There is much debate surrounding ground effect vehicles (GEVs) and whether they should be considered aircraft or watercraft. These vehicles, also known as ground effect craft, wing-in-ground vehicles, wingships and ekranoplans, make use of the ground effect phenomenon where they glide along the surface on a sort of cushion of air that forms under their wings. 

Pilots have been aware of the phenomenon for as long as aircraft have existed, as it can be easily noticed during take-off and landing. However, it was only after WWII when the first experiments began to exploit its uses. It was observed that as the cushion forms at low altitudes, the lifting power of a wing increases, and so does the efficiency of a craft. Hence, vehicles that fly at very low altitudes are more fuel efficient than regular aircraft, which makes them a highly practical means of transportation.

Flight limitations

However, such vehicles are greatly limited in their operational area, flying no higher than a couple of meters above the ground. As a result, any obstacle, such as a tree, a building or a steep hill, is impassable. While deserts and steppes were considered for the use of GEVs, it was discovered that the flatness and emptiness of open water provided the best surface to operate them safely.

So, seas, oceans and lakes have been used as testing grounds for almost all GEV designs. The most famous GEVs, the giant Soviet ekranoplans, were developed for naval forces and intended for anti-shipping operations and assaulting the beaches. Yet, despite their sea-bound nature, Ekranoplans were flown by military pilots as their movement and controls were found to be more like those of airplanes.

To this day, questions about whether they should be referred to as aircraft or watercraft remain unanswered. 

Growing interest

A multitude of small companies continue to carry the torch for building GEVs. Some, such as United States-based Universal Hovercraft, offer small transport GEVs among other kinds of water vehicles. Others, like Russian RDC Aqualines, aim to build upon the legacy of Soviet aeronautical engineering, which began with ekranoplans. Then, there are those, such as Korea’s Wingship Technology, which are startups harboring ambitions to create an entirely new market.

But one region has received more attention from GEV developers than any other. Southeast Asia, with its abundance of islands and relatively calm seas, appears to be the perfect market for vehicles that can travel above the water at a fast pace. 

For some time now, GEV manufacturers have looked at the region with particular interest. Back in the late 1980s, when engineers in the Soviet Union commenced work on the first commercial ekranoplan designs, the Southeast Asian market was considered the holy grail. Lev Schiukin, chief designer of the EKIP (an ambitious project for an amphibious aircraft that could cruise at ground effect altitudes), called Southeast Asia’s ‘island states’ the perfect region for such machines. 

Nowadays, there are a multitude of companies that have developed, are in the process of developing or have announced an intention to develop a GEV intended specifically for the Southeast Asian market. These include small private initiatives, such as the attempt by Capt. Art Velasquez who started building an experimental GEV in a local seaplane hangar in the Philippines some time before 2013. However, other endeavours are more scientific, such as the Winged-In Surface Effect aircraft project, currently in progress with Cebu Technological University Department of Science and Technology (and recently attracted the interest of the Philippine Navy). 

Then, there are the more typical startups, which includes Singapore-based Wigetworks. The company has been working on several prototype WIGs since 2004 and hopes to attract attention and funding by promising to revolutionize transportation in the region.

“South East Asia has more islands than anywhere else on earth, often without the proper first world infrastructure, hence is ideally the best place to realize the GEV technology,” C J Goh, the executive director of Wigetworks, told AeroTime. 

The company has acquired licenses to build WIGs from Airfoil Development, a German company that strived to improve on the designs of Alexander Lippisch, one of the pioneers of ground-effect vehicles. According to Goh, a further reason behind the move to Southeast Asia was the expectation that regulatory difficulties (often encountered by unproven technology in Europe and elsewhere) could be avoided. 

For these reasons, other companies have opened branches or established a presence in the region. Hainan England WIG Manufacturing, a Chinese company based in Haikou, and RDC Aqualines both opened offices in Singapore. Even the WSH-500 GEV prototype created by Korean Wingship Technology is Singapore-registered.

Difficult to implement 

Aerotime attempted to contact Wingship Technology with questions about whether the prototype was registered in Singapore for regulatory reasons or with a hope to employ or test the machine. However, the company has not responded. While the company’s social media accounts remained active until at least 2019, its website was last updated in 2014 and there have been no new developments about the production of WSH-500s.

Aerotime also attempted to contact RDC Aqualines and Hainan England WIG Manufacturing. Both companies are yet to provide a response. RDC Aqualines has recently removed its social media pages, even though it has received at least one order - and failed to deliver on it. Hainan England WIG Manufacturing has shown no activity since 2015.

These developments are not unique. In fact, they are quite common in the world of GEVs. Companies reveal big plans, perhaps build a prototype or two, before fading out of existence several years later. That appears to be the norm.

Out of a dozen or Southeast Asia-based or affiliated firms, individuals and initiatives with GEV plans contacted by AeroTime, only Widgetworks responded. The project has moved slowly, with barely an update in recent years. Additionally, the COVID-19 pandemic has caused significant setbacks.

CJ Goh explained: “Trying to make something that no one has succeeded [in doing] before is easier said than done. There are many reasons for the very long gestation period, but the main one is probably the lack of understanding of fundamental physics, resulting in many failed WIG [wing-in-ground – AeroTime] projects, and [causing] injustice to the industry reputation.” 

This goes some way towards explaining why companies, which have shown at least some progress, including Wigetworks, RDC Aqualines and Wingship Technology, have roots in either prominent Cold War-era projects or are affiliated with large research institutions. Or both. Significant scientific groundwork needs to be established before GEV potential can be exploited.

While most were short-lived, at least modern GEV projects managed to answer one question. All existing prototypes, such as the WSH-500 of Wingship Technology and Airfish of Widgetworks, have been registered as watercraft rather than aircraft. According to Goh, the main reason for this is regulatory. 

Additionally, due to slow progress, these prototypes are mostly docked in water, rather than flown. While this may help to settle the debate, it does not diminish the potential of GEV designs to fly. 

The theory is certainly there and the design shows serious potential. It simply needs to be implemented correctly.

As the few remaining GEV companies continue with their projects, and the groundwork continues to be laid, hope still remains. Perhaps in a few decades or so, when swarms of shiny new GEVs start crisscrossing Southeast Asian seas and regulation adapts to this new reality, people will start equating this mode of transportation with aircraft. Maybe.

UPDATE 11-15-2021, 10:30 (UTC +3): Since the publishing of this article, RDC Aqualines has responded to the inquiry. The company says they still have an office in Singapore, and consider Southeast Asia as one of the most promising markets for ground effect vehicles. RDC Aqualines also continues working on their design and plan testing a technology demonstrator in 2023.