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Truth decay and compromised ethical behavior can be observed when looking back into the history of the aviation industry. The author has presented since 2012 about related questionable views and behavior. In this presentation he compiles the "best" of his slides into one lecture that tries to give an overview of the problem at hand. Commercial aviation provides one of the strongest examples of Jevons Paradox, nevertheless the aviation industry keeps praising efficiency gains as the way to safe fuel and emissions on a global scale. Questionable goal setting with respect to aviation emissions started as early as 2000. Inside the aircraft another problem exists: contaminated aircraft cabin air. Here, the aviation industry rather fights claims of victims in court instead of working on a technical solution. The idea of massive use of air taxies is as old as 1899, but has still not come. Eventually it will most probably be a polluting means of transportation for the super-rich. Battery electric aviation has a clear range limit. Proposals that deny this fact are green washing. Grid-connected electric mobility operates successfully on tracks e.g. as high-speed trains. Claims for a large number of propellers may have been made without looking at certification rules and geometry. The year 2020 came. Those waiting to see a difference in aviation (massive CO2-compensation by the industry) to fulfill at last aviation's goal setting promise of Carbon Neutral Growth (CNG) saw – nothing. However, the Corona pandemic came after two month into the year 2020. Most aircraft rested on the ground. Subsequently, passengers saw more legends than truth about cabin ventilation. The legends were distributed by the aviation industry in an effort to retain at least a minimum of revenues. IATA turned out to be the biggest liar among all. Airbus chief engineer Jean-Brice Dumont was given the new title "guru" and explained cabin ventilation on Facebook. Emirates presented two highly protected technicians mounting a new and clean HEPA filter on an A380. Still in the same year the next legend was presented by Airbus: Aircraft burning hydrogen in jet engines would produce "zero emissions". In contrast to science, this would mean no NOx and no contrails. After the pandemic, industry could not wait to see air traffic reaching again 2019 levels and old growth figures. It was still not understood that instead a reduction in air traffic would be necessary to reach proclaimed goals. It was also not understood that regenerative energy would need to be used first to substitute coal power plants and that massive aviation regenerative electricity demands for LH2 and SAF had no chance to be addressed by society. Aviation would need to produce its green energy itself. Time scales slipped or turned out to have been lies in the first place. 2021 was the year to look back at the "money burning" A380 project. This reminded us that Airbus lied already 20 years ago when demanding a runway extension in Hamburg-Finkenwerder for the A380. The extension was not necessary, but was built (from public money) anyway and against much protest from local population and their precise engineering/aviation arguments. Aviation ethics can be summed up under: "G^4", which stands for "Continuous Growth to increase Gain to satisfy shareholders expectations can lead to Greed and to an ever more ruthless industry behavior accumulating Guilt in the end." Some aviation organizations seem not to be willing to abide by the law, even if enforced and with consequences leading to the end of company existence. Boeing gambled with saving a second angel-of-attack sensor on the B737 MAX, resulting in two crashes and 346 people dying. Airbus paid 3.6 Billion Euro penalty due to bribery. The aviation industry is far from abidance by the law and even further away from taking up the code of a respectable / honorable businessman. The list of unethical issues in the aviation industry is long., SARC Friday Club

Collection of Memoranda from AERO. A memorandum is a note with something memorable, in short a memo. It can be a short technical description or an opinion piece. The word is of Latin origin: memorandum literally means "that which is to be remembered". The plural is memoranda.

Purpose: This paper discusses potential contamination of the air in passenger aircraft cabins. It gives an overview of cabin air contamination basics. It further names possible contamination sources and possible routes of contamination. Methodology: Evidence follows from a review of material found on the Internet and from the documentation of a visit to an aircraft recycling site. Parts were retrieved at the site and investigated later with more time. Findings: Jet engine seals leak oil in small quantities. Metallic nanoparticles are found in the oil and have been detected in human fatty tissue of aviation workers. It has been observed that the potable water on board can also be contaminated. Oil traces have been found in bleed ducts, air conditioning components, and in air conditioning ducts. Deicing fluid and hydraulic fluid can find their way into the air conditioning system via the APU air intake. Fuel and oil also leak down onto the airport surfaces. These fluids can be ingested by the engine from the ground and can enter the air conditioning system from there. Entropy is the law of nature that states that disorder always increases. This is the reason, why it is impossible to confine engine oil and hydraulic fluids to their (predominantly) closed aircraft systems. This is why engine oil with metal nanoparticles hydraulic fluids, and deicing fluids eventually can go everywhere and finally into the human body. Research Limitations: No measurements have been made. Practical Implications: Awareness and prevention of contaminated cabin air can protect passengers and crew. Social Implications: The exposure of contaminated cabin air provides a basis for a general discussion and shows that people should be alerted and need to act. New technologies need to be implemented such as a bleed free architecture. Originality: This paper shows many original images of contaminated parts and air ducts between engine compressor and cabin air outlet. Own observations are combined with similar observations found in literature and online. The collected evidence is visualized in a diagram showing the routes of possible aircraft cabin air (and water) contamination.

Following the successful initial Special Issue on "Aircraft Design (SI-1/2017)" and the relaunch with "Aircraft Design (SI-2/2020)", this is already the third SI in sequence named "Aircraft Design (SI 3/2021)". Activities in the past showed that aircraft design may be a field too small to justify its own (subscription-based) journal. A continuous open access special issue may fill the gap. As such, the Special Issue "Aircraft Design" can be a home for all those working in the field who regret the absence of an aircraft design journal. SI-3/2021 contains six papers (original research articles) about 1.) Oil Fumes in the Cabin and Flight Safety, 2.) Closed-Loop Flying Qualities Requirements, 3.) Preliminary Design of a Medium Range Box Wing Aircraft, 4.) Influence of Novel Airframe Technologies on the Feasibility of Fully-Electric Regional Aviation, 5.) Design and Optimization of a Large Turboprop Aircraft, 6.) Sources of Onboard Fumes and Smoke.

We consider that use of SAF is mainly a question of its availability and price. For engineers, it is a matter of sourcing primary energy involved in producing SAF- not to forget that SAF is only sustainable, if the CO2 is really taken out of the atmosphere in fuel production, which is intended to be put back into the atmosphere during flight. LH2 requires new (or modified) aircraft that are less efficient than conventional aircraft. Calculations show about 40% more fuel consumption (by energy) for LH2. This adds to the demand of LH2 for sourcing more primary energy. Batteries for electric flights suffer from their weight (as we already know). In addition, there are interesting aircraft design questions arising from issues such as: higher number of propellers and propeller integration into the airframe. It is explained, why hybrid electric or turbo electric solutions have clear disadvantages. There are also the non-CO2 effects. Here we shall consider flying lower with LH2 and also kerosene/SAF aircraft., RAeS Conference: Alternative Propulsion Systems – the Challenges and Opportunities for Aircraft Design

Zweck ��� Dieser Vortrag untersucht die sozialen Auswirkungen von Flugzeugen oder Flugzeugprojekten mit einem Lebenszyklusansatz am Beispiel des Programms Airbus A380. Methodik ��� Soziale Auswirkungen werden analysiert, indem eine Social Life Cycle Assessment (S-LCA) basierend auf den "Guidelines for Social Life Cycle Assessment for Products" des Umweltprogramms der Vereinten Nationen (UNEP) und der Society of Environmental Toxicology and Chemistry (SETAC) durchgef��hrt wird. Stakeholder und Unterkategorien werden ausgew��hlt und Daten werden mit qualitativen Interviews und Webrecherchen gesammelt. Eine Folgenabsch��tzung wird mit der Subcategory Assessment Method (SAM) durchgef��hrt. Die Ergebnisse werden interpretiert und verallgemeinert. Ergebnisse ��� W��hrend seiner Lebensdauer hat ein Flugzeug oder Flugzeugprogramm Auswirkungen auf verschiedene Interessensgruppen. Die Lebenszyklusphase "Rohstoffgewinnung" k��nnte zu Menschenrechtsverletzungen f��hren, aber auch lokale Gemeinschaften in der N��he der wichtigsten Produktionsst��tten sind mit sozialen Auswirkungen konfrontiert, sowohl positiv als auch negativ. Die wirtschaftliche Bedeutung des Luftfahrtsektors beeinflusst die Gesellschaft, politische Entscheidungstr��ger, lokale Gemeinschaften und Arbeitnehmer. All dies zeigte sich auch im A380-Programm. Grenzen der Anwendbarkeit ��� Die Datenverf��gbarkeit schr��nkte die Untersuchung teilweise ein. Das Projekt deckt nicht alle Lebenszyklusphasen und Interessensgruppen ab. Stattdessen liegt der Fokus auf ausgew��hlten Phasen und Gruppen. Bedeutung in der Praxis ��� Die Studie kann Entscheidungstr��gern in der Luftfahrt helfen, ein Produkt bereitzustellen, das das Wohlergehen seiner Interessensgruppen verbessert. Soziale Bedeutung ��� Die Durchf��hrung einer S-LCA in der Luftfahrt r��ckt die sozialen Implikationen des Flugzeugprogramms in den Fokus und bietet eine Grundlage f��r eine allgemeine Diskussion ��ber seine soziale Nachhaltigkeit. Originalit��t ��� Dies scheint die erste Arbeit zum Thema S-LCA eines Flugzeugs oder Flugzeugprogramms zu sein., Hamburg Aerospace Lecture Series --- Collection of Presentations --- http://www.AeroLectures.de

