'Whole Aircraft Design: So What?'

A new Aircraft Design Textbook - coming Summer 2020 (at least that is the plan).

I have just reached 100,000 words, over 1/2 million characters (not including spaces), 228 pages (MS Word Page), 50 figures so far (with many more to add to aid comprehension).

The working title, 'Whole Aircraft Design So What?' ('WadSoW') has been borrowed from a long time colleague, some time manager and, most importantly, a friend - Martin Schofield. The 'So What?' question is his simple definition of what question Whole Aircraft Designers need to answer when presented with a new technology, configuration or set of design requirements.

Maybe it end up purely as a vanity project, but I am aiming high with an intent to have this book recognised favourably in comparison with Professor Torenbeek's seminal work 'Synthesis of Subsonic Transport Aircraft'. My extensive experience of transport aircraft design, performance and operation in academic, research, industry and airline organisations brings a pragmatic, industrial approach to the subject.

I also hope to make a little money out of it!

The book's focus is transport aircraft ranging from small turboprops through the large long-range turbofan aircraft (A380) although some of the thought processes could be applied more widely.

If nothing else, the process of writing has been a cathartic experience. I have been pleasantly surprised by how much has come out of is in my head, but also by how much I have did not know and have learnt as I have researched and written.

Whole Aircraft Design encompasses two primary modes of usage:

1. Conceptual aircraft design: forecasting the sizing and attributes of major aircraft components and systems that would be delivered into service by a professional aircraft design programme to meet a given set of top-level aircraft requirements for mission and field performance. This needs to be a rapid process permit design space exploration with different architectural decisions and technology options.

2. Modelling of known aircraft: Assigning efficiency estimates (mass, structural, aerodynamic, system and engine) attributes to the components and systems of known aircraft outline geometry to match published or expected mission (block fuel and range) and field performance. This process is also critical to the conceptual design process as it calibrates the design methods against the results of previous design programmes.

Both usage modes focus on the architectural aspects of the Whole Aircraft Design process for both conventional and less-conventional aircraft and propulsion options (I do not like the term 'unconventional' as much of such an aircraft is 'conventional').

There is a major section on Top Level Aircraft Requirements as this is largely where the success of an aircraft is defined as the choices made here are hard to modify later in a programme. This includes historical development of the requirements.

All aspects of Aircraft Performance, a fundamental and sometimes overlooked building block of Whole Aircraft Design, is also discussed in detail - many top-level aircraft requirements are based on performance - poor performance analysis, poor design. Descriptions and methods are available to model all aspects in both detail or with many rapid shortcuts and trends.

'WADSoW' explores how to best use both semi-empirical and higher fidelity methods to achieve the results in a timely fashion, i.e. the overarching principle is to always use the simplest method to get an answer that is 'good enough' - why spend 2 weeks analysis to get an answer when a good estimate can be derived in 20 minutes, particularly in a rapidly evolving architecturally design space.

For each major aircraft component and system, the following is provided:

1. a short description of historical and expected future developments plus the current state of the art - useful references are also provided for readers wanting more specifics and detail.

2. the options available to the Whole Aircraft Designer with many real-world examples.

3. Semi-empirical methods based on my extensive literature research and my own analysis. Data included for many aircraft designed since the Torenbeek book and methods defined based on these data.

4. A description of inter-dependencies of the component/system with other components

The final section looks at how the Whole Aircraft Designer integrates the various components under various architectural choices to define an aircraft. Again, real world examples are used to illustrate many of the architectural choices.

I will provide more detail as the manuscript develops further.