Summary
- Soviets led in developing ekranoplans.
- Beriev Be-2500 Neptun could be heaviest plane ever.
- Ekranoplans offer unique benefits if constraints are overcome.
Ekranoplans are a sort of mix of an aircraft and a hovercraft using ground effect to fly or skim a few meters above the ground (normally the water). It is sometimes assumed that the Soviets just copied Western aircraft design (such as with the Tupolev Tu-4 – a B-29 copy) and were always playing catch-up.
But this is just wrong (or at least isn’t always right). The Soviets pioneered ground effect vehicles (GEV) or ekranoplans and built remarkable ekranoplans like the Caspian Sea Monster. Perhaps the most eye-catching proposed Russian ekranoplan is the Beriev Be-2500 Neptun.
Beriev Be-2500 Neptun
The Soviet Union may be long over, but Russia has continued to tout the idea from time to time. One of the more recent post-Cold War proposed ekranoplan designs is the Beriev Be-2500 Neptun, developed by Beriev (Beriev has also built the world’s only amphibious jet aircraft, the Be-200).
The design of the Be-2500 is incredible. The maximum takeoff weight is estimated at 2500 tons (hence the name ‘Be-2500’). If ekronoplans were to be considered aircraft and if they were ever built, they would be the largest aircraft in existence, weighing four times more than the now-destroyed Anotonov An-225.
It would be something of a flying ship. As well as flying at high altitudes on long trips, the Be-2500 would be designed to travel intercontinental routes across the sea. It wouldn’t require any special infrastructure to dock.
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Beriev Be-2500 assumed characteristics |
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|---|---|
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Type: |
Super heavy amphibian ground-effect plane |
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Max take-off weight: |
2,500 tons |
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Max load: |
1,000 tons |
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Wingspan: |
511 feet |
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Length: |
403 feet |
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Engine: |
Propfan NK-116 |
Air Forces (writing in 2010) stated the project would cost between $10 and $15 billion to realize. However, it seems the Be-2500 remains a pipe dream. Little or nothing has been reported on its development over the last 15 years.
Russia is now embroiled in its disastrous full-scale Invasion of Ukraine and its limited resources are likely to be channeled to the war effort and not grand projects like the Be-2500.
Related
How Do Propellers Work To Lift Aircraft Off The Ground?
A propeller converts shaft power from the engine into thrust by accelerating air rearward. The equal and opposite reaction pushes aircraft forward.
Ground effect
Ground effect is the reduced aerodynamic drag that fixed-wing aircraft’s wings generate as they are close to the surface (ground or water). Ground effect occurs when an aircraft flies closer to the ground than the length of its wingspan. The profile of the wing deflects the air downwards, compressing the air and creating an area of higher-than-normal air pressure.
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Examples of ekranoplans |
Country |
Purpose |
|---|---|---|
|
Lun-class ekranoplan |
USSR |
Attack/transport |
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Caspian Sea Monster |
USSR |
Prototype/testing |
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Bartini Beriev VVA-14 |
USSR |
Anti-submarine warfare |
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HESA Bavar 2 |
Iran |
Naval patrol |
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AirFish 8 |
Singapore |
Passenger ferry |
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Boeing Pelican (proposed) |
USA |
Heavy military transport |
|
XTW-4 |
China |
Experiments/testing |
|
RFB X-114 |
German |
Testing/maritime surveillance |
Photo: Wiget Works
Passengers can feel the ground effect when flying on commercial airliners. Just before the aircraft’s wheels touch down, there is a feeling of the aircraft hitting a sort of air cushion. This is the air being squeezed under the aircraft’s wings, creating lift.
Related
When Boats Fly: 5 Remarkable Ekranoplans You Need To Know About
Large military “wing-in-ground” vehicles were built by the Soviets while small patrol and ferry types continue to be developed today.
Advantages and disadvantages
Building aircraft to utilize the ground effect has a range of benefits and costs. One of the great disadvantages of ekronoplans is that they are so close to the water surface. This means there is a great danger of collisions with surface objects (like ships and boats), and pilots have few options to avoid collisions.
The low level of the ekronoplan also means the pilots have low visibility. Ekranoplans can’t fly during periods of high winds and large waves.
Photo: Sergey Anufriev | Shutterstock.com
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Select Advantages |
Select Disadvantages |
|---|---|
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Carry heavy loads at great speeds |
More resistance as the air is thicker |
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Flying under the radar for longer |
Lack of time to avoid collisions |
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Avoiding sea mines and torpedos |
Can’t fly in rough seas |
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Require little infrastructure |
Economically limited to short routes (where aircraft are mostly ascending and descending) |
But, if the disadvantages could be overcome, a militarized ekronoplan could approach enemy ships at high speeds under the radar. It could avoid sea mines and enemy torpedos. It could also carry massive loads (perhaps up to 1,000 tonnes) across the oceans at the speed of a slower cargo plane but much faster than a ship.
The Germans, Chinese, Americans, and others have all experimented with developing ekranoplans. If the challenges can be overcome, the advantages are enormous. While the Soviets largely designed ekranoplans for military use, small ferry-like ekranoplans are being developed today. One example is the AirFish 8, designed to carry 6–8 passengers skimming at 80 knots over the surface.
Boeing once revealed the Boeing Pelican concept, which would have transported 17 M1 Abrams tanks across the ocean. It would have been the largest ekranoplan or aircraft ever built. But Congress rejected the plans in 2005, as there just wasn’t a need for such a plane at that point.