Purpose – Reach awareness about the strategy of the aviation industry (manufacturers, airlines, organizations) when faced with restrictions from government. Internal emissions (corona virus) and external emissions (CO2, NOX, AIC) are the threats today. Approach – Industry published information during the corona pandemic as well as related to aviation and climate change is collected from the Internet and set against scientific evidence. Findings – Internal emissions: HEPA filters in aircraft do not produce cabin air "as clean as in a hospital operating theater". External emissions: The goal "zero emission" is proclaimed, but it becomes evident already now that measures are not sufficient and dates will not be met to come even close to set goals. Sustainable aviation fuel (SAF) is very energy intensive. Non-CO2 effects from aircraft burning hydrogen in jet engines must not be ignored. SAF will only make aircraft climate neutral when about 3 times more CO2 is captured with Direct Air Capture (DAC) then emitted. This is necessary to account for the non-CO2 effects. Research limitations – The presentation is based on examples. Practical implications – The public gets ill informed. Therefore, it is important so set the record straight. In addition, the strategy used by the aviation industry is exposed. Social implications – The discussion opens up the topic beyond aviation expert circles. Originality – Not much comparable information is given by other authors., German Aerospace Congress 2021 (DLRK 2021), Online, 01 September 2021--- https://publikationen.dglr.de/?tx_dglrpublications_pi1[document_id]=550292

Passenger aircraft occasionally encounter a Cabin Air Contamination Event (CACE). When these events make themselves know with a distinct smell they are called Smell Events. When they are evident even by smoke (and smell), they are called Fume Events. The objectionable classical cabin air contamination from "bleed", "engine oil", "hydraulic fluid", and "deicing" accounts together for roughly 1/3 of the events. Oil has left traces on its way from the engine to the cabin interior: In bleed air ducts, air conditioning ducts, in recirculation filters, on cabin surfaces (wall panels, seats ...). Hydro carbon concentrations in the cabin can be calculated and agree with measurements. SAE has highlighted the risk of obtaining contaminated air from the engine compressor. It may preclude its use for transport aircraft, regardless of other good reasons. Nevertheless, aviation organizations like IATA claim that "Cabin air is as clean as a hospital operating theatre". Cabin air ventilation in passenger aircraft is done with outside air. At cruise altitude, ambient pressure is below cabin pressure. Hence, the outside air needs to be compressed before it is delivered into the cabin. The most economic system principle simply uses the air that is compressed in the engine compressor anyway and taps some of it off as "bleed air". The engine shaft is supported by lubricated bearings. They are sealed against the air in the compressor usually with labyrinth seals. Unfortunately, the jet engine seals leak oil by design in small quantities. The oil leaking into the compressor contains toxic additives. Furthermore, the oil includes toxic metal nanoparticles – normal debris from the engine. An alternative source for the compressed air is the Auxiliary Power Unit (APU). Like the aircraft's jet engine, it is a gas turbine, built much in the same way when it comes to bearings and seals. For this reason, also compressed air from the APU is potentially contaminated in much the same way. Compressed air from the engine is also used to pressurize the potable water. It has been observed that the potable water on board can also be contaminated. Fan air and bleed air ducts at the interface between engine and wing carry outside compressed air. The inside of the ducts shows differences. The brown stain in the bleed air duct appears to be engine oil residue. In comparison, the fan air duct is clean. This shows that oil leaves the compressor bearings. Ducting further downstream shows a black dry cover. The reason for the change in color seems to result from the different air temperatures: 400 °C at engine outlet and 200 °C further downstream behind the precooler. The water extractor is a part of the air conditioning pack. The inlet of the water extractor is covered with black oily residue, because the temperature is even lower at this point. The air conditioning air distribution ducts in the cabin are black inside from contaminated bleed air. New ducts are clean. Air duct are even clean inside at the end of the aircraft's life, in areas where they are used such that no bleed air flows through them. Flow limiters have been found in ducts of the air conditioning system that are clogged from engine oil. Also riser ducts feeding the cabin air outlets are black inside from engine oil residue. Cleaning on top of the overhead bins brings to light dirt that is clearly more than dust. The black residue known from the ducts settles also on the bin surface. Deicing fluid and hydraulic fluid can find their way into the air conditioning system via the APU air intake. A fence and a deflector around the air intake cannot fully prevent contaminants from entering the APU. Traces of contamination tend to be visible on the lower part of the fuselage. Contaminants are carried by the air flow in flight, from the landing gear bay to the APU inlet. Hydraulic systems are never leak free. A hydraulic seal drain system tries to collect hydraulic fluid leaving the system with partial success. It is impossible to catch all leaking hydraulic fluid. If the containers of the seal drain system are not emptied they spill over. In old aircraft, surfaces in the landing gear bay are covered with a layer of hydraulic fluid. Dirt accumulates on the sticky surface. The hydraulic fluid is not confined to the inside of hydraulic bays, but continues its journey on the lower side of the fuselage towards the APU. Deicing fluid if applied in the winter to the aircraft and can leak from the tail into the APU inlet. Fuel and oil also leak down onto the airport surfaces. These fluids can be ingested by the engine from the ground and can enter the air conditioning system from there. Entropy is the law of nature that states that disorder always increases. This is the reason, why it is impossible to confine engine oil and hydraulic fluids to their (predominantly) closed aircraft systems. This is why engine oil with metal nanoparticles hydraulic fluids, and deicing fluids eventually go everywhere and finally into the human body. Filtration can help to avoid cabin air contamination. HEPA filters are in use with most passenger aircraft that work with recirculated air. Only HEPA carbon filters can also filter some of the Volatile Organic Compounds (VOCs). They are available for only some aircraft types and only lead to about 40% reduction of the concentration of VOCs in the cabin. Necessary would be to filter the incoming air from the engine compressor. Filter manufacturer Pall has worked on such a total air filtration option for the Airbus A320 for several years, but is so far not able to offer the new system. For this reason, we are left with a situation, where engines are longer and longer on the wing without the chance to replace engines seals that get worn out more the longer the engine is operated. This leads to an increasing number of CACEs. Airbus duct cleaning maintenance procedures after a CACE are ineffective. Aircraft released back into service over night after an (oil based) CACE are not cleaned as instructed by Airbus, because ducts cannot be removed from behind the panels in this short time, the inside of ducts is not accessible, and most of the deposit are firmly attached to the surface and cannot be removed. This leaves the passengers in a situation for which the degree of contamination is unknown but real. Strictly, the amount of oil in the cabin cannot be determined from the oil consumption of the engine. For legal benefit of the aviation industry, sensors are missing on board and deprive passengers and crew from data that could be used in court., Hearing of Prof. Dr. Scholz on the operation of air conditioning in aircraft cabins and the associated air quality. The hearing was on July 8th, 2021, from 9h30 to 11h30, by video conferencing.

