What happens when you cross a blimp with a plane, and give it a few helicopter features? A lighter-than-air plimp-hybrid airship is born, according to a Seattle-based company looking for investors.

For $4 million plus overages (paid out over four years), investors can buy their own Model J — a 169-foot-long (51 meters) aircraft that can carry up to 10 people (eight passengers and two pilots), or about 2,000 lbs. (907 kilograms) through the air, thanks to its helium-filled blimp-like body, gas-electric hybrid engines and rotational wings with propellers.

But don't call it a plimp outright. That word is trademarked and meant to be used as an adjective, said James Egan, a Seattle-based attorney who is the CEO of Egan Airships, maker of the plimp-hybrid aircraft. [In Images: Vertical-Flight Military Planes Take Off]

He kept his eye on emerging technologies, such as the Boeing 787 Dreamliner plane, which uses lightweight carbon-fiber composites to make aircraft lighter and more fuel-efficient. Finally, he and his twin brother, Joel, approached Daniel Raymer, an engineer who agreed to take their concept of a half-helium-filled aircraft and turn it into a flyable design.

The helium in the blimp part of the plimp-hybrid aircraft is key, Egan said. "That decreases your unpowered descent rate to that of a parachutist," he said. "You start with a design safety feature that no other aircraft has, which places you safely back on the ground if, for some reason, the engines fail." [The Hindenburg Wasn't Alone: Here's a Look at 23 Intriguing Airship Adventures]

The plimp-hybrid airship is actually faster and safer than a blimp, which has to offgas during unpowered descent, Egan said. The newly designed airships are also different than the Hindenburg — the airship that met a fiery end when its lighter-than-air hydrogen gas leaked and mixed with oxygen, making a flammable mixture that quickly ignited. (In contrast, the plimp aircraft uses helium, which isn't flammable.)

How does it work?

When the Model J is full — carrying the aforementioned 2,000 lbs. — it should be able to cruise at 86 mph (138 km/h) for 3 hours, or a distance of 260 miles (418 km). When empty (for instance, when acting as a flying billboard), it can travel a whopping 1,300 miles (about 2,100 km), a distance equal to a trip from Los Angeles to Dallas.

But whether or not it's occupied, the Model J will take off in the same way: vertically, like a helicopter.

"The pilot tips the wings and nacelles [the engine housing] up to a vertical position and adds power," Raymer, the chief designer of the plimp airship and president of Conceptual Research Corp., told Live Science in an email. "The vehicle lifts off vertically, upon which the pilot slowly brings the wings and nacelles down to the horizontal position, while the vehicle accelerates into forward climbing flight." [In Photos: Building the World’s Largest Airship (Airlander 10)]

To land, the pilot would reduce the power, allowing the Model J to descend and slow down. Once the vehicle nears its landing spot — be it a beach, platform or the water — the pilot would reduce power and allow the aircraft to settle to the ground, Raymer said.

The aircraft will have its perks: Unlike a helicopter, the Model J will be quiet and relatively easy to maintain, and unlike a blimp, it could travel quickly, Egan noted.

The Model J is being designed to handle moderate wind better than a regular blimp, "because only half of the vehicle weight is carried by the helium lift," Raymer said. However, it wouldn't fare well in heavy wind, bad storms or icy conditions, he said.

While the Model J is still in the works (it needs approval from the Federal Aviation Administration), the company already debuted its drone airship— a 28-foot-long (8.5 m) plimp-hybrid aircraft that can cruise at 30 mph (48 km/h) for 1 hour — at the InterDrone exposition in 2017. The drone could be used for advertising, as well as for land and agriculture surveys, search and rescues and surveillance, Egan said.

Egan expects the Model J will be useful to the U.S. armed forces to ferry personnel and equipment, as well as to companies and people who want an easy way to get from point A to B. "Imagine getting off an aircraft in New York and maybe going to a different part of the airport, getting onto one of these [plimp] aircrafts that lift smoothly and carry you the distances to islands and other semi-regional places that otherwise would take hours by car, ferry or train," Egan said.

Flying machines

The plimp airships are part of a growing trend in the aviation industry, with many companies designing small aircraft that can transport just a handful of people. There are even other blimp-like aircraft in the works, including Lockheed Martin's 280-foot-long LMH-1 hybrid airship and the U.K.-based Hybrid Air Vehicles' Airlander (although the Airlander 10 crashed in 2017). As for the Model J, it appears to be a good way to carry people and cargo, said Kristi Morgansen, interim chair of the Aeronautics and Astronautics Department at the University of Washington, who is not affiliated with Egan Airships.

"There's a long history of using lighter-than-air vehicles to transport people and goods," Morgansen told Live Science. However, given that there are so many personal air-transportation vehicles like Egan Airships popping up, there could be challenges down the road as to how air-traffic control will deal with all of them, she said.

In addition, Morgansen asked, How are you going to house the vehicle? Where are you going to park them and maintain them?" (The answer is that is an outdoor storage area, or a hangar, Raymer said.)

"It's an absolute game changer," Egan said. "This is a brand-new form of aircraft."

Originally published on Live Science.