The Future of Flight: Hybrid-Electric VTOL Aircraft

nasa-greased-lightning-10-foot-drone-640x480It may look like something a dedicated hobbyist built, and sound like something cheekily named, but NASA’s new electrical vertical take-off and landing (VTOL) machine is a very serious venture. Known as the GL-10 Greased Lightning, this unmanned hybrid-electric aircraft is the agency’s proposal for a vehicle that one day replace the reigning champion of VTOL – the helicopter.

 

The G-10 is in part the result of the recent strides made in electric propulsion, which is made possible thanks to the growing power and energy density of batteries allows for some very efficient hybrid-electric aircraft designs. With eight prop engines mounted on the two main wings and another two mounted on the tail, the vehicle swivels them into vertical position for takeoff and landing, and then horizontal for conventional flight.

nasa-greased-lightning-prototype1While it’s not particularly hard to create an aircraft capable of VTOL, it has so far proven to be very tough to create an aircraft that can also efficiently cruise through the air after taking off vertically. The helicopter is the only common example of a VTOL aircraft that can also cruise acceptably, but at a cost. Compared to other aircraft, an everyday helicopter has a much lower-lift-drag ratio, which means it burns more fuel, has less range and can carry less weight.

However, electric propulsion allows for much more efficient designs, since vehicles no longer have to accommodate large fossil fuel-powered engines or manage the mechanical stress across the airframe. Instead, they can rely on smaller, more efficient, optimally placed electric motors, and without the mechanical complexity of big jet engines, it suddenly becomes a lot easier to have wings and propellers that can swivel between horizontal and vertical.

https://i0.wp.com/www.extremetech.com/wp-content/uploads/2014/08/nasa-greased-lightning-ground.jpgWhile pure-electric aircraft do exist – in the form of quadcopters – hybrid-electric designs with longer range are generally of more interest to military and commercial groups. In the case of NASA’s Greased Lightning, there are two small diesel engines in the body of the aircraft that turn electric alternators that constantly recharge the lithium batteries. This theoretically gives the GL-10 the same range and duration as a modern plane alongside its VTOL capability.

Interestingly, NASA also says that such a hybrid-electric design is “scale free” — meaning the same principles could be used to revolutionize everything from helicopters, to military UAVs, to massive jetliners. Much like hybrid-electric cars, the concept is set to revolutionize an entire fleet of aircraft designs that could be far more efficient than they currently are. One party who is sure to be interested in the possibilities is the US military, with its ever growing fleet of UAVs.

For now, Greased Lightning only has a wingspan of 3 meters (10 feet), and on its first test flight  – which took place on National Aviation Day, August 19 – it was tethered. Untethered flights are planned for later in the year, an event which is sure to be a media sensation and produce some viral videos!

 

 

Source: extremetech.com

The Future is Here: AirMule’s Autonomous Demo Flight

airmule1Vertical Take-Off and Landing craft have been the subject of military developers for some time. In addition to being able to deploy from landing strips that are damaged or small for conventional aircraft, they are also able to navigate terrain and land where other craft cannot. Add to that the ability to hover and fly close to the ground, and you have a craft that can also provide support while avoiding IEDs and landmines.

One concept that incorporates all of these features is the AirMule, a compact, unmanned, single-engine vehicle that is being developed by Tactical Robotics in Israel. In January of 2013, the company unveiled the prototype which they claimed was created for the sake of supporting military personnel,  evacuating the wounded, and conducting remote reconnaissance missions.

airmule-1Now, less than a year later, the company conducted a demonstration with their prototype aircraft recently demonstrated its ability to fly autonomously, bringing it one step closer to carrying out a full mission demo. During the test, which took place in December, the craft autonomously performed a vertical take-off, flew to the end of a runway, then turned around on the spot and flew back to its starting point.

