May 31, 2023 - No. 022 In This Issue : Snohomish County companies turning electric-powered flight into reality : Should Fuel Cells [Hydrogen] Be Retrofitted Or Worked Into Clean-Sheet Aircraft Designs? : FAA publishes AD to prevent Boeing 777 horizontal stabilizer loss : EASA issues AD to address unsafe conditions with Airbus A350 lavatorie : Water leaks on the 787 : Embraer says it will no longer have executive jets like the Lineage : DEF Contamination Causes Dead-Stick Landing, No Injuries : How a Rusty B-52 Carcass Is Key to the Bomber’s Big Upgrades Snohomish County companies turning electric-powered flight into reality It could be decades before we see a plane the size of a 767 become electrically powered. Author: Glenn Farley Published: 5:11 PM PDT August 4, 2021 Updated: 6:45 PM PDT August 4, 2021 Note: See important video in the original article. SNOHOMISH COUNTY, Wash. — Two Snohomish County companies are turning all electric powered flight into reality. “We picked this part of the world because we would get the right kind of talent,” CEO Omer Bar-Yahay said. Bar-Yahay started the company in Israel then moved it to western Washington, to take advantage of the massive aerospace cluster of companies within the Seattle-Everett-Tacoma metro area. The other is magniX, founded by Roei Ganzarski in Everett. His company builds the electric motors that power the planes. The motors are already demonstrating their ability to power a Cessna Caravan and deHavilland Beaver over the past 18 months. Both of those are single motor airplanes, Eviation’s plane will have two. Eviation’s plane is designed to carry nine passengers 440 nautical miles. It is a swoopy aircraft made from light weight composites. It’s 8,000-pound lithium ion battery is half the weight of a loaded plane. Though it began as a commuter style passenger plane, it got a huge boost this week from global package giant DHL, which ordered a dozen of them to replace fuel burning feeder planes that move packages between its west and east coast U.S. hubs and smaller markets. The plane can carry 2,600 pounds of cargo, according to Eviation. “And it sends a strong message about what we’re saying in this space about sustainability,” said Mike Parra, DHL’s chief for the America’s for the German-based company. DHL also has moved toward more electric ground vehicles to make deliveries and pickups, and airport tugs for its planes at airports as it’s also moving toward Sustainable Aviation Fuels made from things like plants and blended with regular jet fuel for its larger planes, which include Boeing 767s. But it could be decades before we see a plane the size of a 767 become electrically powered. Hydrogen fuel cells and technologies not yet invented could push those technical limitations to get to zero emissions. “These are exactly the problems that we and other companies right now are working to solve,” said Bar-Yohay as he envisions a growing company here in Snohomish County. The plane is in final assembly inside a brightly-lit hangar at the Arlington airport. It is expected to fly this year. Snohomish County companies turning electric-powered flight into reality Should Fuel Cells [Hydrogen] Be Retrofitted Or Worked Into Clean-Sheet Aircraft Designs? BY DR. OMAR MEMON A clean sheet design allows for better fuel mass distribution. In a conventional combustion process of a turbine engine, jet fuel is mixed with pressurized air and ignited in the combustor. Hot gases expand, and the resultant force creates thrust and propels the aircraft forward. An alternate power source is the use of battery packs to deliver electrical power to the aircraft. Batteries have 70 times less energy density than jet fuel, which makes them unviable for large-scale operations. Moreover, there is a significant difference between the performance of a battery used for research and what can be certified as a power source for airliners. Fuel cells have a promising future when it comes to powering energy-efficient aircraft. Fuel cells generate electricity through an electrochemical reaction. Fuel cells require a constant supply of fuel and oxygen to provide continuous electrical power. For a small regional jet of approximately 72 passengers, such as the ATR72, a lightweight and efficient fuel cell system must be designed and installed onboard the aircraft. The question arises, should the fuel cell system be retrofitted on existing turbine engine-powered aircraft, or is a clean sheet design required? This article briefly highlights the two designs, along with their merits and demerits. Retrofit design In order to retrofit an existing 72-seater with fuel cell technology, the cabin space must be cleared. At least 30% of the seats (along with the cabin galleys and other floor space) must be removed. The area is used for the AC/DC converter, motor, and supporting digital systems. Photo: Brussels Airlines At least 500 NM (925 km) of the range is lost due to fuel cell implementation. Stepping up to superconduction may only reduce its range by 250 NM (460 km). Moreover, the fuel cell technology's secondary effects, such as added aerodynamic drag, also reduce the aircraft efficiency. Cooling the fuel cells requires additional systems, which increases the overall mass of the aircraft. While the loss of payload and