Flight Management Computer using Rasperry Pi

Thanks to my colleague Piki from northern Germany and thanks to Dotsha747’s open source FMC PCB and hardware guidance I have been able to complete the first Flight Management Computer (FMC).

It uses a Rasperry Pi 3B instead of the Rasperry Pi Zero recommended by Dotsha747 since I want to use a wired LAN connection throughout the cockpit instead of WLAN. The Rasperry Pi 3B has more computing power and is further able to operate X11 and my custom OpenGC version very elegantly. The lightplates and keycaps are from OpenCockpits. They fit almost perfectly to the PCB of Dotsha747. The only problem was the EXEC light which I had to drill manually into the lightplate.

The 5″ screen comes with a VGA display driver is connected via a VGA-to-HDMI adapter to the Rasperry Pi and the keys are backlighted. The unit now only needs a 12V power supply (and if chosen) a LAN network cable. No more wiring puzzle in the cockpit, which will be especially helpful in the hardly accessible MIP.

One change was done compared to the Dotsha747 hardware: the encoder to tune the display brightness was connected to the display driver board as follows: Encoder Button is connected directly to display driver button “Menu”. Encoder signals are sent to Rasperry Pi and transformed to Up&Down pulses driving the display driver buttons “Up” and “Down” via the transistors Q2 and Q3 (DSPY and FAIL LED’s which are not supported by ZIBO anyway. Please watch out for R24 and R25 which I had to switch on my PCB Version 3.3.


This is straight forward with the rasperry pi zero which can be directly plugged into the connector of the FMC PCB without a cable. But you have to turn around the whole pin assignment by use of a female to female 40 pin connector if you mount the rasperry pi 3b over a flat wire cable. (I have burned a rasperry pi by this mistake, please be careful).

Our open source software package xpcockpit was extended by a Rasperry Pi module called xppi (Many thanks Piki for your edits!) and we also have adapted the OpenGC module Boeing737FMC for more performance and with an option to simply display the FMC screen without the keys.

J-Rails Mounted

Thanks to Pedro von SimuJabs who was able to exactly replicate the Boeing 737-300 J-Rails I could now mount the original cockpit seats. Original J-Rails are very hard to get and the often replicated Boeing 737NG J-Rails are not compatible to the Boeing 737 Classic mounting holes.

At the end, I had to still move the mounting holes by 0.5-1 mm, but the seats now move freely. Like with many completed steps in the cockpit building project it is now time to remove seats again to get space in the cockpit and store them until their final mount.

Where actually is the Minibar in a Boeing 737 Cockpit?

Nowhere. But I figured out that it is definitively a missing feature in a grounded Boeing 737 Cockpit. There is a perfect spot just above the foldable jump seat. And it can fit the adequate amount of glasses serving the maximum number of crew members (4) and a suitable amount of Grappa bottles for a 4-5 hour flight. Please respect the two fuel suppliers Villa de Varda (Italy, Trentino) and Gregor Kuonen (Switzerland, Valais) …

Management Primer (How not to …)

More often than not managers are so busy they fail to think, use intuition and act creatively. In a time when lightspeed governs decisionmaking and e-mails are more important than people, managers often ignore to consult collective intelligence of their people and act with simple (mostly well meant) but self-centric measures to deal with a rather complex world. In fear of losing the game to their peers, managers often fail to request a break during a decision process despite nobody would be harmed. In contrary, these common practices usually yield to short-sighted decisions that generate nothing but inefficiency and anger with the crew on the long term.

We recently have identified five common but fatal types of management you will encounter in many companies or governmental institutions:

  1. Management by Review: the manager has no plan, no vision, no strategy. All he or she can do is rejecting part of your work when you present it. There is never a “good” or “excellent” there is only wrong things among the many things you do for the company. This is discouraging for you on the long term since you will never know how you can be on the right track. Your manager, since he or she has no plan, will possibly also reject things in the second place that were ok in the first place. So you may start on something and will feel after some time that it is not what your boss wants. You will have to build your own strategy of how to get away with your frustration or you should leave the job quite soon.
  2. Management by Buzz Words: the manager reads many blog posts and hip business magazines. There he or she encounters buzz words like “agile”, “cloud computing”, “2.0”, “Social Media”, “artificial intelligence” and the like. Your proposals will have to include those buzz words else they will not be accepted by your manager. Very often those buzz words are neither solutions to management, organizational nor technical challenges, they are just here to feel modern. You are safe with a “buzz word” manager if your manager has a plan, is knowledgeable and emphatic but wants to be a modern person on top of that. You should leave your job if it is just the last.
  3. Management by Key Words: the manager has the strong feeling that your work, your presentation and your proposals need to feature certain organizational, technical or scientific key words in order to be successful. This is not the same as management by “buzz words”. The key words are not necessarily hip ones. But they have to be there for your work to be recognized by your boss. Very often the key words are references to friends of your boss. They can also include rather dull organizational phraseology which may produce a mental hick-up with the reader, but these keywords simply have to be there. I suggest to obey your boss. It is not the worst thing to include some key words and they will not harm. Take it the funny side.
  4. Management by Action: the manager needs to act. If he or she does not act, people will not work or will do the wrong thing. This management style is a common one in today’s world of self-realization and activism. Very likely your manager has a twitter and facebook account and produces daily posts there. The problem with your manager is one of ranking. He or she fails to rank important from unimportant things (the same problem often persists in his or her private life, please check out books and videos of the Austrian Psychiatrist Raphael Bonelli). Burn out can be a consequence of this kind of habit and personality. If you are not a strong activist yourself, this type of management is difficult to deal with. You might need to act like a low pass filter in audio technology: ignore the ripples and squeaks and simply surf the long waves your way.
  5. Management by fear: we get in tough terrain here. Your manager is nice to you, but he or she is governed by fear of losing ground. He will not tell you, but you know. Your company or your team has built the hell of a great asset of things and knowledge during the last few years. You are ahead of the others. You should be proud. But your boss can’t relax, because the house you’ve built needs permanent revision, and your rivals are catching up. Your boss thus wants you to permanently build more stories on top of the roof because he or she is in fear of losing ground relative to competitors. You on the other hand realize that the foundation is slowly collapsing and that you should revise the foundation instead of working on the roof. The reality of today’s long term and big leading institutions is that of a downward moving staircase: you have to run up like hell to stay level. This is unlike the situation for startup companies. They stand at the bottom of the staircase moving up. There is nothing to lose. What to do: as I said, you should be proud, but your boss is in fear. You can’t be agile because you’re too fat. You can either lose weight (focus on essentials) or split in groups (the ones deal with the foundation and the others with the roof). Don’t be mad at your boss, help him. It is a really difficult situation.