Purpose– Reach awareness that the aviation industry (manufacturers, airlines, organizations) is lying about cabin ventilation on board of passenger aircraft. Approach – Industry information published during the corona pandemic is collected from the Internet and set against scientific evidence. --- Findings – HEPA filters in aircraft do not produce cabin air "as clean as [in] a hospital operating theatre". Viruses and other substances like CO2 are generated in the cabin and need to be washed out. Their concentration follows from their source strength and the ventilation air flow rate. Aircraft cabin air is not "fully renewed in 2 to 3 minutes". It takes several such air changes to reach 1% of the initial concentration. The air change rate is not even relevant for the concentration of e.g. viruses or CO2 in the cabin. The "air flow in the cabin" is not "only flow from top to bottom". The air is mixed within several rows and beyond. --- Research limitations – Neither the industry campaign nor the literature on (aircraft cabin) ventilation is fully explored. Only examples are given to illustrate how the aviation industry deceived politics and the public for their economic advantage. --- Practical implications – Learning from the past to be prepared for similar manipulation in the future. Importance to question any given information – also this one. --- Social implications – The discussion opens up the topic beyond aviation expert circles. --- Originality – Not much comparable information is given by other authors., Hamburg Aerospace Lecture Series --- Collection of Presentations --- http://www.AeroLectures.de

Purpose: This conference paper discusses potential contamination of the air in passenger aircraft cabins. It gives an overview of cabin air contamination basics. It further names possible contamination sources and possible routes of contamination. Methodology: Evidence follows from a review of material found on the Internet and from the documentation of a visit to an aircraft recycling site. Parts were retrieved at the site and investigated later with more time. Findings: Jet engine seals leak oil in small quantities. Metallic nanoparticles are found in the oil and have been detected in human fatty tissue of aviation workers. It has been observed that the potable water on board can also be contaminated. Oil traces have been found in bleed ducts, air conditioning components, and in air conditioning ducts. Deicing fluid and hydraulic fluid can find their way into the air conditioning system via the APU air intake. Fuel and oil also leak down onto the airport surfaces. These fluids can be ingested by the engine from the ground and can enter the air conditioning system from there. Entropy is the law of nature that states that disorder always increases. This is the reason, why it is impossible to confine engine oil and hydraulic fluids to their (predominantly) closed aircraft systems. This is why engine oil with metal nanoparticles hydraulic fluids, and deicing fluids eventually can go everywhere and finally into the human body. Research Limitations: No measurements have been made. Practical Implications: Awareness and prevention of contaminated cabin air can protect passengers and crew. Social Implications: The exposure of contaminated cabin air provides a basis for a general discussion and shows that people should be alerted and need to act. New technologies need to be implemented such as a bleed free architecture. Originality: This paper shows probably more images with parts upstream of the engine compressor contaminated by leaking engine oil than any previous publication., This is a publication from the International Aircraft Cabin Air Conference 2021 (Online, 15-18 March 2021)

Cabin air ventilation in passenger aircraft is done with outside air. At cruise altitude, ambient pressure is below cabin pressure. Hence, the outside air needs to be compressed before it is delivered into the cabin. The most economic system principle simply uses the air that is compressed in the engine compressor and taps some of it off as "bleed air". The engine shaft is supported by lubricated bearings. They are sealed against the air in the compressor usually with labyrinth seals. Unfortunately, the jet engine seals leak oil by design in small quantities. The oil leaking into the compressor contains toxic additives. Furthermore, the oil includes toxic metal nanoparticles ��� normal debris from the engine. An alternative source for the compressed air is the Auxiliary Power Unit (APU). Like the aircraft's jet engine, it is a gas turbine, built much in the same way when it comes to bearings and seals. For this reason, also compressed air from the APU is potentially contaminated in much the same way. Compressed air from the engine is also used to pressurize the potable water. It has been observed that the potable water on board can also be contaminated. Fan air and bleed air ducts at the interface between engine and wing carry outside compressed air. The inside of the ducts shows differences. The brown stain in the bleed air duct appears to be engine oil residue. In comparison, the fan air duct is clean. This shows that oil leaves the compressor bearings. Ducting further downstream shows a black dry cover. The reason for the change in color seems to result from the different air temperatures: 400 ��C at engine outlet and 200 ��C further downstream behind the precooler. The water extractor is a part of the air conditioning pack. The inlet of the water extractor is covered with black oily residue, because the temperature is even lower at this point. The air conditioning air distribution ducts in the cabin are black inside from contaminated bleed air. New ducts are clean. Air duct are even clean inside at the end of the aircraft's life, in areas where they are used such that no bleed air flows through them. Flow limiters have been found in ducts of the air conditioning system that are clogged from engine oil. Also riser ducts feeding the cabin air outlets are black inside from engine oil residue. Cleaning on top of the overhead bins brings to light dirt that is clearly more than dust. The black residue known from the ducts settles also on the bin surface. Deicing fluid and hydraulic fluid can find their way into the air conditioning system via the APU air intake. A fence and a deflector around the air intake cannot fully prevent contaminants from entering the APU. Traces of contamination tend to be visible on the lower part of the fuselage. Contaminants are carried by the air flow in flight, from the landing gear bay to the APU inlet. Hydraulic systems are never leak free. A hydraulic seal drain system tries to collect hydraulic fluid leaving the system with partial success. It is impossible to catch all leaking hydraulic fluid. If the containers of the seal drain system are not emptied they spill over. In old aircraft, surfaces in the landing gear bay are covered with a layer of hydraulic fluid. Dirt accumulates on the sticky surface. The hydraulic fluid is not confined to the inside of hydraulic bays, but continues its journey on the lower side of the fuselage towards the APU. Deicing fluid if applied in the winter to the aircraft and can leak from the tail into the APU inlet. Fuel and oil also leak down onto the airport surfaces. These fluids can be ingested by the engine from the ground and can enter the air conditioning system from there. Entropy is the law of nature that states that disorder always increases. This is the reason, why it is impossible to confine engine oil and hydraulic fluids to their (predominantly) closed aircraft systems. This is why engine oil with metal nanoparticles, hydraulic fluids, and deicing fluids eventually go everywhere and finally into the human body., This is a presentation from the International Aircraft Cabin Air Conference 2021 (Online, 15-18 March 2021)

Following the successful initial Special Issue on “Aircraft Design (SI-1/2017)”, this is already the second SI “Aircraft Design (SI-2/2020)”. Activities in the past showed that aircraft design may be a field too small to justify its own (subscription-based) journal. A continuous open access special issue may fill the gap. As such, the Special Issue “Aircraft Design” can be a home for all those working in the field who regret the absence of an aircraft design journal.SI-2/2020 contains seven papers;an Editorial: 1.) "Publishing in 'Aircraft Design'with a Continuous Open Access Special Issue" and six Original Research Articles about 2.)Amphibious Aircraft Developments, 3.)Design Space Exploration ofJet Engine Components, 4.)Study of Subsonic Wing Flutter, 5.)Design Optimization of a Blended Wing Body Aircraft, 6.)Discrete Mobile Control Surfaces, 7.)Electro-Impulse De-Icing Systems.

Purpose ��� This project work shows a literature survey, clearly defines the mass growth factor, shows a mass growth iteration, and derives an equation for a direct calculation of the factor (without iteration). Definite values of the factor seem to be missing in literature. To change this, mass growth factors are being calculated for as many of the prominent passenger aircraft as to cover 90% of the passenger aircraft flying today. The dependence of the mass growth factor on requirements and technology is examined and the relation to Direct Operating Costs (DOC) is pointed out. >>> Methodology ��� Calculations start from first principles. Publically available data is used to calculate a list of mass growth factors for many passenger aircraft. Using equations and the resulting relationships, new knowledge and dependencies are gained. >>> Findings ��� The mass growth factor is larger for aircraft with larger operating empty mass ratio, smaller payload ratio, larger specific fuel consumption (SFC), and smaller glide ratio. The mass growth factor increases much with increasing range. The factor depends on an increase in the fixed mass, so this is the same for the payload and empty mass. The mass growth factor for subsonic passenger aircraft is on average 4.2, for narrow body aircraft 3.9 and for wide body aircraft (that tend to fly longer distance) 4.9. In contrast supersonic passenger aircraft show a factor of about 14. >>> Practical implications ��� The mass growth factor has been revisited in order to fully embrace the concept of mass growth and may lead to a better general understanding of aircraft design. >>> Social implications ��� A detailed discussion of aircraft costs as well as aircraft development requires detailed knowledge of the aircraft. By understanding the mass growth factor, consumers can have this discussion with industry at eye level. >>> Originality/value ��� The derivation of the equation for the direct calculation of the mass growth factor and the determination of the factor using the method for 90% of current passenger aircraft was not shown., http://EWADE.AircraftDesign.org --- http://Presentations2020.AircraftDesign.org