range can be managed by altering operating conditions, the retrofit design cannot change the way the aircraft’s center of mass is designed. The installation of an eight to nine-ton retrofit system with its tank and fuel is therefore critical. The fuel cell installation mass cannot be placed in the wing or nacelles, which enables payload limitations due to the flow of stresses in the aircraft. A clean sheet design A clean sheet design project can optimize the aircraft’s configuration and structural characteristics to fit a fuel cell-based system. In a clean sheet design, the liquid hydrogen tank and fuel must be placed in the center fuselage. Based on that, the bending moments of the wings are designed for subsequent stress levels. The air-cooled high-temperature superconducting systems minimize temperature issues without compromising the capacity or range of the aircraft. In comparison to battery-powered aircraft, the mass deficit for energy will be much lower. Photo: Airbus Airbus focuses on clean sheet design to avoid messing with basic principles of physics while needing to retrofit the fuel cell technology onto an existing design. According to Guillaume Faury, CEO of Airbus, We don’t need changed physics to make hydrogen aircraft work. Hydrogen is an ideal candidate for future fuel cell technology. In an effort to launch a true zero-emissions airliner with useful operational characteristics, liquid hydrogen is considered for the fuel cell. Hydrogen has three times more energy density than jet fuel. When generated from renewable energy, hydrogen does not emit carbon dioxide. And, it can be used as a power source for short-to-medium haul aircraft. Should Fuel Cells [Hydrogen] Be Retrofitted Or Worked Into Clean-Sheet Aircraft Designs? FAA publishes AD to prevent Boeing 777 horizontal stabilizer loss BY RYTIS BERESNEVICIUS 2023-05-29 The latest airworthiness directive (AD) by the United States (US) Federal Aviation Administration (FAA) looks to prevent the potential loss of the Boeing 777 horizontal stabilizer. The FAA issued the AD on May 26, 2023, after it had received reports of “cracks found in the pivot bulkhead forward outer chord of a certain station”. Looking into the matter, the FAA found “higher bending stresses across the chord than originally assessed”, prompting the agency to publish the directive to address the potential cracking of the pivot bulkhead forward outer chord. “The FAA is issuing this AD to address cracking in the STA 2370 pivot bulkhead forward outer chord. Such cracking, if not detected and corrected, could result in a severed pivot bulkhead outer chord, loss of horizontal stabilizer control, and loss of controllability of the airplane,” the regulator outlined. The directive will require airlines operating Boeing 777-200, 777-200LR, 777-300, 777-300ER, and 777F aircraft to conduct repetitive detailed and high-frequency eddy current (HFEC) inspections of the pivot bulkhead forward outer chord of a certain station and longeron fitting for cracking and applicable on-condition actions. The agency estimates that the directive will affect 223 aircraft registered in the US. Detailed and HFEC inspections will cost operators $4,390 per inspection, split into $850 for labor and $3,540 for parts. However, the FAA has no way of estimating the number of aircraft requiring replacements in the event of an on-condition following an inspection, but it estimates the cost to be $40,950 per aircraft per one side ($3,230 in labor and $37,720 in parts cost). In addition, if the inspection results in a required on-condition detailed and open hole HFEC inspection, operators will have to spend $2,380 on labor per one side of a Boeing 777. Applicable actions and the times of compliance are defined in the Boeing Alert Requirements Bulletin (RB) 777–53A0098 RB, dated April 5, 2022. Changes to special tooling requirements and work-hour estimates Several parties commented on the AD, including Air Line Pilots Association, International (ALPA), Air France, FedEx, and United Airlines. While ALPA supported the notice of proposed rulemaking (NPRM) without change, the three carriers stated their concerns to the FAA. Firstly, FedEx argued that the AD should include revised detailed and HFEC inspection costs, as the inspections require parts totaling $3,540, while the replacement for the on-condition requirements is estimated to be 62 work hours. The FAA has agreed to revise the document. Air France also requested to change the number of work hours it will take for operators to implement the directive’s requirements, arguing that Boeing’s Alert Service Bulletin (SB) “greatly underestimates the total manpower hours required to perform the modification”. Speaking from experience, the French carrier said it spent 1,200 hours completing a similar modification on both sides of a Boeing 777. Two other airlines it consulted with also spent 900 and 1,100 hours completing similar modifications. All in all, Air France said that due to the incorrectly estimated time in these service bulletins, “resources were not available and the airplane was grounded for 3 weeks”. However, the FAA replied that there can be discrepancies between the estimated labor hours and operators’ work hours spent to comply with the directive and/or SB, as the FAA’s