Build Your Own Flying Boat
Three Self-Build Ekranoplans
Three 21st century backyard builders have each independently created 1–2 person ekranoplans as leisure craft, making use of freely available information online and affordable components.
This article was first published in Water Craft magazine issue 163 January 2024 titled “Flights of Fancy”. It is reprinted here with kind permission of the editor and has been reformatted for online.
Flying boats have been captivating imaginations for over a hundred years. Boatbuilders J Samuel White and Co of Cowes formed an aviation unit and displayed a partially built flying boat at the 1913 Aero Exhibition at London’s Olympia. The First World War interrupted John Porte’s efforts to build a boat to fly across the North Atlantic, so he honed his expertise at the Royal Navy seaplane experimental station, introducing a ‘notch’ which later evolved into a ‘step’ in the rear of the lower hull in Felixstowe flying boats. In the early days of aviation, being able to take off and land on water was crucial as few runways had been built.
By the 1930s, flying boats were carrying presidents, royalty and members of the social elite such as Eleanor Roosevelt and Ernest Hemingway across oceans. Flying boats required highly skilled pilots and as land-based aviation grew after the Second World War, the popularity of sea-planes declined.
The harrier — the bird of prey, not the jet fighter — inspired subsequent flying boat builders. In the cold war era, the USSR’s Lun-class ekranoplan was designed to be flown within 13' (4m) above the surface of the water. It could carry six missile launchers and up to 15 soldiers. Like the harrier, it made use of in-ground effect to optimize forward movement, the wing compressing the air between itself and the water thus experiencing more lift and less drag.
An ekranoplan, classified as a boat by the IMO, is a vessel designed to fly only from and over water and only in Wing-In-Ground effect. Although they can be classed as a type of seaplane, the majority of seaplanes are designed to fly at very much higher altitudes. Hydrofoil boats have made flying boats well-known in the sailing world but these ekranoplans have no foils. Three 21st century backyard builders have each independently created 1–2 person ekranoplans as leisure craft, making use of freely available information online and affordable components.
Aquaplane K42
Meet Kester Haynes, a professional paramotor pilot with an obsession for making things fly. From a young age he shared time with his older brother in their well-organised workshop, with dad encouraging them to cobble together all manner of vehicles for adventuring — a beach buggy, modified bicycles, and a racing tractor. As he entered the world of para-motoring and para-gliding, his imagination turned skywards figuring out how to make things fly; first a mini motorbike, then a car. Though working in the design and development of paramotors, Kester still dreamed of experiencing fixed-wing flying for himself.
Kester’s K42 ekranoplan design is adapted from tried and tested elements from traditional sea-planes. A previous incarnation built with floats was unable to take off in calm water, so Kester introduced a stepped hull to the GRP floats which made unsticking easier.
The K42 uses a single cylinder water cooled 2 stroke dual ignition engine, commonly seen in microlights. There is currently only an air rudder which necessitates taxi-ing faster than the wind to maintain control before take- off. Operating within harbour speed- limits is therefore challenging, though due to its low weight and draft the ekranoplan leaves minimal wake. The wings’ aluminium frames are covered in Oratex, an aircraft fabric which can be heated with an iron and then shrinks and tightens into place as it cools. Together with a 4-blade fixed-pitch carbon fibre propeller, the K42 prioritizes being lightweight and manageable so that one day it might be airfreighted to be used as an expedition vehicle for exploration.
The K42 does not have a submarine mode. While adventuring around the Needles, one float started to take on water so Kester pulled up onto the beach to let it drain. There, he noticed a tiny crack so small — he thought — that once drained, he could taxi out, take off and fly back to Lymington in about 8 minutes. But when he left the beach, the whole vessel started to list heavily to port and was not accelerating. The left float dug into the water so much that he couldn’t keep a straight course, the choppy conditions sloshing water violently around the hull before bursting through the bulkheads and pulling the left wing under. Taking off was impossible, sinking seemed inevitable. Thankfully he wasn’t out alone and his brother came to the rescue, hooking the bow of the K42 onto the stern of his Zapcat, an inflatable racing catamaran. Fortunately the ekranoplan’s floats lined up perfectly with the Zapcat’s two inflatable tubes. Together they limped back to Lymington.
Kester has clocked up 1000 miles of test flights over the last three years and also qualified for conventional flying. Having achieved the satisfaction of flying his own creation, he wants to share the fun with others. His big dream remains: an expedition to explore the meanders, islands and communities of the Rio Negro in the Amazon basin.
