October 11, 2023 - No. 042 In This Issue : US lawmakers grant Boeing 737 MAX strings-attached deadline extension : FAA grants temporary lightning protection exemption for the Boeing 737 MAX 7 : FAA Finalizes Boeing 737NG Nacelle Retrofit Schedule : AD Mandates Garmin Autopilot Software Fix : Lock Haven Looking At Selling Piper Birthplace Contact the City of Lock Haven; Mayor to express your support for the William T. Piper Memorial Airport! : Philippine Airlines renews engine maintenance partnership with Lufthansa Technik : Boeing selects Pratt & Whitney GTF power for X-66A : RTX joins Boeing in NASA Sustainable Flight Demonstrator Project : EASA is addressing potential Airbus A330/A340 landing gear collapses : Rolls-Royce nozzle breakthrough brings hydrogen plane engines closer to reality : History Depends on the Historian US lawmakers grant Boeing 737 MAX strings-attached deadline extension BY RYTIS BERESNEVICIUS In a recently published bill, the United States (US) Senate has granted approval to Boeing and, subsequently, the Federal Aviation Administration (FAA) to continue working on certifying the 737 MAX-7 and MAX-10. The Fiscal Year 2023 Omnibus Appropriations Bill, released on December 20, 2022, includes changes to the 49 US Code Chapter 447. Lawmakers included amendments to the Flight Crew Alerting section (“§ 44744), essentially giving the FAA and Boeing the go-ahead to continue working on certifying the two 737 MAX types that have yet to enter commercial service. Changes to 737 MAX-7 and 737 MAX-10 alerting systems While the bill reiterated that following the December 27, 2022 deadline aircraft would not be certified without a modern flight crew alerting system, it did include a provision for the exemption of aircraft where certification work began prior to the deadline. However, the exemption comes with strings attached. “The prohibition in subsection (a) shall not apply to any application for an original or amended type certificate that was submitted to the Administrator [The FAA’s Administrator – ed. note] prior to December 27, 2020,” the Senate stated in its latest bill. The Aircraft Certification, Safety, and Accountability Act (ACSAA), which goes into effect on December 27, 2022, will require aircraft to feature modern flight crew alerting systems. According to the document, such a system will, at a minimum, need to have displays and showcase differences among warnings, cautions, and advisories and include “functions to assist the flight crew in prioritizing corrective actions and responding to systems failures”. Still, Boeing will have to make changes to the Engine Indicating and Crew Alerting System (EICAS) on all 737 MAX aircraft, including the 737 MAX-8 and MAX-9, which were cleared by the FAA to fly in November 2020. The bill will mandate Boeing to retrofit all 737 MAX family aircraft with FAA-approved safety enhancements one year after the 737 MAX-10 is certified. Otherwise, the administrator will not be able to issue an airworthiness certificate to newly produced aircraft of the type. Furthermore, three years after the 737 MAX-10 certification, airlines will not be able to operate any of the 737 MAX aircraft unless they meet two conditions. Firstly, the aircraft must include “safety enhancements approved by the Administrator” and secondly, they must either be produced or retrofitted with the FAA-approved design changes. Boeing will also have to bear the costs of these modifications per the latest proposal. Quarterly 737 MAX progress report In addition to monitoring and certifying the design changes, the FAA will also have to brief the US Congress on the continuing progress of the certification of the 737 MAX-7 and MAX-10, the bill added. The first report must be provided no later than March 1, 2023, and after that date, the FAA’s Administrator will have to appear before Congress on a quarterly basis. The current FAA Acting Administrator is Billy Nolen, a former American Airlines pilot. Nolen, or any other head of the government agency, will be required to provide detailed information on how the certification of the 737 MAX-7 and MAX-10 is progressing, “including any design enhancements, pilot procedures, or training requirements resulting from system safety assessments”. They will also have to brief US lawmakers on the implementation of the safety enhancements for the 737 MAX family. The safety enhancements, which include a synthetic Angle of Attack (AoA) system, the ability for