estimates are only representative of the tasks required by the AD. Cost analysis “typically does not include incidental costs such as the time necessary for planning or time necessitated by other administrative actions,” the FAA added. Furthermore, the French airline stated that Boeing’s SB said that no special Maintenance, Repair, and Overhaul (MRO) tools are required to perform compliance actions, yet the “range of reamers and drill bit diameters are not common and not part of the standard available tools for an MRO”. In response, the FAA said that it has “no definitive data regarding the standard MRO tools or what additional tools might be required”. Air France’s third comment expressed that Boeing’s SB does not include clear access instructions, to which the US regulator responded that access instructions are not part of the compliance for the AD. Meanwhile, United Airlines said that the AD should allow operators to inspect both sides of the aircraft to “know the full scope of the project and plan accordingly”. Boeing has already incorporated this change into its RB. While the FAA acknowledged the airline’s concerns, United “has not provided substantiation in support of these exceptions”. As such, the FAA published the directive with “minor editorial changes”. The AD is effective from June 30, 2023. FAA publishes AD to prevent Boeing 777 horizontal stabilizer loss EASA issues AD to address unsafe conditions with Airbus A350 lavatories BY RYTIS BERESNEVICIUS 2023-05-18 The European Union Aviation Safety Agency (EASA) issued an Airworthiness Directive (AD) to address a potentially unsafe condition related to lavatories on the Airbus A350. EASA commented that “occurrences have been reported of finding corrosion on lavatory floor fittings at various locations on A350 aeroplanes”, adding that these could lead to lavatory module detachments. As a result, the safety agency claimed that cabin crew and/or passengers could sustain injuries, “possibly resulting in reduced evacuation capacity from the aeroplane in case of an emergency”. The AD mandates airlines operating the Airbus A350 to conduct repetitive general visual inspections (GVI) of all lavatory floor fittings and, depending on the aircraft’s configuration and the results of GVIs, they should complete any corrective action(s). Airlines will also have to report the results of inspections to Airbus. Carriers utilizing the Airbus A350 will have to carry out the GVIs before exceeding 36 months since the aircraft’s manufacturing date and 36 months since the last accomplishment of the manufacturer’s Maintenance Review Board Report task 254000-00001-01M, or within six months after the effective date of the directive, whichever occurs later. If any discrepancy is detected, airlines will need to consult the Airbus Service Bulletin (SB) A350-25-P208, issued on January 31, 2023. Carriers will also have to report any findings to Airbus, even if no post-inspection corrective actions were required within 30 days after each GVI. The AD is effective May 31, 2023, and is applicable to all Airbus A350-900 and A350-1000 models. However, EASA noted that this directive “is considered to be an interim action,” which is why further corrective instructions could follow. According to ch-aviation.com data, 534 Airbus A350 aircraft have been delivered to customers, while Airbus Orders & Deliveries data, valid as of April 30, 2023, shows that 530 aircraft of the type had been delivered to customers. The latest delivery was an Airbus A350-900, registered as B-32DL, which was handed over to Air China on May 15, 2023, according to data from ch-aviation.com. EASA issues AD to address unsafe conditions with Airbus A350 lavatorie Water leaks on the 787 While the FAA is still inviting data, comments or arguments regarding the proposal, it has indicated that at least 134 Boeing 787s registered in the US would be affected by a finalized AD. However, airlines that operate the affected aircraft would have to conduct a detailed visual inspection ‘of all door 1 and door 3 lavatory and galley potable water systems for any missing or incorrectly installed clamshell couplings and applicable on-condition actions’. Per the regulator, two operators using the Dreamliner reported water leaks. One indicated that the leak was significant due to a loose potable water system hose that was caused by an incorrectly installed clamshell coupling within the lavatory. The other stated that a water leak was caused by ‘a detached clamshell coupling below the Door 1 forward center galley countertop adjacent to the gray water interface valve (GWIV) maintenance access compartment’. ‘The findings include a loss of water pressure during flight and a potable water system leak, discovered after landing, that caused water to migrate into the forward electronic equipment (EE) bay and affect multiple pieces of electronic equipment,’ according to the FAA’s document. Furthermore, the aircraft lost water pressure while in flight. The failure to use and correctly install the relevant couplings could ‘result in water leaks and water migration to critical flight equipment, which may affect the continued safe flight and landing of the airplane,’ the FAA concluded. Overall, the administration calculated that a detailed visual inspection (DVI) of