millions of air travelers who came into contact with them over the decades.

Those memories conjure up romantic feelings of the anticipation of faraway travel or the reuniting with friends and loved ones from overseas. They presented onlookers with a window into the world, presenting the viewer with a menu of exotic destinations that many could only dream of visiting during their lifetime.

But their simple design, combined with the visual spectacle that they created every time they refreshed their displays, is missed by many. You only needed to look up at the Solari board when you heard the distinctive whirr as the information changed to get an update on your flight's status, unlike the characterless digital airport display signage of today.

In summing up, there can't be too many individuals these days that would stand in front of a random airport LED screen marveling at its technical and visual ingenuity in the same way that people once did with Solari boards - an icon of a golden era of air travel that regrettably has since been confined to aviation history.

What are your recollections of split-flap airport displays? Do you know of any airports that still use a working Solari board to convey flight information? Let us know in the comments.

Journalist - Working for several airlines & Airbus, Luke gained a comprehensive knowledge of the commercial aviation industry, before retraining as a lawyer specializing in aviation. A qualified private pilot, Luke also helps to keep one of the world's last WWII Catalina flying boats airworthy. Based in Cambridge, UK.