Technical references - Books, technical papers, software, etc.

Due to the frequency of questions regarding reference materials and suggested reading, I am creating this thread to reference particular sources of information that the designers within our compendium of members can use for the development of their ideas and/or for the refinement of their projects. Since however I do work (more than full time), it's going to take me some time to assemble all that I wish to include, so please be patient. The references will be divided up into major categories/disciplines, each of which shall be prefaced in a short abstract. Following the introductory paragraph, a listing of the resources will follow. Each book or document will also be described in a brief abstract and a differentiation will be made between those that I've worked with directly and those for which the abstract is supplied by others. I have also included a quick rating system (one to five smileys) in order to give the reader a quick feeling for the books applicability. These ratings are my own personal opinion only - they reflect my evaluation of the book for its readability, applicability to the light plane design process, the value and presentation of the data, etc.

Since I of course cannot own each and every book out there, additions will be made as supplied by others. Submittals should be made through HBA's private messaging only, not email. When submitting references, please include the following:

Title
Author(s)
Date published and/or copyright date (first and latest)
Publisher
Language
ISBN

A paragraph that discusses the information within the book, who the targeted audience is and the approximate level of understanding that is required to make useful application of the reference. Please also provide your background so that the review can be viewed within context of the submitters experience (this is only for my reference so will not be included for public viewing). Industry and/or design experience by submitters is preferred, especially as that experience relates to the homebuilt arena. Submittals by others will be identified by the Maroon color of the book particulars.

Due to the number of references, the list will be divided up into several posts, each containing materials under the major heading:

Aeronautics and Configurational Development

Structures and Structural Design

General Engineering

Propulsion - Engines, Propellers, Systems

Software​

 

Aeronautics and Configurational Development​

Aeronautics and Associated Subject Matter

Although the subject of "design" could have been lumped into one category, I decided to differentiate between aeronautical references and those relating to configurational development because in effect they are two separate disciplines, despite being interrelated. It is often thought that a person with an aeronautical degree can somehow automatically design an airplane. That however is often not the case. The aeronautical curriculum is focused primarily on issues of theory and analysis, not design. True, one cannot design without the understanding and background one gets through the analysis curriculum however, designing a functional aircraft requires the individual to be versed in multiple disciplines, something that few organizations teach. The process of configuration design encompasses not only the aeronautical aspects but those of the other disciplines also. It needs to focus the overall effort towards a functional end product rather than a series of mathematical exercises. As such, I felt it would be useful to separate those references that focus strictly on aeronautical subjects from those that work at presenting the process of overall development.

Title: Handbook of Airfoil Sections for Light Aircraft
Author(s): M. S. Rice
Date published / copyright: 1971
Publisher: Aviation Publications
Language: English
ISBN: NA
Rating:

In a sense this book is very similar to Theory of Wing Sections but without the technical discussion. I actually purchased this small book because it presents airfoil sections that we normally don't see data for in contemporary publications including a series from Goettingen, Eiffel, Coanda, R. A. F., and U. S. A., in addition of course to the N. A. C. A. shapes. It may not be all that applicable to modern design but it is a useful historical reference, especially if you're analyzing something from the past.

Title: Theory of Wing Sections
Author(s): I. H. Abbott and A. E. Von Doenhoff
Date published / copyright: 1949 / 1959
Publisher: Dover Publications
Language: English
ISBN: 60-1601 (Library of Congress)
Rating:

The standard for the classic NACA families of sections, used for design purposes for decades. The pages also include nine chapters that discuss theory and design practices, including issues of three dimensional wings, high lift devices, characteristics of section families, etc. It's another one of those books that every designer should have if for no other reason than to have a good practical reference for section and wing design.

Title: GA Airfoils - 6th Edition
Author(s): Harry Riblett
Date published / copyright: 1996
Publisher: Harry Riblett / EAA
Language: English
ISBN: NA
Rating:

This publication by Harry Riblett has become one of the more contentious technical papers in the aero field - some folks dismiss it as garbage while others give it high marks for finally correcting several design errors made in the original work conducted by NACA. Furthermore, the latter folks also feel that much of the criticism published within its pages is justifiable in light of recent years' accidents, especially of some of the smaller commuter type aircraft. Personally, I fall somewhere in the middle. When I asked several folks who were highly critical of this volume what it was that they especially objected to, virtually no-one could give me a specific answer outside of the language used within its pages (some of which borders on the quintessential soap-box diatribe), and the program Profil (Eppler code) used in the analysis of the new foil family. Many even admitted that the technical information was essentially correct and although the work is not revolutionary by any means, it actually does correct one or two "minor" problems encountered with the use of the classic laminar sections found in Theory of Wing Sections. Basically, what I concluded is that the engineering crowd wanted a more technical and less emotional treatise on the subject(s) within, without the seemingly frequent distractions of the "exclamations" and tangential off-subject discussions. However, if one can get past all that, the net information within is essentially correct and useful but he perfomrance plots found within should probably be checked with a more modern piece of software. Despite the fact that the data and design guidelines within are essentially correct, I gave it only three smileys primarily because of the way it's written and organized. This could've been presented in a much better and professional format.

Title: Aerodynamics, Aeronautics, and Flight Mechanics
Author(s): Barnes W. McCormick
Date published / copyright: 1979
Publisher: John Wiley and Sons, Inc.
Language: English
ISBN: 0-471-03032-5
Rating:

The title pretty much says it all. This is a fairly complete treatise of the subject of aerodynamics and aircraft performance, handling and the physics of flight. The book covers pretty much the whole range of information ranging from the fundamentals of flows, through aircraft related aerodynamic principles, and into issues of propulsion. Within its pages are also a numerous data tables and plots, many of which I have not seen in other sources. Personally, I've found it quite valuable in a number of areas that may not have been covered in as much detail in other publications.

Title: Airplane Performance, Stability and Control
Author(s): C. D. Perkins and R. E. Hage
Date published / copyright: 1949
Publisher: John Wiley and Sons, Inc.
Language: English
ISBN: 0-471-68046-X
Rating:

As with many of the older reference texts, this one too is well written, presenting the subject matter of airplane performance and stability subjects in a clear and concise form. The text has been and continues to be the standard many designers use to this day for the formulation of flight characteristic data. The book also contains numerous bits of information or techniques that are not commonly used today due to the increasing use of numerical methods however, for the amateur designer, these techniques can be invaluable and often times are as accurate as more advanced methods. This is another one of those books that should be on a designer's desk, rather than on his bookshelf.

Title: Aerodynamics for Engineering Students
Author(s): E. L. Houghton and N. B. Carruthers
Date published / copyright: 1960 / 1982
Publisher: Edward Arnold
Language: English
ISBN: 0-7131-3433-X
Rating:

A very complete aeronautics text that really is for the engineering student - I don't think that anyone who is interested in designing his own wants to go through the level of information that is gathered within these pages. The book however is well written and organized, and can be a useful reference (which is actually why I bought it) but the other publications listed here are usually a much more practical source of applicable data.

Title: Fundamentals of Aerodynamics
Author(s): John D. Anderson
Date published / copyright: na
Publisher: McGraw-Hill
Language: English
ISBN: 0072373350
Rating:

This text is oriented towards university students and covers all the basics of aero, compressible and non-compressible, viscous and non-viscous. Many universities utilize this text as the basic aero-book. It follows a rather "scientific" explanation, using a large amount of mathematics, mainly algebra. 1st year university math is probably required to follow all derivations and examples. The book has numerous examples, clarifying the matter of discussion (examples are 50/50 in imperial and metric units). This book is an excellent way to get a thorough understanding of aerodynamics and the underlying physics, but one can question whether it should be the preferred book for amateur designers, given it's wide scope and that a significant part of the book discusses topics, far out of our reach, like supersonic flight and jet engines.

