How many times did we struggle to reproduce or simply understand a public technical work or even a private one, in our workplaces, for example? Despite of all the powerful media we have nowadays, it is sometimes difficult to get over the drag forces of the legacy, as usual.

In this article, I try to do a very simplified analysis of the communication mechanism of a technical subject. Choosing a topic as simple as quadratic equations, I show the first known text about this, followed by the one showing the equation solution the way we know it today. …


If we think about the common design techniques applied to flight control, we will notice that most of them start from a linearized plant model. Certainly the linear models rise as an intrinsical part of the mathematical framework required by these techniques (MAGNI, 1997), but such models may provide useful insights about the dynamics of the flying machines and, at least, give us a first glance of the size of the control problem that we are supposed to solve as control designers.

In the early ages of the flight stability and control history (beginning of 19th century), solving numerically the…


When I heard about “breaking the sound barrier” for the first time, this seemed to me even more supernatural than, for example, a bunch of metal weighing more than 77000 kg lifting up from the ground and transporting about 180 passenger from one place to another. Coincidentally, the same science made me understand both phenomena, but still nowadays, after having studied a bit of aerodynamics, I am impressed by videos showing fighters breaking the sound barrier.

But what does sound have to do with the speed? Why is the sound a sort of physical limit to the speed of a…


Few days before the Farnborough International Airshow (FIA) 2018, some followers noticed the intriguing post in the Airbus LinkedIn profile.

In the following days, they posted the challenges. I put the corresponding pictures all together below in case the reader is interested to solve them, before checking the solutions. We will also find the links in the Reference section below.


Imagine a conventional aircraft, like the ones which are flying across the world carrying passengers, for example. There is a very subtle and intriguing fact (at least for flight mechanics geeks) when the aircraft is commanded “to climb up”: the very first response of the aircraft body, for a short time period, is in the other way round, i.e., it dives a very little bit before climbing up. This fact is well explained by the aeronautical engineering experts and I’ll try to build up this explanation throughout the following lines. …


If we take a closer look in the most successful approaches in software development followed by the giants and also adopted by the smaller tech startups, we can identify a framework with some common elements which are actually widely spread by platforms that describe themselves as code management platform (Bitbucket), application for DevOps lifecyle (Gitlab) or software development platform (Github), just to enumerate few of them. If we track a need of change in a software (a bug, a new feature, etc) since the description of this need until the moment its implementation is delivered in production, making an wise…


Flight Control Engineer is certainly one of those jobs you would struggle to explain to your grandparents and by the end there is a high chance that they think “this kid should rather be a doctor” (unless they are aerospace engineers themselves). But which are exactly the skills expected from such kind of engineers? Which are the crucial differences between a confirmed/mid-career and a senior Flight Control Engineer (and more specifically Flight Control Laws Engineer)? In order to try to answer these questions, I went through the typical development process of the Flight Control Systems (FCS) and searched for the…


Imagine a very simple conventional aircraft, with very simple mechanical controls. From an initial straight flight condition of constant altitude, constant airspeed and wings leveled, in a given moment, for some reason, it is required that the aircraft climbs with a constant angle of trajectory. In order to perform this maneuver, the pilot will have to find the right combination of surfaces deflections (let’s say elevator and horizontal stabilizer) and possibly engine throttle setting. Now imagine that there was a device interfacing the pilot and the surface deflection commands such that, somehow, it was possible to the pilot to simply…


Recently I wrote an article where I needed an aircraft model to simulate the phenomenon I was trying to describe. I’ve used a six-degrees-of-freedom (6 DoF) nonlinear model of an F-16 provided by the book Aircraft Control and Simulation (Stevens & Lewis, 2003). The codes were in Fortran and I translated them to Scilab scripts doing a little bit of software engineering and turn all of them into a small project at GitHub named McFlight. Through the next lines I will detail what is supposed to be a six-degrees-of-freedom nonlinear aircraft model, using the structure at McFlight as an example…

Andre Ferreira da Silva

Flight Control Laws Engineer and Software Developer https://www.linkedin.com/in/andre-ferreira-da-silva

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