December 7, 2022 - No. 045 In This Issue : Hydrogen Fuel Cell : EASA could mandate Boeing 737 MAX safety retrofits : A Second PHOENIX E Added to the Lufthansa LEOS GSE Fleet : BLR FastFin Certified for Black Hawk Helicopters : Small Screen Upgrade! : MTU gets support from Pratt & Whitney to develop the WET engine : Airbus and Renault Group to advance research on electrification : Airbus unveils hydrogen engines to be tested on the A380 : The military is the reason for the Boeing 747’s iconic hump : Boeing 777X flight tests suspended over GE9X engine issue Hydrogen Fuel Cell Invented by : William Robert Grove Invented in year : 1839 A fuel cell is an electrochemical conversion device. It produces electricity from fuel (on the anode side) and an oxidant (on the cathode side), which react in the presence of an electrolyte. The reactants flow into the cell, and the reaction products flow out of it, while the electrolyte remains within it. Fuel cells can operate virtually continuously as long as the necessary flows are maintained. A hydrogen cell uses hydrogen as fuel and oxygen (usually from air) as oxidant. Other fuels include hydrocarbons and alcohols. Other oxidants include chlorine and chlorine dioxide. Sir William Robert Grove, a Welsh judge, inventor and physicist invented the first fuel cell in 1839. He mixed hydrogen and oxygen in the presence of an electrolyte, and produced electricity and water. The invention, which later became known as a fuel cell, didn't produce enough electricity to be useful. Development in the invention of Hydrogen Fuel Cell The term fuel cell was first coined by Ludwig Mond and Charles Langer in 1889. Langer attempted to build a working fuel cell using air and industrial coal gas. Another source states that it was William White Jaques who first coined the term "fuel cell." Jaques was also the first researcher to use phosphoric acid in the electrolyte bath. In the 1920s, fuel cell research in Germany paved the way to the development of the carbonate cycle and solid oxide fuel cells of today. In 1932, engineer Francis T Bacon began his vital research into fuels cells. Early cell designers used porous platinum electrodes and sulphuric acid as the electrolyte bath. Using platinum was expansive and using sulphuric acid was corrosive. Bacon improved on the expensive platinum catalysts with a hydrogen and oxygen cell using a less corrosive alkaline electrolyte and inexpensive nickel electrodes. It took a long time for Bacon to perfect his design. And in 1959 he demonstrated a five-kilowatt fuel cell that could power a welding machine. Francis T. Bacon, a direct descendent of the other well known Francis Bacon, named his famous fuel cell design the "Bacon Cell." In October of 1959, Harry Karl Ihrig, an engineer for the Allis - Chalmers Manufacturing Company, demonstrated a 20-horsepower tractor that was the first vehicle ever powered by a fuel cell. During the early 1960s, General Electric produced the fuel-cell-based electrical power system for NASA's Gemini and Apollo space capsules. General Electric used the principles found in the 'Bacon Cell' as the basis of its design. Today, the Space Shuttle's electricity is provided by fuel cells, and the same fuel cells provide drinking water for the crew. NASA decided that using nuclear reactors was too high a risk, and using batteries or solar power was too bulky to use in space vehicles. NASA has funded more than 200 research contracts exploring fuel-cell technology, bringing the technology to a level now viable for the private sector. The first bus powered by a fuel cell was completed in 1993, and several fuel-cell cars are now being built in Europe and in the United States. Daimler Benz and Toyota launched prototype fuel-cell powered cars in 1997. In February, 1999, Europe's first public commercial hydrogen fuel station for cars and trucks opened for business in Hamburg, Germany. In April, 1999, Daimler Chrysler unveiled the liquid hydrogen vehicle NECAR 4. With a top speed of 90 mph and a 280-mile tank capacity, the car wowed the press. The company plans to have fuel-cell vehicles in limited production by the year 2004. Role of Hydrogen Fuel Cell in the Improvement of Human Life • Hydrogen Fuel Cell has lead to increase in awareness of environment protection • Using hydrogen-powered fuel cells has and can cut down on pollutants that contribute to urban air-quality problems, because fuel cells don't produce any particulates, carbon monoxide, nitrogen oxides or volatile organic compounds. • Fuel cells also operate silently, reducing noise pollution. • Fuel cells are expected to become a multi-billion-dollar market worldwide over the next decade, creating new employment opportunities • Fuel cells are very useful as power sources in remote locations, such as spacecraft, remote weather stations, large parks, rural locations, and in certain military applications. A fuel cell system running on hydrogen can be compact and lightweight, and have no major moving parts. Because fuel cells have no moving parts and do not involve combustion, in ideal conditions they can achieve up to 99.9999% reliability Hydrogen Fuel Cell EASA could mandate Boeing 737 MAX safety retrofits RYTIS BERESNEVICIUS With legislators on both sides of Congress having differing opinions on whether Boeing must retrofit systems to get the 737 MAX-7 and MAX-10 certified, Europe’s aviation regulator appears to have made the decision to mandate the manufacturer to do so. While “Boeing has committed to make these upgrades available for retrofit,” stated Janet Northcote, the Head of Communications at the European Aviation Safety Agency (EASA). “The actual retrofit of the in-service fleet can be achieved by different means, including possibly mandatory action from the FAA or EASA,” she added. EASA’s statements were first reported by the Seattle Times. At the heart of the debate in the United States Congress is whether Boeing should be required to retrofit two safety systems on the 737 MAX-7 and MAX-10 