Quarantäne mit Familie, aber wie?

Liebe Kindes- und Erwachsenenschutzbehörde.

Wir haben für unseren Sohn vom Kantonsärztlichen Dienst des Kantons Bern eine 10-tägige Quarantäne verordnet bekommen, mit der Bitte “Wenn sie mit weiteren Familienangehörigen zusammenleben, müssen sie sich von diesen isolieren”

Wie sie sich vorstellen können, gestaltet sich dies mit einer 5-köpfigen Familie in einer Wohnung nicht so einfach. Wir sind jetzt etwas in der Zwickmühle zwischen den Anforderungen des Kantonsarztes und unseren Wertevorstellungen, wie wir unsere Kinder behandeln sollten.

Wir haben unseren Sohn nun in einer Kiste im Garten untergebracht, wo er von uns Abstand hält. Wir bringen ihm auch viel Liebe und Schoggi nach draussen. Es wird im Februar schon etwas kalt in der Nacht, aber wir glauben, dass wir damit sowohl die Isolations-Empfehlung des Kantonsarztes wie auch die extravaganten Wünsche von Kindern bestmöglichst erfüllen**.

** für alle diejenigen, die jetzt zum Sorgentelefon greifen wollen: Dieser Blog ist nicht ernst gemeint. Und falls doch: es geht allen gut!

Thermal Insulation using Sheep Wool

There are all-natural thermal insulation materials out there. The Swiss company Fisolan AG is specialized in turning sheep wool into thermal insulation blankets ready to be used to insulate buildings … or commercial aircraft. Unlike glass wool the sheep wool blankets can be handled without health protection measures.

So that is how the Cockpit looked like before:

And after putting the sheep wool blankets:

Maybe a hint for aircraft manufacturers to plan their next zero-fossil-fuel aircraft with a natural insulation like sheep wool from Fisolan AG ?

From old make new …

The COVID-19 lockdown during spring with good weather was the start of a major refurbishing action of all cockpit interior parts. This included removing 2-3 layers of paint by sanding, filling and remodeling broken parts, sanding again, filling scratches, sanding again, painting with primer and with the RAL 7011 (gray) and 9001 (beige) Boeing colors and finishing with matte paint. The interior was finished a few days ago in November 2020 and thus took some time. The thing could now be sold again as a brand new B737-300 cockpit …

Reworking interior parts. Left: before after 30 years of use; middle: after paint removed and while remodeling broken parts; right: finished with RAL 9001 color.

Sanding, scraping off paint in the interior of the Cockpit … and …

… finally finished with almost “living room quality”. Includes an entry carpet and an anti-slip grip cover which would otherwise find its use on a skateboard.

Next in line is piping work for the air conditioning outlets in front of, above and behind the pilots. Then we’ll proceed to thermal insulation (likely with natural sheep wool) and start planning the electrical wiring of cockpit lighting and placement of computers, power supplies and audio equipment. Maybe the design of the minibar will have priority.

4 Apple Varieties on a Single Tree

Planting season has also started (see last post on porcino season). Thanks to Peter Coendet’s professional connection to Glauser’s Bio Baumschule in Noflen (BE) we planted an organically grown apple tree with four varieties of apples on a single tree. Three of them (from left to right Ariwa, Topaz, Opal, Julia is missing) are seen on this picture:

Our last Saturday thus involved digging, planing and a small party around the tree:

We also planted a new row of rasberries (Primalba, Amira and Regina) a grape (Vitis Ferninand Lesseps) and a cornelian cherry (Schönbrunner Gourmet Dirndl):

Porcino Season has startend!

In a place not far away culinaric treasures of nature are growing, waiting to be picked …

Best enjoyed with other treasures oft nature, such as the Kuonen Muscat wine from Salgesch …

Pitot probes and AOA Vanes mounted … Cockpit Minibar to be designed!

Thanks to Nick from the Airline Pilot’s Historical Society the Lufthansa B737-300 shell was outfitted with 4 Pitot Probes and 2 Angle of Attack vanes! Looks professional although these probes will never be used again.

Now to something more serious: I’ve found the perfect location for the Cockpit Minibar: just right to the jump seat there is a niche which perfectly fits a few bottles of Grappa and Vieille Prune as a reward after the heavy work of sim building or after a difficult landing (once the whole thing is finished in 15.75 years from now …):