Blade Runner. Back to the Future. The Fifth Element. Science fiction classics that all have one thing in common: flying cars.
Whether it_s gliding taxi cabs or hovering DeLoreans, Hollywood has embraced the idea of a vehicle that is as happy on the motorway as it is in the clouds. But away from the silver screen, this science fiction staple has failed to take off.
Over the years, there have been ambitious and attempts _ such as the Taylor Aerocar - but few would agree that the designs are in any way practical or user-friendly.
But the ever increasing number of cars on the roads means that a vehicle that can soar into the skies remains an attractive option.__ _We need to try to relive congestion on our road, and one potential solution is an aerial vehicle_ says Dr Michael Jump, a lecturer in aerospace at Liverpool University in the UK.
He is behind one of a clutch of firms and projects that aim to ensure the flying car doesn_t remain grounded for another century.
One of the most high-profile attempts is the Transition, an aircraft that can fold its wings, allowing it to also operate as a street-legal road vehicle. Terrafugia, the company behind the machine, see owners driving their car to an airport where the wings can be deployed for take-off. Once in the air, the vehicle has a range of 740 km (460 miles) on a single tank of regular unleaded fuel and, can carry two people plus luggage.
The machine, which had its first successful test flight earlier this year, will cost around $300,000 and is scheduled for release in 2012. Wanabee pilots will only need to have completed 20 hours of observed flying time to take to the skies.
Hot on its contrails is the PAL-V (personal air and land vehicle), which looks more like a mini-helicopter than plane. The machine, developed by a Dutch firm, is actually an autogyro, with a propeller at the rear to provide forward thrust and a free-spinning rotor to give it lift. On the ground, it operates more like a streamlined tricycle that is able to lean into corners at high speeds.
It has a similar range (560km/350 miles) and speed to the Transition (110mph/180 km/h) and is also expected to cost around $300,000. The firm is still looking for investment to help with what it calls _the birth of a new class of vehicles_.
While projects like the Transition and PAL-V aim to slot into our current transport systems, a EU-funded project called myCopter is pushing for a complete rethink. Rather than driving a car that is compromised by a requirement to fly, or flying a vehicle that is compromised by needing to drive like a car, Dr Jump's team is looking to a future where we whizz to work in Personal Aerial Vehicles (PAVs) with dedicated highways in the sky.
_This project is looking at how the air transport industry might change over the next 150 years,_ says Dr Michael Jump, a lecturer in aerospace at Liverpool University.
It has already identified a number of key problems that need to be solved to make personal air transport a success.
First, is the design of the craft.__ The team wanted to design something that had the _familiarity of a car_. But other than that, says Dr Jump, _all bets are off_.
Some of the design proposals for the exterior of myCopter show a suitably futuristic looking vehicle, that would not look out of place in George Jetson_s garage. The system is a hybrid of a light aircraft and helicopter.__ It has three helicopter type rotors, but they are embedded within the large triangular wing that makes up the top surface of the aircraft, one on each side, and one on at the back. These embedded rotors are known as ducted fans, which can create greater thrust at higher safety, albeit with less efficiency.
_We have gone for something that is capable of vertical lift, rather than having to drive to your local airfield, and requiring a runway,_ says Dr Jump
_Vertical lift generally means rotors of some kind. We don_t believe the future is us all flying around in helicopters. You don_t really want lots of whirling rotors flying in your suburbs, so that really drives you to ducted fans._
The team also want to reduce the level of skill required to operate an aircraft - the goal being a _highway in the sky_, where an individual is able to fly from point to point with the ease of driving an automobile. _Imagine getting in with your iPad, and plugging it in and just telling it where to go and away you go,_ says Dr Jump.
The team believes this will require _an effective human machine interface_ to allow people to easily control the vehicle. A simulator set up at the lab in Liverpool with just two levers shows the level of simplicity they are aiming for.__ One controls altitude, or up-and-down, and another controls direction.__ _If you can remember left and right that_s all you need to know,_ Mark White, flight simulation laboratory manager of myCopter, recently told Discovery on the BBC World Service. The team are currently recruiting for a group of novice _pilots_ to test their design.
However, they will not be flying on their own. The team intends to draw on drone technology to automate as much of the flying as possible. Current fly-by-wire technology, as well as some of the features being used in the development of autonomous or robotic vehicles could all help fleets of these vehicles fly along predefined highways _ and crucially avoid each other.
But perhaps the biggest problem the team aim to tackle are the regulatory and safety issues, as well as those of public opinion.__ _The technology is the easiest bit,_ says Dr Jump.
Introducing flying cars raises a number of issues, many of which have probably already run through your mind. Who will govern where they fly? Will they interfere with planes? What will stop a drunk driver (flier?) crashing into my house?
_People get very annoyed by motorways at the bottom of their garden, what they will feel about motorways above their house?_ he asks.
The team has until 2014 to answer that question. Then, could we finally begin to see the rise of the flying car?__
When pressed about a likely launch date, the project scientists are reluctant to commit but have no doubts that it will come to pass.
_We are trying to apply rational scientific engineering approach to this problem_ says Dr Jump. _What sounds strange and wonderful today can very often become tomorrow_s reality._