Aircraft Configurational Development

In simplest terms, configuration design is a discipline of generalization and balance. Those involved in the process should be familiar with all aspects and requirements of aircraft development including the disciplines of aeronautics and flight mechanics, structures and structural design, systems, human factors, operational requirements, materials, manufacturing processes, and at times even marketing issues and customer preferences. In short, the process encompasses the disciplines needed to design an entire airplane to any set of requirements and performance goals. Those wishing to undertake this evolutionary road can be specialists in one or more areas of design however, the focus should be relatively wide, covering all aspects of the airplane at the same time throughout the process. This is beneficial in that it allows for a minimum amount of entrenchment in any particular level of detail, beyond that which is necessary to achieve the design requirements. Furthermore, this "overview" ability often allows the designer to account for variables and design issues up front, thus minimizing redesign and rework cycles, which can be very expensive and time consuming in even the smallest of operations. Although the distinction between analysis and design is not always clear cut, I have tried to list below only those references that address the overall discipline of airplane evolution.

Title: Jane's All the World's Aircraft
Author(s): Various
Date published / copyright: Various
Publisher: Jane's Information Group
Language: English
ISBN: 0-7106-1066-1
Rating:

The quintessential collection of all the world's airplanes - you want to know what's out there, what works and what's popular, you'll most likely find it in here. The reason I'm including this book here is simply because it is in the designer's best interest to understand of what the market already has. Even if one's goals are not commercial sales, it's always a good idea to take a look at what others are up to. This is not so much to try and copy someone's design but more so to get ideas or an inspiration. The information cold also be used to possibly dissuade one from trying to design something that has a less likely chance to work right. In short, additional information is always useful and there's no better gathering of airplane data than here.

Title: Aircraft Design: A Conceptual Approach
Author(s): Daniel P. Raymer
Date published / copyright: 1992
Publisher: AIAA
Language: English
ISBN: 0-930403-51-7
Rating:

In my personal opinion this is probably the best reference text written on the subject of aircraft design. Unlike a standard aerodynamics textbook, this publication approaches the question of design from the perspective of configurational development, taking into account many of the different variables that have to be selected or addressed throughout the design process and thus demonstrating that airplane design is not just a simple process of selecting a few systems and sketching out a wing and a tail. To the best of my knowledge, no other book on the subject matter provides a reader with as thorough a compendium of information, nor of practical examples. Whether you're designing a small puddle-jumper or a personal jet, this is one book that needs to be on your desk and not on the bookshelf.

Title: Design for Flying
Author(s): David B. Thurston
Date published / copyright: 1978
Publisher: McGraw-Hill
Language: English
ISBN: 0-07-064553-1
Rating:

One of the most respected authors and designers in the light plane industry presents the reader with an outline overview of some of the more basic design considerations one has to deal with in coming up with a successful design. The book should be required reading for anyone contemplating designing his own in that it covers material that more conventional texts may gloss over. The book material includes configurational choices, human factors, loading considerations, effects of landing gear type, and even a chapter devoted to seaplane hulls. While nowhere near as detailed as many more technical publications, this book covers most of the subjects in sufficient detail for the amateur designer to be able to get an idea of what's involved and more importantly, get an overview of subject matter that will have to be covered in more detail in coming up with a new plane. The text of the book is very readable and understandable, as is the bit of math that the book does include.

Title: Introduction to Flight
Author(s): John D. Anderson Jr.
Date published / copyright: 1978
Publisher: McGraw-Hill
Language: English
ISBN: 0-07-001637-2
Rating:

Another overview like David Thurston's publication however this one attempts to present the reader with a bit more of a mathematical basis and understanding. The book should be read as an overview only since it tries to cover a lot material in its four hundred some odd pages (including rocket and satellite design considerations), thus necessarily skimming over some subjects or simply passing over others. It is a bit more on the technical side but still a relatively understandable read, even for the layman.

Title: Fluid-Dynamic Lift
Author(s): Dr. Sighard F. Hoerner and Henry W. Borst
Date published / copyright: 1967 / 1975 and 1985
Publisher: Mrs. Liselotte A. Hoerner
Language: English
ISBN: 75-17441 (Library of Congress Catalog Card Number)
Rating:

I wasn't sure where to place this excellent reference since its primary subject matter is pretty much constrained to the field of lift aeronautics. However, unlike many aero texts, this book is a gathering of aeronautical knowledge and its presentation is geared more to the process of design rather than theory so, in the end I think it fits within the scope of configurational development more so than just straight aeronautics. The book was written as part of a U. S. Navy contract in an attempt to at least in part consolidate thousands of technical resources into one compendium of practical design reference - if there's a biblical level of aero resources, this is it. The book is well written and is generally understandable even by amateur designers working on their own ideas. It covers the subject matter with sufficient detail and background that in my opinion, it should suffice by itself for a large part of the aero-evolutionary process. The book (and its corresponding volume on drag) is a bit on the expensive side however if one is serious about designing an airplane, this should be one of the principal references on the shelf.

Title: Fluid-Dynamic Drag (second edition)
Author(s): Dr. Sighard F. Hoerner
Date published / copyright: 1957; first edition - 1951
Publisher: Sighard F. Hoerner
Language: English
ISBN: 64-19666 (Library of Congress Catalog Card Number)
Rating:

An unbeatable compendium on the subject of drag. It is actually the predecessor of his book on lift, covering a multitude of design considerations for the reduction of resistance to movement within a fluid. In the author's own words: It is the author's objective in this book, to present information on drag or fluid-dynamic resistance in a comprehensive, generally-valid and intelligible manner to students, engineers, and researchers. The text is not always a "handbook", however, giving ready results. The reader is expected to work out the desired information himself, considering cause and effect involved in the problem he wants to solve. Although the author cautions that this is not a handbook, the information within tends to be so complete that often it can be used as one. Again, not the cheapest book on the shelf but well worth the price.

Title: Synthesis of Subsonic Airplane Design
Author(s): Egbert Torenbeek
Date published / copyright: 1976
Publisher: Delft University Press
Language: English
ISBN: 90 298 2505 7
Rating:

Another one of those interesting books that at first tends to come across as an aeronautical dissertation however, a deeper reading reveals that like Hoerner's publications, this is a gathering of an amazing amount of information that is presented in a concise format that is almost directly formulated for application to design and configurational development. Its presentation of data and equations is free of derivation and theory and as such, is more user friendly and directed at those looking for direct solutions to their inquiries. It's information is presented for applications ranging from small aircraft all the way to airline scale and I think can be successfully used by anyone with a bit of tenacity and reasonable math skills. It's also interesting from the standpoint where each time you open it up you find something you can use and yet were not sure how to find. I used to use this book more as a secondary backup however nowadays it's one of the first texts I turn to when I need just about any bit of particular data.

Title: Elements of Sport Airplane Design for the Homebuilder
Author(s): P. E. Bird (editor)
Date published / copyright: 1977
Publisher: Vogel Aviation
Language: English
ISBN: N/A
Rating:

This "publication" is more in the format of a university paper rather than an actual book however despite its rather amateurish look, it actually contains a good deal of information that applies to the entire process of aircraft development, taking the reader from the stages of design to initial flight tests. It contains only 95 pages but the information is curt, concise and sufficient to form a good outline on which to build on. Some folks might be tempted to use the publication as a cookbook type guide for the actual design process - those I would strongly urge to reconsider. This document does address some specifics but not to the level necessary that an airplane should be designed to. But despite its brief nature, I would have no problem recommending it to anyone who is interested in getting a good overview of the steps necessary to go from idea to first flight.

Title: The Design of the Airplane - Second Edition
Author(s): Darrol Stinton
Date published / copyright: 2001
Publisher: AIAA
Language: English
ISBN: 0632018771 or 978-0632018772
Rating:

Originally I purchased this book out of curiosity - it was recommended by several individuals whose opinion I trust, and having another good reference on the shelf is always useful. My first glance at the book lead me to believe that this was just another aero reference but a closer examination revealed that this was more of a design reference than another exercise in theory. The author discusses design characteristics and trade-offs without spending too much time in complicated aerodinamics formulations. But the subjects are covered well enough to encompass most of the necessary details of the design process. I might recommend that the reader has a background in or understanding of the basics of flight but with a bit of reading and contemplation, I think this book could be a good resource even for the amateur designer.