pilots to turn off stall warnings and overspeed alerts, were mandated following the two fatal crashes of the Boeing 737 MAX-8 aircraft in Indonesia and in Ethiopia. The two accidents, which occurred in October 2018 and March 2019, respectively, claimed the lives of 346 people. However, the bill also reiterated that additional design changes deemed appropriate by the FAA could be added. AeroTime approached Boeing for comment. FAA grants temporary lightning protection exemption for the Boeing 737 MAX BY RYTIS BERESNEVICIUS 2023-09-22 The United States (US) Federal Aviation Administration (FAA) has granted Boeing’s petition to temporarily exempt the 737 MAX 7 from lightning protection rules. According to the FAA’s document, Boeing filed the petition on June 29, 2023, with the 737 MAX’s Development Chief Project Engineer Gary Hamatani asking the regulator to exempt the 737 MAX 7 from certain Code of Federal Regulations (CFR) requirements. The company also provided additional documents to the FAA in August 2023 to support its petition. “This exemption, if granted, would allow time to incorporate system updates and certify the Stall Management Yaw Damper (SMYD)” on the 737 MAX 7 until March 1, 2027. Boeing specifically requested exemptions from two CFR regulations, namely that each electrical and electronic system’s design, the failure of which would prevent the safe operation of the aircraft, must not be affected by a lightning strike and/or be able to restore normal functionality following exposure to lightning. Furthermore, each electrical and electronic system must be designed to function properly after exposure to high intensity radiated fields (HIRF) or recover to normal functionality after exposure to HIRFs. “Boeing states that granting the exemption would allow the use of the [part number] 285A1010-113 SMYD on the Model 737-7 airplane until necessary changes are made as part of the Model 737- 10 amended type certificate program and the subsequent service bulletins are released,” the FAA’s filing read. Once the 737 MAX 10 is certified, changes would apply to all the MAX models, including MAX 8, MAX 9 and the type in question, MAX 7. According to the manufacturer, the 737 MAX’s SMYD was based on the same part used on the aircraft family’s forebear, the Boeing 737 NextGeneration (NG). The FAA noted that the part includes no hardware changes between the generations, with only “a minimal update to the software to address model specific [737 MAX 7 – ed. note] data for stall warning, stall identification schedule, yaw damper filter and schedule coefficients, and gain schedules”. However, “subsequent to the development” of the new SMYD, Boeing discovered that it was not compliant with the CFR. As such, “Boeing states that additional certification activity will need to be performed, which Boeing proposes to complete as part of the Model 737-10 amended type certification project”. Boeing also pointed out that the exemption would allow a new aircraft to enter service more quickly, which “would replace an aging fleet; thus, providing environmental improvements, improved operating economics, and safety enhancements”. The manufacturer further supported its request by stating that the SMYD’s hardware has remained the same between the NG and MAX aircraft families. Additionally, since the 737 NG and MAX aircraft families accumulated over 240 million flight hours in more than 20 years of service, the part has had “an established performance and safety record with no reported issues related to HIRF or lightning-caused malfunctions”. Although the FAA requested “additional information from Boeing to better understand the SMYD failure modes, safety assessment, and system architecture”, the regulator eventually granted a time-limited exemption for the 737 MAX 7, to last until March 1, 2027. However, by August 1, 2025, Boeing will need to provide the FAA with a service bulletin (SB) for a software retrofit for the fleet for the approval of the regulator, which has warned that the 737 MAX 7 will not be allowed to operate beyond the exemption date without the update. In addition, Boeing is required to incorporate the update into its production no later than March 1, 2027. The update must also to be mentioned in the “airworthiness limitations section of the instructions for continued airworthiness” of each delivered MAX 7. FAA Finalizes Boeing 737NG Nacelle Retrofit Schedule Sean Broderick September 19, 2023 Credit: NTSB The FAA has