Purpose – Establish a "journal" for the aircraft design community. --- Approach – Aircraft design is too small as a topic for a journal. Use a continuous Special Issue i.e. only a subset of a journal. Follow the Open Access publishing model that can life already on a low number of papers annually. --- Findings – The well established publisher MDPI published already one Special Issue "Aircraft Design" in "Aerospcae" (ISSN 2226-4310) and was willing to follow the approach. The journal has a CiteScore (2019) of 2.6 from Scopus and is part of the Emerging Sources Citation Index - Web of Science (Clarivate Analytics). --- Tradition – The tradition of the journal Aircraft Design at Elsevier (ISSN: 1369-8869) which was published from 1998 to 2001 with Prof. Egbert Torenbeek and Prof. Dr. Jan Roskam as Editors is continued. --- Limitations – Article Processing Charges (APC) have to be paid. A large discount is available for authors from EWADE/SCAD and READ. Further discounts are granted based on reviews. --- Originality and Value – This is the only "journal" fully dedicated to aircraft design., http://EWADE.AircraftDesign.org --- http://Presentations2020.AircraftDesign.org

Purpose – Find optimal flight and design parameters for three objectives: minimum fuel consumption, Direct Operating Costs (DOC), and environmental impact of a passenger jet aircraft. --- Approach – Combining multiple models (this includes aerodynamics, specific fuel consumption, DOC, and equivalent CO2 mass) into one generic model. In this combined model, each objective's importance is determined by a weighting factor. Additionally, the possibility of further optimizing this model by altering an aircraft's wing loading is analyzed. --- Findings – When optimizing for a compromise between economic and ecologic benefits, the general outcome is a reduction in cruise altitude and an unaltered cruise Mach number compared to common practice. Decreasing cruise speed would benefit the environmental impact but has a negative effect on seat-mile cost. An increase in wing loading could further optimize the general outcome. Albeit at the cost of a greater required landing distance, therefore limiting the operational opportunities of this aircraft. --- Research limitations – Most models use estimating equations based on first principles and statistical data. --- Practical implications – The optimal cruise altitude and speed for a specific objective can be approximated for any passenger jet aircraft. --- Social implications – By using a simple approach, the discussion of optimizing aircraft opens up to a level where everyone can participate. --- Value – To find a general answer on how to optimize aviation, operational and design-wise, by using a simple approach., https://dlrk2020.dglr.de

During its investigations into a series of ten aircraft crashes from 1979 to 1981, US National Transportation Safety Board (NTSB) officials were presented with a hypothesis that “several” of the crashes could have been caused by pilot impairment from breathing oil fumes inflight. The NTSB and their industry partners ultimately dismissed the hypothesis. The authors reviewed the crash reports, the mechanics of the relevant engine oil seals, and some engine bleed air data to consider whether the dismissal was justified. Four of the nine aircraft crash reports include details which are consistent with pilot impairment caused by breathing oil fumes. None of the tests of ground-based bleed air measurements of a subset of oil-based contaminants generated in the engine type on the crashed aircraft reproduced the inflight conditions that the accident investigators had flagged as potentially unsafe. The NTSB’s conclusion that the hypothesis of pilot incapacitation was “completely without validity” was inconsistent with the evidence. Parties with a commercial conflict of interest should not have played a role in the investigation of their products. There is enough evidence that pilots can be impaired by inhaling oil fumes to motivate more stringent design, operation, and reporting regulations to protect safety of flight.

The conference proceedings deal with aircraft air supplies in current large passenger transport aircraft. Apart from the Boeing 787, all passenger aircraft utilize nonfiltered air (bleed air) drawn from the compressor stage of turbine engines to provide pressurization and breathing air. This design has been utilized since the 1950s and 60s. Synthetic jet engine oils and other fluids in aircraft systems are recognized and known to contaminate the bleed air supply, impacting flight safety, occupational and public health. The conference principal organizer was the Global Cabin Air Quality Executive (GCAQE), which was established in 2006 as a global coalition of health and safety advocates committed to raising awareness and finding solutions to poor air quality in aircraft. The conference program of the 2017 International Aircraft Cabin Air Conference included more than 30 oral and video presentations presented by scientists, doctors, pilots, cabin crew, engineers and experts from 11 countries covering a broad spectrum of topics. Most of these presentations are presented in these proceedings published first with the Journal of Health & Pollution. The topics include engine design and mechanisms of oil leakage, flight safety, occupational health and safety, regulatory issues, risk management, international actions, reporting, medical and scientific evidence, jet oils, filtration, air quality sensors, legal implications and causation., https://www.AircraftCabinAir.com

Air conditioning in aviation means temperature control, pressure control and ventilation. The cabin is vented with a certain percentage (e.g. 50%) of fresh outside air. The remaining part of the air for cabin ventilation is provided as air from the cabin, filtered and recirculated back into the cabin. At cruise altitude, ambient pressure is below cabin pressure. Hence, the outside air needs to be compressed before it is delivered into the cabin. The air is compressed in the engine compressor and tapped off as "bleed air" at temperatures reaching 400 ��C or more. Hence, bleed air cooling is necessary. The engine shaft is supported by lubricated bearings. They are sealed against the air in the compressor usually with labyrinth seals. It is explained why jet engine seals leak oil by design in small quantities. The amount of oil leakage can be estimated with a new equation. The estimate shows the same order of magnitude as measured in flight (Cranfield study, EASA study). The oil leaking into the compressor contains problematic additives which get pyrolized (burned) at the elevated temperatures in the compressor, leaving more than 100 substances behind, some of them hazardous and some known as Volatile Organic Compounds (VOC). An alternative source for the compressed air is the Auxiliary Power Unit (APU). Like the aircraft's jet engine, it is a gas turbine, built much in the same way when it comes to bearings and seals. For this reason, also compressed air from the APU is potentially contaminated. Engineering standards from SAE contain guidance about sound engineering design principles for air conditioning systems of airplanes. Also certification standards give some guidance, however, more general. In essence, bleed air systems as we see them on today's passenger jet aircraft should not be built the way they are. For immediate action, hints are given: In case of smoke in the cockpit pilots should read the carbon monoxide (CO) concentration from a personal CO detector as an objective indicator in addition to their human senses. The present CO concentration should be compared with values obtained under normal conditions. If pilots are alerted and it is suitable (fuel reserves, terrain clearance), pilots should consider to descend to 10000 ft, reduce speed and ventilate the aircraft by means of the ram air inlet. This is the only source of fresh air in flight, independent of engines or APU. If smoke is present, checklists tell pilots to put on their oxygen mask. Cabin crew should consider wearing a personal breathing mask in such cases. Technically the easiest way to install carbon filters to filter VOCs in existing aircraft is in the recirculation path, where HEPA filters are already in use. Unfortunately the physics are such that filters in the recirculation path cannot remove substances fully. It is only possible to reduce the concentration down to a value depending on filtration rate and recirculation rate. With typical values the incoming VOC concentration can be reduced to about 60%. In case of full filtration (including ducts from the bleed air sources) incoming VOC concentration can be reduced to about 18%. Aircraft from the beginning of the jet age (B707, DC-8) used turbocompressors keeping bleed air and outside air compressed for cabin ventilation separate. Based on past experience, turbocompressors cannot be considered a solution for future aircraft. A final solution to the problem of contaminated cabin air is seen in electric (bleed free) cabin air supply architectures. Here, outside air for cabin ventilation is compressed separately in dedicated clean compressors. Bleed free cabin air architectures have the additional advantage of much improved fuel economy. So far, the Boeing 787 is the only passenger aircraft in service with a bleed free cabin air architecture. Airbus could follow with related technology already available and checked in test flights., This is a presentation from the International Aircraft Cabin Air Conference 2017 (Imperial College, London, 19-20 September 2017)

This presentation gives straight advice to calculate induced drag of box wings for the conceptual aircraft design phase. Common for passenger aircraft is a Box Wing Aircraft (BWA) with negative stagger: The forward wing is the low wing. As such the aft wing can use the vertical tail structure for highest h/b ratio. This configuration could use slight positive decalage (more angle of attack on the upper wing) to adapt the upper wing to the downwash from the front wing. However: Positive decalage can lead to separation already at lower angle of attack and hence reduced maximum lift coefficient. A conservative design should do without decalage. An unequal lift share (between forward and aft wing) – as required by static longitudinal stability – does not necessarily lead to increased induced drag at (typical) negative stagger. Wind tunnel measurements and Vortex Lattice Method (VLM) calculations lead to a proposal of "k-values" for the "box wing equation" not far from Prandtl's results., https://dlrk2019.dglr.de