Title: Design of Light Aircraft
Author(s): Richard D. Hiscocks
Date published / copyright: 1995
Publisher: Patricia Hiscocks
Language: English
ISBN: 0-9699809-0-6
Rating:

This Book is of interest to aeroplane enthusiasts. The elements of design are described in a historical context with many examples to illustrate and explain the process. Wing theory is examined together with the aerofoil selection process, scale effect, performance as required for a flight envelope aspects of stability and control, biplane theory, loads on components, structural stiffness requirements, flutter, fatigue life, and factors of safety. All are viewed in the light of practical requirements and good design practice. The Art that is required in design to balance the demands of performance, safety and cost is described. Often a highly precise analysis is not justified when the limitations of the theory and materials of construction are considered. In the design examples provided all of the arithmetic can be performed on a pocket calculator. Readers who do not have the time or inclination to study official airworthiness standards and texts written for specialists in aerodynamics and structures will find this book a useful design guide. Extensive data is provided for those who do not have ready access to a technical library. (Review from Amazon)

Title: Tailless Aircraft
Author(s): Carl Nickel
Date published / copyright: 1994
Publisher: Elsevier Science and Technology
Language: English
ISBN: 0340614021
Rating:

The book discusses the full range of tailless designs, from hanggliders to the US 'Stealth Bomber', and includes a detailed look at particularly significant designs. The authors' own experience in this field allows them to explain and illustrate the topic in a way that will both appeal to the enthusiast and satisfy the professional aerodynamicist's need for academic rigour: a rare mix of sound science and first hand experience. (Review from Amazon)

Title: Fundamentals of Aircraft and Airship Design
Author(s): Leeland Nicolai and Grant Carichner
Date published / copyright: 2010
Publisher: AIAA Education Series
Language: English
ISBN: 1600867510
Rating:

The aircraft is only a transport mechanism for the payload, and all design decisions must consider payload first. Simply stated, the aircraft is a dust cover. "Fundamentals of Aircraft and Airship Design, Volume 1: Aircraft Design" emphasizes that the science and art of the aircraft design process is a compromise and that there is no right answer; however, there is always a best answer based on existing requirements and available technologies. (Review from Amazon)

 

Structures and Structural Design​

Structures - Wood

Although structural design could have been one category, I decided to divide up the subject matter by materials. At this point I'm not sure if that's the thing to do since many references either overlap or can be generally applied to all aircraft materials and structural types, but for now I'll keep it separated in this manner. This first section covers the oldest of the materials used within airplanes and some say, probably one of the most versatile - wood. Due to its light weight, wood is still a surprisingly efficient material. Given its user friendly properties, its wide availability and usually, reasonable cost, its application to light aircraft has been and continues to be very successful. Even today, some of the highest performance airframes are still of wood construction.

Title: ANC-18: Design of Wood aircraft Structures
Author(s): Munitions Board Aircraft Committee
Date published / copyright: 1943 / 1952
Publisher: Department of Defense
Language: English
ISBN: NA
Rating:

Probably the most comprehensive design reference for wood aircraft structures. Wood properties are specifically formulated for application to flight. Chapters cover specifications for quality, moisture content, properties and design guidelines for all aspects of the airplane. The material contains sufficient test/statistical data for high levels of confidence when dealing with this organic product. Being that wood is orthotropic (material properties vary with respect to orientation), some of he general design guidelines can also apply to the subject of composite design and construction. Definitely worthwhile reading.

Structures - Metal

As the price of metals after WWII decreased, aluminum's application to the light plane industry had exploded. With only very few exceptions, aluminum structures have pretty much taken over in general aviation's certified product lines. And despite the introduction of more "modern" materials, the alloys are also used extensively in the homebuilt sector. Given today's capabilities of numerically controlled production methods, technologies such as matched hole tooling have significantly advanced the metal kit's quality and user friendliness.

Title: Analysis and Design of Airplane Structures
Author(s): E. F. Bruhn
Date published / copyright: 1943 / 1952
Publisher: Tri-State Offset Company
Language: English
ISBN: ASIN: B001UZ1X6E or B0007EAC70
Rating:

One of the most respected structural design texts on the market. Although somewhat dated in a few areas, the vast majority of the work is still directly applicable, verified by many decades of successful products. The text has been widely accepted by many leading universities as well as by almost an entire generation of designers and engineers. The writing is relatively clear and comes with many fully worked out examples and practice problems (including answers). I've used it on several occasions as a basis for writing design software, using the worked out example problems as verification for the programs. If you want to teach yourself not only the basics of structural analysis/design but also how to analyze flight structures, I can think of no better place to start.

Title: Aircraft Structures
Author(s): David J. Peery
Date published / copyright: 1950
Publisher: McGraw-Hill Book Company
Language: English
ISBN: 007049195X
Rating:

As with the book written by Bruhn, this is indisputably a classic reference for students and practicing engineers as well. Personally, I think this is most likely the best text book ever written on the subject of the static strength and stability of metallic aircraft structures and its components. Given the principal and secondary consideration of aircraft structural design, including issues such as gust loading, this should be a must read for anyone contemplating the design of their own. I've seen numerous examples of more modern structural references for the aircraft discipline but none have come even close to the level of material presented, nor to the direct applicability of the material to airplane design. Another one of those "should have" volumes.

Title: Aircraft Structures
Author(s): David J. Peery and J. J. Azar
Date published / copyright: 1982
Publisher: McGraw-Hill Book Company
Language: English
ISBN: 0-07-049196-8
Rating:

If there was ever an example of why classics should not be "updated" and rewritten, this is it. While this new version of the original covers much of the same material, it has been turned almost generic and useless simply due to the trimming out of many of the original chapters. These edits presented information on aircraft unique design considerations that no other modern day reference has. I really do not understand why a text that claims to be a teaching tool for aircraft structural engineers would remove data vital to that discipline. In short, avoid this rewrite.

Structures - Laminate

Due to do the potential efficiency that laminate structures can achieve, and the aesthetics the designers can create given the materials' flexibility of application, composites are becoming more and more popular in the light plane industry. The drawbacks of their use however includes the high costs of the raw products, the increased time/cost of developing tooling and at times the specific knowledge required for the design process and even for the steps and techniques necessary throughout the manufacturing and assembly steps. To the best of my knowledge, there are very few references written for the purpose of practical design application, which of course has resulted in many airplanes being simply metal concepts built of plastic. In other words, the designers build composite airplanes however with structural concepts and arrangements that are similar or identical to those that would be used within a typical metal or wood airframe. While functional, this approach fails to take advantage of the materials' flexibility and benefits, often resulting in structures that are substantially heavier and more difficult to assemble than what we'd see with the more conventional products. As with other airplane related subjects, most references within this heading were written primarily for the commercial and military sectors however, in this particular case most of the technology and concepts can be successfully adapted to the light plane also.

Title: Design of Durable, Repairable and Maintainable Aircraft Composites
Author(s): Various - Collection of Papers
Date published / copyright: 1997
Publisher: Society of Automotive Engineers
Language: English
ISBN: 0-7680-0020-3
Rating:

Written with commercial airplanes in mind, the subject matter within covers everything from lightening strikes to damage repair. Examples within also show ideal structural configurations, methods of joining various structural components, installation of hard points, etc. Although written for commercial airplane application, the concepts and configurations within are perfectly suitable for light airplanes also. The reference is well written and easy to follow. The ideas are well illustrated so the subject matter is easy to follow and visualize.

Title: Composite Airframe Structures - Practical Design Information and Data
Author(s): Michael C. Y. Niu
Date published / copyright: 1992
Publisher: Conmilit Press, Ltd.
Language: English
ISBN: 962-7128-06-6
Rating:

Probably the best, most straight forward text written thus far on the practical considerations of composite design and fabrication. The covered information represents a wide field of subject matter, including laminate design practices. The latter is written in a relatively straight forward manner so if one wants to delve into the mathematical background of non-orthotropic, multi layered structures, one can do so without having to understand a masters level dissertation. The book is full of practical examples of assembly, failure mode concerns, quality control, inspection procedures, and on an on. Much of the text seems to be written with commercial applications in mind however general aviation and experimental sectors are presented also. Personally, I feel that this is another one of those books where if you're serious about designing your own plane out of laminate structural concepts, you need to have this on your shelf.