signed off on Boeing’s proposed 737 Next Generation nacelle retrofit program, setting an August 2028 deadline for operators to complete the modifications, and giving the company until the end of 2029 to deliver maintenance error mitigation plans linked to the new designs. Under Boeing’s plan, it will finalize service bulletins detailing the modification work by the end of 2024. Operators will then have until July 31, 2028, or another 43 months, to retrofit their fleets. The FAA formalized the plan via an exemption granted to Boeing earlier in September. The step was needed so Boeing can roll out the changes incrementally, instead of getting the entire redesign approved as a system before retrofits begin. This gets the individual modifications into the fleet more quickly. Boeing’s redesign focuses on three main areas: new inlet spacers and fasteners, a fan cowl support beam, and a stiffer exhaust nozzle. The combination is meant to make nacelles less susceptible to breaking apart if a fan blade fails. Boeing agreed to make the changes following two CFM56-7B engine failures involving Southwest Airlines Boeing 737-700s, including one in April 2018 with a passenger fatality. Boeing filed its initial exemption request in July 2021. The company asked for seven years to develop the modifications and get them into the fleet. The FAA exemption adopts this schedule, with one notable change. Boeing has until the end of 2029 to deliver “solutions to address potential maintenance errors,” such as ensuring fan cowl doors are always secured before flight. Regulators around the world are likely to mandate the retrofits as well, setting the stage for as many as 6,500 aircraft to undergo modifications. The Aviation Week Network Fleet Discovery database shows 6,300 737NGs of all types in service and another 230 in storage. Boeing asked for the extra time earlier in 2023, citing an FAA “policy letter” sent in response to a company query. The letter, which has not been made public, relates to new system safety assessment (SSA) requirements the FAA is introducing. Among the myriad changes is reclassifying some human factors-related failure modes as unsafe system operating conditions that must be addressed—and mitigated—by manufacturers. An unlatched fan cowl door is one example. The exemption also gives Boeing an additional 17 months, or until the end of 2024, to ensure its proposed designs can comply with the new SSA requirements before finalizing them and the related modification instructions. “Boeing’s requested extension of the exemption maintains the level of safety of the existing exemption by ensuring operators will have service instructions available to begin implementing design changes without change to the original schedule,” the FAA said in granting the exemption. “The revised exemption will allow both Boeing and operators more time to address appropriate solutions to potential maintenance errors, further improving the level of safety of the airplane AD Mandates Garmin Autopilot Software Fix By Amelia Walsh Published: October 7, 2023 Updated: October 11, 2023 On Oct. 6, the FAA proposed a new airworthiness directive requiring operators of thousands of aircraft to update Garmin autopilot software to address a flaw causing the autopilot to make unintended flight-control inputs. According to the agency, the AD was issued in response to an incident involving an F33A Bonanza experiencing “an un-commanded automatic pitch trim runaway when the autopilot was first engaged.” The proposed rule states: “The affected autopilot system software does not properly handle certain hardware failures of the pitch trim servo. This could result in an automatic uncommanded pitch trim runaway and loss of control of the airplane.” The FAA estimates the AD would affect 5,900 aircraft equipped with the autopilot system— including Beechcraft Bonanzas, Commander Aircraft 112s and 114s, Cessna 172s, 182s, 206 and 210s, along with Daher TB20s and TB21s, Mooney’s M20 series and Piper Cherokees. However, the FAA estimates a fix will be relatively cheap for operators at around $85. The agency is proposing operators complete the installation of the updated Garmin autopilot software within a one-year time frame. The proposed rule will be published on Oct. 10, and the FAA will accept public comment until Nov. 24. Meanwhile, many of those affected have already resolved the issue since Garmin released the software fix earlier this year. “The updated GFC 