The Woracle

Ideas are popping out of the woodwork now that aviation is beginning to understand the threat global warm-gaming* poses to its reputation and livelihood. The latest has been published in the UK Institute of Physics' journal Superconductor Science and Technology, where researchers say the technology is available to build a non-polluting all-electric aircraft using superconducting motors for propulsion and actuation and liquid hydrogen for cryogenic cooling and power generation. High-temperature superconducting motors would replace the gas-turbine cores in the aircraft's high-bypass turbofans, and be driven by electrical power produced from the hydrogen through fuel cells or by burning it in high-speed turbogenerators.

The propulsion and power system for an all-electric Boeing 737 would be heavier, but the fuel required would be less, researchers estimate. You can read read the report here.

*Woracle definition – global warm-gaming: exploiting public fear of climate change to further personal ambitions.

There is interest in supersonic business jets, no doubt. The question is whether anyone will build one anytime soon. And the next question always is: who would buy one?

At $2 billion to develop an SSBJ and $80 million to buy one, these are good questions.

Gulfstream and Dassault are studying SSBJs. Even Cessna is interested, as it builds the fastest civil aircraft flying – the Mach 0.92 Citation X. But all the established players have other priorities. Bombardier’s next bizjet is a Challenger replacement, Cessna is looking at a large-cabin jet, Dassault is developing its super mid-size Future Falcon, and Gulfstream is working on the ‘Fat Five’ (or G600, or G6000).

Europe's HiSAC - will it stay a study? (Flight art by Tim Bicheno-Brown)

Here's one to watch. DARPA's BioFuels programme is seen as the strongest candidate to produce an economically viable process for turning biomass into a jet fuel equivalent to everyday JP-8 or Jet-A1, with a net reduction in carbon dioxide production.

DoD pushes to reduce its dependence on oil (USAF photo)

Pulse detonation engines, active flow control, nano-engineered materials and open rotor noise reduction were among the technologies on show when I toured General Electric's Global Research Center in upstate New York this week.

You can see some of the technologies in action at the research centre’s blog, From Edison’s Desk, at www.grcblog.com. (Thomas Edison’s actual desk is in the foyer of the centre.)

Many of the technologies are aimed at GE’s jet engine business, but some have application elsewhere in the aircraft. It was a glimpse into the future - how far into the future I’m not sure.

A detonation wave exits a PDE (GE photo)

NetJets - the world's largest fractional-ownership operator, with a fleet of almost 700 aircraft making it larger than most airlines - has announced an initiative to reduce its emissions.

It includes sponsoring efforts to develop an ultra-low-emission jet fuel - the Next Generation Jet Fuel Project - at Princeton University and the University of California, Davis. More news to come on this.

UPDATE - here is the Princeton University press release.

The European Commission has unveiled the first tranche of aeronautics research projects to be funded under its Seventh Framework Programme (FP7). No real surprises among them: there is a big emphasis on reducing the environmental impact of air transport and advancing the use of composites in aircraft.

Leading the list of oh-so-European-sounding projects are: MAAXIMUS, looking for better, quicker, cheaper ways of designing and producing composite structures; DREAM, for alternative fuels, active controls and open rotors to reduce fuel consumption and emissions; and SCARLETT, for open architecture, fault tolerant, scalable and reconfigurable avionics.

Funding for all 36 "first call" projects selected totals €217 million, out of the €2.1 billion that the EC plans to send on aeronautics and air transport research over the seven years of FP7, which runs from 2007 to 2013. And most of that money is directed at projects that could benefit European industry in the near-term - in time for the next generation of Airbus narrowbody.

One or two "blue sky" projects made the first cut, including a second phase of the LAPCAT study of combined-cycle engines and airframe technologies for a future Mach 4-8 airliner able to fly from Brussels to Sydney in 2-4h. Despite LAPCAT participant Reaction Engines' optimistic artwork, I doubt Airbus will be building one of these any time soon...

We are all wondering what the next Airbus and Boeing narrowbodies will look like, but NASA is already looking beyond that - waaaay beyond that, to airliners that could enter service in 2030-35.

The agency is holding a pre-proposal conference in Washington DC on 29 November as a precursor to inviting bids for advanced concept studies of what it calls "N+3 Generation" subsonic and supersonic fixed-wing transports.

Under NASA's revitalised Fundamental Aeronautics programme, N equals Now and is represented by today's CFM56-powered Boeing 737. N+1 is aircraft that could enter service in 2012-15. They would still look fairly conventional. N+2 is aircraft that could enter service in 2018-20. They could look like Boeing's Blended Wing Body, or this...

N+3 is way out there, and no-one yet knows what the aircraft could look like. Well NASA has some ideas, but it is not revealing them. It also has some targets. For a subsonic 160-seater they include noise 81dB below Stage 3, NOx emissions 80% below CAEP 2, fuel burn 50% lower than the 737 - and a 70% reduction in field length to allow access to more runways.

Realistically, NASA doesn't expect all of these targets to be met in a single vehicle. They are what the agency calls the "corners of the trade space" - what could be possible if the design is focused on that target.

There is no "N" for a supersonic airliner, except Concorde, but NASA's N+3 metrics for a 100- to 200-seat airliner include an efficient Mach 2 cruise where supersonic flight is unrestricted and a low-boom Mach 1.6 over land, airport noise 20-30dB below Stage 3 and a 6,000nm range. Far out, indeed.

