Free Flight, Free Speech

Okay, that's wierd...

It works fine:

http://prntscr.com/erj5v9

Everything updates fine as well.

Note that the plane doesn't know how fast it needs to descend to meet the restriction yet. So it might miss by a bit.

But it appear to work as I intended. Are you sure the ITAF Dialog altitude was set lower than FL340, and that the aircraft was direct to NARGO? 18ish miles out, he starts descending as he should, and he crosses NARGO just about levelling off at FL281. Then 36nm from RESTU, he goes down again, but he didn't meet the restriction. Once I implement the system which tells the VNAV his optimum descent profile, then I can make it hit the altitudes 100% of the time. But it should go down correctly.

Increasing speed in SPD DES or VNAV SPD modes will increase descent rate. It does Speed by PITCH, as the ITAF box shows PITCH in the speed box. In the MD-88/MD-90, the best descent speed is about 290kts, or mach 0.70, whichever is lower.

I found a small bug where VNAV doesn't deactivate the Hold logic when it switches out of VNAV mode to SPD DES. I'll fix that right now.

Alt hold is a little rough from descending too, I'll have a look at that.

Josh

Okay, I've pushed the bugfix update. It should be all working now.

Bye,
Josh

Retested, and the plane now does the descending steps very nicely. The distance from the waypoints where descent starts is calculated quite accurately. arrival at the fl of the waypoint is just about 5 miles early. Being down a bit early is good, because being to high over the waypoint would be bad.

Kind regards, Vincent

Vincent,
Wonderful! Good to know!

Thanks,
Josh

717 and A320Family now available for beta testing.

OK I've updated all the ITAF VNAV equipped aircraft with the proper PFD annunciations. Even the MD-88/90 non EFD where the FMA isn't working yet. So when I do make it work, the annunciations are correct. I did not yet add the VNAV arm annunciation.

EXCEPTION: KC-137R. I need to change more code before the VNAV stuff shows up there properly. For now, it will just show "VNAV", as it grabs it's Annunciations right from the ITAF GUI Dialog.

OK Found some bugs:

* Fixed: Roll Flight Director does not work properly in T/O, ALIGN, or LVL modes
* Fixed: T/O LVL Roll mode does not engage properly
* Fixed: VNAV sometimes engaging, where VNAV calculation is not possible
* Fixed: VNAV disregarding current altitude, when setting CLB/DES/XX mode, if the previous
waypoint had no altitude restrection

From the Changelog of ITAF 170, not yet available.

Once the fixes have been tested, I will push Build 170.

OK:
Build 170 is out to all the test aircraft:

URGENT testing needed, as I don't have enough time at the moment.

Thanks,
Josh

All,
I worked very hard with my Physics/Math Professor Grandfather and we have now created ETA system for calculation for waypoints, and a decent rate calculation for VNAV system, and even some FMS Speed predictions.

I will begin programming the formulas soon, and I did some tests in FGFS with him, and the manual calculations, and manual inputs to the AP, and it worked just fine. So now I just need to automate everything so that the VNAV system can do it all on it's own. I'm very excited to get this done!

Best Regards,
Josh

Hi It0uchpods,

I noticed you try to calculate the top of descent nearest to the waypoint, and then descend as fast as the plane can. Another more smoother approach could be to calculate the necessary descent rate between two waypoints, and also end at the right altitude.

So e.g. a waypoint at fl 350 and the next fl 300 at 20 miles apart, you wait till 10 miles before the next and then descend fast. My suggestion is to start descent at the first waypoint at a much lower rate.

Well, just an idea this is.

Kind regards, Vincent