Publishing in “Aircraft Design” with a Continuous Open Access Special Issue

: The article looks at publishing options in the ﬁeld of aircraft design to ﬁnd that no dedicated journal on aircraft design exists. For this reason, a Continuous Special Issue Aircraft Design of the well established journal “Aerospace” at the Open Access publisher MDPI is started. Often special issues of a journal are introduced for “hot topics”. Here, the subset “special issue” is used for a scientiﬁc domain—in this case “aircraft design”. Recurring single special issues are numbered in sequence and are identiﬁed by the year of the deadline for manuscript submissions. This allows for the delivery of several single special issues over time in a row without the need to deﬁne a publishing schedule up front. Together these single issues form the Continuous Special Issue Aircraft Design and o ﬀ er a new publishing home for the aircraft design community.

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Furthermore, the motivation back in 1998 for establishing a journal was much the same as today. The European Workshop on Aircraft Design Education (EWADE) had been started in 1994 and was held every two years [13]. No workshop passed without expressing regret about the absence of a dedicated aircraft design journal [13][14][15]. In the same way as in the past, today people working in the domain of aircraft design also see each other as a close-knit and affectionate community. The European Workshop on Aircraft Design Education (EWADE) [16] was continued along with the Symposium on Collaboration in Aircraft Design (SCAD) [17], both became independent activities under the CEAS Technical Committee Aircraft Design (TCAD) [18]. CEAS is the Council of European Aerospace Societies [19]. Presently, CEAS has twelve European national aerospace societies as members. In eastern or central Europe engineers come together in a workshop called Research and Education in Aircraft Design (READ) [20]. Similarly, in the USA the AIAA Aircraft Design Technical Committee is very active [21]. AIAA is the American Institute of Aeronautics and Astronautics. For these and other aircraft design related communities a Special Issue Aircraft Design can serve as a publishing home in the absence of a dedicated journal for the discipline.

Set Up of the Special Issue "Aircraft Design"
MDPI (Multidisciplinary Digital Publishing Institute) uses the Open Access publishing model for all of its journals including its special issues. "Aerospace" (ISSN 2226-4310) is one such journal at MDPI, which was started in 2014, and its aims include the "design . . . of aircraft" [22]. The first Special Issue Aircraft Design (SI-1/2017) [23] at "Aerospace" was managed by Guest Editor Dr. Mohammad Sadraey and includes five papers. The second Special Issue Aircraft Design (SI-2/2020) [24] is managed by Prof. Dr. Dieter Scholz, MSME [25] as Guest Editor. In addition, Prof. em. Egbert Torenbeek contributes with his experience as Honorary Guest Editor.
As can be seen above, the special issues are consecutively numbered. The year given after the issue number is the year in which the Special Issue closed or is scheduled to close. This allows for the delivery of a continuous sequence of special issues over time without the need to define a certain publishing sequence from the start. It enables the Continuous Special Issue Aircraft Design, which stands for the sum of all individual Special Issues Aircraft Design and the mechanism to make this an ongoing activity.
Each special issue has its own home page at MDPI. These separate home pages allow for changes to be expressed in the aims and scope or among the Guest Editors. In addition, the special issue home page can be seen as the front matter of a particular special issue. The banner of the special issue (Figures 1 and 2) can be shown on the home page as the graphical abstract of an Editorial located at the start of the list of papers.
Aerospace 2020, 7, 5 2 of 8 Furthermore, the motivation back in 1998 for establishing a journal was much the same as today. The European Workshop on Aircraft Design Education (EWADE) had been started in 1994 und was held every two years [13]. No workshop passed without expressing regret about the absence of a dedicated aircraft design journal [13][14][15]. In the same way as in the past, today people working in the domain of aircraft design also see each other as a close-knit and affectionate community. The European Workshop on Aircraft Design Education (EWADE) [16] was continued along with the Symposium on Collaboration in Aircraft Design (SCAD) [17], both became independent activities under the CEAS Technical Committee Aircraft Design (TCAD) [18]. CEAS is the Council of European Aerospace Societies [19]. Presently, CEAS has twelve European national aerospace societies as members. In eastern or central Europe engineers come together in a workshop called Research and Education in Aircraft Design (READ) [20]. Similarly, in the USA the AIAA Aircraft Design Technical Committee is very active [21]. AIAA is the American Institute of Aeronautics and Astronautics. For these and other aircraft design related communities a Special Issue Aircraft Design can serve as a publishing home in the absence of a dedicated journal for the discipline.

