Tuesday, August 25, 2015






Here's the latest version of Precious Metal's paint job, courtesy of Gary Brown.

Also, I just added some propeller inflow code to JSBSim.  This should tone down the thrust a bit at low speeds, and should result in more realistic behavior.

New Precious Metal liveries

Gary Brown has made four liveries for the Precious Metal racer, covering many years of the airplane's ownership history.  These are true works of art, so check it out.  Note that there is no livery switching here - each livery is a different model name.

The airplane puts out a lot of thrust at low speed, and this is probably due to a lack of propeller inflow modeling.  I'll take a look at inflow, and maybe the JSBSim propeller code can be updated.

Monday, August 24, 2015

F-106, video of falcon launch

Here's a video of a launch of an AIM-4 Falcon from the F-106.  Captured using ffmpeg.

video

In case it doesn't show up, here's a link to the video file:
https://dl.dropboxusercontent.com/u/12562954/F-106.mpg

Thursday, August 20, 2015

F-106 Update

The new F-106 version has a lot of animation for the missle firing sequence - doors open, missles descend, missle fires, missle carrier retracts, doors close.  So far only the forward-left missle fires.  Research was tough on this mod, since the door arrangement was changed when the gun was installed.

Also new are some tailhook fairings, data link antennas, windscreen supports,  semi-transparent windscreen structure, gun gas purge inlet, fuel gauge with refueling light, fixes to position lights, fixed elevon mixer, and lots of work on the missle bay.

Friday, July 31, 2015

Bell P-39D Airacobra

A new project is posted at the Hangar - a P-39D.  This was originally a model made by Akemi Misoguchi for CFS2.

Wednesday, July 15, 2015

Tailwheel lock

I'm in the process of adding tailwheel locks to all the tail draggers.  I'm using "Ctrl-L" to toggle the lock.  By default the lock will be on at startup for all tail draggers.  After landing be sure to release the lock before taxiing.  Models uploaded today are the :  P-26A, A-1H and AD-6.

Wednesday, July 1, 2015

Sound updates

Some sound files are being brought up-to-date.  Some of the configuration items, like and were wrong.  Also, I've added a new channel to the ADC which models a 3-gear squat switch with a two second delay.  This should solve once and for all the problems I've had getting the "tire squeal" sound to play at the right time.  

Edit:  The sound problem is solved on runways, but not on the carrier.  The problem is that airplanes using the JSBSim FDM no longer initialize properly on the carrier.

Wednesday, June 24, 2015

Density Altitude

It's been a long time since density altitude appeared in JSBSim, so I've replaced it with a system called "ADC", which stands for Air Data Computer.  So far all the ADC does is take air density (rho) as an input and looks up a corresponding altitude, resulting in a density altitude figure.  This value is then used by the turbine engine thrust lookup tables.  This allows the turbine engine output to be effected by non-standard air temperature.

Airplanes modified so far are the F-105, A-3D, A-7E and F-4C.

Saturday, June 6, 2015

New Afterburner Effect

Thanks to FG dev Thorsten we now have great looking afterburner plumes in FG.  I've added this to the newest DavePack, version 5.2.  I also uploaded to the hangar one model that has been modified to use it, the F-4C version 1.0.  Here's an earlier test with the F-105 (not uploaded yet).


The DavePack version is a one-size-fits-all plume, using a new 12 sided bounding cylinder to keep the plume within the nozzle.  The plume is added to the model in the usual way, in the model's XML wrapper file.  You just specify the XYZ locations and any tilt (i.e. pitch-deg).

I'm running this in FG 3.5.  I don't know if will run in earlier versions.  I hope it doesn't crash earlier versions.  If it doesn't work for you just comment out the new afterburners in the XML file and uncomment the old ones.

UPDATE:  Added two other plumes, a smaller one for smaller engines, and a new full sized plume with a different shape to make it easier to fit it into the nozzle hole.  DavePack updated to version 5.3.

UPDATE, PART DEUX:  Since this effect is so new I've added code that will use the old-style burners on FlightGear 3.4.x or earlier.  You'll need 3.5.x or newer to see the new burners.  DavePack updated to version 5.4.  So far only the F-4N has the conditional burner code.

UPDATE, PART TROIS:  The F-4C, F-4D, and F-4E now have the conditional burners.

Thursday, January 8, 2015

Some JSBSim Updates

I've added some new things to JSBSim.  The first is a new FDM configuration item called pitot-angle that goes in the metrics section.  This will make a slight change in indicated airspeed, as the speed is now calculated using a pitot coordinate frame rather than the body frame.  In most airplanes the pitot frame will be rotated nose-low by a few degrees from the body frame.  About -4 degrees is a good estimate.

The second change is the air refueling onload rate is now configurable.  It used to be a hard-coded 6000 lbs/min, which is OK for cargo/bomber type aircraft but too much for fighter types, which onload in the 1000-2000 lbs/min range.