500 software for GI 275, G5 and G3X Touch installations allows pitch trim to be enabled as a closing action to Service Alert 22109 and STC Service Bulletin 22110,” Garmin said in a statement to AVweb. “The Aviation Service Document Notification describes the software update procedures for impacted owners and operators. Lock Haven Looking At Selling Piper Birthplace By Amelia Walsh Published: October 8, 2023 Updated: October 9, 2023 Contact the City of Lock Haven; Mayor to express your support for the William T. Piper Memorial Airport! The future of Lock Haven’s William T. Piper Memorial Airport, former home of Piper Aircraft Corporation, is up in the air as the city grapples with selling the facility. Despite an economic impact of more than $13 million, the City of Lock Haven says the airport is not making the city enough money to justify continued operation by the city. City Manager Greg Wilson indicated that the finances generated by the airport do not return to the city, but rather remain with businesses on the field or others nearby who profit from transient aircraft. Wilson said the city does not intend to sell the airport for non-aviation purposes and suggested businesses collaborate to buy the airport and oversee its operations. However, airport advocates are holding out hope the city will reconsider given the airport’s history and its importance to the community. As the birthplace of the iconic Piper Cub, the aircraft manufacturer called the airport home from 1937-1984. While Piper’s factory production has since moved to Florida, the airport continues to pay tribute to its historic past with a museum dedicated to preserving its legacy located adjacent to the airport. During a recent meeting on the matter, Ron Dremel, president of the Piper Aviation Museum, which sees 2,500-3,000 annual visitors, said the airport is an important community resource. “This isn’t just a place for some rich playboys to have their expensive toys. Most of us are just middle-class people. I own 50 percent of an airplane that doesn’t cost more than my friends have invested in their Harley Davidsons. We’re just middle-class people that like to fly. Economically, this airport is just a tremendous asset.” The airport averages 48 operations per day—63 percent being local, 34 percent transient and 1 percent military. As the only public airport in Clinton County, local tenants say the airport is vital for pilot training, a reliever for emergency flights and instrumental in the case of natural disasters. Additionally, the airport is home to nine aviation businesses including maintenance services, aircraft brokerage, avionics sales and flight training. Philippine Airlines renews engine maintenance partnership with Lufthansa Technik Photo Credit: Lufthansa Technik October 1, 2023 Len Varley Lufthansa Technik has welcomed back former customer Philippine Airlines in the field of Engine Maintenance Services. The German maintenance provider has announced the firming of a three-year commitment covering the maintenance of eight CFM56-5B engines belonging to Philippine Airlines (PAL) A320ceo fleet, starting in 2024. Phillippine Airlines Relationship The collaboration between the Philippines national flag carrier and Lufthansa Technik is not new. PAL has previously engaged Lufthansa Technik for Total Component Support (TCS) for its Boeing 777 fleet and Base Maintenance Services (BMS). This was carried out through Lufthansa Technik’s subsidiary in the Philippines. This renewed partnership in engine maintenance services underscores the trust PAL places in Lufthansa Technik, backed by a track record of excellence. PAL’s Vice President of Procurement & Logistics, William G. Tan, expressed confidence in Lufthansa Technik, saying, “Lufthansa Technik is a very reliable partner who ensures that our aircraft engines remain in optimal condition.” “Thanks to their technical capabilities and innovative solutions, they can significantly extend the life of our engines. We decided to work with Lufthansa Technik again with the expectation that they will deliver excellent performance in the field of engine maintenance.” Lufthansa Technik’s Capabilities Lufthansa Technik, with its state-of-the-art facilities and a team of experienced engineers and technicians, is well-prepared to provide efficient and high-quality engine maintenance services. Their goal is clear: minimize downtime and maximize fleet performance for PAL. Dennis Kohr, Senior Vice President