Title: Introduction to Composite Materials
Author(s): Stephen W. Tsai and H. Thomas Hahn
Date published / copyright: 1980
Publisher: Technomic Publishing
Language: English
ISBN: 0-87762-288-4
Rating:

Text book for an engineering college course in composites, covers governing principles and analytical mechanics for lamina and laminate elastic behavior (stiffness and coupling), failure criteria (strength), hygrothermal beahvior, and micromechanics. Excellent book for those interested in designing composite structures. To use this material, plate theory and matrix algebra are used.

Title: Mechanics of Composite Materials
Author(s): Robert M. Jones
Date published / copyright: 1999
Publisher: Taylor and Francis
Language: English
ISBN: 1-56032-712-X
Rating:

College Mechanics Textbook, with development of mechanics, applications, lamina and laminate elastic behavior, strengths and failure criteria, micromechanics, design of composites, joints, optimization. It includes a review of the matrix algebra necessary to do the work, and a cursory review of beam and plate theory.

Title: Primer on Composite Materials: Analysis
Author(s): J. E. Ashton, J. C. Halpin, P. H. Petit
Date published / copyright: 1969
Publisher: Technomic Publishing
Language: English
ISBN: 72-81344 (Library of Congress)
Rating:

Despite the rather ancient date of this publication (where composites are concerned that its), the information and analysis presented within the pages is just as applicable today. This however is a very math oriented theoretical book so don't expect any useful material data here. It is purely a theoretical analysis primer on orthotropic structures so if you're heavy into math, you'll love it.

Title: Handbook of Plastics, Elastomers and Composites
Author(s): Charles A. Harper
Date published / copyright: 1996
Publisher: McGraw - Hill
Language: English
ISBN: 0-07-026693-X
Rating:

A fairly complete primer on plastics and composites including chapters on failure modes, fabrication and joining (adhesives), and application. I haven't usd this reference a whole lot but if somone is looking for a good industry primer on the various materials that fall under this heading, this is about as good as I've seen.

Structures - Landing Gear

There are very few publicly available references for landing gear design. The few references that are available to the general public tend to be focused on commercial aircraft, something that has very little application to the person designing/building a typical light plane. That really leaves only two principal sources of information: The FARs and probably the only concise design manual for light aircraft gear, written by Ladislao Pazmany. If there are others I'd be more than happy to post them here but at this point I have not seen anything else.

Title: Landing Gear Design for Light Aircraft - Volume 1
Author(s): Ladislao Pazmany
Date published / copyright: 1986
Publisher: Pazmany Aircraft Corp. / EAA
Language: English
ISBN: 0-9616777-0-8
Rating:

An excellent reference for the designer as well as for the individual who is simply interested in getting an overview of landing gear design and systems. The book reads almost like a design manual and includes not only all the design requirements but also has sufficient examples of analysis that should allow most folks to design a functional and durable gear system. The book contains excellent resources of photos and technical drawings, all of can be used to massage a design to fit just about any application. It also has sections on regulations and testing, brake systems, tire tables, etc. This is another one of those books that should be a "must have" for anyone designing his own. Despite the title though, Volume 2 was never written.

Title: Emerging Technologies in Aircraft Landing Gear
Author(s): Several (collection of SAE technical papers)
Date published / copyright: 1997
Publisher: Society of Automotive Engineers
Language: English
ISBN: 0-7680-0091-2
Rating:

An interesting collection of technical papers focused on a variety of technologies in the field of aircraft landing gear. The subject matter however is focused on subjects that mostly relate to the commercial and military sectors so for most light plane designers, this book would be just an overpriced door stop.

 

General Engineering​

General Engineering

As has been correctly pointed out by many going through the design process, the work involved encompasses numerous technical disciplines - those undertaking the journey of designing their own plane should not only understand that fact but also be ready to learn much more than just making pretty airplane shapes in their CAD systems. This reference section will therefore list several texts that might be useful for those additional disciplines - some are strictly technical in nature while others will be useful to have on the shelf for general background information.

Title: Kitplane Construction
Author(s): Ron Wanttaja
Date published / copyright: 1991
Publisher: TAB Books - McGraw-Hill
Language: English
ISBN: 0-8306-3565-3
Rating:

Although this is not exactly an engineering text, it is one that every designer and builder should have read and understood in its entirety. The sections on airplane selection, the build requirements and the techniques needed for the different materials are well thought out and their consideration is very applicable to the decision making process. One of the more interesting sections in the book is the one that discusses the question of whether a person can actually afford airplane ownership. This should also be an important part of selecting or designing, and building said airplane since it can become a rather sizable factor in your personal finance picture. Simply said, there's a lot of information in here, all of it useful to someone considering jumping into the pool.

Title: Mechanical Engineering Design
Author(s): Joseph E. Shigley
Date published / copyright: 1977
Publisher: McGraw-Hill
Language: English
ISBN: 0-07-056881-2
Rating:

Although written for engineering students who are in the early stages of learning mechanical design, the book is complete enough to act as overall reference for most mechanical and structural design problems. Whether you're looking at structural elements, stress concentrations, gears and drivetrains, lubrication issues, bearings, or whatever else, this publication covers most issues in complete enough detail to enable one to go a ways into the design cycle. Most of us that have used this book in school tend to turn to it first more so than any other. It's one of those that falls under the classification of "must have" if one is looking to do any serious mechanical design.

Title: Technical Drawing - Sixth Edition
Author(s): Giesecke, Mitchell, Spencer and Hill
Date published / copyright: 1974
Publisher: Macmillan Publishing
Language: English
ISBN: 0-02-342700-0
Rating:

The last decade or so computers have taken over much of the technical presentation of parts and assemblies so some might think this book is somewhat out of date. Not the case though. Most of the information within is still valid in that it teaches the individual how to present said information in a logical and understandable manner for the fabrication and assembly disciplines. Whether drawn by computer or hand, the standards of notation, tolerancing and dimensioning have not changed. Furthermore, learning how to think in three dimensions is also as applicable to the computer as it was to the old drawing board. For those reasons this book is an excellent resource for anyone looking to learn the practical standards of technical drawing. Furthermore, being familiar with the concepts of this book will allow folks to read and understand drawings, blueprints and manufacturing drawings, something that's fairly essential even in the assembly of a kit.

Title: Marks' Standard Handbook for Mechanical Engineers
Author(s): Baumeister, Avallone and Baumeister
Date published / copyright: 1916 / 1979
Publisher: Kingsport Press
Language: English
ISBN: 0-07-004123-7
Rating:

The quintessential mule-choking compendium of mechanical engineering data and concepts. Covers the subjects of math, basic electronics, mechanics, gas dynamics, heat transfer, and on and on. The data within may not be to the level of detail to do a complete design project but there is certainly more than enough to get one started on just about any mechanics problem. This may not be the book you always turn to but it is a handy reference, especially for those who are working at a level of self education.

Title: Mechanisms and Dynamics of Machinery
Author(s): H. H. Mabie, C. F. Reinholtz
Date published / copyright: 1957 / 1987
Publisher: John Wiley and Sons
Language: English
ISBN: 0-471-80237-9
Rating:

Originally I purchased this textbook for the chapters on gear and drivetrain design. But it contains much more within its pages and if you're really into mechanism design and analysis, this book does an excellent job of explaining the process. There is quite a bit of motion theory and somewhat more advanced mathematical concepts used herein (after all, it is a university level text) so parts may require a bit more study, but overall I've found this book to be very useful and usable for the design process.

Title: Materials Science and Engineering Series - Mechanical Metallurgy
Author(s): George E. Dieter
Date published / copyright: 1961 / 1976
Publisher: McGraw - Hill
Language: English
ISBN: 0-07-016891-1
Rating:

This is an excellent reference for anyone interested in the mechanics of materials. It also has a very good dissertation on fatigue and fracture mechanics. If you're looking for a more in-depth background in metal behavior (valuable if you're designing your own aluminum airplane), this is a great single source for everything from the basics to methods of forming and testing. And the background that one might get is also a useful building block to working with composites since many of the concepts and terms introduced apply to all materials.