the 134 Boeing 787s, per lavatory or galley, would cost airlines $85 in a single hour of labor. The total cost for all affected aircraft is calculated to be $11,390 for US-based carriers. Water leaks on the 787 Embraer says it will no longer have executive jets like the Lineage Ricardo Meier May 21, 2023 Planemaker admits to developing a new aircraft larger than the Praetor, but designed specifically for the corporate market Embraer said that it may launch a new executive jet in the long term, to be positioned above the Praetor model line, which carry up to 12 passengers. In an interview with Flight Global, the CEO of Embraer Executive Aviation, Michael Amalfitano, stated that the company intends at some point to launch an aircraft above the super-medium category, which includes the Praetor 600. However, the executive denied that this hypothetical executive jet will be derived from a commercial aircraft as happened with the Lineage 1000E, which was based on the E-Jets. “We’re going to stay true to a clean-sheet, purpose-built executive jet aircraft that are designed for the markets in which they serve,” said Amalfitano, on the eve of the new edition of EBACE, the world’s largest executive aviation event , which takes place in Switzerland. The Brazilian planemaker’s executive division has enjoyed growth in sales and financial income, accumulating an order backlog of US$4.1 billion. The agreement with NetJets, from the US alone, gave Embraer an order for 250 Praetor 500 jets – the company already flies dozens of Phenom 300s. Currently, Embraer’s product line includes the Phenom 100EV, which operates in the entry-level segment, the Phenom 300E, considered the most successful in its class, and the medium Praetor 500 and Praetor 600, which replaced the Legacy 450 and 500. Portfolio at EBACE Embraer debuted in the executive market with an adaptation of the ERJ 145 regional jet, the Legacy, which offered plenty of internal space, however, lower performance than the models originally designed for the category. Later, the Brazilian manufacturer decided to offer an executive E-Jet, in line with what Boeing and Airbus do. Based on the E190, the Lineage 1000 was born with a capacity to carry 19 passengers and a range of around 4,600 nautical miles (8,500 km). Lineage sales would not have reached 30 aircraft until Embraer announced the suspension of sales in 2020. While still planning its future, Embraer confirmed the participation of the Phenom 300E, Praetor 500 and Praetor 600 jets at EBACE 2023, which starts on May 23 in Geneva. Embraer says it will no longer have executive jets like the Lineage DEF Contamination Causes Dead-Stick Landing, No Injuries By Russ Niles Published: May 24, 2023 Updated: May 25, 2023 Despite a major awareness and training campaign, the National Air Transportation Association says diesel exhaust fluid (DEF) remains a potentially catastrophic hazard for aviation. In a news release, the organization said a business jet in the southeastern U.S. recently experienced a double flameout and glided to a dead stick landing 280 miles away. There were no injuries but the report didn’t say if the aircraft was damaged. It was the fifth such incident in five years and so far there have been no injuries, but aircraft engines and fuel systems were damaged. DEF is not a fuel additive. Its use is mandated for diesel vehicle engines (including those in airport fuel trucks) where it is stored in a separate tank and injected into the exhaust to reduce emissions. When added to fuel, it forms crystals that quickly clog lines and filters and damage moving parts. In the previous cases, DEF was mistaken for fuel system icing inhibitor and added by the FBO. Both are clear fluids. It’s not clear if that’s what happened in the most recent mishap, but NATA is urging fuel handlers to ensure staff training on preventing this kind of contamination. DEF Contamination Causes Dead-Stick Landing, No Injuries How a Rusty B-52 Carcass Is Key to the Bomber’s Big Upgrades May 24, 2023 | By John A. Tirpak OKLAHOMA CITY—Within a brand-new, gleaming-white facility called the “high bay” at the Oklahoma City Air Logistics Complex, a battered and rusty-looking fuselage and left wing of a B-52H has become a laboratory for the government-industry team that will revamp the aged Stratofortress fleet for the next 30 years. Still bearing its nose art—nicknamed “Damage, Inc. II”—the B-52H, which sat in the “Boneyard” at Davis-Monthan Air Force, Ariz., for more than two decades, will serve as a testbed for engineers looking to align new digital models of the bomber with the hands-on real world. The right wing and tail horizontal stabilizer from the aircraft are in a separate stress test facility—McFarland Research and Development in Wichita, Kan.