Purpose – This presentation takes a critical look at various electric air mobility concepts. With a clear focus on requirements and first principles applied to the technologies in question, it tries to bring inflated expectations down to earth. Economic, ecologic and social (noise) based well accepted evaluation principles are set against wishful thinking. Design/methodology/approach – Aeronautical teaching basics are complemented with own thoughts and explanations. In addition, the results of past research projects are applied to the topic. Findings – Electric air mobility may become useful in some areas of aviation. Small short-range general aviation aircraft may benefit from battery-electric or hybrid-electric propulsion. Urban air mobility in large cities will give time advantages to super-rich people, but mass transportation in cities will require a public urban transport system. Battery-electric passenger aircraft are neither economic nor ecologic. How overall advantages can be obtained from turbo-electric distributed propulsion (without batteries) is not clear. Maybe turbo-hydraulic propulsion has some weight advantages over the electric approach. Research limitations/implications – Research findings are from basic considerations only. A detailed evaluation of system principles on a certain aircraft platform may lead to somewhat different results. Practical implications – The discussion about electric air mobility concepts may get more factual. Investors may find some of the information provided easy to understand and helpful for their decision making. Social implications – How to tackle challenges of resource depletion and environment pollution is a social question. Better knowledge of the problem enables the public to take a firm position in the discussion. Originality/value – Holistic evaluation of electric air mobility has not much been applied yet. This presentation shows how to proceed., Hamburg Aerospace Lecture Series --- Collection of Presentations --- http://www.AeroLectures.de

Purpose – This presentation gives an introduction to the problem of contaminated cabin air and points out possible solutions especially by looking at carbon filters placed in the main path of the bleed air from the engine to the cabin ("total cabin air filtration") in additon to filters in the cabin air recirculation path. Maintenance issures related to the topic are also considered. --- Design/methodology/approach – The literature review is complemented with own explanations, thoughts and derivations. --- Findings – There is a real health and flight safety risk due to contaminated cabin air. For the infrequent flyer the risk is very low. Also aviation statistics are not dominated by cabin air related accidents. Nevertheless, a bleed air based air conditioning system can be regarded as applying a fundamentally wrong systems engineering approach. A substantial improvement of the situation can only be reached with filters added to the large fleet of existing airplanes. A full solution, however, requires air conditioning with outside air and dedicated compressors. --- Research limitations/implications – The study is based primarily on references. --- Practical implications – Passengers and crew are made aware of the risk of cabin air contamination based on technical facts. Given detailes of technical solutions contribute to the scientific discussion. --- Social implications – Better knowledge of the problem should enable passengers and crew to maintain a firm position in the sometimes heated discussion. --- Originality/value – Engineering based information with a critical view on the topic seems to be missing in public. This presentation contributes filling this gap., https://dlrk2018.dglr.de

Purpose – This presentation takes a critical look at various electric air mobility concepts. With a clear focus on requirements and first principles applied to the technologies in question, it tries to bring inflated expectations down to earth. Economic, ecologic and social (noise) based well accepted evaluation principles are set against wishful thinking. --- Design/methodology/approach – Aeronautical teaching basics are complemented with own thoughts and explanations. In addition, the results of past research projects are applied to the topic. --- Findings – Electric air mobility may become useful in some areas of aviation. Small short-range general aviation aircraft may benefit from battery-electric or hybrid-electric propulsion. Urban air mobility in large cities will give time advantages to super-rich people, but mass transportation in cities will require a public urban transport system. Battery-electric passenger aircraft are neither economic nor ecologic. How overall advantages can be obtained from turbo-electric distributed propulsion (without batteries) is not clear. Maybe turbo-hydraulic propulsion has some weight advantages over the electric approach. --- Research limitations/implications – Research findings are from basic considerations only. A detailed evaluation of system principles on a certain aircraft platform may lead to somewhat different results. --- Practical implications – The discussion about electric air mobility concepts may get more factual. Investors may find some of the information provided easy to understand and helpful for their decision making. --- Social implications – How to tackle challenges of resource depletion and environment pollution is a social question. Better knowledge of the problem enables the public to take a firm position in the discussion. --- Originality/value – Holistic evaluation of electric air mobility has not much been applied yet. This presentation shows how to proceed.

In attempting to increase the environmental awareness in the aviation sector and to eliminate the green washing phenomenon, an investigation was done into the development and definition of an ecolabel for aircraft. Based on life cycle assessment it was found that aviation affects the environment most with the impact categories resource depletion and global warming (both due to fuel consumption), local air pollution (due to the nitrogen oxide emissions in the vicinity of airports) and noise pollution. For each impact category a calculation method was developed based solely on official, certified and publicly available data to meet the stated requirements of the ISO standards about environmental labeling. To ensure that every parameter is evaluated independent on aircraft size, which allows comparison between different aircraft, normalizing factors such as number of seats, rated thrust and noise level limits are used. Additionally, a travel class weighting factor is derived in order to account for the space occupied per seat in first class, business class and economy class. To finalize the ecolabel, the overall environmental impact is determined by weighting the contribution of each impact category. For each category a rating scale from A to G is developed to compare the performance of the aircraft with that of others. The harmonization of the scientific and environmental information, presented in an easy understandable label, enables the traveling customers to make a well informed and educated choice when booking a flight, selecting among airline offers with different types of aircraft and seating arrangements., https://dlrk2017.dglr.de

The report summarizes groundbreaking aircraft cabin developments at Pan American World Airways (Pan Am). The founder and chief executive Juan Terry Trippe (1899-1981) established Pan Am as the world's first truly global airline. With Trippe's determination, foresight, and strategic brilliance the company accomplished many pioneering firsts – many also in aircraft cabin design. In 1933 Pan Am approached the industrial designer Norman Bel Geddes (1893-1958). The idea was to create the interior design of the Martin M-130 flying boat by a specialized design firm. Noise absorption was optimized. Fresh air was brought to an agreeable temperature before it was pumped into the aircraft. Adjustable curtains at the windows made it possible to regulate the amount of light in the compartments. A compact galley was designed. The cabin layout optimized seating comfort and facilitated conversion to the night setting. The pre-war interior design of the Boeing 314 flying boat featured modern contours and colors. Meals were still prepared before flight and kept warm in the plane's galley. The innovative post-war land based Boeing 377 Stratocruiser had a pressurized cabin. The cabin was not divided anymore into compartments. Seats were reclining. The galley was well equipped. The jet age started at Pan Am with the DC-8 and the B707. The B707 featured individual overhead "service clusters" with reading light, air outlet, and stewardess call button. The aircraft had no night time settings anymore. Inflight entertainment (video and music) was introduced. Early jets had hatracks. Overhead bins were introduced on the B747., Hamburg Aerospace Lecture Series --- Collection of Presentations --- http://www.AeroLectures.de, {"references":["HÜHNE, Mathias C. (2016). Pan Am: History, Design & Identity. Berlin : Callisto Publishers. – ISBN 978-3-9816550-6-3, URL: https://www.callisto-publishers.com/en/pan-am"]}

Purpose – This presentation gives an introduction to aircraft cabin air quality and contamination risks. Beyond these fundamentals, most of the current engineering issues discussed with respect to the topic are explained. Design/methodology/approach – The literature review is complemented with own explanations, thoughts and derivations. Findings – There is a real health and flight safety risk due to contaminated cabin air. For the infrequent flyer the risk is very low. Also aviation statistics are not dominated by cabin air related accidents. Nevertheless, a bleed air based air conditioning system can be regarded as applying a fundamentally wrong systems engineering approach. Measures have to be taken. Research limitations/implications – This review study is based on references. Own measurements have not been made. Practical implications – Passengers and crew are made aware of the risk of cabin air contamination based on technical facts. Steps towards a solution of the problem are presented as they can be applied by passengers, pilots, airlines and manufacturers respectively. Social implications – Better knowledge of the problem should enable passengers and crew to maintain a firm position in the sometimes heated discussion. Originality/value – Engineering based information with a critical view on the topic seems to be missing in public. This presentation tries to fill this gap., Hamburg Aerospace Lecture Series --- Collection of Presentations --- http://www.AeroLectures.de

