It seems that once a month I end up writing some rant about a piece of software. Believe me, this is not my intention but once a month something essentially stupid happens with a piece of technology. This month it is microsoft’s turn. I joke about other companies turning into Microsoft as, in some aspects, […]

These methods are only applicable to simple, traditional aircraft configurations. Part 23 Appendix A should be read in its entirety to fully understand the context of these loads methods.

Weight and thickness of sheet metal, standard thickness of sheet metal and wire. Material Specifications for Steel Sheet Metal: A366: Cold Rolled Commercial Quality A569: :Hot Rolled Commercial Quality A570: Hot Rolled Structural Quality A526: Zinc Coated (Galvanized) Steel A526/A527: Galvanneal A591: Electrolytically Zinc Plated

Download our free structures textbook and analysis manual or view the online version AA-SB-001. Machinist Drill Bit Size Table – ANSI Drill Size Chart – ISO Metric Drill Bit Size Table. Millimeter to inch conversion Fractional and Metric Sizes ref. ANSI/ASME B94.11M-1993

Minimum (minor) and maximum (major)  thread diameters, threads per inch, tap size and drill sizes. ANSI External screw thread dimensions. Installation torque values from two different sources. The data fastener thread pitch and diameter data below is taken, in part from,  from  MIL-S-8879 External screw thread dimensions from ANSI standard: Bolt installation torques are taken […]

Rivet Shear Strengths for common rivet materials, drill bit sizes and modification for sheet thickness   Rivet Shear Strengths are taken from  (MIL-HNDBK-5H, 1998) Table 8.1.2(a) and Table 8.1.2(b). These strengths are the solid rivet shear strengths and describe the shear strength of the shank of the rivet. For the double shear strength of a rivet, the […]

We are very happy to announce that the second edition of our free engineering textbook “Analysis and Design of Composite and Metallic Flight Vehicle Structures” is now available. We have also added many new free spreadsheets to our collection and now have over 200 free spreadsheets available to complement the textbook available in the Technical […]

This method is taken from our free textbook “Analysis and Design of Composite & Metallic Flight Vehicle Structures” and gives a way to calculate the shape factor in the plastic range for a ductile material. The Ramberg-Osgood Stress-Strain Curve Shape Factor in the yielding region (NACA-TN-902, 1943) can be found for most common ductile materials from  (MIL-HNDBK-5H, 1998). A more […]

This post is taken from our free textbook “Analysis and Design of Composite & Metallic Flight Vehicle Structures” and defines a method for calculating the stresses due to an interference fit bushing. The method in this section is referenced to (AFFDL-TR-69-42, 1986) Section 9.16. Note that several errors in the source material have been corrected. The […]

Excel as a Reporting Tool – Part 4, The First 3 Rules Excel as a Reporting Tool – Introduction – Part 1 here Excel as a Reporting Tool – The Basics – Part 2 here Excel as a Reporting Tool – Printing, Columns and Rules – Part 3 here In the previous post we outlined the […]

Excel as a Reporting Tool – Part 3, Printing, Columns and Rules Excel as a Reporting Tool – Introduction – Part 1 here Excel as a Reporting Tool – The Basics – Part 2 here Excel does not cope well with different printers and adapting page breaks and scaling from one printer to another. An […]

Excel as a Reporting Tool – Part 2 – The Basics – Part 1 here Choosing your Font Font selection is important. It is important to select a font that looks clear on the screen and when printed out. It is preferable to select a font that is part of the windows native font package […]

Recently I got pulled into some problem solving on a part 23 aircraft program. It is great to suddenly get thrown into a new group of people and try and unravel all of the technical and personal knots. These were a great bunch of engineers and it was a pleasure to spend an afternoon with them. […]

First Post – Introduction In writing our free textbook I had to make what I consider to be a huge personal and professional concession. I had to use Microsoft Word. I started out writing the book in Excel but the page formatting and section numbering and referencing issues were too great. Word is great writing […]

As we work towards the second edition of our textbook we are completing and uploading the accompanying spreadsheets. We have finally completed the simple beam analysis section of the book and the 33 spreadsheets that will accompany that chapter in the book are now written and uploaded (We will leave multi-span beams and curved beams […]

In my spare time I have been working on the next edition of the textbook. I was aware that the first edition was ‘incomplete’. In essence, every edition will be incomplete as there is always something more we can add. The First Edition was less comprehensive than I had hoped, but we had to release […]

Our website was down for half a day yesterday due to our hosting service suffering through a targetted Denial of Service cyberattack. It looks like everything is back up and running normally now. Thanks for your patience.

We are a family owned business – most small businesses are. We work for larger corporations. Some of our clients are also small businesses and are family owned as well. Simple stuff. Well, it is simple until one of your clients start to owe you money. Like all businesses we are understanding of clients having […]

On the 21 November 2016 the Stratos 714 took to the sky. We are proud to have played a part in this program and give our congratulations to CEO Michael Lemaire, CTO Carsten Sundin and the rest of the team. I am the structures manager for the program (with more than able assistance from the in-house Stratos engineers […]

In our office, we have been discussing how to implement effective design cost control and/or monitoring. We have had the good fortune to have worked on many different levels of projects from multi-billion dollar high-performance  jet program to much more humble part 23 prototypes. We have learned the importance of asking the following questions: Why use […]