to get the two types certified. With the Aircraft Certification, Safety, and Accountability Act (ACSAA) going into effect on January 1, 2023, the planemaker is running out of time to certify the aircraft. Even then, Boeing has already stated that the MAX-7 will not be certified in 2022, while the certification of the MAX-10 could be pushed back as far as early 2024. Different opinions on the 737 MAX In Congress, legislators on both sides have presented different options on how to proceed further regarding the certification of the two yet-uncertified aircraft types. Senator Maria Cantwell, a Democrat from Washington, put forward a draft proposal that would eliminate the December 31, 2022 deadline, which would switch the focus of the debate from a date to safety concerns. READ MORE: New legislation could extend Boeing MAX 7, MAX 10 certification deadline A United States Senator has drafted new legislation proposing an exemption of the certification deadline for the Boeing 737 MAX 7 and the 737 MAX 10. If passed, the law would require Boeing to retrofit an improved Angle of Attack (AoA) system, which would include a third sensor that would cross-check the data from two other AoA angles on the aircraft’s fuselage and an ability for pilots to switch off an inaccurately activated stick shaker. The shaker indicates that the aircraft is stalling and an erroneous activation, which startled the pilots on the two fatal flights, was deemed as one of the factors as to why Lion Air and Ethiopian Airlines’ aircraft crashed. Senator Sam Graves, a Republican from Missouri, in turn, has told Reuters he will support an extension without mandating retrofits. Graves is expected to become the chairman of the House Committee on Transportation and Infrastructure in January 2023. Whether Canada, another major market for the 737 MAX will require the retrofits remains unclear. AeroTime has approached Transport Canada (TC), the local aviation safety regulator, for a comment. EASA, meanwhile, has recertified the 737 MAX-8 and MAX-9 with the condition that Boeing would eventually retrofit these safety improvements on all aircraft within the MAX family. “In parallel, and at our insistence, Boeing has also committed to work to enhance the aircraft still further in the medium term, in order to reach an even higher level of safety,” stated EASA’s Executive Director Patrick Ky when the European regulator ungrounded the aircraft in January 2021. WestJet, a Canada-based carrier, has ordered 42 Boeing 737 MAX-10 aircraft as recently as September 2022. EASA could mandate Boeing 737 MAX safety retrofits A Second PHOENIX E Added to the Lufthansa LEOS GSE Fleet Nov. 29, 2022 Lufthansa LEOS has invested in the battery-powered towbarless aircraft tractor from Goldhofer as part of a commitment toward sustainable, zero-emission ground operations. Following a convincing performance of its first PHOENIX E, LEOS has acquired a second battery-powered towbarless aircraft tractor from Goldhofer. The first PHOENIX E battery-powered towbarless aircraft tractor from Goldhofer has been in successful operation at Frankfurt Airport since January 2022. In its first nine months of service, the tow tractor has handled more than 4,000 zero-emission pushbacks and maintenance tows. Lufthansa LEOS is committed to an ongoing shift to sustainable, zero-emission ground operations and in this context has chosen to invest in the battery-powered towbarless aircraft tractor from Goldhofer. Following the success of the first PHOENIX E at Frankfurt Airport, a second, identical model is now going into service, and further purchases are already being considered. In this initial period of service with Lufthansa LEOS, a wealth of operational data has been generated – including the fact that the PHOENIX E has already traveled more than 25,000 km. “Our drivers are thrilled with the vehicle,” says Peter Unger, CEO at Lufthansa LEOS. “The figures so far exceed our expectations and have enabled us to take a huge step forward in zero-emission ground handling. So now we want to follow up with a second PHOENIX E in order to achieve our goals even faster.” Frankfurt Airport’s first PHOENIX E performs up to 26 tows a day thanks to the IonMaster technology employed by Goldhofer, an efficient and powerful electric drive concept with 700 V lithium-ion batteries from Borg Warner/Akasol. In addition, the Thermo Management System (TMS), which is part of the IonMaster technology, maintains a constant battery temperature – for up to 25 percent more range and longer battery life. “At the same time, we are continuing to upgrade our charging infrastructure in order to make efficient use of our other electric tow tractors,” says Unger. A Second PHOENIX E Added to the Lufthansa LEOS GSE Fleet BLR FastFin Certified for Black Hawk Helicopters by Mark Huber - November 30, 2022, 6:10 PM BLR Aerospace has received FAA STC approval for its patented FastFin system for the Sikorsky UH-60 Black Hawk helicopter. (Photo: BLR Aerospace) BLR Aerospace has received FAA supplemental type certificate (STC) approval for its patented FastFin system for the Sikorsky UH-60 helicopter. The kit is offered with an FAA-certified flight manual supplement that includes significant increases in useful load of 400 to 600 pounds, along with increased maneuverability and controllability margins commensurate with other BLR FastFin systems. BLR classifies the UH-60 FastFin as a “second generation FastFin system” that achieves greater performance benefits in part due to the asymmetric shape attached to the tail boom that enhances the anti-torque performance of the tail rotor. The system also includes tail boom strakes and vortex generators. In addition to the UH-60, the system is available for medium-size Bells and the Airbus AS350 helicopter family. BLR claims other benefits of the system include improved hover holding in crosswinds, better stability in the hover, and largely eliminating loss of tail rotor effectiveness. It works on any helicopter with an