Hi, I've been working on some smaller issues with the Ground Proximity Warning System. Is someone currently maintaining or actively working on the mk-viii module, or is any help wanted?
* The "Bank angle!" warning wasn't working. It's because the module reads the planes angle from /instrumentation/attitude-indicator/indicated-roll-deg However, with the planes I have tested (B737, B747, B777, A380) this value is never updated (value is constant at 40 degrees). This sometimes triggers an incorrect "Bank angle!" warning (at lower heights, where 40 degrees is outside the allowed range). Changing the input property to /orientation/roll-deg made the feature work for me. I'm not familiar with this attitude indicator. Is anything broken so the property above isn't updated? Or could we just change the module's input property? Alternatively, a configuration property could be added, so the location of the input property isn't hard-wired in the sources and could be configured for every plane... * The "Too low - flaps!" and "Too low - gear!" warnings are issued too late. The planes I have tested did not select appropriate mk-viii configuration modes. The default mode only matches small/light aircraft. Issuing warnings only when below 150ft agl and below 148 knots (with no flaps and no gear!) certainly seems a little late for an A380/B747 ;-) . Unfortunately, the manuals (see http://wiki.flightgear.org/index.php/Ground_proximity_warning_system and http://www.mail-archive.com/flightgear-devel@lists.sourceforge.net/msg01902/mk-viii-manual.tgz ) do not document the available configuration modes, e.g. for the different supported aircraft types. You can only see them in the sources - but documentation is also missing there. Maybe this explains why few (maybe none) of the planes properly configure it... ;-) * It's (almost) impossible to avoid "Glide slope! Glide slope!" call outs in the last few moments before touchdown. The instruments also show the glide slope is lost just before touchdown. I guess it's because there is no ILS once the plane is beyond the transmitter and above the runway. So it's probably better if the EGPWS suppressed glide slope warnings in the very final moments. * With larger aircraft only the height call outs down to "20" feet are triggered, the "10" feet call out is never issued. This seems to be a problem with the radio altimeter in general. The plane's gear already touches the ground before the radio altimeter is at 10ft agl. The steeper the plane's angle of attack - the sooner its gear touches ground... And it's not just a problem with the plane's angle. For some planes the radio altimeter shows heights of 2-10ft even when taxiing. According to http://www.pacificavionics.com/viewPage.php?pgID=84 : "A properly calibrated radio altimeter indicates zero feet at the moment the aircraft contacts ground. This requires taking into account the height of the antennas above ground (at touchdown) [...] After touchdown, the weight of the aircraft may cause the radio altimeter to read slightly below ground level". So I guess the radio altimeter isn't perfectly accurate right now - or are there already configuration settings to tune/adapt the altimeter to a specific plane? Maybe that's where the problem is... If you want to test the mk-viii warnings yourself, you'll need the latest GIT and probably also two additional patches from the bug tracker (issues #98, #139). Thorsten ------------------------------------------------------------------------------ This SF.net email is sponsored by Sprint What will you do first with EVO, the first 4G phone? Visit sprint.com/first -- http://p.sf.net/sfu/sprint-com-first _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