A new concept of a passenger aircraft using hydrogen as fuel is presented. Due to the future depletion of fossil fuels and growth of aviation within the next years, the aeronautical industry must get ready now for a realistic solution. Many projects were conducted for hydrogen-fueled aircraft designs in the past, however all the effort was focused on an expensive totally new aircraft design. In this work, research is based on the Airbus A320 with a requirement for 1510 NM range at 19.3 t maximum payload. Goal is to redesign the aircraft under the premise of minimum change and minimum costs. Hydrogen as the new energy carrier will be stored at cryogenically temperatures. Still it needs more tank volume. This extra volume is best generated with an aircraft stretch leading to an increase of aircraft length. A minimum change option would be to simply use A320 seating in an A321, using the additional space for the new hydrogen fuel tanks. Unfortunately, the additional volume on its own is not sufficient. Therefore, three different hydrogen-fueled versions are developed. 1.) The A321-HSO stretched beyond the length of the A321. 2.) The A321-HWO with A321 fuselage and additional under-wing podded hydrogen fuel tanks. 3.) A321-H19O with A321 fuselage and A319 cabin. All three versions were designed and optimized in OPerA, the in-house conceptual design and optimization program based on a genetic algorithm. Objective function for the optimization are minimum Direct Operating Costs (DOC). Assumed is a price for hydrogen, energy-equivalent to kerosene and estimated for 2030 to be 1.12 USD/kg. All three versions stayed in feasible dimensions. The weight of the aircraft is decreased between 3.4% (A321-H19O) and 0.7% (A321-HSO). Depending on the version considered, the DOC of the aircraft is increased by 20% to 30%. Hydrogen aircraft do not show CO2 emissions, releasing only water vapor, NOx and particles into the air. However, water emitted at altitude can form cirrus clouds. This effect on global warming is presently not fully understood. The result: If fossil fuels get near to depletion and kerosene gets so scarce that the price of hydrogen matches that of kerosene, passenger air transport remains available with hydrogen-fueled minimum change conversions of existing aircraft types., https://dlrk2015.dglr.de

Task was to find an innovative aircraft design for a new medium range aircraft. The aircraft design methodology is based on equations (in contrast to numeric methods) and formal optimization with a genetic algorithm called differential evolution. Airbus has postponed an all-new A320 to 2025 or even 2030. This allows including also unconventional configurations into the search. Economic requirements are extreme: 25 % to 40 % reduction in fuel consumption, 35 % reduction in Cash Operating Costs. To achieve this, all aircraft design parameters have to be open for discussion. An aircraft called "The Rebel" is prepared to go to extreme parameters: low cruise speed, high wing span and long take-off and landing distance. Without new technologies it achieves 36 % reduced fuel consumption. The "Smart Turboprop" stays in conventional limits with its parameters, but makes use of a braced wing with natural laminar flow. It also achieves 36 % reduced fuel consumption plus a 17 % reduction in Direct Operating Costs (DOC). In addition, several Box Wing Aircraft where designed: Diamond Box Wing and Biplane Box Wing as Wide Body and alternatively as Slender Body. The Biplane Box Wing shows overall advantages due to its conventional tail. The details of Box Wing Aircraft design where mastered, but the Direct Operating Costs of the Box Wing Aircraft turned out to be higher than those of the A320 reference. This leaves the "Smart Turboprop" as the proposed configuration for an Airbus A320 replacement. As a short term measure, it is proposed to offer a horizontal wing tip extension as an option for the A320neo instead of the winglets. An extension with the same length as the winglet height offers far greater drag reduction. Airports will tolerate and accommodate some aircraft with a wing span above the ICAO limit in Class C of 36 m.

A 3D visualization is missing for many aircraft preliminary sizing tools. NASA’s Open Vehicle Sketch Pad (OpenVSP) is easy to use, but lacks an interface to input consistent aircraft data. Such an interface has been programmed and is called OpenVSP-Connect. Aircraft are sketched from about 50 parameters. If these are not known to the user, the interface calculates them as good as possible based on simple equations from aircraft design or statistics. Taken this to the extreme, a decent looking aircraft is drawn from as few as two or three input parameters., http://EWADE.AircraftDesign.org --- http://ProceedingsEWADE2013.AircraftDesign.org

The first Open Access (OA) peer reviewed online journals in aerospace were all established after 2007. Still today more and more OA aerospace journals get started. Many publishers are located in less developed countries. The benefits of OA publishing are undisputed in the academic community, but there is disagreement if the new publishers can work to required standards. The current situation is evaluated based on an Internet review. OA journals in aerospace are listed with their major characteristics. Well known OA publishers charge high publication fees, whereas less known OA publishers tend to charge relatively low fees. All publishers need to be carefully checked for their level of rigor in peer review and their offered service in the scholarly publication process. Authors should evaluate OA journals and publishers against provided lists of criteria before submitting their work.

These are the Proceedings of the 11th European Workshop on Aircraft Design Education (in short: EWADE 2013). The workshop took place from 17. to 19.09.2013 in Linköping, Sweden. EWADE 2013 was for the first time integrated into the CEAS European Air & Space Conference. Location was the congress center located right in the heart of the city of Linköping. The workshop was organized by Prof. Dieter Scholz, Aircraft Design and Systems Group (AERO), Hamburg University of Applied Sciences, in close cooperation with Prof. Petter Krus, Head of the CEAS2013 Programme Committee and Head of the Division of Fluid and Mechatronic System, Linköping University and Dr. Tomas Melin, CEAS 2013 Programme Secretary and Research Associate in the Division of Fluid and Mechatronic System, Linköping University. The workshop had 4 technical sessions: EWADE 1 - Presentations from EWADE Founders and Hosts. EWADE 2 - Teaching and Research Activities in Aircraft Design. EWADE 3 - Aircraft Design Studies. EWADE 4 - Aircraft Design - Methods and Tools. The proceedings cover all 19 presentations. 6 of these presentations are accompanied by full text papers.

Following on from the success of the 2017 and 2019 Aircraft Cabin Air Conferences, the 2021 conference will be an essential four-day free modular online event via Zoom. 2021 is providing an in-depth overview, update and debate for those seeking to understand the subject of contaminated air, the flight safety implications, the latest scientific and medical evidence investigating the contaminated air debate and the solutions available to airlines and aircraft operators., This is the programme of the International Aircraft Cabin Air Conference 2021 (Online, 15-18 March 2021)

The International Aircraft Cabin Air Conferences have developed into a series of conferences that were organized so far in 2017, 2019 and 2021. The conferences are mapping the business, regulatory and technical solutions to aircraft cabin air contamination. These proceedings contain the contributions to the conference in 2021. From the 39 contributions to the conference 33 are included in the proceedings. Most contributions are contained in the proceedings in form of a presentation. Some are contained in more than one format (adding an extended abstract or a paper). For this reason the proceedings contain 48 documents and links to 11 short documentary films, all together on 791 pages., All results of the International Aircraft Cabin Air Conference 2021 (Online, 15-18 March 2021). Download the PDF and use the Table of Contents to navigate to the contributions. https://www.AircraftCabinAir.com

Featuring one of the most voluminous cargo holds of any civil or military aircraft flying today, the Airbus Beluga plays a key role in keeping Airbus production and assembly network operating at full capacity. The current fleet of 5 Beluga, based on A300-600, carries complete sections of Airbus aircraft from different production sites around Europe to the final assembly lines in Toulouse, France and Hamburg, Germany. To support the A350 XWB ramp-up and other production rate increases, Airbus will gradually replace its current Beluga’s with six BelugaXL aircraft, derived from the company’s versatile A330 widebody product line. Veronique Roca, Chief Engineer of the BelugaXL, describes the BelugaXL since its launch in Nov 2014: with the First Flight in July 2018, the BelugaXL is now completing the Flight Test Campaign and has achieved certification., Hamburg Aerospace Lecture Series --- Collection of Presentations --- http://www.AeroLectures.de

Winglets, the small "wings" at the tip of aircraft wings, have long been of particular interest. Do they only offer a convenient area for the airline logo, or are there any other good reasons for equipping an aircraft with winglets? In fact, winglets have a global influence on the flow field and can thus make a significant contribution to reducing air resistance. But how does a winglet work in detail? How can aerodynamic mechanisms be used to generate a noticeable effect on the aircraft system in a severely restricted parameter space? It also requires profound knowledge of various interactions with other disciplines. Is the integration of winglets the real challenge? There are clear differences between retrofitting existing aircraft or a new design. Finally, all solutions, along with their respective motivations, will be presented on the basis of the complete Airbus fleet.