enclosed tail boom. BLR provides performance-enhancing products on more than 10,000 helicopters and airplanes worldwide. Mike Carpenter, president of BLR Aerospace, said that the FastFin kit for the UH-60 “is just another example of how BLR’s patented FastFin system can dramatically improve the performance of an existing helicopter.” BLR FastFin Certified for Black Hawk Helicopters Small Screen Upgrade! It’s a matter of Touch. By Paul Dye - November 21, 2022 (NOTE: See source URL for figures noted in this article.) When we built our RV-3 back in 2011, Garmin had just introduced its first Experimental EFIS, called the G3X. Garmin had actually teased the G3X with the GPSMAP 696, and the vertical-format system had by then found success with builders. Designed to be fully networked, the first G3X systems could have multiple screens sharing a single AHRS module and a remote engine-monitoring/sensor box. I have been fairly fortunate to be involved in the developmental testing of numerous EFIS products over the years, and that means I have a lot of display units with two-digit serial numbers. The units we installed in the RV-3 were no exception. Along with the “silver box” GSU 73 (which combines the ADAHRS and engine monitor in one chassis), we had to find a home for the magnetometer in the tail. There was no Garmin autopilot at the time, but TruTrak was building a Garmin-tailored unit designed to talk specifically with the new G3X, called the GX Pilot; it is what we put in the panel. It’s all worked incredibly well for 11 years of flying, with nary a problem. Time does not stand still, especially in avionics. Our RV-6 is equipped with the full G3X Touch system, and we have gotten used to certain features and the continued growth afforded by its beefier processor. Things like the glide circle, the ability to see sectionals and upgrades with emergency functions and envelope protection meant that the writing was on the wall for the early, pre-Touch G3X in the RV-3. There is something to be said for commonality within the family. Because of the nature of aviation journalism and the desire to test the new stuff for you, every one of our aircraft has a different EFIS. Making two of them the same can certainly cut down on the workload of remembering how to do things in the cockpit when it gets busy. So bringing the RV-3 up to the latest display standards—and user interface—was a net gain and allegedly an easy thing to do. So we set out on the process to prove—or disprove—what we had heard. Upgrading Made Easy Before getting started on the hardware installation, hook up external power to your plane and power up the old EFIS. Go to the configuration mode and pull out your cellphone camera. Take pictures of every configuration page you can find—we ended up with 55 pictures! They will make the configuration process of the new units a piece of cake. Without them, you’ll be in for a slog. Take pictures of all the configuration pages before you power down and remove the old system. Once you erase the configuration module, the data will be lost! Also, in configuration mode, go to the fuel level calibration page, select Calibrate, then hit the Menu button. You’ll be presented with a dialogue box that asks if you want to save the calibration file to the SD card. You definitely want to do this—and you have to do it for both the left and right tanks. (In case you missed it, the calibration tables equate sensor values for a given amount of fuel in each tank so that the fuel gauges read accurately. If you don’t save the cal data, you’ll have to repeat the add-a-gallon calibration procedure you did originally.) You’ll be able to re-import these from the card into the new units and won’t have to drain and refill your tanks. With all of this saved, you can power off the units and begin the hardware work. The new displays come with a drill guide, just like the old displays—the differences are minor but mean you’ll have to enlarge the corner holes and drill new holes for the mounting screws (left). Laying the old and new mounting templates on top of each other makes the differences obvious (right). Fortunately, the rivet holes line up, keying the displays to the panel. The finished bezel sizes of the original and Touch (portrait) screens are essentially the same, so there is no question that the panel real estate supports the upgrade. Garmin did, however, change the size and shape of the box behind the bezel just enough that the panel opening has to be slightly modified and the locations of the mounting nut plates changed. Fortunately, Garmin provides a mounting “ring” for each unit that includes Nutserts in the corners and also has four rivet holes so that the ring can be riveted to the back of the panel—and these four rivet holes are in exactly the same position on both flavors of ring. That makes it easy to drill off the old one and mount the new one. Thank you, Garmin! Garmin also supplied us with a steel “drill guide” with the units—essentially the same ring, without the Nutserts, that can be Clecoed in place using the rivet holes and then used to drill the new corner holes for the display mounting screws as well as to deepen the corner cutouts for the new units. Removing the old displays takes an Allen wrench and about 30 seconds of time (left). The old displays have one big connector and an antenna cable—disconnect them, and the removal is complete (center). The two big connectors and antenna wires will be reused exactly as they are—just tuck them safely out of the way for the minor panel grinding and drilling (right). (I should note that because Garmin sent us a couple of demo units for our installation, we got the drill guides, but not the mounting rings with the Nutserts—but this was no problem since we had a handful of small #6 ClickBond nut plates that we could glue to the back of the drill guides and use for our installation. We can easily change to the aluminum rings by drilling out the four rivets at a future time—the total work will take 10 