kejaed

“I really like systems that do one essential thing and do it well. Good examples are Dropbox and Twitter. Dropbox just works. Twitter has a no fuss 140 character tweet box. Simple, easy to understand and minimalist.”

They used to... Maybe even when this was published in 2014.

It is REALLY nothing exciting or novel, sorry to disappoint.

I got tired of finding documents with a figure we needed somewhere else and hunting for 15 minutes for the source material.

We number the figures PRJ-FIG_0001 and have the source files in a top level shared folder (or svn/git). Note it’s important to have the figure id in the figure itself as well as the file name so when it’s imported into a doc the ID is embedded in the figure itself.

We’ve started to embrace PlantUML in our Systems and Software engineering teams at work.

One nice feature of this markup language is creating diagrams programmatically. We wrote a small python tool that will take a State Transition Table (States cross Events) and create the diagram. I have found it helpful to start from the table to ensure States and Events are well defined and all options are considered, but once that is done the diagram is also quite useful for discussion.

Things that we have found helpful are the MediaWiki plugin and the Word plugin.

We’ve also started adding unique identifiers to all diagrams across our large development program, and keeping all diagrams in one central spot. That alone has been almost as useful as PlantUML.

The marketing videos say the airport needs to have a published GPS approach.

Yes it’ll squawk emergency transponder and broadcast on the radio.

They are both using the Garmin Autonomi Autoland system.

Some final matches in the opening round of the Rugby World Cup have been cancelled as well.

https://www.rugbyworldcup.com/update/505639

Has anyone around here set up a GPS Simulator / spoofer with an SDR with any success?

As an aerospace and defence systems engineer & software engineering manager I came here to note exactly the same thing, however it’s not hugely surprising on a SW-centric site like HN.

I think this applies to all disciplines “under” systems engineering too, the thing is with software there are often a lot more chances for things to go sideways compared to EE or mech in development.

The sooner you get the smart people in each discipline (Software or otherwise) to the table the better off everyone will be. This is why in systems engineering processes like ARP4754 you’ll see the word “preliminary” a lot. Preliminary architecture can be developed along with the system requirements as a basis for discussion with those performing the safety analysis and those implementing the software and hardware items. Having a software architect at the table, someone who can reason about the software architecture and its impact on the systems as a whole and the safety case can only help.

As someone who works in this field I have to say this is a really well written article.

Discussing topics like Design Assurance Level and failure condition classification(major vs catastrophic), Single Event Upsets (bit flips), safety assessments in a really clear and well written way.

Also known as a Single Event Upset in the industry.

https://en.wikipedia.org/wiki/Single_event_upset

Thanks a lot for this, appreciate it.

+5 Funny

Did you do anything in particular to break out of the cycle?

There are generally agreements between the various countries’ aviation certification authorities so that a system or aircraft is certified in the country of its design/manufacture and it is accepted in other countries. The harmonization of the rules between countries is always fun.

For example, I worked on a program where we certified the glass cockpit upgrade for the US Navy trainer, T-6A to T-6B with Transport Canada, the aircraft with the new avionics was certified by the FAA, and the whole system was then accepted by the US Navy. Satisfying all 3 stakeholders at the same time often proved difficult.

We implemented the community version. One thing that we almost upgraded for was to implement a custom rule which seemed to be more complicated than it should be. It looked like there were some other options if we had the paid version but we figured it out.

We have implemented SonarQube and found it useful. There was initial pushback from our developers but once we had a couple of review sessions we got some serious value out of it.

Ottawa has the Imagine Space at one of its branches. Quite popular and some great tools and resources.

I’ve also considered starting a community makerspace in the west end of town, a coop or some sort of publicly funded model. This comment section is a good reminder that we had better have a solid operations plan in place for it to be a success.

https://biblioottawalibrary.ca/en/imagine-space-0

MMIST | Android Developer, Embedded Software Developer | ONSITE | Ottawa, Ontario

MMIST is a provider of Precision Aerial Delivery products and services including the Sherpa family of GPS guided parafoils and the self-launch capable SnowGoose unmanned aerial vehicle (UAV), our SkyLink Android-based parachutist navigation aid, and our growing space recovery business.

My team is currently looking to hire software developers both for Android and our various embedded platforms. We are looking for people to join us on-site in the west end of Ottawa.

Embedded https://www.indeed.ca/m/viewjob?jk=32e66f5f60ce2342&from=com...

Android https://www.indeed.ca/m/viewjob?jk=09ed3ee187c4ddbb&from=com...

We’ve started to use PlantUML for diagrams on the systems and software team. It allows for the diagram source to be stored in version control and has built in support in our Wiki and VSCode.

http://plantuml.com/

Thinking about this a little more, I also see a failure here in terms of naming things, which I have noticed in my career can be scoffed at but is so important.

As the article says, the function of MCAS changed and its operational envelope was greatly expanded. What if, internally at least, the new system was referred to as MCAS2?

This is somewhere that things can get political, as was exactly the case with the Max, where they did not want anything to be considered a change to the aircraft type, let alone knowing the MCAS system existed in two majorly differing versions.

Yup, the difference between Fail Safe and Fail Operational.

I really see this as a failure of the Systems Engineering process. With so many people unaware of the impacts of the changes, it’s up to the systems types to have the big picture view and make sure these sorts of things are taken into account.

Especially if as the article says a failure of the AOA sensor on the system would be Hazardous (looks like it was Catastrophic when paired with MCAS in retrospect), that would have made the functional Design Assurance level for this system DAL B, which adds enough rigour not only in the software development process but so much before you even get to that in terms of Safety Assessments and ESPECIALLY change impact analyses when the function changes.

For sure there may have been pressure from management to keep MCAS out of the manual but it’s not really up to he regulatory agency to be experts on the aircraft design, if things are being hidden by the company then I’d consider this bordering on professional misconduct on the parts of the engineers overseeing this work.

I say this as a Professional Engineer working as an aerospace systems engineer.

You wouldn’t be able to know which one was wrong but you’d be able to know and annunciate an AOA MISCOMPARE (which was an option on the Max) and then disable MCAS.

How did that work out in the short term and then in the long run?

Making your own cheat sheet is half the battle when you are trying to learn the topic. I remember in my 4th year Stochastic Processes class [0] (back in 2005, wow) we could bring in a double sided page of notes. I wrote my sheet up in LaTeX [1] and shared it with the class, of course this made it better by having others contribute. Some didn’t understand why I would “help others out” by giving it away, but I never understood that, like a page of formulae are going to get you an A (also why not help others out?).

Of course after spending so much time developing the formula sheet and working through the example problems (always the most important thing you can do), I think I looked at the sheet twice in 3 hours during the exam.

Also, Dr. Glen Takahara, this class and your instruction are one of my fondest memories at Queen’s!

[0] http://kje.ca/school/stat455/cheat2.pdf

[1] https://mast.queensu.ca/~stat455/

This is a great question, the whole GlowScript vs. VPython thing is really confusing and I feel presented in a complicated way on their site. It works great in plain old Jupyter and also from plain old python. If you use it in non-Jupyter Python, it'll launch a web server and browser to play the animation.

I found vpython extremely helpful for visualizing an aerodynamic model of one of our parachute systems at work

https://vpython.org/

There’s a reality tv show that follows the Canadian border patrol, in the couple episodes I’ve seen the agents have found emails about the person crossing actually going for work when they say for tourism or visiting family.

Man, what is it’s both clever and stupid? Like too clever by half?