Purpose – This project work shows a literature survey, clearly defines the mass growth factor, shows a mass growth iteration, and derives an equation for a direct calculation of the factor (without iteration). Definite values of the factor seem to be missing in literature. To change this, mass growth factors are being calculated for as many of the prominent passenger aircraft as to cover 90% of the passenger aircraft flying today. The dependence of the mass gain factor on requirements and technology is examined and the relation to Direct Operating Costs (DOC) is pointed out. --- Methodology – Calculations start from first principles. Publically available data is used to cal-culate a list of mass growth factors for many passenger aircraft. Using equations and the result-ing relationships, new knowledge and dependencies are gained. --- Findings – The mass growth factor is larger for aircraft with larger operating empty mass ratio, smaller payload ratio, larger specific fuel consumption (SFC), and smaller glide ratio. The mass growth factor increases much with increasing range. The factor depends on an increase in the fixed mass, so this is the same for the payload and empty mass. The mass growth factor for subsonic passenger aircraft is on average 4.2, for narrow body aircraft 3.9 and for wide body aircraft (that tend to fly longer distance) 4.9. In contrast supersonic passenger aircraft show a factor of about 14. --- Practical implications – The mass growth factor has been revisited in order to fully embrace the concept of mass growth and may lead to a better general understanding of aircraft design. --- Social implications – A detailed discussion of flight and aircraft costs as well as aircraft de-velopment requires detailed knowledge of the aircraft. By understanding the mass growth fac-tor, consumers can have this discussion with industry at eye level. --- Originality/value – The derivation of the equation for the direct calculation of the mass growth factor and the determination of the factor using the iteration method for current aircraft was not shown in the examined literature.

The International Aircraft Cabin Air Conferences are developing into a series of conferences organized every two years. The conferences are mapping the business, regulatory and technical solutions to aircraft cabin air contamination. The conferences in 2017 and 2019 provided networking opportunities for those seeking to understand the subject of contaminated air, the flight safety implications, the latest scientific and medical evidence investigating the contaminated air debate and the solutions available to airlines and aircraft operators. The two conferences held so far have been the most in-depth conferences ever on the topic of aircraft cabin air contamination. In total 30 presentations were given at the 2019 International Aircraft Cabin Air Conference (ACA 2019). This document contains the 25 presentations provided by the authors. It combines the presentations into one PDF for further dissemination and archiving., Presentations of the International Aircraft Cabin Air Conference 2019 (Imperial College London, 17-18 September 2019). Download the PDF and use the PDF-Table-of-Contents to navigate to the presentations. https://www.AircraftCabinAir.com

Design work began on the De Havilland Comet in September 1946. Key features: 36 passengers, range 2800 km, cruising speed 780 km/h, cruising altitude 35000 ft, aluminium construction, four de Havilland Ghost Jet engines. The pressurised cabin was designed for a cabin pressure equivalent to an altitude of 8000 ft. De Havilland were aware of the likelihood of fatigue and had installed several safety measures and tests in line with certification requirements. First flight was on 27th July 1949. The aircraft entered service on 2nd May 1952 (G-ALYP) and put the UK aircraft industry at the forefront of technology. First accident of a De Havilland Comet was on 10th January 1954. G-ALYP crashed into the sea leaving Rome. Flight services was resumed on 23rd March 1954. The second accident was on 8th April 1954. G-ALYY crashed also into the sea leaving Rome. The Certificate of Airworthiness was withdrawn 12th April 1954. Intensive research followed, concentrating on the understanding of structural fatigue. A Comet fuselage was pressurized in a water tank. The recovered wreckage of the "YP" was assembled on frames by the RAE. It was found that the aircraft disassembled in the air. The accident was caused by structural failure of the pressure cabin, brought about by fatigue. The square windows were the cause of high stresses. The bolt hole which failed on "YP" had a defect in the chamfer which indicated the potential for manufacturing defects on all skin holes. The interaction of the skin stresses and the manufacturing defects was beyond the scientific knowledge base of the early 1950s. The Comet flew again as the Comet IV with different window design. The Comet was the first airliner to fly a scheduled service across the Atlantic on 4th October 1958. It remained in service as the Nimrod until 60 years after first Comet flight. The presentation revisits the Comet case and shows a modern investigation based on the research done in the 1950th and the "Paris Law" from 1963 which allows the calculation of crack growth. Using the data from the 1950’s, it was calculated: parameter A = 49.5 MPa m^(1/2) and exponent m = 5. As such, the material behaved slightly worse than current similar alloys. Crack growth analysis calculated the life of "YP" as 1272 cycles. The actual number of pressurised flights was 1290., Hamburg Aerospace Lecture Series --- Collection of Presentations --- http://www.AeroLectures.de

Purpose - This thesis presents a comparison of aircraft design concepts to identify the superior propulsion system model among turbo-hydraulic, turbo-electric and classic jet propulsion with respect to Direct Operating Costs (DOC), environmental impact and fuel burn. --- Approach - A simple aircraft model was designed based on the Top-Level Aircraft Requirements of the Airbus A320 passenger aircraft, and novel engine concepts were integrated to establish new models. Numerous types of propulsion system configurations were created by varying the type of gas turbine engine and number of propulsors. --- Findings - After an elaborate comparison of the aforementioned concepts, the all turbo-hydraulic propulsion system is found to be superior to the all turbo-electric propulsion system. A new propulsion system concept was developed by combining the thrust of a turbofan engine and utilizing the power produced by the turbo-hydraulic propulsion system that is delivered via propellers. The new partial turbo-hydraulic propulsion concept in which 20% of the total cruise power is coming from the (hydraulic driven) propellers is even more efficient than an all turbo-hydraulic concept in terms of DOC, environmental impact and fuel burn. --- Research Limitations - The aircraft were modelled with a spreadsheet based on handbook methods and relevant statistics. The investigation was done only for one type of reference aircraft and one route. A detailed analysis with a greater number of reference aircraft and types of routes could lead to other results. --- Practical Implications - With the provided spreadsheet, the DOC and environmental impact can be approximated for any commercial reference aircraft combined with the aforementioned propulsion system concepts. --- Social Implications - Based on the results of this thesis, the public will be able to discuss the demerits of otherwise highly lauded electric propulsion concepts. --- Value - To evaluate the viability of the hydraulic propulsion systems for passenger aircraft using simple mass models and aircraft design concept.

Kenntnisse über Parametereigenschaften und Charakteristiken von Flugzeugkomponenten sind eine wesentliche Grundlage für Methoden des Flugzeugentwurfs. Daher ist Ziel dieser Arbeit, statistische Merkmale und Kenngrößen einer für den Flugzeugbau und Entwurf relevanten Auswahl an Komponenten zu erschließen. Dabei wurden zunächst superkritische Tragflügelprofile hinsichtlich ihrer geometrischen Eigenschaften (relative Profildicke, Wölbung, Dickenrücklage, Wölbungsrücklage und der sogenannte "Leading Edge Sharpness Parameter") untersucht. Diese Eigenschaften wurden mit der Software XFLR5 aus einer Auswahl an superkritischen Profilgeometrien erhoben und mit grafischen und beschreibenden Statistikmethoden ausgewertet. Die Profile wiesen relative Wölbungen von 0 % bis 3,4 % auf, die Mehrzahl entfiel auf Wölbungen von 1 % bis 2 %. Die Wölbungsrücklagen zeigten die für superkritische Profile typische Lage im hinteren Profilbereich zwischen 70 % und 90 % der Profiltiefe. Die Dickenrücklagen verteilten sich um einen Mittelwert von 37 % der Profiltiefe. Eine Betrachtung von Flugzeugreifendimensionen sollte das Verhältnis von Reifenbreite zum Durchmesser w/d charakterisieren. Es wurde ein annähernd lineares Verhalten festgestellt. Die Werte des Parameters w/d umfassten einen Bereich von 0,3 bis 0,4. Durch Regressionsanalysen konnten auch die Abhängigkeiten des Parameters w/d von nur einer bekannten Reifendimension (Breite oder Durchmesser) aufgezeigt werden. Die im Rahmen dieser Arbeit dargestellten Erkenntnisse können als Grundlage weiterführender Untersuchungen genutzt werden.

Purpose – Find optimal flight and design parameters for three objectives: minimum fuel consumption, Direct Operating Costs (DOC), and environmental impact of a passenger jet aircraft. --- Approach – Combining multiple models (this includes aerodynamics, specific fuel consumption, DOC, and equivalent CO2 mass) into one generic model. In this combined model, each objective's importance is determined by a weighting factor. Additionally, the possibility of further optimizing this model by altering an aircraft's wing loading is analyzed. --- Findings – When optimizing for a compromise between economic and ecologic benefits, the general outcome is a reduction in cruise altitude and an unaltered cruise Mach number compared to common practice. Decreasing cruise speed would benefit the environmental impact but has a negative effect on seat-mile cost. An increase in wing loading could further optimize the general outcome. Albeit at the cost of a greater required landing distance, therefore limiting the operational opportunities of this aircraft. --- Research limitations – Most models use estimating equations based on first principles and statistical data. --- Practical implications – The optimal cruise altitude and speed for a specific objective can be approximated for any passenger jet aircraft. --- Social implications – By using a simple approach, the discussion of optimizing aircraft opens up to a level where everyone can participate. --- Value – To find a general answer on how to optimize aviation, operational and design-wise, by using a simple approach.