minutes, if that.) With the new drill guides in place, you can see where the corners need to be ground away and the new holes drilled (left). After grinding and drilling, the panel holes look a little rough, and you have figure-eight mounting holes. These are of no consequence and will be covered up by the display bezels (right). We removed the old GDU 37x displays and tucked their connectors up out of the way. We then draped some towels behind the panel and on our legs to collect aluminum shavings and dust. After drilling out the rivets for the old mounting rings, we Clecoed the steel drill guides in place and used a die grinder to enlarge the corner cutouts, finally using a #24 bit to drill the new mounting holes. Note that the old and new mounting holes actually overlap slightly, so you’re going to end up with figure-eight holes in your panel. They will be covered up by the bezels, and the mounting ring is behind the panel, effectively sandwiching the panel between the bezel and the ring, so it’s not a structural issue. If the look bothers you when the displays are removed, you can always build a new panel—but it certainly is more work than necessary. The Oshkosh judges will never see the holes. With the new drill guides in place, you can see where the corners need to be ground away and the new holes drilled (left). After grinding and drilling, the panel holes look a little rough, and you have figure-eight mounting holes. These are of no consequence and will be covered up by the display bezels (right). After grinding and drilling, we carefully removed the towels that had captured the shavings and pulled out some short countersunk rivets and our squeezer. After bonding the nutplates to the back of our drill guides, we simply riveted them in place—and we were ready to mount the new displays. The old units have captured corner screws—the new ones use non-captive screws—we like Allen-head cap screws. Since we don’t have a compass in the panel, using steel hardware is not a problem, so we picked up eight 5/8-inch #6 screws and were ready to go. Attach the big connectors from your old units to the new ones, connect the GPS antenna cables and mount the units in the panel. The hardware work is done! We used ClickBond nut plates on our drill guides because we didn’t have the official mounting rings at the time—we got the right ones later and swapped them out, saving a few grams (left)! The nut plate rings are easily riveted in place with a squeezer—or you could use flush pulled rivets if you like (right). It’s All in the Configuration It’s important to understand that all of the configuration data for a G3X system (of any flavor) is stored in a chip buried in the big display connector backshell. Unfortunately, the non-Touch and Touch versions of the G3X do not use compatible data formats—so the first thing you’re going to do is erase and reformat your data module—a disquieting thing if you think about it too much. So don’t think about it, just do it. You should reference paragraph 37.2.1.5 in the G3X Installation Manual, which outlines the complete process for the software upgrade. This also references other spots in the 900-page manual—get the PDF online and the links will take you where you need to go. That paragraph also gives you step-by-step instructions to reformat the configuration module—a necessary first step. The opening paragraphs of Section 35 in the G3X installation manual also help describe the process—read and understand it before you begin. Basically, configuration is easy, if a bit time-consuming—only because this is a very capable system—and it’s more capable if you take the time to set up all the gauge limits and markings. This is where your photos of the previous configuration come in. If you worked your way through the original configuration screens in order, the new system configures in roughly the same order, so you just march on through. Our system found the ADAHRS, EIS and magnetometer, as well as immediately recognizing the TruTrak GX autopilot. From there it was mostly importing the fuel-level calibrations from the SD card and simply touching through the tiles on the configuration page. I strongly recommend an external power supply when doing the configuration work—it takes away the time pressure you might otherwise feel when working through the voluminous choices that come with the Touch system. And, of course, you should also know that you don’t have to get it all right the first time—you can go back in and fix things if you don’t like the results or you get something wrong. I don’t know of any way that you can “brick” the system (turn it into a useless box that has to go back to Garmin), so don’t be too worried, just press ahead. It’s also useful to know that when you come to a drop-down set of choices and one of them is User Defined, that means the pilot can configure this from the in-flight menus—so it’s not a bad idea to leave things that can be user defined that way. You won’t have to go back into config mode to try different options. We used Allen-head cap screws to mount the new displays for a professional look (left). With first power applied, the displays had already found much of the data from the ADAHRS and EIS—and proved that the connectors are interchangeable between old and new (right). The only thing that threw us—and cost us some time and a little bit of avgas—was that when we went to configure the ADAHRS, the magnetometer options were grayed out. Based on our (incorrect) knowledge from a long time ago, we thought this meant we couldn’t do anything with them until we had done the magnetic interference checks and magnetometer calibration—so we fired up, taxied out and did them, only to learn later from Garmin tech support that they were grayed out because you can’t “disable” the #1 magnetometer. The previous calibrations were safely stored in the ADAHRS box and we hadn’t needed to do anything. Oh well, it’s probably not a bad idea to check the magnetometer calibration once a decade