Spinner
Over in Cocoa Beach, Florida is an almost finished 2-person electric ekranoplan and a lesson in determination. Although Milton Miller (https://knik.us/) is no stranger to the practicalities of boat restoration and sailing, he had little previous experience of building anything from scratch, other than furniture. But this was more than made up for by his extreme endurance training when he ran 2,842 miles from Miami to Los Angeles in 117 days in 2011. In 2014, he ran back.
Doing so, he learned how to manage an audacious project that he could not copy from anyone else, instead finding others who had done similar things, connecting with other disciplines and adapting them to his own unique situation. Milton wanted a craft to have fun with on the water. In contrast to his career as a software designer developing apps which serve as intermediaries between people and reality, building and flying an ekranoplan is a direct connection to reality, to your sense of sight, smell, immediate feedback from both nature and the machine you have crafted.
Milton was inspired by the elegance of small 1970s and 80s ekranoplans which used motorcycle engines. Yet when he imagined experiencing that alluring smooth flight, he realised that it would be more satisfying without the racket of an engine blasting in his ears. He decided to go electric. At just under 16' (5m), the Spinner is small enough to avoid Florida’s stricter regulations for large boats. The lower hull is formed from 4mm mahogany plywood sheathed in glass cloth. The topsides are made from foam covered in carbon fibre or glass - the same materials being used in the construction of the wings.
When Milton started work on the Spinner, he believed it would take three months to build and launch. Four years later, he recently moved the Spinner and his tools into a new workshop — a former storage area in an aircraft factory — and is thriving being surrounded by people and things that fly. Spending his mornings working at an avionics shop across the street, he is now dedicating all his time, money, and energy to completing the project. He says that if the Spinner takes off on its first test flight, that will be a success. “The story you create will not be linear, you will start, slow down, be unhappy, try again, fail, cry and eventually you’ll have something ready to use.”
Mudskipper
When James Greenberger took his 2-person ekranoplan out for its second test flight at Deep Water Point in Perth, Australia, he noticed a police car pull up at the beach. Despite knowing he was operating legally, he wondered if the police might be waiting for him. Soon, a second police car arrived, followed by another and another until around nine police cars were were gathered as he taxied back to shore.
“I guess you’re here for me?”
“We think so,” said a police officer;
“We’ve had reports of a plane crash in the water”.
Once James had explained, the police encouraged him to go back out to show off his flying boat again. He realised it was probably time to discuss his project with the relevant authorities. Representatives from the Western Australian Department of Transport were so impressed with his 80-slide presentation, they updated their regulations, with a picture of his ekranoplan on their website.
Although working as a pilot was partially fulfilling his love of flying, James nevertheless yearned for freedom in flight. An airline pilot flies to all sorts of places with a diversity of passengers but much remains outside the pilot’s control. The eye-watering costs of owning an aircraft coupled with the aviation authority’s steep regulations against the unknown left James searching for an alternative.
James built his first ekranoplan to test-flight in five months, combining elements of various hovercraft and a traditional sea plane. He had previously built two hovercraft from plans before the UH18SPW hovercraft, which proved the concept of flying watercraft. Yet it flew with a high nose and with its skirts tearing, salt water rapidly rusting the multiple moving parts always ready to break, it seemed that for every hour spent on water, two hours of maintenance were needed.
James removed the skirt and opted for a hull, which needed to be both light and strong enough to handle forces on the water and in flight. It is made from 4mm marine ply, with 25 building moulds and bulkheads spaced every 10" (250mm) attached to a central spine. The wings are simply made from PVC coated nylon — the material of bouncy castles — which reduces efficiency but makes them easier to store and set up. He also increased the angle of incidence of the wings to resolve the issue of the high nosed flight. The Mudskipper has just one moving part — a wooden home-built 2-blade propeller.
After solo testing, James was ready to share the fun. The first passenger was his dad who had travelled across Australia to visit him for Christmas. Together they flew around Swan River.
If You’ve Been Tempted…
The ekranoplan builders who kindly shared their projects with me all show an ingenuity, a determination and a love of flying, floating and most of all fun. While wing-in-ground effect craft have been included in COLREGS since 2003, small leisure ekranoplans do not seem to be overly restricted by too many maritime and aviation regulations. And imagining the ability to fly so close to the swell that you can see it and feel it as a lurch forward in efficiency, is both intriguing and exciting.
Evolution and diversity go hand in hand; there are fish that fly, birds that dive and boats that surf the air. If you are also designing and building – or have built and flown — your own personal ekranoplan, let the rest of us
know about it in WaterCraft.