Set Up of the Special Issue "Aircraft Design"
MDPI (Multidisciplinary Digital Publishing Institute) uses the Open Access publishing model for all of its journals including its special issues. "Aerospace" (ISSN 2226-4310) is one such journal at MDPI, which was started in 2014, and its aims include the "design … of aircraft" [22]. The first Special Issue Aircraft Design (SI-1/2017) [23] at "Aerospace" was managed by Guest Editor Dr. Mohammad Sadraey and includes five papers. The second Special Issue Aircraft Design (SI-2/2020) [24] is managed by Prof. Dr. Dieter Scholz, MSME [25] as Guest Editor. In addition, Prof. em. Egbert Torenbeek contributes with his experience as Honorary Guest Editor.
As can be seen above, the special issues are consecutively numbered. The year given after the issue number is the year in which the Special Issue closed or is scheduled to close. This allows for the delivery of a continuous sequence of special issues over time without the need to define a certain publishing sequence from the start. It enables the Continuous Special Issue Aircraft Design, which stands for the sum of all individual Special Issues Aircraft Design and the mechanism to make this an ongoing activity.
Each special issue has its own home page at MDPI. These separate home pages allow for changes to be expressed in the aims and scope or among the Guest Editors. In addition, the special issue home page can be seen as the front matter of a particular special issue. The banner of the special issue (Figures 1 and 2) can be shown on the home page as the graphical abstract of an Editorial located at the start of the list of papers.   The URL of the currently open Special Issue Aircraft Design is always: https://www.mdpi.com/journal/aerospace/special_issues/aircraft_design. Linking to this URL also means linking to the central anchor point of the Continuous Special Issue Aircraft Design as a whole now and in the future. This page shows links to direct readers to all past special issues. Linking directly to a single past issue is also possible: a long user-friendly URL is available as well as a short URL based on MDPI's internal number of that special issue. Table 1 shows the systematic of these URLs.
Presently, the special issue is also advertised on a CEAS web page. The URL of the page is particularly easy to remember: http://journal.AircraftDesign.org. The page provides further details about the Continuous Special Issues Aircraft Design, e.g., related to possible reductions of the standard article processing charges (APC) [26] and links to all relevant web pages. The Digital Object Identifier (DOI) is always used when linking to an individual paper. The DOI for a recent "Aerospace" paper at MDPI is structured as follows: https://doi.org/10.3390/aerospaceVMMxxxx. Here, 10.3390 stands for MDPI, V is the Volume (related to the year, starting with 1 in 2014), MM is the month, and xxxx is the number of the paper. Allocation starts with 0001 in the beginning of each year, counting up. The setup is shown in Figure  3.
When writing for the Special Issue Aircraft Design, authors should make sure to use persistent links to archived resources. Often we refer to journal articles that are usually long term archived by the publisher and have a persistent identifier (a DOI) to connect to the online resource. But in all other cases, it is the author's responsibility to archive the web pages, PDFs, or other data files. Please refer to Appendix A to see how references can be archived with available tools on the Internet.
A Continuous Special Issue as described above is not much different from what is otherwise known at MDPI as a "Topical Collection". A topical collection is a variant of a special issue. Topical collections run continuously (without any numbering) under the same home page. Topical Collections are just another form to structure journal content. The URL of the currently open Special Issue Aircraft Design is always: https://www.mdpi.com/ journal/aerospace/special_issues/aircraft_design. Linking to this URL also means linking to the central anchor point of the Continuous Special Issue Aircraft Design as a whole now and in the future. This page shows links to direct readers to all past special issues. Linking directly to a single past issue is also possible: a long user-friendly URL is available as well as a short URL based on MDPI's internal number of that special issue. Table 1 shows the systematic of these URLs. Presently, the special issue is also advertised on a CEAS web page. The URL of the page is particularly easy to remember: http://journal.AircraftDesign.org. The page provides further details about the Continuous Special Issues Aircraft Design, e.g., related to possible reductions of the standard article processing charges (APC) [26] and links to all relevant web pages.
The Digital Object Identifier (DOI) is always used when linking to an individual paper. The DOI for a recent "Aerospace" paper at MDPI is structured as follows: https://doi.org/10.3390/aerospaceVMMxxxx. Here, 10.3390 stands for MDPI, V is the Volume (related to the year, starting with 1 in 2014), MM is the month, and xxxx is the number of the paper. Allocation starts with 0001 in the beginning of each year, counting up. The setup is shown in Figure 3.
When writing for the Special Issue Aircraft Design, authors should make sure to use persistent links to archived resources. Often we refer to journal articles that are usually long term archived by the publisher and have a persistent identifier (a DOI) to connect to the online resource. But in all other cases, it is the author's responsibility to archive the web pages, PDFs, or other data files. Please refer to Appendix A to see how references can be archived with available tools on the Internet.
A Continuous Special Issue as described above is not much different from what is otherwise known at MDPI as a "Topical Collection". A topical collection is a variant of a special issue. Topical collections run continuously (without any numbering) under the same home page. Topical Collections are just another form to structure journal content.

