TFDi Design 717: IRS and MCDUs

Our first post under our new brand will be a fun one. Today, we’ll go into more detail about where we’re at on the FMS and navigational equipment.

 

MCDU and Flight Management System

717_irs_and_mcdus_1

Yes, the keyboard has been disabled while we’re still working on the FMS. There are three main pieces – navigation, performance, and miscellaneous (everything not covered by the first two). We’ve made solid progress in fractions of the time it traditionally takes, which is music to all of our ears. As of now, the flight planning and navigation portion of the flight computer is mostly complete. Basic planning such as departure airport and arrival airport are already complete, and terminal procedures (SIDs fully, STARs partially), airways, and direct legs are functional. We’ll be cleaning up a few areas of concern and implementing the last of the features on that front.

I’m sure you’re wondering how we’ve made such progress without an in-sim keyboard. We build all of our technology in a notoriously modular fashion – this means we are able to plug and play components in a matter of minutes. For those of you with coding background, our modularity extends to the point that installing the electrical system, for example, consisted of adding a call to “execute_electrical_system();” to our main system function. Once installed, it reads from the rest of the aircraft’s systems and populates them with information about the electrical system. What this means for the 717 is that, when more complete, we’ll install our extensible and configurable “FlightManagementSystem” module to the aircraft and hook it up to the screen. Until then, we’re developing it in a sandbox project where testing and changes are infinitely easier (this is part of how we optimized the process).

 

Navigation Data

We had intended to use Aerosoft’s NavDataPro for our navigation data source. Since that decision was originally made, we were finally able to get in touch with Navigraph (the fault was ours – we had reached out to them via the wrong venue and our message got lost). Since then, they’ve been equally as supportive and friendly as Aerosoft. Additionally, Navigraph has provided us with a navigation data format that has worked very well with our FMS platform and that has made development more efficient. Our plan is to work with Aerosoft to unify the formats, but we can’t officially confirm whether or not we’ll be able to support NavDataPro.

 

IRS and GNSS

Recently, we have been researching inertial navigation systems (IRSs) and the Global Navigation Satellite System (GNSS). These two concepts┬áplay major roles in providing the 717 its navigation and gyroscopic (pitch, bank, heading, etc.) information. We’re working on creating an IRS that will drift, over time, if not updated by other systems and a GNSS unit that reports┬árealistically accurate positions. As well, we’re working on isolating both on and off-side air data and inertial reference units to bring function to the gusset panel. We have mapped out and begun coding modular IRS and GNSS systems to install into the 717 – that, and its implications, will fit nicely into our next article. The displays are prepared to accept IRS input, however, and our air data computer sensor simulation will integrate nicely.

717_irs_and_mcdus_2

 

The Immediate Future

We’ll be posting more soon, as there are other developments happening that we haven’t covered in this article (hint, there isn’t an INOP sticker on DU2 and DU4 anymore), but we wanted to leave off on this. We’ve confirmed that this is the year of the 717 – it will be released in 2016. When, exactly, we can’t confirm, of course, but it’s safe to say that the majority of the hurdles that were mystifying our date estimates, such as the autopilot, FMS, and some of our unnamed but exciting features, have all progressed better than expected. We’re at a very good place.

Posted in News.

Collin Biedenkapp

I am the lead programmer at TFDi Design.