Corporate Sales Asia Pacific at Lufthansa Technik, expressed his delight, stating, “We are delighted and very grateful that Philippine Airlines has chosen us as their engine maintenance partner again.” “We take this as an opportunity to further strengthen our long-lasting partnership and are committed to delivering outstanding results for Philippine Airlines.” About Philippine Airlines Philippine Airlines (PAL), also known as Philippine Air Lines from 1941 until 1970, is the flag carrier of the Philippines. Founded in 1941, it is the first and oldest commercial airline in Asia. PAL is headquartered at the PNB Financial Center in Pasay, Philippines, and is a subsidiary of PAL Holdings, Inc., which is part of the LT Group. PAL operates a network of over 100 domestic and international destinations in Asia, North America, and the Middle East. Its main hub is Ninoy Aquino International Airport (MNL) in Manila, with secondary hubs at Mactan-Cebu International Airport (CEB) in Cebu City and Francisco Bangoy International Airport (DVO) in Davao City. Boeing selects Pratt & Whitney GTF power for X-66A by Addison Schonland Oct 3, 2023 Photo: Aerospace, Boeing, Pratt & Whitney With all the negative news around the GTF, it is encouraging that RTX announced this morning that Boeing selected the Pratt & Whitney GTF to power the X-66A. RTX also announced that the project would use nacelles and engine accessories from another one of its units, Collins Aerospace. Pratt & Whitney and Collins will also support ground and flight tests, slated to start in 2028. The X-66A is a Sustainable Flight Demonstrator and is part of NASA’s broader Sustainable Flight National Partnership, which is dedicated to developing technologies needed to achieve net-zero CO2 emissions for commercial aviation. Boeing’s X-66A program focuses on developing a Transonic Truss-Braced Wing (TTBW) concept, which could significantly improve fuel efficiency and reduce emissions for next-generation single-aisle aircraft. Regarding the GTF, the current concern with powered metal material does not apply to engines from 2022 onward. The GTF is also certified to operate with SAF. Unsurprisingly, Boeing selected RTX as a partner, as it is the world’s largest aerospace and defense company. Virtually every Western commercial aircraft has inputs from an RTX unit. RTX joins Boeing in NASA Sustainable Flight Demonstrator Project Image Credit: Boeing October 7, 2023 Len Varley RTX has been selected by Boeing as a collaborator on the X-66A flight demonstrator, part of NASA’s Sustainable Flight Demonstrator project. RTX is the world’s largest aerospace and defense company, operating through its business units Collins Aerospace, Pratt & Whitney and Raytheon. Pratt & Whitney and Collins Aerospace RTX will bring its formidable expertise to the table through two of its business units: Pratt & Whitney and Collins Aerospace. Pratt & Whitney will contribute its groundbreaking GTF™ engines, while Collins Aerospace will provide nacelles and engine accessories. These components are poised to play a pivotal role in Boeing‘s ambitious X-66A flight demonstrator project, which is slated to kick off in 2028. Sustainable Flight Demonstrator The Sustainable Flight Demonstrator is a vital cog in NASA’s broader Sustainable Flight National Partnership, an initiative dedicated to developing technologies that will help the aviation industry achieve net-zero CO2 emissions. Boeing’s X-66A program, a central part of this endeavor, is laser-focused on advancing the Transonic Truss-Braced Wing (TTBW) concept. This innovation holds the potential to usher in a new era of fuel efficiency and reduced emissions for the next generation of single-aisle aircraft. Geoff Hunt, Senior Vice President of Engineering & Technology at Pratt & Whitney, emphasized the significance of NASA’s Sustainable Flight Demonstrator, stating, “NASA’s Sustainable Flight Demonstrator is a leading example of how public-private partnerships can help foster the technological breakthroughs needed to deliver on the industry-wide goal of a more sustainable, net-zero emissions future.” This underscores the vital role that collaboration between industry leaders and government agencies plays in propelling aviation toward a cleaner future. The GTF Engine Pratt & Whitney’s GTF engine boasts a revolutionary geared fan architecture, setting a new standard for fuel efficiency and sustainability in single-aisle aircraft. With a remarkable 