This AC considers the iPad (or any tablet computer) as a Class 1 EFB – this means it’s a portable device that does not rely on aircraft power. More importantly, the AC authorizes you as the pilot-in-command to use a Class 1 EFB as a replacement for paper charts in all phases of flight, provided that:
• the data/charts displayed on the EFB are the functional equivalent of the paper reference material
• the data/charts are current, up-to-date and valid
Both of these should come as common sense. You’ll also want to review FAR 91.21 covering portable electronics in the cockpit, which basically requires you to ensure the EFB doesn’t cause interference with panel-mount avionics. There are no additional regulatory items you need to follow under Part 91 for using electronic charts in lieu of paper charts.
What should be weighing in the back of your mind though is the consideration for some type of secondary or backup reference material. The one thing that paper charts always had going for them is they never fail (unless you consider blowing out the window a possibility). While reliable, any piece of electronic hardware always runs the risk of failure, whether it stems from a power issue or software bug.
Naturally, you should still strongly consider bringing along some type of backup reference, especially when flying IFR. In my opinion, you should selectively carry a few essential backup paper charts, or another electronic device (like a 2nd iPad). Most of the aviation chart applications run on both a tablet and a smartphone, so you could also keep the charts loaded on your phone as well. While viewing the smaller screen of a phone isn’t practical for everyday flying, looking up an ILS frequency or crossing altitude from a chart on an Android phone or iPhone would work out just fine if the primary EFB became unresponsive.
I’ve been flying with an iPad running the ForeFlight app for over a year now in Part 91 turbine and piston operations and it’s been 100 percent reliable. I treat it like a required piece of equipment in the aircraft, ensuring it’s always fully charged and loaded with up-to-date charts. For a VFR flight to an unfamiliar airport, I typically print out a few sheets showing the airport info and taxi diagram as a backup. On IFR flights, I like to print out airport diagrams, and at least one approach to each of the airports I’m planning on using. I’ve never had to use them, but it’s reassuring to know I have a Plan B in case the iPad decides to have a bad day.