So why can't we just equip the military with Apple iPhones and save a lot of time and money networking our armed forces? Apparently those developing the Joint Tactical Radio System (JTRS, or "Jitters") get asked that a lot when folks see the billions of dollars and the years it will take to equip the US military with next-generation web-enabled radios.

Much harder than it seems, says Rick Baily, who is leading Boeing's bid for the next big chunk of JTRS - development of the airborne, maritime and fixed station (AMF) radio. And here's his explanation:

Infrastructure - JTRS has no cellphone towers to anchor the network or IT specialists to configure the radios. Where forces gather, an ad hoc network will form itself and each node - from a soldier to an aircraft - will be able to join or leave at will.

Environment - JTRS radios have to work in vibration, temperatures and other extremes that are "the next level on from Toughbooks".

Security - JTRS has to meet information assurance standards set by the National Security Agency that are "way beyond" the commercial methods used to protect personal information such as banking details.

Baily also argues the IT industry has spent billions to bring us things like the iPhone, but is able to amortise that cost over tens of millions of customers. The billions that JTRS will cost has to be spread over tens of thousands of users.

Bottom line - iPhones are cool, but if you are in the desert, moving fast under fire, and need to be absolutely sure no-one has hacked into your network maybe JTRS is what is needed. But commercial technology advances relentlessy, so you never know...

Okay, "open rotor" I understand. But "ducted open rotor", what's with that? Better ask Boeing. Its name is on the recent patent application my colleague Steve Trimble came across when browsing the US patent office website. And it actually is for an open rotor with a duct around it....

The patent application talks about "an aerodynamically shaped propeller duct that...fully houses a propeller driven by an engine...[and] significantly reduces the noise associated with a turboprop engine". But the applicability of the design to open rotors, unducted fans, propfans or whatever you want to call them is clear. Is this a sign of Boeing's thinking on how it could install open rotors on its next-generation single aisle?

Noise is the big issue with open rotors, and fitting a duct around them would be one answer, although the drag and weight of a duct that large would seem to be issues. But if the fuel and emissions savings from open rotors are substantial enough, maybe those are penalties worth paying.

Electricity was discovered and harnessed over 200 years ago, but for most of its 100-plus years powered flight has relied on hydrocarbon energy and hydraulic force. That is changing, fast. Aircraft designers recognise the benefits of an all-electric systems architecture. No more pipes and pumps, filters and vales, regulators and reservoirs, and the ability to channel the energy wherever it is needed whenever it is needed.

The Boeing 787 and Lockheed Martin F-35 are the first big steps in that direction. But they still draw the energy to propel the vehicle and power its systems from hydrocarbon fuel. Now the first small steps towards electric propulsion are being taken. France is claiming the first flight of an electrically powered aircraft with the 23 December debut of the Electra, a single-seat ultralight powered by a 25hp electric motor and lithium polymer batteries.

The 49min flight round a 50km closed circuit was a "world premier", says APAME, the French association for electric-powered aircraft. The retro-looking Electra was conceived and built by ACV Aero Service and Electravia, with French aerospace laboratory Onera helping with the aircraft's "silent propeller".

Every year, around this time, someone somewhere says: "Another year gone and still no flying cars." This time it was a comic strip in Sunday's Washington Post. After all this time, it seems having an aeroplane in every garage is still a yardstick of technological progress. And it remains an unfulfilled dream. There have been many attempts over the years, but the results have not been good aeroplanes or good automobiles. There's quite a good recap of past efforts on howstuffworks. But take anything you read on current flying-car projects with a healthy pinch of salt.

The outfit getting most of the ink these days is Terrafugia. It go a writeup as recently as October in the MIT Technology Review. But then the company was formed by a bunch of ex-MIT folks. So far Terrafugia has raised some money, flown a radio-controlled scale model and made some cool graphics (check out the video). It says it will fly a proof-of concept vehicle in 2008.

Terrafugia's Transition is basically a roadable aeroplane, rather than a flyable automobile, but what it promises to be that previous designs were not is a successful "transformer" - able to switch between aero- and auto- mode without the need to attach or detach things. Terrafugia also aims to get the Transition approved as a light sport aircraft, making learning to fly easier for mere drivers.

But the Transition is still an aircraft. Pilots might buy one for the fun of driving home from the airport without changing vehicles, but it is not going to put an aeroplane in every garage. More technological progress than a neat folding wing is needed for that to happen. And it may come from the unmanned aircraft sector. The technology that will allow UAVs to mix safely with manned aircraft in civilian airspace could allow auto/aeroplanes to take off from streets and land in office carparks. In fact, I might feel safer in an automated air taxi than in one with a pilot!

Sikorsky has flown its coaxial-rotor X2 Technology demonstrator, in secret. To keep the private-venture project out of the public eye, the company took the unusual step of flying the small helicopter indoors. But in a blow for Sikorsky security, clandestine video of the secret first flight has been posted on youtube.

From the video, it's clear the initial flight was conducted in hover mode and the tail-mounted propeller, which is expected to push the X2 to speeds as high as 250kt, was not engaged. The helicopter, which has a pair of rigid contra-rotating rotors, lifts off quickly, but appears "twitchy" in the hover. Another potential problem is the noise, which one observer describes as "irritating as h*ll after a few seconds".