anyway. Flying the Touch The next morning, I took the plane up to try out the new EFIS and, wow, it was just like flying with the big G3X Touch screens in our RV-6—only the screens were smaller! It’s nice to have the option of looking at sectional charts, which we didn’t have with the previous version, and simple things like the glide rings that show where you can reach with an engine failure are really nice to have in the mountains. Of course, with the smaller screens, real estate has to be managed a little more carefully, and since the tiny RV-3 cockpit doesn’t have room for the physical autopilot control panel from Garmin, I had to use the virtual panel on the EFIS—which covers up other data while you’re using it. But that’s not really a problem—it’s just something to get used to. I was very happy with how well the Garmin software integrated with the TruTrak GX Pilot—in fact, I really didn’t notice any real differences in normal operations between it and the Garmin autopilot we have in the RV-6. All the modes are available, and it was smooth and crisp in pitch and roll. Just like with the older G3X, the new Touch can control the autopilot completely, so you never have to touch the TruTrak head. (But the TruTrak is there in case the EFIS goes blank, so there is an extra level of redundancy.) One notable difference: Flying with the Touch panel is much easier than with the older autopilot buttons on the bottom of the original screens—it more easily approximates a real autopilot panel and seems more intuitive. The new EFIS works great with the RV-3’s IFR navigator as well. While I am not doing a lot of IFR flying these days, I still try to keep my skills up using the navigator instead of the internal flight planning in the EFIS—but perhaps I need to practice a little with the EFIS now that we have the newer version. We don’t have com radios that can be controlled from the EFIS in this airplane, but the transponder (a Garmin GTX 330ES) works great with the EFIS and is controlled from the screen. We do have control of the radios in the RV-6 and are happy with the way that works, especially with the ability to push frequencies from the EFIS navigation database to the radio. With most of the configuration complete, the airplane was ready to fly! There were a few things we later changed, but it was ready to go after just a few hours of work. Is It Worth It? While we have always been happy with the original G3X screens, there is no doubt that the Touch adds new capabilities as well as giving us a common user interface with our RV-6. It also gives us 10-years-newer technology—important in a day when consumer electronics have a finite supportable lifetime due to parts availability. So bringing the airplane up to date with new capability and new hardware is a plus. The list price of the new screens is currently $3260 (each)—so two of them is going to set you back about 6.5 AMUs. Based on the private notes I received when I mentioned that I had done the upgrade on a popular homebuilder’s internet forum, there are lots of folks looking to buy the older GDU 37x displays—so some of that outlay can likely be recovered. Since you’re upgrading, everything else in the aircraft remains the same, and those figures should reflect your total outlay. The ease with which the upgrade is done is remarkable. I have installed many new, improved EFISes in our airplanes over the years, and the process usually takes the airplane down for weeks. It generally involves complete rewiring and, oftentimes, an entirely new panel blank to start with. Replacing the older GDU displays with the new GDU 470s is truly plug-and-play from an electrical standpoint, and the mechanical installation is not much harder—especially for someone who has built their airplane and still has their tools. But if you have bought your little machine and want to do the upgrade, it doesn’t take much more than a drill, file and a rivet tool—heck, there is no reason you couldn’t use flush pulled rivets using a tool from Ace Hardware and Aircraft Supply—so don’t let “not being a builder” scare you away from the upgrade. If you have any computer literacy at all (and really, the level required to configure an iPad or iPhone is all you need) then this upgrade is in reach—and gives you that “new airplane” feeling when you fly away and head into the sky. For us, it was worth it. Small Screen Upgrade! MTU gets support from Pratt & Whitney to develop the WET engine By Bjorn Fehrm (NOTE: See source URL for figures noted in this article.) November 29, 2022, © Leeham News: MTU and Pratt & Whitney presented an EU Clean Sky project today where they will develop an advanced engine concept based on the Pratt & Whitney GTF. The project is called SWITCH, an acronym for Sustainable Water-Injecting Turbofan Comprising Hybrid-Electrics. There are participants from 11 countries in the project, among them Pratt & Whitney’s sister company Collins aerospace, GKN’s Swedish part, and Airbus. The engine, which has a mild parallel hybrid architecture, extracts more energy from the turbofan fuel by driving the core exhaust through a vaporizer, where it recovers more heat from the core exhaust, Figure 1. Water from the exhaust, extracted from the core exhaust in a condenser, is heated to steam by the vaporizer and then drives a steam turbine that co-drives the fan. The steam is finally injected into the combustor to lower emissions. The WET cycle will gain about 10% efficiency compared to today’s GTF. The concept also has a hybrid part which is primarily used for a low-emission taxi. The SWITCH engine The SWITCH project is a European Clean Sky project with several participants, Figure 2. MTU, as a European company, is the lead. In total, Industry partners and Universities from 11 countries are involved in the project. The first part, between 2023 and 2025, develops the WET engine components and further develops the hybrid technologies that Pratt & Whitney/Collins worked on in the STEP project and the regional turboprop