Aims and Scope
The Special Issue "Aircraft Design" is open to the full range of article types. In addition to original research articles, review papers, letters or communications, technical reports, and the extended version of conference papers are also accepted. Furthermore, an interest exists in aircraft design education. Certainly, the special issue is also the place to discuss topics like zero-emission airplanes, electric flight, urban air mobility-you name what is currently debated. Nevertheless, the classic topics in aircraft design remain: The keywords are: aircraft, design, overall aircraft design (OAD), configuration, requirements, payload, range, certification, safety, constraints, objectives, synthesis, optimization, aerodynamics, drag, high-lift, structure, mass, performance, stability, control, aeroelasticity, engine, systems, operating costs, direct operating costs (DOC), passenger, cabin, ticket, price, environment, profit, asset, wing, fuselage, tail, undercarriage, landing gear, engine, systems.

Aims and Scope
The Special Issue "Aircraft Design" is open to the full range of article types. In addition to original research articles, review papers, letters or communications, technical reports, and the extended version of conference papers are also accepted. Furthermore, an interest exists in aircraft design education. Certainly, the special issue is also the place to discuss topics like zero-emission airplanes, electric flight, urban air mobility-you name what is currently debated. Nevertheless, the classic topics in aircraft design remain: Authors from all economic sectors (private, public, civic, and general public) can submit to this Special Issue. Education and training in aircraft design is considered as important as research in the field.

The Journal "Aerospace" at MDPI
"Aerospace" (ISSN 2226-4310) is a well reputed journal as can be seen from the authors publishing with "Aerospace". Its latest journal metrics CiteScore (CS), SRJ and SNIP (from Scopus, Elsevier) is given on the journal's home page. Articles have a high visibility; papers are visible Open Access at the journal "Aerospace" and also alongside the Special Issue Aircraft Design as soon as they are ready. The journal "Aerospace" is covered by many databases [28] including Web of Science (Clarivate Analytics) and Scopus (Elsevier). Papers from "Aerospace" are archived for centuries to come at CLOCKSS and in the Swiss National Library Digital Archive [28]. "Aerospace" adheres to best practice in Open Access publishing (accessibility, openness, discoverability, reuse author rights, and many other criteria). This is expressed at the Directory of Open Access Journals (DOAJ) with the "DOAJ Seal" given to "Aerospace" [29,30]. MDPI is a member of many relevant publishing organizations (OASPA, COPE, STM, …) [31]. Membership to most organizations is only granted after a thorough check of the publisher and its journals.
The journal "Aerospace" is known for rapid publication [32]. Manuscripts are peer-reviewed and a first decision is provided to authors approximately three weeks after submission; the length of the peer review itself can vary considerably, but reviewers are reminded by the editorial office to make the review a priority; acceptance to publication is undertaken in one week. Once accepted, the manuscripts undergo professional copy-editing, proofreading by the authors, final corrections, and publication on the journal website. This means that papers will be visible alongside with the "Special Issue Aircraft Design" and the journal "Aerospace" as soon as they are ready.

Aircraft Design
Aircraft design is the first fascinating step in the life of an aircraft, where visions are converted into reality.
In a practical sense, aircraft design supplies the geometrical description of the aircraft. Traditionally, the output is a three-view drawing and a list of aircraft parameters. Today, the output may also be an electronic 3D model. In the case of civil aircraft, a fuselage cross-section and a cabin layout are provided in addition.
In an abstract sense, aircraft design determines the design parameters to ensure that the requirements and constraints are met and design objectives are optimized. The fundamental requirements for civil aviation are payload and range. Many constraints come from certification rules demanding safety. The objectives are often of a financial nature, like the lowest operating costs. Aircraft design always strives for the best compromise among conflicting issues.
The design synthesis of an aircraft goes from conceptual design to detailed design. Frequently, expert knowledge is needed more than computing power. Typical work involves statistics, the The keywords are: aircraft, design, overall aircraft design (OAD), configuration, requirements, payload, range, certification, safety, constraints, objectives, synthesis, optimization, aerodynamics, drag, high-lift, structure, mass, performance, stability, control, aeroelasticity, engine, systems, operating costs, direct operating costs (DOC), passenger, cabin, ticket, price, environment, profit, asset, wing, fuselage, tail, undercarriage, landing gear, engine, systems.
Authors from all economic sectors (private, public, civic, and general public) can submit to this Special Issue. Education and training in aircraft design is considered as important as research in the field.

