iFly GPS Forum

Greg,

Very good points.

Correct me if I am wrong, you would want to use "pressure altitude', not GPS altitude, especially when in the hands of ATC control. You could get into trouble by using GPS Altitude versus Pressure. Alerting at GPS Altitude would not be the best practice.

The iFly is a portable GPS that is to be used as supplementation, not primary navigation, especially IFR. Some of these features are possible, but would promote IFR and worst case IMC navigation on a non-certified device.

Please understand we want to add viable features and many of these very well are, we just have to be careful not to steer pilots into a questionable behavior. I hope this helps.

I hadn't taken it to that level although I do have the VST alarm turned off completely and I do not show either the actual (GPS) altitude or VST instruments in the group I created for Plates.

The iFly actually stores the 'plan altitudes' for a waypoint. My suggestion was to have a smart instrument that only changed to the target waypoint plan altitude upon reaching the TOD (top of descent) calculated based on the aircraft profile (this currently appears as a little black dot on the course line) to get me to the target altitude for the next waypoint by the time it is reached. Adequate to support my vertical flight planning and terrain avoidance.

If you go to the trouble of setting up a flight plan based upon an approach, whether that would result in a chop-and-drop or a steady descent rate between fixes I hadn't thought about (I suppose if you set a lower descent rate and it would switch earlier,higer descent rate more of a chop-and-drop).

I have experimented a couple of times with creating flight plans based on plates but inevitably I'll be coming from a direction that gets me closer to some waypoint on the plan than another and the thing will change waypoints on me due to the iFly's tendency to guess what waypoint is next based on relative poisition rather than waiting until I got within 'x' miles of the target point regardless. For example I'm coming from north of the airport for an approach to Runway 5, so as soon as I get anywhere near the airport (which I intend to overfly) and keep going the iFly immedaitely switches my target waypoint to the airport so all that flight plan entry is wasted at that point anyway.

In summary, the iFly isn't an IFR GPS and I'm very content with just using the IAF as the last waypoint on my flightplan then pulling up the plate to follow along on the video game (for situational awareness).

Perhaps this should be a separate wish-list item but still it does bring back up the issue of having the option to choose between the current 'waypoint guess' logic and the more traditional 'don't switch the waypoint until I get within 'x' miles of it regardless of which one I'm closest too (I think that's much more doable now that we have the 'direct to' button on the flight plan lines). Anyone have thoughts on that one?