demonstrator with De Havilland Canada. Figure 2. The SWITCH principal project members and the goal for Phase 1 of the project. Source: SWITCH. WET the main innovation The main innovation in the project is the WET engine principle that uses the water created in the combustion process of a gas turbine to enhance engine efficiency. The combustion gases are routed to a Condensor placed in the bypass stream, where the water is condensed and extracted, Figure 3. The water is then routed to the Vaporizer, where the heat from the core exhaust converts the water to steam that drives a Steam turbine attached to the low spool of the engine. The core’s remaining heat in the exhaust is thus used to add power to the low spool and the fan. The more complete extraction of heat from the core’s exhaust gases increases the engine’s efficiency.Figure 3. The WET enhanced turbofan components. Source: SWITCH. After the steam turbine, the water is routed to the combustor as steam, where it’s injected to lower the combustion temperature. The lower combustion temperature reduces NOx creation by up to 80%. The mass increase from the water gives the combustion gasses a higher energy level so that more power can be extracted from the turbines. The concept also lowers contrail generation as the amount of recirculation can be managed, and any excess water can be dumped into the atmosphere after the condenser. A mild hybrid The hybrid part is an add-on energy conservation part. During the ground stop, batteries in the fuselage are charged. The energy is then used to drive the fan via a motor generator working in parallel on the low spool, Figure 4. The taxi and takeoff will consume the energy stored in the aircraft battery; therefore, the function during the rest of the flight is to assist the engine during power changes (by allowing more aggressive scheduling of the compressors) with the remains of the battery energy. Figure 4. The hybrid parts of the SWITCH engine. Source: Switch. The assistance during takeoff is modest as the spool powers are north of 20MW each in this phase, and the motor generators are 1MW (low spool) and 0.5MW (high spool). At cruise, the spools need between 5 to 7 MW each, dependent on the engine variant. The motors could then contribute up to 20% of the booster/fan shaft power, but I see no chance of having batteries with enough energy so these can contribute in these phases. We need a minimum 1,000 kWh battery for taxi and takeoff, and it would weigh about 4t, so a battery that would have energy for climb and cruise is out of the question (it would weigh more than the whole propulsion system). Couldn’t the gas turbine charge the battery via the motor generators? Yes, but as discussed several times, charging a battery with the aircraft’s gas turbines make little sense. You add over 10% of losses in the chain generator-power distribution-battery-power distribution-inverter-motor-fan compared with driving the fan directly. In effect, the hybrid then increases the fuel consumption and CO2 emissions for the aircraft compared with using the gas turbine to do the job directly. Aircraft integration aspects The hybrid part requires a power distribution system in the aircraft and a propulsion battery, Figure 5. Airbus is looking after the integration aspects of these parts of the project. Figure 5. The integration of the SWITCH engines in a single-aisle aircraft. Source: SWITCH. The mass of the GTF engines would increase from 3t to about 4.5t when WET is integrated. So the engine mass goes from 6t to 9t. The hybrid part adds another 5t to this figure, dependent on the battery size. Energy efficiency and emissions The WET technology is projected to save about 10% of fuel consumption and, thus, CO2 emissions. It also lowers the NOx emissions of the engine by about 80% and reduces contrail generation. The ambition of the project is to save up to 25% fuel and, by it, CO2 emission compared with today’s GTF turbofan that powers the Airbus A320/A321. Where the other 15% comes from is for the project to explain. It can’t come from a hybrid part that is active during taxi (where it provides all necessary fan power) and takeoff, where it contributes about 5% of the needed power to drive the compressors and fan. Conclusion The WET engine concept is an interesting idea, equally applicable to Jet-A1, SAF, or hydrogen-burning engines. What about the hybrid part? It makes sense to include it in a research project where the technology can be brought forward and knowledge gained. As presented, it doesn’t make sense for a serial application. MTU gets support from Pratt & Whitney to develop the WET engine Airbus and Renault Group to advance research on electrification Partnership to mature technologies associated with next-generation battery systems Toulouse / Boulogne-Billancourt, 30 November 2022 – Airbus and Renault Group, worldwide leaders in the aerospace and automotive industries, have signed a research and development agreement which aims at enhancing transversalities and synergies to accelerate both companies’ electrification roadmaps, improving their respective range of products. This partnership will help Airbus mature technologies associated with future hybrid-electric aircraft and will be detailed at the Airbus Summit taking place 30 November - 1 December. As part of this partnership, Airbus’ and Renault Group’s engineering teams will join forces to mature technologies related to energy storage, which remains one of the main roadblocks for the development of long-range electric vehicles. The cooperation agreement will notably cover technology bricks related to energy management optimisation and battery weight improvement, and will look for the best pathways to move from current cell chemistries (advanced lithium-ion) to all solid-state designs which could double the energy density of batteries in the 2030 timeframe. The joint work will also study the full lifecycle of future batteries, from production to recyclability, in order to prepare the