Purpose - This master thesis evaluates the hybrid-electric aircraft project E-FAN X with respect to its economical and environmental performance in comparison to its reference aircraft, the BAe 146-100. The E-FAN X is replacing one of the four jet engines of the reference aircraft by an electric motor and a fan. A turboshaft engine in the cargo compartment drives a generator to power the electric motor. --- Methodology - The evaluation of this project is based on standard aircraft design equations. Economics are based on Direct Operating Costs (DOC), which are calculated with the method of the Association of European Airlines (AEA) from 1989, inflated to 2019 values. Environmental impact is assessed based on local air quality (NOx, Ozone and Particulate Matter), climate impact (CO2, NOx, Aircraft-Induced Cloudiness known as AIC) and noise pollution estimated with fundamental acoustic equations. --- Findings - The battery on board the E-FAN X it is not necessary. In order to improve the proposed design, the battery was eliminated. Nevertheless, due to additional parts required in the new configuration, the aircraft is 902 kg heavier. The turboshaft engine saves only 59 kg of fuel. The additional mass has to be compensated by a payload reduced by 9 passengers. The DOC per seat-mile are up by more than 10% and equivalent CO2 per seat-mile are more than 16% up in the new aircraft. --- Research limitations - Results are limited in accuracy by the underlying standard aircraft design calculations. The results are also limited in accuracy by the lack of knowledge of some data of the project. --- Practical implications - The report contributes arguments to the discussion about electric flight. --- Social implications - Results show that unconditional praise given to the environmental characteristics of this industry project are not justified.

In this report an equation is derived to calculate the dynamic effect of primary and secondary aircraft cabin air contamination. The equation is applied in order to understand implications and hazards. Primary contamination is from an outside source in form of normal low level contamination or high level contamination in a failure case. Secondary contamination originates from deposited material released into the cabin by a trigger event. The dynamic effect is described as an initial value problem (IVP) of a system governed by a nonhomogeneous linear first order ordinary differential equation (ODE). More complicated excitations are treated as a sequence of IVPs. The ODE is solved from first principles. Spreadsheets are provided with sample calculations that can be adapted to user needs. The method is not limited to a particular principle of the environmental control system (ECS) or contamination substance. The report considers cabin air recirculation and several locations of contamination sources, filters, and deposit points (where contaminants can accumulate and from where they can be released). This is a level of detail so far not considered in the cabin air literature. Various primary and secondary cabin contamination scenarios are calculated with plausible input parameters taken from popular passenger aircraft. A large cabin volume, high air exchange rate, large filtered air recirculation rate, and high absorption rates at deposit points lead to low contamination concentration at given source strength. Especially high contamination concentrations would result if large deposits of contaminants are released in a short time. The accuracy of the results depends on the accuracy of the input parameters. Five different approaches to reduce the contaminant concentration in the aircraft cabin are discussed and evaluated. More effective solutions involve higher implementation efforts. The method and the spreadsheets allow predicting cabin air contamination concentrations independent of confidential industrial input parameters.

In 2017 Airbus delivered a record 718 aircraft to its customers. Before its delivery each individual aircraft has to pass a ground and flight test phase to obtain the certificate of airworthiness. This lecture gives an overview of the production flight testing in an industrial environment. It describes the series of tests from the moment the aircraft leaves the final assembly line until its delivery to the customer. Flight test engineer Andreas Balk is part of the production flight test department team at Hamburg Finkenwerder and provides an inside view on his daily work testing A320 family and A380 production aircraft., Hamburg Aerospace Lecture Series --- Collection of Presentations --- http://www.AeroLectures.de

Ziel - Die Zeit die ein Flugzeug benötigt, um auf eine bestimmte Höhe zu steigen (die Steigzeit) kann mit einer Formel berechnet werden, die vereinfachend annimmt, dass die Steiggeschwindigkeit über dem gesamten Steigflug mit zunehmender Höhe linear abnimmt. Ziel der Untersuchung ist, zu ermitteln, ob die Annahme einer linear abnehmenden Steiggeschwindigkeit realistisch ist bzw. welche Fehler sich aus der Annahme ergeben. ----- Methode - Mit der Höhe ändern sich Parameter wie Luftdichte, Widerstand, Schub und damit auch die optimale Fluggeschwindigkeit für den Steigflug. Die Parameter beeinflussen sich dabei gegenseitig. Der Schub wird dabei nach drei unterschiedlichen Methoden berechnet, gegeben von Bräunling, Scholz und Howe. Analysiert wird der Verlauf des Schubes mit der Höhe und der Verlauf der Steiggeschwindigkeit mit der Höhe für jede der drei Schubberechnungen. Abschließend wird für jede Schubberechnung die Steigzeit verglichen wie sie sich ergibt a) aus der einfachen Formel und b) aus einer Integrationsberechnung, bei der der Verlauf der Steiggeschwindigkeit durch eine Funktion beschrieben wird. ----- Ergebnisse - Die drei Schubberechnungen liefern ausgehend vom gleichen Startschub unterschiedliche Schübe in der Höhe. In die Methode nach Bräunling gehen mehr Parameter ein als in die anderen beiden Methoden. Es kann angenommen werden, dass die Methode nach Bräunling genauer ist, der Beweis kann aber nicht geführt werden. Der Schub nach Scholz und Howe fällt nahezu linear mit der Höhe ab. Der Schubverlauf nach Bräunling zeigt eine deutliche Nichtlinearität. Es wird die Steigzeit von 0 km auf 11 km Höhe berechnet nach a) und b), mit jeder der drei Schubberechnungen. Dabei wird jeweils der Unterschied in der Steigzeit ermittelt. Aufgrund der Nichtlinearität im Schubverlauf zeigt die Methode nach Bräunling dann auch den größten Unterschied zwischen den Berechnungsmethoden von 7,1 %. Bei einer Schubberechnung nach Scholz ergeben sich 1,7 % und nach Howe 1,4 %. Wenn bereits zu Beginn Vereinfachungen, z.B. bezüglich des Triebwerksschubes, vorgenommen wurden, ist es in Hinblick auf den Aufwand und die zu erreicheneden Ergebnisse möglich, und zum Teil sinnvoll, die Berechnungen der Steigzeit mittels linearer Abnahme der vertikalen Geschwindigkeit durchzuführen. Es wird ausdrücklich darauf hingewiesen, dass es hier um den Vergleich von zwei Methoden zur Berechnung der Steigzeit geht und nicht um die Bewertung von Methoden zur Schubberechnung (für die keine Vergleichswerte vorlagen). ----- Praktischer Nutzen - Es konnte festgestellt werden, dass eine einfache Formel zur Berechnung der Steigzeit mit geringem Fehler angewandt werden kann - insbesondere wenn Methoden zur Schubberechnung vorliegen, bei denen der Schub annähernd linear mit der Höhe abnimmt. Bei großem Aufwand und realitätsnaher Betrachtung, z.B. nach Bräunling, führt der lineare Ansatz jedoch zu einem zu großen Fehler. Hierfür sollte die Berechnung der Steigzeit mittels Integration durchgeführt werden.

Purpose of this project is a) the evaluation of the Thrust Specific Fuel Consumption (TSFC) of jet engines in cruise as a function of flight altitude, speed and thrust and b) the determination of the optimum cruise speed for maximum range of jet airplanes based on TSFC characteristics from a). Related to a) a literature review shows different models for the influence of altitude and speed on TSFC. A simple model describing the influence of thrust on TSFC seems not to exist in the literature. Here, openly available data was collected and evaluated. TSFC versus thrust is described by the so-called bucket curve with lowest TSFC at the bucket point at a certain thrust setting. A new simple equation was devised approximating the influence of thrust on TSFC. It was found that the influence of thrust as well as of altitude on TSFC is small and can be neglected in cruise conditions in many cases. However, TSFC is roughly a linear function of speed. This follows already from first principles. Related to b) it was found that the academically taught optimum flight speed (1.316 times minimum drag speed) for maximum range of jet airplanes is inaccurate, because the derivation is based on the unrealistic assumption of TSFC being constant with speed. Taking account of the influence of speed on TSFC and on drag, the optimum flight speed is only about 1.05 to 1.11 the minimum drag speed depending on aircraft weight. The amount of actual engine data was extremely limited in this project and the results will, therefore, only be as accurate as the input data. Results may only have a limited universal validity, because only four jet engine types were analyzed. One of the project's original value is the new simple polynomial function to estimate variations in TSFC from variations in thrust while maintaining constant speed and altitude.