After 15 years of development, an Israeli tech firm is optimistic it will finally get its 1,500 kilogram (3,300 pound) passenger-carrying drone off the ground and onto the market by 2020.

Israeli tech firm Urban Aeronautics originally designed its people-carrying drone as an "air mule" for military use. Now called the Cormorant, it takes off vertically and has a standard helicopter engine, but no large main rotor. Its lift comes from two fans buried inside the fuselage. Two smaller ducted "fans" mounted in the rear provide forward movement. It can fly between buildings and below power lines, attain speeds up to 115 mph, stay aloft for an hour and carry up to 1,100 pounds

Urban Aeronautics 'flying car' Cormorant Credit: YouTube

It completed its first automated solo flight over terrain in November. Its total price is estimated at $14 million.

Developers Urban Aeronautics believe the dark green drone, which uses internal rotors rather than helicopter propellers, could evacuate people from hostile environments and allow military forces safe access.

"Just imagine a dirty bomb in a city and chemical substance of something else and this vehicle can come in robotically, remotely piloted, come into a street and decontaminate an area," Urban Aeronautics founder and CEO Rafi Yoeli told Reuters.

Open gallery view This image provided by Urban Aeronautics/Tactical Robotics shows an Israeli-made flying car. Urban Aeronautics conducted flight tests of its passenger-carrying drone call the Cormorant in Megiddo, Isr Credit: /AP

Yoeli set up the company, based in a large hanger in Yavneh, south of Tel Aviv, in 2001 to create the drone, which he says is safer than a helicopter as it can fly in between buildings and below power lines without the risk of blade strikes.

There is still plenty of work required before the autonomous vehicle hits the market. The Cormorant, about the size of a family car and previously called the 'Air Mule', is yet to meet all U.S. Federal Aviation Administration standards, and a test in November saw small issues with conflicting data sent by on-board sensors.

With 39 patents registered to create the vehicle, Yoeli has little concern about competitors usurping him.

One industry experts said the technology could save lives. "It could revolutionize several aspects of warfare, including medical evacuation of soldiers on the battlefield," said Tal Inbar, head of the unmanned aerial vehicle research center at the Fisher Institute for Air and Space Strategic Studies in Herzliya.