iFly GPS Forum

Great question. Here is an overview of two of the more complex features of this release. Our manual edits are in the works, and I'll have full documentation on these features in a few weeks.

Thanks,
Walter

“Altitude Planning” or "Vertical Speed" feature
There are two new instruments:

1. “Vert. Speed”. This displays your vertical speed, in Feet per minute, averaged over the prior 5 seconds.
2. “VST”. Short for “Vertical Speed to Target”. This instrument shows the required ascent / descent rate required to reach your target altitude. Your target altitude can be set manually as part of your flight plan. When you are approaching an airport in your plan, the target altitude is assumed to be pattern altitude x miles from the airport.

You should add these instruments to your display using the Customize Instruments mode. The VST instrument will only show up when a climb is required, or when the descent requirement is greater than a given amount. Goto “Menu / Setup / Alerts and Warnings / Vertical Speed to Target Settings” to modify the settings associated with the VST instrument.

So, here is a typical scenario: You are approaching an airport. You have setup the VST settings to have you arrive at pattern altitude 1 NM from the airport. Based on your speed and altitude, as you approach the airport, the descent rate required to reach this altitude is constantly changing; the closer you are to the airport, the steeper the descent requirements. The iFly lets you configure the threshold when the VST instrument will appear, the default is -350 FPM. So when your required descent rate exceeds -350fpm, the VST instrument will appear and a tone will sound indicating it’s time to begin your descent. To fly a steady descent you should attempt to match the “Vert. Speed” instrument the value shown in the “VST” instrument.

You can also plan an ad-hoc descent or climb. If you touch the screen, select “Add Waypoint”, then select “Lat/Lon, Specific Altitude”. You will be prompted to enter an altitude at the selected lat/lon. The VST instrument will show you the required value to reach the desired altitude.

You may also define altitudes for non-airport waypoints in your flight plan. Touch the “Flight Plan” button, select “Opt” on the desired waypoint, then select “Set Altitude”

To play with this feature prior to flight, we’ve added an “Altitude” option to the simulator controls. Enter simulation mode by touching “Menu” / “About” / “GPS Information”, then “Begin Simulation”. The control allows you to steer left/right, change speed, and change your altitude. Each touch of the “Altitude” arrows will change your Vertical Speed by 100 fpm. So if you touch the up arrow 10 times, you will be climbing at 1000 fpm. You should make sure the Vert. Speed instrument is being shown before playing with this feature.

**Please note, a pressure altimeter shows the altitude based on the air pressure recorded at ground level. A GPS shows actual altitude above sea level. These altitudes can vary by as much as 10%. If there is a discrepancy, you should always use your pressure / indicated altitude as the correct source, not the GPS altitude.

Airspace Warning feature:
The iFly will now, optionally, pop an alert when you are approaching an airport airspace, SUA, or TFR. You can control when and if these alerts pop for each airspace type. Do this by touching Menu / Setup / Alerts and Warnings / Airspace Alerts. The following options are available under this menu:

1) Types: Let’s you select the airspace types that will pop an alert box or show an alert button. The Alert Button is basically an unobtrusive alert; you get a tone and the button will light up, but you must push the button to get details. The Popup Message option will cause a large message box to appear.

2) Altitude Buffer: Used to define the altitude buffer for an airspace. If your GPS altitude is within the buffer distance of the airspace’s floor or ceiling, an alert will pop. If you are above or below the airspace by more than the buffer, an alert will not pop.

3) Alert Distance: Defines how far out an alert message should pop. Distance can be defined in terms of distance from the airspace, or time to intercept the airspace.

When an airspace alert pops up, the dialog will show details of the airspace you are approaching, and an estimated number of minutes until arrival. You will also have the option to “Acknowledge” the airspace, or “Inhibit” the message for this specific airspace. This is the difference in these options:

If you touch “Acknowledge”, the warning will go away and will not reappear if your course never changes; you will fly into the airspace without being warned again. But, if you change course so you are no longer intercepting the airspace, then turn back to an intercepting course – the warning will pop again. So for example, if you are flying in circles next to an airspace, the warning will keep popping up.

If you touch “Inhibit”, the warning will go away for a set number of minutes, then the warning will pop again if you are still approaching the airspace. For example, you are approaching a Class B, 10 minutes out you are warned. You can select “Inhibit” / “5 Minutes”, the message will pop again in 5 minutes if you are still approaching the airspace.

“Inhibit” also has the effect of ensuring a warning does not re-pop for the specified number of minutes. In other words, you can perform circles next to a class B and if you “Inhibit” a warning rather than “Acknowledge”, the message will not pop for the selected time frame. “Entire Flight” is also an option in the Inhibit menu, so you can basically disable the warning for a specific airspace for an entire flight.

David, that would work. Also the iFly will work with a USB hub. So you can listen to music, drive an autopilot, and use other future features that will integrate via this port, ie ADS/B. Depending on your mounting situation this option could also help with cable management in the future: Picture one cable from the USB port to a hub stuck on your panel somewhere.

-Walter