20% improvement in fuel efficiency, GTF engines have already saved airlines more than 1.4 billion gallons of fuel and over 14 million metric tons of CO2 emissions since their debut in 2016. Notably, these engines are certified to run on sustainable aviation fuel (SAF) and offer an astonishing 75% reduction in aircraft noise compared to their predecessors. Collins Aerospace’s Contribution Collins Aerospace is no stranger to innovation and collaboration within the aerospace industry. Dr. Mauro Atalla, Senior Vice President of Engineering & Technology for Collins, highlighted their extensive experience in pushing the boundaries of aerospace innovation. He stated, “Now, as part of the Sustainable Flight Demonstrator program, we will work together to demonstrate new technologies and systems to support the next generation of low-emission single-aisle aircraft that will play an integral role in reducing the environmental footprint of the aviation industry.” Nacelles and Engine Accessories Collins’ nacelles are a marvel of engineering, crafted from lightweight and durable composite and metallic materials. These nacelles serve multiple crucial functions, including safeguarding the engine, controlling airflow, reducing noise, and enabling thrust reversal for deceleration during aircraft landings. Additionally, Collins supplies essential control system components for the GTF engine, including heat exchangers, the integrated fuel pump and control, the air turbine starter, and electronic controls. Dr. Todd Citron, Boeing’s Chief Technology Officer, highlighted the importance of collaborations like the Sustainable Flight Demonstrator. He stated, “The learnings from the Sustainable Flight Demonstrator, X-66, and the partnership with NASA are important elements in the industry’s efforts to decarbonize aviation.” Pioneering Sustainable Aviation RTX is at the forefront of pioneering technologies for a sustainable aviation future. Their efforts extend to engine readiness for unblended 100% SAF, hybrid-electric propulsion, and hydrogen fuel. In addition to their collaboration on the Sustainable Flight Demonstrator, Pratt & Whitney and Collins are actively engaged with NASA on other Sustainable Flight National Partnership projects, including Hybrid Thermally Efficient Core (HyTEC) and Hi-Rate Composite Aircraft Manufacturing (HiCAM). EASA is addressing potential Airbus A330/A340 landing gear collapses BY RYTIS BERESNEVICIUS 2023-08-30 The European Union Aviation Safety Agency (EASA) has acted upon being notified of irregularities in quality of manufacturing of the Airbus A330 and A340 main landing gear (MLG), which could result in the collapse of the MLG. EASA has noted that “occurrences have been reported of quality non-conformity on MLG axles where the high velocity oxygen-fuel coating on the bearing journal runout areas had excessive coating compared to the drawing limits,” according to its latest airworthiness directive (AD). The excessive coating “could lead to spalling of the protective coating, which could expose the base material and allow corrosion to develop”. Subsequently, the condition, if not corrected, “could lead to an MLG axle failure, possibly resulting in MLG collapse, with consequent damage to the aeroplane and injury to occupants”. The AD affects all Airbus A330ceo and A330neo, as well as A340-300 aircraft of all Manufacturer Serial Numbers (MSN). Airlines operating either the A330 or A340-300s will have to inspect MLGs with Part Number (P/N) 55-2117042-00, with EASA providing a list of 59 aircraft with the affected part installed on them on the date of manufacture. The inspections will need to be conducted within 24 months of the part’s entry into service date. Thereafter, operators will be required to inspect the affected part at intervals of no more than 24 months. If discrepancies are found during any such inspections, airlines are urged to contact SAFRAN Landing Systems before the aircraft’s next flight to receive instructions on how to amend the condition. SAFRAN should then provide the compliance time to fix the parts. If the manufacturer does not, EASA urges airlines to ensure that they do so before the next flight of the A330/A340-300. If airlines have an aircraft whose Manufacturer Serial Number (MSN) matches the list of MSNs provided by EASA, they will have to replace the affected part within 150 months of the part’s entry into service. The European regulator has noted that replacing the whole MLG