All the while, it maintained altitude using two laser altimeters, while maintaining positioning via a combination of GPS, an inertial navigation system, and optical reference to markers on the ground. These autonomous systems, which allow it to fly on its own, can also be countermanded in favor of remote control, in case a mission seems particularly harry and requires a human controller.

airmule-0In its current form, the AirMule possesses many advantages over other VTOL craft, such as helicopters. For starters, it weighs only 770 kg (1,700 lb) – as opposed to a Bell UH-1 empty weights of 2,365 kg (5,215 lbs) – can carry a payload of up to 640 kg (1,400 lb), has a top speed of 180 km/h (112 mph), and can reach a maximum altitude of 12,000 ft (3,658 m).

In short, it has a better mass to carrying capacity ratio than a helicopter, comparable performance, and can land and take-off within an area of 40 square meters (430.5 sq ft), which is significantly smaller than what a manned helicopter requires for a safe landing. The internal rotor blades are reportedly also much quieter than those of a helicopter, giving the matte-black AirMule some added stealth.

BD_atlasrobotPlans now call for “full mission demonstrations” next year, utilizing a second prototype that is currently under construction. And when complete, this vehicle and those like it can expected to be deployed to many areas of the world, assisting Coalition and other forces in dirty, dangerous environments where landmines, IEDs and other man-made and natural hazards are common.

Alongside machines like the Alpha Dog, LS3 or Wildcat, machines that were built by Boston Dynamics (recently acquired by Google) to offer transport and support to infantry in difficult terrain, efforts to “unman the front lines” through the use of autonomous drones or remote-controlled robots continue. Clearly, the future battlefield is a place where robots where will be offering a rather big hand!

 

And be sure to check this video of the AirMule demonstration, showing the vehicle take-off, hover, fly around, and then come in for a landing:


Sources: gizmag.com, tactical-robotics.com

The Future is Here: The AirMule!

urbanaero_muleMilitary necessity has been an engine for creation since the beginnings of recorded history. With soldiers constantly looking for new ways to kill each other, as well as save the lives of their own, one can always expect to see new and exciting technologies taking the field. And often as not, these developments have a way of trickling down and impacting society as a whole.

Take the AirMule, a compact, unmanned, single-engine vehicle that is being developed by Urban Aeronautics. Based in Israel, this company is dedicated to the creation of Vertical-Takeoff-and-Landing (VTOL) craft that utilize internal lift rotors to get in and out of tight areas, ostensibly for the purpose of supporting military personnel,  evacuating the wounded, and conducting remote reconnaissance missions.

airmuleIn an age where military forces are relying increasingly on unmanned aerial vehicles, the AirMule is designed to be used in operations that fit the 3 D’s: Dirty, Dangerous or Dull. In addition, it is controlled through remote operation and Tele-Presence, meaning the pilots who operate it do so from the safety of a base behind the front lines. The addition of this technology allows remote operators to stay safe while still feeling like they are physically on the scene.

The immediate benefits of this vehicle lie in the fact that it is able to fly at extremely low altitudes, allowing it to pass beneath enemy fields of fire and radar. At the same time, it is capable of taking off and landing in regions that are not accessible by conventional CasEvac craft, such as helicopters. This represents another concern for military planners, who are forced to contend with the fact that wars are increasingly fought against insurgents in places like cities, villages and other inaccessible environments.

The vehicle is capable of airlifting a 500 kg load, which can take the form of wounded personnel or 500 kilos of supplies. In this way, the AirMule is able to provide point to point logistic support as well as life-saving evac missions for wounded soldiers. However, it also has a number of applications for non-military use, such as assisting EMTs in rescuing injured people, delivering supplies to disaster-stricken areas, and offering assessment capabilities to companies who need to conduct inspections in potentially hazardous zones.

No telling when the AirMule will be taking the field, but in all likelihood, it won’t be more than a few years. What’s more, with the nature of military engagements changing and unmanned technology on the rise, just about every advanced military on the planet is likely to be following suit. And as always, we can expect the technology to trickle down to society as a whole, with robotic hovercraft replacing ambulances and medevac choppers within a decade’s time.

Check out the video of the AirMule concept and its field tests. It’s a few minutes long, but quite interesting: