Sunday, September 27, 2015

Does The Solar Impulse Plane Need A Battery Upgrade?

Despite recently finishing its round the world trip earlier this year when the weather allows it, does Bertrand Piccard and AndrĂ© Borschberg’s Solar Impulse need a battery upgrade?

By: Ringo Bones 

It is not only the most insured prototype aircraft to set out a record breaking feat, but the Solar Impulse – that solar-powered that could – barely finished its Japan to Hawaii leg of its circumnavigation when its lithium ion batteries overheated back in July 3, 2015 when the weather allows it, but could be facing a battery upgrade. After all, the lithium ion batteries used in the "somewhat successful" round the world flight were deemed not airworthy after one used on a Japan Air Lines 787 Dreamliner’s auxiliary power unit caught fire back in January 7, 2013. Even though the designers might concentrate on sturdier composite materials to make the Solar Impulse better withstand inclement weather while preserving its lightness, Bertrand Piccard and AndrĂ© Borschberg now have several models of newfangled rechargeable batteries to chose from that offer more storage, lighter weight, quicker charge time and more fire resistance than the current lithium ion batteries they currently use. 

If Piccard and Borschberg chose quick charge as a paramount importance, they could ask the folks at Store Dot because their Fast Charging Flash Batteries were demoed at the 2015 CES Show at Las Vegas back in January and it was able to drive an electric car for 300 miles or 480 kilometers with just 5 minutes worth of charge. This quickness of charge is akin to the time it takes to fill the tank of a conventional internal combustion engine powered aircraft’s fuel tank to full. 

Another attractive battery upgrade for the Solar Impulse is Solid Energy Systems’ Anode-Less Rechargeable Batteries which was introduced earlier this year in the 2015 Mobile World Congress in Barcelona, Spain. Though the demonstration model is only sized to power a mobile phone, it managed to power a mobile phone for 24 hours with just 5 minutes worth of charge and its designers will make a larger model for powering electric cars and even electric planes once they get appropriate funding. Solid Energy Systems’ Anode-Less Rechargeable Batteries last twice as long as current lithium ion battery models and has a 1,200 watt-hour per liter energy density which approaches the energy density of aviation grade kerosene. 

If Piccard and Borschberg prefer fire resistance when they chose to upgrade the batteries of the Solar Impulse, Stanford University’s Advanced Aluminum Battery could be the ideal choice. Even though their demonstration model is still sized to power a mobile phone, its quick charge feature allows it to power a mobile phone for 24 hours with just one minute’s worth of charge. The new aluminum ion rechargeable battery developed at Stanford University is not only less prone to bursting into flames than lithium ion types but can also be built at a fraction of the price. According to Dai Hongjie, a Stanford University chemistry professor and one of the developers of the Advanced Aluminum Battery says that their newfangled batteries won’t catch fire even if you drill through it. Unfortunately, they still are looking for financial backers to fund the mass production of their battery or design a larger prototype that could power an electric car or an electric plane. And whatever rechargeable battery technology Piccard and Borschberg uses, hopefully it would offer a better performance for the Solar Impulse once it resumes its circumnavigation flight in April 2016. 

Monday, September 7, 2015

Airbus’ E-Fan: The Future Of Pilot Training Aircraft?

Given that climate-friendly battery-powered aircraft has been a working proof of concept for almost five years now, does the battery-powered Airbus E-Fan represent the future of pilot training aircraft?

By: Ringo Bones

According to the Airbus Group, the Airbus E-Fan has successfully flown as far back as March 2014 and during the July 2014 Farnborough Air Show a prototype was flight demonstrated in front of the world’s press and was pitched as a pilot training aircraft with low running cost and, perhaps, climate-friendly credentials. But the Airbus E-Fan really began to be well known to the general public back in July 9, 2015 when it took off from Lydd, England at 9:17 in the morning in order to do a first ever crossing of the English Channel, in which it eventually did, landing successfully later in Calais-Dunkerque Airport. And despite Airbus’ claims of for being the first electric aircraft to successfully cross the English Channel, it was actually the Solar Challenger that did it first back in 1981, which Airbus later said that their E-Fan is “the first all-electric-two-engine-aircraft to make the crossing.” 

Ever since PC Aero aircraft designer Calin Gologan’s Elektra One made its first successful flight back in March 21, 2011, battery powered electric aircraft has been pitched as the climate-friendly alternative to the kerosene burning large passenger aircraft favored by the world’s major airline companies. Its 250-volt DC electrical system is powered by Lithium Polymer battery packs sourced from a South Korean firm Kokam and even though more efficient and faster charging batteries with lighter weight and much less volume while offering the same power storage capacity had been demonstrated successfully in various consumer electronic shows at the start of 2015, E-Fan designer Didier Esteyne is probably already designing an improved version of the E-Fan that uses Store Dot’s quick-charging Flash Batteries . But the design of Airbus’ E-Fan’s propulsion system – the two ducted variable-pitch fans spun by two 30-kilowatt 250-volt DC electric motors – is where the newfangled electric plane is light-years ahead from competing designs due to ducting principle allows it to increase its thrust while reducing noise, By the way, ducted fan aircraft designs had been around since the start of the 1960s. 

Saturday, August 22, 2015

Qantas Back In The Profit Again?

After a recent aggressive restructuring, is Qantas set to be back in profit again?

Given that a number of flag carriers had since gone the way of the dodo as the global fiscal environment got more austere, it can be a refreshing piece of good news that one manages to get back from the brink. Qantas – an acronym for Queensland and Northern Territories Airline Service – Australia’s troubled national carrier manages to get back from the brink with a recent aggressive restructuring and says it is on course to deliver its first pre-tax profits this year in three months to September. The news comes after the airline firm reported a net loss of 2.8 billion Australian dollars (2.6 billion US dollars, 1.6 billion UK £) for the 12 months to June – its biggest annual loss. Back in Wednesday, August 19, 2015, shares in the Sydney-listed airline rose more than 3-percent before midday trading. 

Qantas chief executive Alan Joyce made the announcement in Sydney at the company’s annual general meeting. In a report to the Australian Stock Exchange, Mr. Joyce said he could confirm the airline come through the worst. Shareholders were told passenger numbers were up 2.7 percent compared to a year ago. Mr. Joyce also said yields for its international arm had been positive for 6 months in a row. All of which means good news to anyone who owns Qantas stock or whose frequent business trips make them a frequent flyer with a airline firm. 

Friday, August 14, 2015

Flying Platforms: Aeronautical Engineering’s Evolutionary Dead End?

Despite being portrayed as the “most fearsome must have military vehicle” in 1960s era comic books, are flying platforms really nothing more than aeronautical engineering’s evolutionary dead end? 

By: Ringo Bones 

Despite giving the impression to those who should have known better that it is the ultimate must-have logistical transport vehicle with unlimited potential military applications and ever since film documentaries made about them in the 1970s and 1980s about the US Army’s barmy equipment acquisition programs during the latter half of the 1950s, policymakers who should have known better often hailed them that if the US Army had them during the Vietnam War, or during former US President George “Dubya” Bush’s Operation Iraqi Freedom, America’s overseas military intervention campaigns could have had a different – supposedly better – outcome. And despite being portrayed in 1960s era comic books as high-tech airborne Segway transports for both superheroes and super-villains alike, are flying platforms nothing more than a representation of the Cold War era aeronautical engineering’s research-and-development’s evolutionary dead end? 

In the world of aeronautical engineering research-and-development, flying platforms are a subclass of rotary-wing aircraft. Like helicopters and convertible aircraft, they are supported in hovering flight by the jet-momentum reaction produced by constantly accelerating a portion of the surrounding air downwards. Flying platforms are unlike helicopters in that the rotors used to produce the supporting jets are relatively small and unlike convertible aircraft in that no winglike appendages are provided for high-speed level flight. Flying platforms are unlike ground-effect machines, hovercrafts, or Ekranoplan-type craft, in that the flying platforms are capable of rising to higher altitudes in comparison to their maximum dimension. Thus, the flying platform is a rotary-wing aircraft whose aerodynamic characteristics have been “compromised” by reducing the size of the lifting-rotor system relative to the central body. 

Flying platforms have been envisioned as military personnel carriers for short-range operations at moderate speeds over terrain which is impassable to surface vehicles. The comparatively small size of the lifting rotors is dictated by the necessity of reducing the overall-dimensions of the vehicle for the purposes of storage and concealment.    