Title: Engineering Fluid Mechanics
Author(s): Alan Mironer
Date published / copyright: 1979
Publisher: McGraw - Hill
Language: English
ISBN: 0-07-042417-9
Rating:

This is a basic text for the introduction in fluid mechanics, covering everything from air and water characteristics and how they apply to internal flows, external flows, and various forms of machinery. This may not be the best primer for aircraft design issues but there is a lot of information here that will enable the reader to get a better understanding of fluid behaviors. Although far from a "must have" text, it still might be useful for some.

Title: Engineering Mechanics - Statics
Author(s): R. C. Hibbeler
Date published / copyright: 1978
Publisher: Macmillan Publishing
Language: English
ISBN: 0-02-354020-6
Rating:

There are three books that I'd recommend to anyone looking to grasp and understand the fundamentals of mechanical analysis, this is the first. This basic engineering text provides the reader with the fundamentals of static analysis. It does not delve into materials and stresses - it concentrates on the mechanics of static analysis, resolution of loads and load distributions on structures, reaction loads and the basics of load diagrams. It looks at beams, trusses, mechanisms, cables, and the basics of static fluids. The math is relatively simple but the understanding one might get here is useful for virtually any structure one might find within the shell of an airframe.

Title: Engineering Mechanics - Dynamics
Author(s): R. C. Hibbeler
Date published / copyright: 1978
Publisher: Macmillan Publishing
Language: English
ISBN: 0-02-354040-0
Rating:

This is the second of the three recommended books mentioned above. It builds on the foundation of static analysis and introduces motion, vibration and the associated dynamics. The mathematics are a bit more complex in that it introduces the reader to vector math, but with a bit of study it should be within the scope of most folks with basic math skills. Since the airplane is subject to numerous loading scenarios that are a function of motion and acceleration, this book will do a pretty good job of explaining said concepts and how to deal with them in the design/analysis cycles.

Title: Introduction to Mechanics of Solids
Author(s): E. P. Popov
Date published / copyright: 1968
Publisher: Prentice - Hall Publishing
Language: English
ISBN: 0-13-048776-7
Rating:

This is the third of the recommended books mentioned above. It is the primer on the behavior of solid structures, including an introduction to the considerations of design. It introduces the reader to stress analysis and the various considerations for the consideration of tensile stresses, compressive stresses, shear stress, and the combination thereof. It also deals with deflections due to loads, free-body diagrams and contains numerous examples and worked out exercises. Since it also covers the basics of material behavior beyond the elastic limit, it will be useful to the designer in visualizing structural effects of yield and other forms of failure.

Title: Internal Combustion Engines and Air Pollution
Author(s): Edward F. Obert
Date published / copyright: 1973
Publisher: Harper and Row, Publishers
Language: English
ISBN: 0-352-04560-0
Rating:

A basic university text covering the theory and application of fuel combustion. The text covers just about everything from the combustion process and the different cycles, to carburation, fuel injection, turbocharging, combustion byproducts, etc. All in all this is a very good text on the subject of fuels and propulsion, although a bit heavy of theory for those who are more into the nuts and bolts end of things. Still, if someone is looking for a better background n connection to this subject matter, be it for personal curiosity or practical application, this is a very good book with plenty of examples, charts and a fairly complete explanation of the processes involved.

Title: Handbook of Practical Gear Design
Author(s): Darle W. Dudley
Date published / copyright: 1984
Publisher: McGraw - Hill
Language: English
ISBN: 0-07-017951-4
Rating:

Although the title refers to the text as a handbook, in reality this is a university level design curriculum for gears, shafts, drivetrains, enclosures, etc. It not only looks at the gear requirements, it also discusses materials, applications, failure modes and causes, and provides solutions to many drivetrain design issues. This is a very good overall design text for anyone looking to delve into fabricating his own reduction drive, or any other similar device.

Title: Classical Mechanics - A Modern Perspctive
Author(s): V. Barger and M. Olsson
Date published / copyright: 1973
Publisher: McGraw - Hill
Language: English
ISBN: 0-07-003723-X
Rating:

A very theoretical text on the physics of motion. Overall this is a fairly complete treatise on the physics of motion however for many this may be a bit too theoretical. The read is relatively straight forward but the math is a bit more advanced - anyone interested in the science behind motion and reaction would get a good background from this relatively thin text. The contents cover a wide variety of subjects ranging from planetary motion to linear and angular momentum conservation.

Title: Formulas for Stress and Strain
Author(s): Roark and Young
Date published / copyright: 1938 / 1982
Publisher: McGraw - Hill
Language: English
ISBN: 0-07-053031-9
Rating:

This is another one of those "must have" references. It covers a pretty wide range of mathematical representations of structural considerations and analyses. It is one of the most widely used references in connection with structural analysis and is applicable to just about any material or discipline within the field. The text covers a brief background of the subject matter of each section, and provides a tabulated series of references for just about any design problem encountered.

Title: The Fatigue of Metals and Structures
Author(s): H. J. Grover, S. A. Gordon, L. R. Jackson
Date published / copyright: 1954
Publisher: Battelle Memorial Institute
Language: English
ISBN: NAVAER 00-25-534
Rating:

The subject of fatigue is rarely discussed in the field of aircraft structures however it should be. Aircraft structures fatigue even when subject to loading well below any critical factor. Fatigue is cumulative so even benign operations will cause long term issues within the assembly. This text is an in depth study of metal fatigue, causes of failure and design considerations to be used to address said issue. Prepared for the Bureau of Aeronautics of the Department of the Navy, this is a professional level reference with numerous practical examples and design solutions. Whether designing airframes or power components, this reference will have useful material for just about any application.

 

Propulsion - Engines, Propellers, Systems​

Here we will address those publications that relate to engines, propellers, installation considerations, cooling technologies, etc. It is one area that will need lots of membership support since my library of propulsion related texts is relatively limited. Furthermore, given the large variety of choices out there, especially on the lower end of the power range, I'm sure there are specific publications out there that address every classification one can think up. A quick glance at the subject matter, even here within this board, we see discussions on everything from the basic two strokes to Merlins so if there's something that should be included, please provide the information in the form outlined above.

Propulsion - Engines

In this section we will endeavor to keep the references focused on the subjects of engines, engine installation and support systems. The range of references will stretch from the basic ultralight two strokes, all the way to turbojets and turbofans. Not all here will relate just to the light plane industry - higher end applications will also be included for those wishing to delve into more advanced or complicated subject matter.

Title: Aircraft Propulsion Systems Technology and Design
Author(s): Gordon C. Oates. Editor
Date published / copyright: 1989
Publisher: AIAA
Language: English
ISBN: 0-930403-24-X
Rating:

A fairly high level collection of technical papers covering many aspects of turbojet and turbofan design and installation. Much of the subject matter is well beyond the amateur but for those wishing to get intimately familiar with turbo-machinery design and operation, this is an excellent resource.

Title: Aircraft Powerplants - sixth edition
Author(s): Kroes, Wild, Bent, Mckinley
Date published / copyright: 1990
Publisher: McGraw-Hill
Language: English
ISBN: 0-07-035569-X
Rating:

If you want a great overview of aircraft engines, I think this is one of the first books to have on the shelf. The soft cover text has over 640 pages of material ranging from reciprocating engines and associated systems, all the way to turbojets and turbofans. The chapters cover in good detail (including great illustrations) not only the components of the engines but also their function, maintenance, troubleshooting and support instrumentation. The format of the book is similar to the better automotive manuals, providing a surprising level of detail about each engine or engine type.

Title: Firewall Forward
Author(s): Tony Bingelis
Date published / copyright: 1983
Publisher: EAA
Language: English
ISBN: 0940000938 or 978-094000933
Rating:

A respected author in the Experimental community, Mr. Bingelis presents the homebuilder with a very readable manual for just about any engine installation configuration you might think of. The book is a manual of most design consideration, including issues of cooling, exhaust installation, fuel systems, electrical, etc. The book includes many photos as well as excellent drawings of associated hardware and systems. Even if the book doesn't discuss the exact configuration that one might be considering, the material within will provide the builder with a sufficient outline of considerations that will enable him to put together a good and functional propulsive package.

