EFB's tend to cause problems on the Oral, because they don't tell you what they are doing in the back ground. Trying to explain navigation basics or even finding basic navigation information using an EFB can be challenging. If you can do it, it shows an exceptional understanding of the Navigation principles but is often requires a better understand than what the ACS or most examiners require.
A couple gotcha type questions that are easy on paper and can be challenging on some EFB's.
What is the True Course from the airport to the corner of this lake (not a defined waypoint)?
What will be the wind correction angle when flying to the corner of that lake?
What would the correction angle be if the winds were from x degrees at x knots?
Is that course shown on a your EFB a Magnetic or True course?
I recently observed and applicant plan his cross country using a paper navigation log.
That is good and I recommend it because it make you think about all the components of navigation that go in to getting a magnetic heading to fly.
But he used his EFB to get the True Course, but didn't realize the EFB was showing him Magnetic course. So then of course he applied the Magnetic variation to that course again, in fact doubling the error (30 degrees now) .
Also know how to read a sectional chart.
pick a random airport and just read every little mark, letter, asterisk of the data and explain what it means. Just read the data block, don't skip around.
On the chart especially around airports you should be able to describe what every marking is. Use of the legend will only be allowed for a few items. This is in part due to how hard it is to find legends on your EFB.
know your airspace, cloud clearances, and required equipment in each airspace.
launch an imaginary rocket at a give point on the map and describe what kind of airspace, equipment and cloud clearance requirement are at each altitude above that airspace. The more complex the airspace the better.
know your minimum required equipment. Tomato Flames. Hint it may help some people to draw an instrument panel. Mark which instruments are electric, which are Vacuum, which require a Pitot system and and which require a static system. Mark on your drawing which are required instruments. Maybe draw and extra little block of instruments that are required in some airplanes, but not yours. If you can draw this from memory you will do fine on the oral.
Know how to explain an Minimum Equipment list. Hint, it has nothing to do with Minimum Equipment.
It may have have sounded like was was bashing EFB's, I wasn't, just pointing out limitations when used during the oral. I highly recommend using one if you are familiar with it during the flight portion of the practical. In fact depending on the airplane you use, it may be required. Use all the tools you have available but always plan for any one tool to fail.
Good luck on you check ride.
Brian
CFIIG/ASEL
