Wednesday, 02 May 2012 16:48

Hydraulics - a bit more


We are just about done with our hydraulics simulation and our tech consultant Jan, recently completed a video on our IXEG YouTube channel demonstrating some of the features of our simulation. If you haven't seen it yet, we suggest you watch it. There are some other things in our simulation though that Jan did not have time to show in the video so we will just let you know about it here.

Monday, 28 November 2011 00:00

Welcome to the IXEG Blog

We are finally getting our own home. 
Still under construction, but we hope you will visit for updates on our project.

Saturday, 23 January 2016 15:38

Flap Vortices

Short clip of the flap vortices.  Dependant of the weatherconditions 

Saturday, 12 December 2015 19:27

VNAV Preview

Jan takes us for a quick LNAV/VNAV climb explaining some of the FMC functions of the aircraft

Saturday, 14 November 2015 14:41

FMC Route Editing

Tom is showcasing some of the route editing features of the FMC in this video

As release is in sight now, you might want to follow progress on a more day to day basis in the forums;

There we will also try to answer questions you might have regarding the project or the aircraft in general.

Sunday, 06 September 2015 13:58

Final stretch - Progress update

Hi everyone,

This time we don´t have a new video for you, but things keep progressing nonetheless. We are still targeting a release in 2015 - again this is not a promise, but our very urgent desire. So where are we at?

As you all know, the airplane is almost complete, save for some minor 3D items, like the outboard landing lights, movable cabin doors, a moving ouflowvalve vane, and a few more. The bulk of the documentation is also there, but it needs to be formatted into a nice document.

The biggest chunk is still the FMS. We have the PERFormance part working, maintaining weights, takeoff page, approach page, etc. The RTE page and entry of a lateral route already works (as you could see in the latest videos). We are still missing the VNAV calculation, and the PROGgress calculation (estimating times, fuel usage).

Two weeks ago, Tom Kyler, our lead FMS programmer, spent a week at my place in Germany, so we could crunch down on the VNAV part. We had done a similiar session a few months ago, where we worked on the VNAV climb part, now it was time to do the VNAV PTH and SPD descent. So what is VNAV? In a nutshell, VNAV is the vertical path that the plane takes along the lateral route. The climb, cruise, descent and missed approach phases. VNAV is pretty complicated, as the computations try to predict the vertical profile (a non-linear climb), and the descent (mostly an idle-power descent), provides altitude and speed predictions for the waypoints (therefore changing the lateral route again, due to changing turn radii) and heeding several different types of restrictions.

The climb is "fairly" straightforward: The aircraft will climb with maximum climb power to the cruise altitude. It will, however, change airspeed at least three times, and possibly come up against altitude restrictions that delay the climb. All of this can be changed and modified by the pilot, so we need to take that into account as well.

The descent is almost a climb in reverse, but the goal is now to target a three-dimensional spot in space, again changing speeds and descent regimes, ducking under and levelling off for altitude restrictions, taking into account all sorts of influencing factors (wind, weight, etc.).

We also have to provide steering cues for the autopilot to do the right thing - climb while in the climb phase, level off for altitude restrictions and the cruise altitude, follow a three-dimensional path during the VNAV PTH descent, hitting deceleration segments, etc.

It is absolutely mind-boggling - but we are on a good way to get it right! Tom has actually written the code to identify the E/D (end of descent) point correctly and reliably. It is "the last point before the end of route or route discontinuity with an AT altitude restriction". Try to put that into code. Phew.

We hope to have VNAV in testing by early October. The CRZ page and PROG page are mere matters of coding crunch, adding up mileage, divide by groundspeed, multiply with fuel-flow... that kind of thing. Not trivial, but a piece of cake compared to the LNAV and VNAV computations.

I really hope that many of you will exert the effort to understand and use the VNAV functionality of this aircraft - unlike most real-life pilots, who consider the VNAV button a "magic button" where you "never quite know what the airplane will do". :rolleyes:

That´s it for now - you can expect to see more frequent updates here from now on until we relase.

Cheers, Jan

Sunday, 12 April 2015 13:02


Jan takes us from KPHX-KLAX - but as usual not everything goes according to plan....




Monday, 16 March 2015 19:09


As we near our 5th year of development work on the 737, even we have to ask ourselves, when will this get done? why is it taking so long? is it even worth it?


Wednesday, 24 December 2014 11:19

Engine Fire (Part 2)

Jan felt bad for the passengers he left in the sky alone with a single engine and decided to get them home for Christmas

Saturday, 20 December 2014 10:29

Engine Fire

To get you over the Christmas Holidays, Jan put together this short preview video.  No aircraft this year, but we are confident this will be the last xmas you will spend without this in your aircraft folder

Friday, 05 December 2014 21:00

While you are waiting

Jan put together a few video's showing some of the less known systems and features of the aircraft

- Weather radar and rain effects

- Speed protection system

- TR3 disconnect (electrical system)

- Speed trim system

Wednesday, 14 May 2014 16:52



Hi all,

We daily get similar questions from many people about the project.  So we will try to answer a few of the top FAQs.

Saturday, 22 March 2014 15:27


Part 1:  "Cold and dark to power up"

This is a series of videos where Jan, the project technical advisor and professional pilot, walks and talks us through a typical day, in the 737 Classic. 

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