Propulsion - Propellers

This section will concentrate on the actual propulsor, be it a conventional propeller, a fan, a shrouded or ducted system, etc.

Title: Ducted Fans for Modern Jets
Author(s): David James
Date published / copyright: 1993
Publisher: Biddles Ltd.
Language: English
ISBN: 0-85242-977-0
Rating:

Although a bit dated and written specifically for model aircraft, the text is still interesting and will provide most readers with a light background in ducted fan application. The beginning chapters covers some basic design considerations, including an introduction to the field and a section on fan theory and design, which are followed by chapters that focus pretty much on scale jet airplanes. The books application to full sized airplanes is limited but given the lack of publicly available reference for the subject matter, this will at least provide the individual with a cursory look.

 

Software​

This is a very wide subject matter and I am not sure how well I'll be able to cover all the available material. My company of course uses many forms of software in our own aircraft design/development work and that will of course be listed and reviewed however, there are many other packages available both, commercial and freeware, much of which is unknown to me. Therefore, as with the references above, I will from time to time, be depending on the HBA's membership to supplement the information herein in order to provide the readers with a more complete listing. As before, any supplementary information should be sent my way through private messaging within this board.

As software has advanced and matured, a fairly substantial number of folks today appear to be of the opinion that we should by now have the ability to develop a computer based system that essentially becomes our own private engineering team, allowing even the amateur to design a safe and functional aircraft with only a few basic inputs. While this is an interesting goal for someone to try, all can be assured that this type of "expert system" has as of yet not been developed. Although the analysis of airplanes has advanced, the software discussed in the following sections can really be thought of as nothing more than an advanced tool set - a tool set that still must be understood, along with the sciences of flight, structures and overall configurational design. Even an advanced piece of software will still not enable one to understand the design of an airplane any more than a hammer and tape measure will enable an apprentice carpenter to understand the construction of a house. The designer still needs to understand the technology of the design process in order to use these tools in an effective and realistic manner.

No, this does not require a university level education in engineering (although that certainly doesn't hurt) - there are many here who are essentially self taught, doing the job of research and asking a lot of questions in order to teach themselves the proper techniques and forms of these disciplines in order to enable themselves to design that plane they've maybe dreamed of for many years. The software may help, but in of itself, is no substitute for that hunt for information.

The other consideration one must ponder herein is simply that the true value of the software is, for the most part, directly related to the cost. With only one or two exceptions, the more expensive the package the better results it will deliver - there really are no cheap shortcuts. However, by the same measure, the more expensive the software, often times the more complex it is. But then in this realm, the better the results, the more complex the program must be in order to do its job. Here is where every designer must balance between making that purchase and then going through the learning curve, or simply hiring a consultant to cover the bases. Given the prices of some of this stuff, the latter often seems to be the best solution.

Software - CFD

CFD simply stands for computational fluid dynamics. The flow analysis software is usually fairly complex, requiring specific experience and knowledge to not only properly model and setup the analysis but to also get meaningful results. Without said experience, CFD can also stand for confusion, frustration and despair.

There are several versions of this type of software ranging in cost from web based freeware to professional packages costing upwards of $50,000. The more expensive, the better the software and the more dependable the results, assuming of course the operator has specific knowledge and experience to use it. CFD works in a similar manner to a finite element modeler in structural analysis - in essence the shape to be analyzed is divided up into a multitude of small elements over which a flow is superimposed. The software then calculates a series of physical variables that act on said element as a result of that flow, the results of which can then be manipulated to get various forms of data ranging from pressures and forces, to design coefficients. But it must be understood that CFD is really not a design tool - it is more a tool for optimization.

A few years back there was an aero analysis presentation that was sponsored by United Technologies. The speaker was one of the principal designers for the turbine arm of the company, although he also had a background in airframe applications of the solver technologies. One of the more eye opening parts of the presentation was a point where he indicated that for the most part, unless the analysis is conducted properly and by specifically trained individuals, they consider the vast majority of CFD results no better than clown puke. In other words, the results are filled with pretty colors that are often arranged into an impressive presentation, but outside of that, because of the way the CFD software was used, the results have no dependable use. In his experience he felt that it is critical to understand that at no point is CFD a design tool, nor is it really an analysis tool. It is more than anything else an optimization tool, a job it cannot do without some form of accurate environment basis and hardware based verification.

In the design of a new engine, the vast majority of the work is done by experienced engineers, the results of which are tested along the way as the engine program matures. The engine is then built (usually based on an advancement of an existing engine core, or similar) and tested in available facilities. This is then followed by a CFD model, the environment of which is massaged and tweaked until the CFD results match those of the hardware tests. Only then is the mathematical geometry model modified, in small increments, to generate a new configuration or geometry that advances the propulsion product.

Over the years I come across several very experienced aero types who specialize in CFD modeling and analysis. And interestingly enough, virtually all agree with that statement and approach. True, I have not heard the others express it as colorfully as at the UT presentation, but in general the identical sentiment comes out over and over again - CFD is not a design tool and unless you are very well versed in the technology and in its application, depending on the results may simply lead you down the wrong path. Yes, it may be fun to play with, but then you're just playing, not designing.

In short, there is no software that will do the airplane design for you, aero nor structural. There is no shortcut to knowledge and experience. We already have more than enough design information publicly available to develop a safe airplane, even a very high end one. The trick then is learning that and not trying to find shortcuts. However, for those still interested in what's available, the following is a short list of the more mainstream packages.

VSAERO - Desktop CFD - VSAERO couples integral methods for potential and boundary layer flows for low runtimes (a complete Boeing 727 in 300 seconds). Flowfield properties are computed for off-body velocity surveys and on/off-body streamlines. The ability to calculate internal and external flows, non-uniform inflow and body rotation, makes VSAERO applicable to fluid flow problems in aerospace, automotive and marine engineering. Special purpose modules like FSWAVE and ROTOR expand VSAERO's simulation capabilities to include nonlinear hydrodynamic wave effects on ships and helicopter rotor/ fuselage interactions. Zonal coupling to Navier-Stokes codes is also available. Running on a wide variety of computers, from Cray Supercomputers to desktop PCs, VSAERO is used worldwide. VSAERO has been used in the development of Rutan Voyager and Beech Starship aircraft, the Stars and Stripes racing yachts and the Sunraycer solar automobile.

VLAERO+ - VLAERO+ is a planar vortex lattice method for the aerodynamic analysis of subsonic and supersonic aircraft configurations. With it's own GUI, VLAERO+ is ideally suited for the preliminary design environment where it can be used to quickly produce loads, stability and control data. Thousands of calculations have demonstrated that VLAERO+ is not only extremely simple to use but is also highly accurate within the limitations of the governing equations. Geometry is represented by a series of trapezoidal patches. Camber and twist (including airfoil sections, wing twist, and control surface deflections) are easily specified using common aerodynamic design parameters. Output data are clearly tabulated, including interpolated geometry, surface pressures, force and moment coefficients, and distributed loads.

VLAERO+ includes a graphical user interface for geometry creation, program execution, and solution visualization. Intuitive toolbars provide geometry creation and editing functions. Component ordering and input file creation are performed transparently without the need to edit fixed format text files. Airfoil data management and specification are greatly simplified. Execution of the flow solver is controlled by the interface, and the results are processed for visualization.

Features available from the graphical interface include:

Toolbar for quick intuitive access to file and visualization functions and asymmetric models.
Display window for quick visualization of geometry, airfoils, and flaps.
Geometry editor allows addition, deletion, and sorting of model components.
Component operations for translation, scaling, and stretching of components.
Control surface editor allows graphical specification of control surfaces.
Wing editor for quick generation/modification of model geometry using standard wing design data.
Advanced functions include viscous correction calculator, ground effect model generator, and batch processing.

MGAERO - Although this software is often advertised for application to aerodynamic preliminary design, it must be understood that it is still a fairly complex (and expensive) piece of software that requires a fairly detailed level of knowledge in order to obtain useful data. However, in the terms of mainstream aerospace applications, it can be said that this is one of the more useful pieces of software for running quick and relatively accurate trades. The Cartesian Euler code allows you to rapidly model and analyze the most complex configuration. Cartesian embedded grids simplify grid generation and automatic component intersections simplify geometry definition. Multi-stage Runge-Kutta integration with multi-grid acceleration yield an efficient solution on Unix and PC platforms (not for Windows machines). The user can create geometries as sectional data, generate wireframe components, or provide an IGES file from your CAD system. All these can be used to develop MGAERO input.