industrialisation of these future battery designs while assessing their carbon footprint across their entire lifecycle. “For the first time, two European leaders from different industries are sharing engineering knowledge to shape the future of hybrid-electric aircraft. Aviation is an extremely demanding field in terms of both safety and energy consumption, and so is the car industry. At Renault Group, our 10 years of experience in the electric vehicle value chain gives us some of the strongest feedback from the field and expertise in the performance of battery management systems. Driven by the same ambition to innovate and reduce the carbon footprint, our engineering teams are exchanging with those of Airbus to converge transversal technologies that will enable both hybrid aircraft to be operated and the vehicles of tomorrow to be developed,” said Gilles Le Borgne, EVP, Engineering, Renault Group. “This cross-industry partnership with Renault Group will help us mature the next generation of batteries as part of Airbus’ electrification roadmap,” said Sabine Klauke, Airbus Chief Technical Officer. “Reaching net zero carbon emissions by 2050 is a unique challenge that requires cooperation across sectors, starting today. Bringing together Renault Group’s experience in electric vehicles with our own track record in electric flight demonstrators will allow us to accelerate the development of the disruptive technologies required for future hybrid aircraft architectures in the 2030s and beyond. It will also foster the emergence of common technical and regulatory standards in support of the clean mobility solutions needed to achieve our climate targets.” Technological trends are moving in the same direction. Airbus and Renault Group’s cooperation on electrification will play an important role in bringing change to the transport landscape, successfully contributing to the ambition of net-zero emissions by 2050, of both the automotive and the aviation sector. Airbus and Renault Group to advance research on electrification Airbus unveils hydrogen engines to be tested on the A380 RYTIS BERESNEVICIUS On day one of the Airbus Summit 2022 on November 30, 2022, the manufacturer unveiled its hydrogen-powered zero-emission engine. The fuel cell power plant will be considered as one of the potential options for the emissions-free aircraft that is scheduled to enter service in 2035. The turboprop-like engine will convert hydrogen into electricity to power itself. “Fuel cells are a potential solution to help us achieve our zero-emission ambition and we are focused on developing and testing this technology to understand if it is feasible and viable for a 2035 entry-into-service of a zero-emission aircraft,” said Glenn Llewellyn, the Vice President of Zero-Emission Aircraft at Airbus. According to Llewellyn, such technology-based engines “may be able to power a one hundred passenger aircraft with a range of approximately 1,000 nautical miles”. “By continuing to invest in this technology we are giving ourselves additional options that will inform our decisions on the architecture of our future ZEROe aircraft, the development of which we intend to launch in the 2027-2028 timeframe,” he added. ZEROe demonstrator The propeller engine was not the only propulsion system to be revealed by Airbus, as the ZEROe demonstrator was also rolled out. According to the planemaker, the fuel cell engine will begin ground and flight tests in the middle of the decade. It will power the ZEROe demonstrator, which is a to be converted Airbus A380, Manufacturer’s Serial Number (MSN) 1. The double-decker will have a fifth engine installed on the upper left side of the aircraft just behind the wing. Airbus is currently modifying the jet to carry liquid hydrogen tanks and fuel distribution systems. The ZEROe demonstrator will also be equipped with a hydrogen combustion engine, akin to a regular jet engine seen on today’s aircraft. Much like the propeller power plant, the combustion engine will be mounted along the rear fuselage and coupled with a hydrogen distribution system. The difference is that liquid hydrogen will be transformed into a gaseous state and introduced into the engine via combustion, powering the aircraft throughout flight. The combustion engine will be a modified General Electric (GE) Passport, a derivative of the CFM LEAP turbofan. CFM, a joint version of GE and Safran Aircraft Engines, will modify the Passport for it to be able to run on hydrogen. “The A380 MSN1 is an excellent flight laboratory platform for new hydrogen technologies. It's a safe and reliable platform that is highly versatile to test a wide range of zero-emission technologies,” said Mathias Andriamisaina, Airbus’ ZEROe Demonstrator Leader. According to Andriamisaina, the platform of the double-decker is safe, reliable, and highly versatile. Due to its sheer size, the aircraft “can comfortably accommodate the large flight test instrumentation that will be needed to analyze the performance of the hydrogen in the hydrogen-propulsion system,” he added. The hydrogen tanks, combustion engine, and distribution system will be tested on the ground individually and then collectively, the manufacter said. If all goes well, the hydrogen-powered Airbus A380 will take to the skies for a flight test, which is expected to take place in the next five years. On November 28, 2022, Rolls-Royce announced that the company and easyJet had completed the first-ever hydrogen-powered regional jet engine test, using the Rolls-Royce AE2100-A engine. Airbus unveils hydrogen engines to be tested on the A380 The military is the reason for the Boeing 747’s iconic hump Miguel Ortiz Published December 01, 2022 11:19:08 The VC-25 that serves as Air Force One is a modified military version of the Boeing 747 (U.S. Air Force). In October 2022, the last Boeing 747 rolled off the production line. Dubbed the “Queen of the Skies,” the 747 was the original jumbo jet and opened air travel to a wider market. With its large size and high lift