Heads Up Guidance system question

[jongibbs]

Hey everyone,. .I have made an award winning freeware heads up guidance system for Microsoft Flight Simulator 2000 and 2002 (for all you jealous FO's out there) based on the one Southwest Airlines Uses. . .For any one that uses the Flight Dynamics Heads Up Guidance system in the 737, in PRI mode, if one is doing an approach in PRI mode, does the radio altitude show above the HSI or not. Also how often does the system update the track information? One more question: Since the 737-700 has a GPS reciever, does the HUD use it for navigation data instead of the IRS?. .Thanks for your help,. .Jon Gibbs. .p.S. the hud is availible at <a href="http://www.alliedfsgroup.com" target="_blank">www.alliedfsgroup.com</a> Also if any pilot interested in testing a new version of my HGS or my version of the 737-700 insturment panel for flight simulator please send me an email. [email protected]

[jbc2001]

GPS is only used for lateral nav as a sensor for the FMS (at least until WAAS or LAAS is finally here). The HGS uses a control law primarily derived from the IRU and the ILS with the Radio Altimeter providing checkpoints at which the various sensors must agree with increasing accuracy.

[TR4A]

I answered this also in the Questions section.

The Radar Altitude value is removed from the display at 1500 feet when ascending and is again displayed at 1400 feet when descending. If the Flight Path sysmbol is not displayed, the Radar Altitude is displayed relative to the Aircraft Reference sysmbol.

The digital value is displayed in flight in ten foot increments between 50 and 1500 feet, five foot increments between 10 and 50 feet and one foot increments between -20 and 10 feet. Radar Altitude is not displayed on the ground.