MSES/MISES - Whether you need a single airfoil section, multiple sections for a highlift system, or an airfoil for a cascade, this suite of codes allows you to quickly translate your design requirements into an optimum configuration. Two-dimensional codes driven with X-Window GUIs allow rapid geometry changes, parametric flow studies, and configuration development; MSES for multi-element airfoils in subsonic and transonic flow; MISES for airfoils in a transonic cascade. Both codes offer inverse design, forced and natural transition, and direct and inverse interactive boundary layer methods. Grid generation is automatic using a streamline coordinate solution, allowing the grid to adapt to the evolving flow field.


NSAERO - The answer to all your fluid flow questions in a single code. Focus on problem solution and not on multiple flow code inputs. Get one software product - NSAERO - for all flow speeds and Reynolds numbers, including gaseous combustion, Rapid problem set up; flexible and general boundary conditions; structured, unstructured and hybrid grids; and many turbulence and chemistry model options give you access to the most complex applications.

OMNI3D, our interactive 3D data visualization tool and TECPLOTTM, the industry standard visualization software, are recommended with NSAERO to give you immediate feedback from results and flexible display of flow properties. NSAERO, TECPLOT, and our GridgenTM preprocessing code provide you the ideal software system for fluid dynamics analysis.

TECPLOT is a trademark of Amtec Engineering, Inc., Bellevue, Washington. Gridgen is a trademark of Pointwise, Inc. , Dallas Texas.

USAERO - Challenged by relative motion aerodynamic or hydrodynamic simulations? Multi-store release from a complex aircraft? Trains passing in a tunnel? Ships with rotating propellers operating near the free-surface? USAERO is the engineer's choice for these and other transient calculations. USAERO's unique coupling of potential flow and boundary layer methods with a time-stepping procedure for arbitrary motions assures timely and cost effective assessments of unsteady surface pressures and loads.

USAERO calculates the transient aerodynamic characteristics of complex configurations in arbitrary motion. It is based on a time-stepping procedure, which allows relative motions of configuration components. As integral potential flow and boundary layer methods are the basis of this CFD software, the aerodynamics solution is only required on the boundary surfaces for each time step and requires only surface meshing.

Furthermore, while components or bodies may involve relative motions, no regridding is required by the solution scheme. Because of these features, USAERO supports practical engineering solutions for such problems as maneuvering aircraft, formation flying, aircraft stores carriage, gust response, rotor/body interactions, and train passing and tunnel entry. Special application modules, FPI and FSP, couple with USAERO to provide, respectively, flight-path integration calculations with six degrees of freedom and ship nonlinear free-surface simulations.

XFOIL - Although not really a CFD tool, it is used widely enough and given the headings used, seems best to fit here. XFOIL is an interactive program for the design and analysis of subsonic isolated single-segment airfoils. Written by MIT professor Mark Drela, it is viewed as one of the better section design/analysis packages available.

XFLR5 - XFLR5 uses XFOIL as its computation kernel and adds a graphical user interface for Windows operating systems. You still need the XFOIL manual to find your way around. XFLR5 also offers a 3D wing design capability, using two different calculation schems. The one similar to MIAReX uses the built in XFOIL kernel to determine local wing section properties. MIAReX is a calculation method for Xfoil and multi-airfoil wings, based on formulae developed by James C. Sivells & Robert H. Neely in NACA TN-1269 (1947). Basically it takes 2D wing section data and integrates the various 2D section properties across the span to arrive at a 'semi-3D' solution.

AVL: Athena Vortice Lattice Method - Yet another design program by professor Mark Drela and Harald Youngren. AVL is an extended vortice lattice method (VLM) software that supports aircraft configuration development by offering aerodynamic analysis, trim calculation and dynamic stability analysis, among other things.

Personal Simulation Works - PSW is a streamline-body design and analysis package for the PC, based on what's generally referred to as a panel code. It includes programs for surface definition, CFD flow analysis, and visualization. Its three principal elements are Loftsman/P, Cmarc, and Postmarc. An optional fourth component, Digital Wind Tunnel, performs stability and control analysis for aircraft. The program was written up in the December 1995 issue of Sport Aviation and has seen some moderate level of success. Current status is unknown as the web site does not seem to have been updated in more than seven years.

Software - Airplane Design

This is sort of an interesting subcategory in that it represents software that's being presented or marketed as an automated design system. The interesting thing is that in several cases the software may come close however, the advertising tends to skim over the limitations or shortcuts that were incorporated in order for the tool to be more user friendly at the amateur level. While these simplifications do not invalidate the program, they do impose certain loose tolerances that cause less than precise results. That does not necessarily make it a bad tool, just one that has to be used with a certain amount of care and restraint.

Airplane PDQ - AirplanePDQ (by DaVinci Technologies) is a conceptual/preliminary design tool for light homebuilt and general aviation aircraft. It is specifically designed to be intuitive and easy to use by amateur airplane designers. AirplanePDQ includes tools for doing a first cut analysis of aircraft performance, handling, and stability and control as well as a CAD component for developing your aircraft drawings. Initial airplane sizing is done rapidly using a wizard-based approach. The designer enters a few basic performance requirements, chooses from among a wide variety of aircraft configuration options (high wing or low wing, tricycle gear or tail-dragger, canard, three-surface, pusher, twin, etc...) and then the wizard performs sizing calculations and generates an initial three-view drawing of the aircraft based on the designer's inputs. Once the initial drawing has been generated, the designer can modify the design using the CAD engine to meet his or her needs. The analysis tools are then used in an iterative fashion to verify that the design is meeting the performance goals and determine what further changes to the design are needed for safety, handling qualities or performance reasons. The analysis tools not only generate detailed performance estimates, they also guide the designer in sizing and adjusting the configuration of the aircraft to help ensure that the design is safe and practical. Although it does have some level of limitations, this is about as close to an expert system as we have int he light plane industry. For the price, it is a good beginning tool for those wishing to experiment with their ideas. However, based on input from several members of this board, it is unclear whether this software is still being developed and/or supported in any way. Web site has not been updated since 2007.

X-Plane - I am generally against using this program for any real world design or analysis work since this is one of the best examples of the computer theory of garbage in-garbage out. To date the program tends to be used by individuals with little or no actual design background, who seem to be of opinion that this is an expert system that will provide them with everything they need to develop a safe plane. And of course nothing could be further from the truth.

In order to provide a more compete answer I made a number of phone calls to those who are familiar with this program and the science behind it. Furthermore, I’ve also contacted several individuals who are intimately familiar with CFD modeling and those who are or have been involved in developing simulator software, be it for the civilian/amateur market or the higher end, mainstream aerospace level. In inquiring whether X-Plane is specifically useful for analysis or dependable flight prediction, the answers were pretty interesting, if for no other reason than their consistency.

The following is a paraphrased version of the responses I’ve been able to gather. I’ll try to do this in two parts: The first part will concentrate on what a flight simulator actually is and some of the functionality behind it; the second part will discuss the math basis involved and the resulting limitations.

As the name implies, the purpose of the modern computer flight simulator is to give the operator a fairly seamless representation of an airplane in flight. Furthermore, many flight simulators like this also incorporate various subroutines that enhance said experience with systems functionality so that the would be pilot not only flies the plane but also operates the equipment within. As such, the focus of the program is on the environment inside and outside the airplane and that is of course why we see the emphasis of many of these pieces of software at simulating not only the cockpit but also a seemingly realistic set of scenes depicted outside the window.

But in order to be truly functional and realistic, the software must be able to do all this in real-time at a rate of many cycles per second, in order for the flight experience to be smooth (I believe X-Plane updates at 15 times per second). To allow this to happen, the math behind the program must be relatively simple since anything complex would bog even the most powerful desktop workstation nearly to a stop. For this reason the machine’s ability to make analysis decisions is extremely limited – in real terms it’s more like a program that has a particular and almost predictable set of reactions to any particular set of inputs. One can think of this as “Action A” causes “Reaction B”.