capacity, the aircraft has also become iconic in its service as a Space Shuttle Carrier and Air Force One. A defining feature of the 747 is its iconic front-end hump. Whereas the Airbus A380 has a full-length upper deck with its cockpit slightly above the lower deck, the 747 has an abbreviated upper deck where its cockpit is located. The reason for this unique design can be traced back to a military contract. In 1963, the U.S. Air Force began a series of studies to research the development of a very large transport aircraft. Although the Lockheed C-141 Starlifter already made its first flight and was in the process of entering service, the Air Force anticipated needing an even larger transport. From these studies, the requirements for the CX-Heavy Logistics System were established. The new aircraft needed to have a load capacity of 180,000 pounds, a speed of Mach 0.75, a range of 5,000 nautical miles with a payload of 115,000 pounds, and a cargo bay measuring 17×13.5×100 feet. Moreover, the cargo bay had to have access from the front and rear. An artistic render of Boeing’s CX-HLS proposal that bears a striking resemblance to the future 747 (Boeing) In May 1964, major American aeronautical companies submitted proposals for the CX-HLS airframe. Along with Douglas and Lockheed, Boeing was awarded an additional study contract for their airframe. In order to accommodate the front cargo access, Boeing designed a long pod on top of the aircraft that stretched from just behind the nose to just behind the wing. The cockpit and other crew compartments were placed in this pod, allowing the rest of the aircraft underneath to be used for cargo. This also allowed the nose of the aircraft to open for cargo loading and unloading. Although Lockheed won the CX-HLS contract in 1965, Boeing would hold on to its raised cockpit and nose door designs. The 747’s swing-up nose and top-deck cockpit are carryovers from Boeing’s bid for an Air Force contract (Atlas Air) In the early 1960s, Pan Am president Juan Trippe approached Boeing to design a passenger aircraft 2.5 times larger than the existing 707. Congestion at airports and increased passenger demand led Trippe to look for an aircraft with more capacity. With Pan Am being one of Boeing’s biggest customers, Trippe’s request led to the 747 project. However, by 1965, supersonic airliners looked to be the future of air travel. Although America’s Supersonic Transport Program didn’t pan out, France, Britain, and the Soviet Union were pushing on with their designs. Boeing and Pan Am needed to future proof the subsonic 747 in case supersonic airliners took over. A Shuttle Carrier Aircraft, modified from a Boeing 747, takes off with the shuttle Atlantis on its back (NASA)A Shuttle Carrier Aircraft, modified from a Boeing 747, takes off with the shuttle Atlantis on its back (NASA) The 747 was initially designed with a full-length double-deck fuselage, like the later A380, to achieve its high passenger capacity. However, concerns over evacuation routes during an emergency prompted the design of a wide single deck. Moreover, the single-deck design allowed for increased cargo capacity. This became key when Boeing and Trippe agreed to design the 747 as a passenger plane that could be easily converted for use as a cargo plane. With Pan Am committed to purchasing 25 aircraft, a fleet of heavy-lift cargo planes could still provide the company with revenue if supersonic airliners caught on. Lufthansa is one of the last airlines operating the 747 as a passenger aircraft (Lufthansa) The military is the reason for the Boeing 747’s iconic hump Boeing 777X flight tests suspended over GE9X engine issue GABRIELE PETRAUSKAITE Boeing has temporarily suspended 777X wide-body aircraft test flights after an unspecified issue was detected on the aircraft’s GE9X turbofan engine. The US planemaker and engine manufacturer GE Aviation are currently investigating the issue, leading Boeing to pause its 777X flight test program. The technical engine issue occurred during post-certification testing on October 6, 2022. A Boeing 777-9, registered N779XW, was undergoing several test flights between Seattle and Moses Lake in the United States when one of its GE9X engines failed. The engine has already completed more than 2,600 flight cycles and around 1,700 hours of run time. The N779XW was one of four 777X jet prototypes involved in the testing process, but none of the planes have flown again since the incident. READ MORE: A look into the largest jet engine ever made: who will beat the giant? Among the variety of turbofans, the GE9X holds the title of the world’s largest engine. However, it could soon be usurped by a competitor. GE Aviation has already completed a borescope engine inspection and agreed with Boeing to remove the part and send it for further investigation in GE’s test facility in Peebles, Ohio. “During these runs, a temperature alert was observed, and the operator shut the engine down normally. [...] GE is coordinating next steps with Boeing to support the resumption of flight tests,” the engine manufacturer explained in a statement to FlightGlobal on November 30, 2022. Will the GE9X engine issues affect the Boeing 777-9 certification program? Boeing 777X, the new generation of the 777 family, was announced in 2013, accumulating about 300 orders during the years that followed. However, after numerous problems and delays, the first prototype only conducted its first flight in January 2020. Boeing had initially expected the 777X to be certified during the final quarter of 2023, with the first delivery before the end of that year. However, in April 2022, it announced a more realistic term. According to the manufacturer’s first quarter 2022 financial report, delivery of the first 777X jet was expected to take place in 2025. But recently detected issues with the GE9X engine could force Boeing to adjust the already substantially delayed certification program. Boeing 777X flight tests suspended over GE9X engine issue Curt Lewis