The first free flight of a flying platform was made on February 4, 1955. Manufactured by the Hiller Aircraft Corporation, the “platform” was 6 feet in diameter and was powered by two Nelson aircraft engines driving the rotors through V-belts. 

If you think “pervertiplanes” – i.e. convertiplane / convertible aircraft are aerodynamically perverted products of aeronautical engineering, flying platforms could be well-described as the “super-freaks” of Cold War era products of aeronautical engineering. There are three serious problems in the operation of flying platforms and these are directly attributable to the small size of the lifting rotors. 

One of the problems is that the small size of the lifting rotors leads to high lifting-jet velocities which cause trouble directly by creating a serious erosion and dust problem. The high lifting-jet velocities also cause trouble indirectly, since the continuous dissipation of the kinetic energy of the lifting jet leads to high rotor-power consumption that result in much higher fuel consumption in comparison to a conventional helicopter. A second problem affecting flying platforms is that the small size of the lifting rotor leads to catastrophic rates of descent in the event of power plant failure. Unlike the helicopter, which can make an autorotative descent with a wind-milling rotor, or a fixed-wing aircraft, which can glide, the flying platform falls like a rock in the event of a complete power plant failure. This problem is commonly solved by providing two or more independent power plants, so that the machine may descend at a safe rate if one power plant fails. The third serious problem is that the small size of the rotors relative to the rest of the vehicle leads to serious interference-flow effects between the hull of the vehicle and its rotors, particularly in forward flight. These interference effects lead to poor stability and control properties of flying platforms. Thus, this is the very reason why no flying platform type armored personnel carriers and VIP transport vehicles are deployed during the prosecution of former US President George “Dubya” Bush’s Operation Enduring Freedom and Operation Iraqi Freedom. 

Thursday, July 30, 2015

Pervertiplanes: A Forgotten Argot Of Aeronautical Engineering?

Even though the term dates back to the Cold War era 1960s American aeronautical engineering boom, does anyone still use the term “pervertiplane” these days? 

By: Ringo Bones

Any group of specialists has its own private lexicon and aeronautical engineers are surely no exception. The word “pervertiplane” could be defined as a corruption of the term “convertiplane” – which is a contraction of the term “convertible aircraft” – pertaining to aircraft constructed in such a way that their lifting and propulsion systems may be converted to permit efficient operation either for vertical take-off and hovering or for high-speed forward flight. Such craft are now more commonly termed as VTOL or vertical take-off and landing aircraft. 

Convertiplanes – at least their experimental prototypes – began life back in the beginning of the 1960s. Examples of which are the X-19 broad-bladed tilting rotor turboprop VTOL plane, the X-22 tilting ducted fan VTOL plane, or was it the XC-142A, which is probably the great-granddaddy  of the V-22 Osprey that got fielded back in 2007 and some jet-engine high-performance experimental VTOL fighter planes like the British-built Hawker P1127 cascade vane-nozzle turbojet VTOL that later became the USMC’s Hawker Siddeley Harrier / Harrier Jump Jet and the then West German EWR VJ-101C tilting engine turbojet VTOL interceptor. 

Convertible aircraft are sometimes called “convertiplanes”; however, one prominent aeronautical engineer – legend has it that it was Igor Sikorsky – has suggested the name “pervertiplanes” because so many of the machines, in his view, combine the worst features of the helicopter and the fixed-wing aircraft. The necessary provision of such structurally difficult features as tilting wings, tilting rotors, cascade-vane assemblies and the like which may be subjected to high gas temperatures and periodically fluctuating air loads, all at minimum structural weight, leads to the development of very complicated mechanical devices that in turn leads to a high probability of mechanical failure. 

By far, the most serious problem with convertible aircraft lies in its characteristics following engine failure at low altitude. Unlike fixed-wing aircraft, which can fly as a glider following engine failure or the helicopter, which can descend at a safe – but rapid – rate with its rotor being spun by the flow of air past it (a process called autorotation), the convertible aircraft commonly lacks wings large enough to descend slowly as a glider, or a rotor large enough to permit a safe autorotation descent. Worse yet, if power failure occurs during transition, it may not be possible to achieve either type of descent and the vehicle will fall like a rock. Looks like a convertible aircraft or convertiplane’s reputation as a “pervertiplane” seems apt.  Or should we also include L7 guitarist Donita Sparks’ battered Gibson Flying V which she christened as the “flying vagina”?