—to determine how much structural life is left in the wings and control surfaces of the B-52 fleet, among other things. The carcass will be a valuable tool for engineers “who have never had the chance to get inside” one of the bombers, said Jennifer Wong, head of bomber programs for Boeing, which along with Rolls-Royce provided travel, meals, and lodging for reporters traveling to Oklahoma City to report on the B-52J program. Boeing is responsible for integrating the various upgrades that will turn the B-52H into the B-52J, including new engines, a new radar, communications and navigation, new weapons, and other improvements. “In order to perform all of the necessary mods of this program, we are touching more than just the engines,” Wong said. A carcass of a B-52H sits in the “High Bay” at the Oklahoma City Air Logistics Complex. Staff photo by John Tirpak/Air & Space Forces Magazine The carcass will allow engineers to crawl around in the airplane, to see how much space there is for installation of new gear and for maintainers to work on new equipment, and to appreciate the variations present in an aircraft built with sheet metal methods and blueprints more than a half century ago, Wong said. And crucially, it will allow these explorations without taking any of the Air Force’s current B-52s out of commission. The aircraft made the month-long, 1,500-mile flatbed journey from Davis-Monthan to Oklahoma City in early 2022 and is already serving as a reality check on the B-52 engineers’ digital models, used to project how they will mount new engines and pylons, run new cable, replace cockpit instrumentation, and otherwise organize the B-52’s rebirth. The carcass has also helped engineers determine the proper placement of the B-52’s new Rolls-Royce F130-200 engines, to see how the flaps will have to be re-shaped to accommodate the new engine nacelles. It will also offer an opportunity for fit-tests of new cockpit displays, wiring, and generator accessories that will be located in the landing gear bays, for example. The digital models are intended to make sure those new items don’t interfere with older ones; the carcass ensures the models haven’t missed something, such as “finding out you can’t reach a particular panel once this new thing is in place,” one engineer said. “We like to say everything underneath the wing is pretty much brand new … or modified for this program,” Wong said. “But in doing so, when you integrate new engines, you’re also affecting the wiring … the hydraulic system, the power system. … All of those have to be redesigned, modified and/or developed.” The hope is the B-52 carcass will smooth the way toward final designs. The nose of a B-52H sits in the “High Bay” at the Oklahoma City Air Logistics Complex. Staff photo by John Tirpak/Air & Space Forces Magazine The virtual reality systems developed by Rolls-Royce and Boeing for the new engines and other aircraft gear have gotten high marks from maintainers and will likely be offered to the Air Force as a maintenance training system at some point, company officials said. But that is not part of the B-52 upgrade effort, according to Col. Louis Ruscetta, senior material leader for the program. “This is an upgrade with a lot of moving parts,” Ruscetta said. “I want to keep this … as simple as possible.” For example, installing the new radar and preventing it from interfering with other systems is a formidable task in itself. It comes in two parts: the sensor of the AN/APG-79V4 used on the F/A-18 will be in the new radome, but the processor will come from the APG-82 flown on the F-15. They will be mounted—together—and must fit in fuselage space occupied by the current system. The new system is also heavier than the old one, and though it doesn’t affect the aircraft’s weight and balance, the structure in that part of the aircraft has to bear a new load. The radar will be used for both targeting and navigation but won’t be integrated with the electronic warfare system, Ruscetta said. “We have that as a growth requirement,” he said. “It will have the hooks to do that. But under the KISS methodology [Keep It Simple, Stupid], I wanted to make this a radar integration program, and not an EW integration program, which is a lot different scope.” In the cockpit, the digital models can be checked to see if crewmembers can see and reach new displays and controls associated with the new systems or upgraded to new standards. Because the B-52 was built in the 1960s—from a 1950s design—not all sizes of Airmen will be able to operate the aircraft, but the program is aiming to make the cockpit friendly to more pilots. An illustration of what the B-52 cockpit will look like after proposed upgrades. Staff photo by John Tirpak/Illustration courtesy of Boeing The High Bay will also serve to test interfaces for various weapons, pylons, and other B-52 accessories. Present in the facility were two dummy rounds of the AGM-158 Joint Air-to-Surface Standoff Missile (JASSM), several variants of the GBU-31/32/38 Joint Direct Attack Munition, the ADM-160 Miniature Air-Launched Decoy, B-52 wing-mounted weapons pylons, a Common Strategic Rotary Launcher, and various items of B-52 ground equipment. There also appeared to be other weapons which a Boeing official said might be future “notional” munitions. One aspect of the B-52 not getting a refresh is its basic appearance. While the C-5M Galaxy got fresh interior paint and soft surfaces when it was re-engined in the 2010s—Air Mobility Command generals said they wanted their Galaxy pilots to feel like it was a new airplane—the B-52 won’t be getting any such cosmetic improvements. “That’s not part of this program,” Ruscetta said, though the Air Force might opt to do it at some later date. How a Rusty B-52 Carcass Is Key to the Bomber’s Big Upgrades Curt Lewis