One gentleman I spoke with equated this action/reaction to sort of a clockwork mechanism with a multi-speed transmission – you move one particular lever in this manner and the mechanism will react (maneuver the plane) in a prescribed way. There is no thinking or analysis in this act/react scenario, just a physical reaction to a set of preprogrammed variables (gears designed during the input phase). And this is where the software falls apart as a design tool. The variables and constants that one would be normally looking for in a typical analysis package (like CFD software) must actually be predefined by the builder of the airplane model. If one inputs the incorrect variables, the results will be meaningless since the program has no way of knowing or telling you whether those values are accurate or not, or even correct. Without having the ability to judge the correctness of input values, the program has demonstrated that it will allow fly nonsensical configurations that normally would not even get off the ground, let alone stay in the air. As such, if one does not have a background in aircraft design, the likelihood that the configuration the designer has input will behave in the same way in the real world, is pretty low.

The other limitation the program has for the purpose of design is the math that makes it work. The math behind the functionality is called blade-element-theory. This is sort of a macro element methodology that was developed to analyze propeller blades and propeller performance. Given the very finite expanse of a typical prop the methodology works since the information covers a very finite structure operating in a finite space and volume of fluid. However, when considering multiple blades the theory failed to produce accurate results so in order to get a better performance model, the blade element theory was combined with momentum theory, which was able to better account for and model air flow behavior in front and behind the blade. All this works quite well for the finite expanse of a typical prop however it was never intended for analyzing a full sized plane. Furthermore, to keep the mathematics relatively simple, the X-Plane software does not incorporate the momentum theory thus making any information that one might actually get from a typical run a bit suspect.

The blade-element theory has another limitation and that is that it cannot very well deal with non-wing bodies and bodies within wings (like flying wings or blended wing-bodies), as well as numerous other geometry shapes. For this reason some folks who are playing with configurational variations have encountered some fairly inconsistent results, despite making only very slight changes in their model geometries. Making a minor geometric tweak and slightly moving a fin and getting a 50% drag rise is one of the examples seen recently, even by folks who use this board.

And of course we can further nitpick by bringing up things like boundary layer and/or viscous effects, wakes, propulsion effects, mass and momentum issues, compressibility, induced velocities, etc., most of which the program has no way of addressing or dealing with. Taking all the above into account, we can only conclude that X-Plane is a very good flight simulator for the pilot but is far short of what one could call an engineering design tool.

So then the question comes up regarding the FAA’s certification of the program: “If this is such a basic tool and so inaccurate, how can it get certified by the FAA for pilot proficiency training?” That one I had to do a bit of digging on but the answer is simpler than you think. First off, for basic level flight and simple maneuvers the software is satisfactory in presenting the pilot with the experience of flying, navigating and operating the aircraft. For that you don’t need the sophistication that you’d need for any form of dependable analysis. Furthermore, to get the certification, the program variables are tweaked so that the aircraft’s behavior as the pilot sees it, conforms to the Pilot Operating Handbook. In other words, they input the airplane model but then go back in and start tweaking and prodding the variables until the airplane behaves just like the manual says it should. In this way it meets the FAA’s requirements and the pilot’s, so certification is feasible.

So given all this, how dependable can it be? Well, it depends. It depends on what information you’re trying to get from it, how good you are at aircraft design and programming in the correct variables, and what part of the flight envelope you’re looking at. When I asked those I contacted this question I got a variety of answers so the following is sort of an average. The numbers assume the designer is very experienced however is hampered by the finesse or accuracy of the program’s math. The percentages are a best guess at how close the model and its results could be to the real word hardware. They can easily be worse but are unlikely any better.

For conventional configurations (Cessna, Piper, etc.):

Level flight - 90%
Maneuvering - 75% to 85%
Abrupt maneuvers or near stall – 60% to 70%
Stall, unusual attitude, corners of operating envelope - less than 60%

Unconventional configurations (highly dependent on layout)

Level flight - 80% or lower
Maneuvering - 70%
Abrupt maneuvers or near stall - 60% or less
Stall, unusual attitude, corners of operating envelope - low (no one gave me any guesses here)

In short, the consensus among those I spoke with is that X-Plane is a very good flight simulator and obviously has a loyal and enthusiastic following. It is however not a design tool nor should it be thought of as one unless you are using it for your own education or entertainment. If you wish to model your own design, do so with the understanding that this is only a potential representation but none of the information you gain from said exercise should be depended upon, used or applied in any way towards developing an actual flight vehicle.

ADS (Aircraft Design Software) - Developed by OAD. ADS is particularly suitable for aircraft designers, homebuilders, university staff and students, as well as for pilots and future aircraft owners. If you are a homebuilder, ADS can help you design or modify a light aircraft. You do not wish to spend time learning to use complex software and you are looking for something user-friendly. ADS makes it possible for you to size the dimensions of your future aircraft, without any fuss and at a very low cost, while ensuring the greatest chance of success.

If you are a professional aircraft manufacturer and you want to design an aircraft, you need an efficient, fast and accurate tool to analyse the market and design the best product in the least possible time; the product which best meets your specifications. ADS enables you to achieve optimisation, i.e. to find the best configuration of the aircraft at the planning stage so that it meets the requirements of the specifications with maximum efficiency and in as short a time as possible.

If you are student or teacher, ADS is a tool perfectly tailored to your needs. You want to understand and explain. ADS is of considerable assistance in providing a better understanding of the aircraft design process, viewing the effects of a parameter variation on aircraft geometry and performances, apprehending aircraft design in a comprehensive way, teaching both the interest of the analytical approach where everything is broken down to the smallest detail and the synthetic approach where all the details form a whole.

I've been following the development of this tool for some time and so far have been pretty encouraged with what I've seen. No, I do not have a copy as of yet but may invest in one to use as a reference and check to the software we've developed in-house. The software is available in several versions, a couple on the bottom end being quite affordable, yet with a nearly full functionality.

Advanced Aircraft Analysis - Developed by the DAR Corporation: Advanced Aircraft Analysis (AAA) has been making inroads in the aerospace industry as a tool for aircraft design, stability, and control analysis software. The program provides a framework to support the iterative and non-unique process of aircraft preliminary design. The AAA program allows students and preliminary design engineers to take an aircraft configuration from early weight sizing through open loop and closed loop dynamic stability and sensitivity analysis, while working within regulatory and cost constraints.

AAA is used for preliminary and Class II design and stability and control analysis of new and existing airplanes. Class II design incorporates detailed weight & balance, aerodynamics, stability & control calculations including trim analysis and flying qualities used in conjunction with the preliminary design sequence. Class II design accounts for power plant installation, landing gear disposition and component locations on the airplane. Furthermore, it uses more sophisticated methods than Class I and requires more detailed information of the airplane to be known. The accuracy of Class II methods is therefore greater than Class I methods.

Advanced Aircraft Analysis can be used for small (civil), military and transport airplanes. The program is designed to assist in the design learning process while reserving for the user the individual creative judgment which is essential to the process of airplane design.

The design methodology used in Advanced Aircraft Analysis is based on Airplane Design I-VIII, Airplane Flight Dynamics and Automatic Flight Controls, Parts I and II, by Dr. Jan Roskam, and Airplane Aerodynamics and Performance, by Dr. C.T. Lan and Dr. Jan Roskam. AAA incorporates the methods, statistical databases, formulas and relevant illustrations and drawings from these references.

The last sentence is critical to understanding this tool in that it virtually requires that one takes the university courses that use Dr. Roskam's books in order to gain a functional understanding of the methodologies used. Some years ago we purchased this software for our company and found it extremely cumbersome for the design process. The software seemed quite useful for analysis of existing configurations but the working requirements were such that the program required input that one would normally assume an analysis program would generate, not need supplied.

I have known a few individuals that give this software good marks but all admit that it is much more an analysis tool and that the learning curve is relatively steep if one is not familiar with Dr. Roskam's curriculum. Personally, I probably would not recommend this to anyone, especially for homebuilding applications.

Software - Structures



Software - CAD