The Journal "Aerospace" at MDPI
"Aerospace" (ISSN 2226-4310) is a well reputed journal as can be seen from the authors publishing with "Aerospace". Its latest journal metrics CiteScore (CS), SRJ and SNIP (from Scopus, Elsevier) is given on the journal's home page. Articles have a high visibility; papers are visible Open Access at the journal "Aerospace" and also alongside the Special Issue Aircraft Design as soon as they are ready. The journal "Aerospace" is covered by many databases [28] including Web of Science (Clarivate Analytics) and Scopus (Elsevier). Papers from "Aerospace" are archived for centuries to come at CLOCKSS and in the Swiss National Library Digital Archive [28]. "Aerospace" adheres to best practice in Open Access publishing (accessibility, openness, discoverability, reuse author rights, and many other criteria). This is expressed at the Directory of Open Access Journals (DOAJ) with the "DOAJ Seal" given to "Aerospace" [29,30]. MDPI is a member of many relevant publishing organizations (OASPA, COPE, STM, . . . ) [31]. Membership to most organizations is only granted after a thorough check of the publisher and its journals.
The journal "Aerospace" is known for rapid publication [32]. Manuscripts are peer-reviewed and a first decision is provided to authors approximately three weeks after submission; the length of the peer review itself can vary considerably, but reviewers are reminded by the editorial office to make the review a priority; acceptance to publication is undertaken in one week. Once accepted, the manuscripts undergo professional copy-editing, proofreading by the authors, final corrections, and publication on the journal website. This means that papers will be visible alongside with the "Special Issue Aircraft Design" and the journal "Aerospace" as soon as they are ready.

Aircraft Design
Aircraft design is the first fascinating step in the life of an aircraft, where visions are converted into reality.
In a practical sense, aircraft design supplies the geometrical description of the aircraft. Traditionally, the output is a three-view drawing and a list of aircraft parameters. Today, the output may also be an electronic 3D model. In the case of civil aircraft, a fuselage cross-section and a cabin layout are provided in addition.
In an abstract sense, aircraft design determines the design parameters to ensure that the requirements and constraints are met and design objectives are optimized. The fundamental requirements for civil aviation are payload and range. Many constraints come from certification rules demanding safety. The objectives are often of a financial nature, like the lowest operating costs. Aircraft design always strives for the best compromise among conflicting issues.
The design synthesis of an aircraft goes from conceptual design to detailed design. Frequently, expert knowledge is needed more than computing power. Typical work involves statistics, the application of inverse methods, and use of optimization algorithms. Proposed designs are analyzed with respect to aerodynamics (drag), structure (mass), performance, stability and control, and aeroelasticity, to name just a few. A modern aircraft is a complex, computer-controlled combination of its structure, engines, and systems. Passengers demand high comfort at low fares, society demands environmentally friendly aircraft, and investors demand a profitable asset.
Overall aircraft design (OAD) comprises all aircraft types in civil and military use, considers all major aircraft components (wing, fuselage, tail, undercarriage) as well as the integration of engines and systems. The aircraft is seen as part of the air transport system and beyond contributing to multimodal transport. Aircraft design applies the different aerospace sciences and considers the aircraft during its whole life cycle [33].

Summary
A journal titled "Aircraft Design" was published successfully from 1998 to 2001 by Elsevier, but had to be discontinued due to the low number of subscriptions. The demise was caused by a publishing model not adequate for the small aircraft design community. No other attempt to start an Aircraft Design journal has been made since then. The Open Access publishing model is a viable and better alternative for small communities. In a new endeavor toward creating something like an Aircraft Design journal, the subset of an Open Access journal within the wider topic "Aerospace" was used. The form of a Continuous Special Issue was chosen as the journal subset. The established journal "Aerospace" helps to overcome the problem of achieving "critical mass" for the new venture. Furthermore, MDPI provides a proven publishing infrastructure and support.