by Michael Bryant » Thu Apr 06, 2017 5:09 pm
Alan,
I am a bit puzzled. You say you want the iPad for a backup, but then say you have everything you need on your primaries. To me, a backup is there in case you loose the primaries. I think you need to ask yourself what you want to back up to help make a decision.
As far what you need to use Foreflight on an iPad, it depends on which model you purchased. If the iPad you purchased has cellular, it's built-in GPS will provide you with reasonable accuracy inflight with no need for an external GPS or antenna. If the iPad you purchased has Wi-Fi only (read no cellular capabilities), you will need an external GPS such as the Stratus, Stratux, or Bad Elf to provide the iPad with position information. To see ADS-B In information, something has to provide that to the iPad via Bluetooth or Wi-Fi. Bluetooth will only connect to one device, while Wi-Fi will connect to multiple devices. Which GPS you choose depends on how much back-up you desire, and how many devices will use the output, as some now provide ADS-B In as well as GPS position.
Whether you also need power for the iPad depends on how you will use it. It sounds like you would only use it as a backup, so most likely it would be asleep until needed. In that case, the iPads battery should be sufficient. If you will use it continuously, a panel mount USB charger or a charging brick (spare battery to charge the iPad) would be needed for longer flights. We started with the brick and added panel mount chargers when we added ADS-B out.
For our aircraft, we have a GNC-300XL, an IFR GPS/comm. It has no VHF nav so it is for non-precision GPS approaches only and has a small, black on green moving map display but no way to display Wx or traffic. The moving map is very small and difficult to use in flight. We use the iPad to provide a more usable moving map display. We use the Bluetooth output from our GTX-345 WAAS to display ADS-B In info such as traffic and Wx on the iPad. The GTX-345 also has an AHRS, so we can use the horizon and synthetic features in Foreflight for added situational awareness. Also, we do fly IFR and can use it in an emergency to help keep the recognize a vacuum failure and then clean side up.
To back up the GTX-345 ADS-B In information, we also have a Stratus 2. It has the same GPS, ADS-B In, and AHRS as the GTX-345 providing backup for all the GTX-345 functions except the Mode-S transponder.
We have a Mid-Continent MD-93 digital clock with 2 USB ports on the left side of the panel for charging the iPad and Stratus, because we usually are running both constantly. We also replaced the cigarette lighter on the right side of the panel with a powerport to add 2 more USB chargers (my partner and I both have iPads minis. If we fly together, we like to follow along with our own iPad from the right seat. We can also keep a phone charged. The fact that there are 2 USB ports on the left and right sides of the panel reduces the tangle of wires as well.
Hope that helps.
Michael