with an MLG with a serviceable part – that is, one not affected by the AD – complies with the requirements of the directive. Requesting a grace period Two Airbus A330 operators, Delta Air Lines and Cathay Pacific, have commented on the directive. In total, Delta Air Lines provided three comments to EASA. In one, the carrier asked to include the permanent repair of the MLG as a means of complying with the directive, with the airline mentioning a repair procedure defined by Airbus’ Component Maintenance Manual (CMM) 32-13-25. EASA disagreed, saying that the current CMM does not have the repair procedure as yet. However, when Airbus does include the procedure in the manual, the regulator will amend the directive accordingly. Furthermore, Delta Air Lines requested that the compliance time would also include “24 months after the AD effective date, whichever is later” in addition to the part’s entry into service date benchmark. The United States (US)-based airline said that, if EASA would not grant a grace period, it would have to ground three aircraft on the AD’s effective date. “Existing data does not support a general extension of the compliance time as proposed,” the European safety agency replied. Meanwhile, Cathay Pacific has noted that not all Airbus A330 and/or A340 MLGs can support the affected parts, which should exempt certain aircraft from the directive. “The AD should be exact as to which aircraft and landing gear are affected by this quality issue specified in the AD,” the Hong Kong International Airport (HKG)-based airline continued. EASA disagreed, saying that the affected MLGs “can be installed on aeroplanes having specific mod installed in production, or service bulletin [SB] in service”. “Consequently, the AD has to be applicable to all MSN of those [aircraft] models on which an enhanced MLG is eligible for installation (either mod or SB),” EASA concluded. The European regulator published the AD on August 30, 2023, with the effective date being September 13, 2023. Rolls-Royce nozzle breakthrough brings hydrogen plane engines closer to reality By Jack Loughran Published Tuesday, September 26, 2023 Rolls-Royce has reached a key milestone in developing a hydrogen-powered engine as part of plans to develop net zero planes, the engine maker has said. The firm is working with partner easyJet to develop hydrogen combustion engine technology capable of powering a range of aircraft from the mid-2030s onwards. It said it completed tests on a full annular combustor of a Pearl 700 engine, which was running solely on hydrogen fuel. The test proves that the fuel can be combusted at conditions needed to achieve maximum take-off thrust. The engine used newly developed fuel spray nozzles to allow for precise control over the combustion process. “This involved overcoming significant engineering challenges as hydrogen burns far hotter and more rapidly than kerosene,” Rolls-Royce said. The nozzles, which were tested at Loughborough University’s recently upgraded National Centre for Combustion and Aerothermal Technology (NCCAT), were able to control the flame position using a new system that progressively mixes air with the hydrogen to manage the fuel’s reactivity. Earlier this month, a group of UK-based aviation and renewable energy companies including easyJet and Rolls-Royce established the UK Hydrogen in Aviation alliance in a bid to decarbonise flying. The partnership aims to ensure that the UK puts in place the infrastructure, policy, regulatory and safety frameworks needed to be ready for when the first hydrogen-powered aircraft takes to the skies. Last year, easyJet and Rolls-Royce ran a modern aero engine, an AE2100, on green hydrogen at Boscombe Down, UK. The recent tests have improved the engineers’ understanding of the combustion element of the hydrogen programme, while work continues on systems to deliver the fuel to the engine and integrate those systems with an engine. Grazia Vittadini, technology chief at Rolls-Royce, said: “This is an incredible achievement in a short space of time. Controlling the combustion process is one of the key technology challenges the industry faces in making hydrogen a real aviation fuel of the future. We have achieved that, and it makes us eager to keep moving forward.” Johan Lundgren, CEO of easyJet, said: “We believe hydrogen is the future of short-haul aviation, and the success of this test and progress being made demonstrates that this is becoming ever closer. We remain optimistic that it will play a critical role in helping us achieve the ambitious goals we set out in our net zero roadmap.” Rolls-Royce and easyJet are now preparing to undertake a full ground test on a Pearl engine running on solely liquid hydrogen. History Depends on the Historian Jules Ashley British manufacturer de Havilland's first aircraft of all-metal stressed–skin construction, the DH.95 Flamingo was designed by R. E. Bishop as a medium-range transport to carry between 12 and 17 passengers in addition to its crew of three. The DH.95 featured hydraulically retractable landing gear and split trailing-edge flaps, and was powered by two 890-horsepower Bristol Pegasus XIIC radial engines. The prototype was first flown by de Havilland's chief test pilot, Geoffrey de Havilland Jr. at Hatfield on 28 December 1938, and during subsequent testing a centreline third fin was fitted temporarily to complement the original pair of endplate vertical tail surfaces. In May 1939 this aircraft was delivered to Guernsey & Jersey Airways Ltd. for route-proving trials, linking Heston and Southampton's Eastleigh Airport with the two main Channel Islands. However, the outbreak of World War II in 1939 precluded the use of the type for scheduled services. Meanwhile, the initial performance trials had attracted the attention of the British Air Ministry who having evaluated the prototype as a military transport in March 1939 ordered three Flamingo aircraft for the Royal Air Force. The two Flamingos ordered by the airline were diverted, along with the prototype, to No. 24 Squadron at RAF Hendon for use as VIP transports, and the third was delivered to the King's Flight at RAF Benson on 7 September 1940, for possible emergency evacuation of the Royal Family. This aircraft was subsequently transferred to No. 24 (VIP) squadron in February 1941. The squadron also acquired the airframe that the manufacturer had used for development with the Bristol Pegasus XVI supercharged radial engine. This engine was subsequently fitted to all later production Flamingo aircraft, including one, the 11th aircraft, which was impressed by the Admiralty in 1940 for use by the Royal Navy's No. 782 Squadron at RNAS Donibristle in Scotland, United Kingdom where it served the Orkneys and Shetlands and Northern Ireland. It was joined in 1945 by an ex-RAF Flamingo and was the only aircraft to return to civil use after World War II, seeing limited service, in its original civilian markings, with British Air Transport Ltd. at Redhill Aerodrome in Nutfield, Surrey, England, United Kingdom, until it was scrapped in 1954. Seven other Flamingo aircraft were flown by BAOC (created on 1 April 1940 by the amalgamation of Imperial Airways and British Airways) and based at Cairo, Egypt for Middle East routes, including services to Asmara, Aden, Addis Ababa, Adana, Jeddah and Lydda. Of these aircraft, two were lost in 1943 in separate crashes at Asmara, one crashed at Adana in 1942 and the other four were brought back to the UK, being scrapped at Redhill in 1950. Flamingo production ultimately totalled 16 aircraft, including the prototype, of which twelve were completed to civilians (impressed into wartime service) and three as military standard machines. Another de Havilland project was the Hertfordshire which was to have been a fully militarised version of the Flamingo, to meet Air Ministry specification 19/39, for the carriage of up to 22 troops; only the prototype was completed and tested at Boscombe Down, becoming one of the aircraft sent to No. 24 Squadron, and the contract for forty was subsequently cancelled. The only visible difference in the Hertfordshire was the substitution of portholes for windows. The sole Hertfordshire crashed on 23 October 1940 killing five crew and six passengers, including Air Vice-Marshal Charles Blount, the commanding officer of No. 22 Group travelling from RAF Hendon to Belfast, Northern Ireland, United Kingdom, apparently due to jamming of the elevator. Picture taken: DH.95 Flamingo aircraft G-AFUE during route proving flights with Jersey Airways, over Portelet Bay, Jersey, Jun 1939; note Portelet Tower in center of photograph; seen in 10 Aug 1939 issue of Flight magazine (1 of 3) DH.95 Flamingo aircraft of No. 24 Squadron RAF based at RAF Hendon, England, United Kingdom, 1940s. ( 2 of 3) DH.95 Flamingo G-AFYH of British Air Transport at Redhill Aerodrome, Nutfield, Surrey, England, United Kingdom, 6 Jun 1953. 3 of 3 Curt Lewis