Plane & Pilot
Tuesday, February 8, 2011

FlightPrep ChartBook-S

Daylight-compatible EFB for VFR and IFR

The ChartBook-S is not TSO’d, and thus can’t be used on Part 135 or Part 121 revenue flights. It can legally replace paper charts on Part 91 general aviation flights, but can’t be used as a primary navigation source for IFR operations. According to FAA advisory circular 91-78, Class 1 commercial off-the-shelf EFBs like the ChartBook-S are supposed to be stowed during critical phases of flight (including takeoff, approach and landing). FlightPrep offers several mounting options, including a Velcro strap for the pilot’s leg and a yoke mount. Using either of those turns the ChartBook-S into a Class-2 device that can be legally used during any phase of flight.

I tested the ChartBook-S during a 1.5-hour IFR flight from my home base in Modesto, Calif., to Bakersfield, Calif., 160 miles to the southeast. I used the yoke mount, and found that the unit worked best in a vertical orientation. With some fiddling, I was able to come up with a position that didn’t obscure my flight instruments. Having the aircraft position clearly indicated on the airport diagram was nice, and would be genuinely useful at an unfamiliar airport. After departure, I switched between en route IFR and sectional views, and found the unit quite effective as a functional replacement for my IFR and VFR chart atlases. The ability to quickly switch to a sectional chart display was extremely helpful when weather forced me to change destinations and ATC cleared me for a visual approach under a low cloud deck in marginal visibility.

As the sun went down on my return flight, which began at dusk several days later, I found the ChartBook-S display far too bright. Turning down the backlight as far as it would go helped, but not enough. Ultimately, I turned the unit off and switched to paper charts for the remainder of the flight. This problem isn’t unique to the ChartBook-S. Every off-the-shelf computer we’ve tried in the cockpit has the same problem. ChartCase has a trip kit function that lets you print the charts you expect to use; I could have used that for my return trip with the ChartBook stowed. I also experienced one anomaly: ChartCase distorted its low-altitude en route chart display in the vicinity of Lemoore Naval Air Station (about halfway between Modesto and Bakersfield). I reported this to FlightPrep, and they told me they would get the problem fixed. Aside from that, my overall experience was quite good.

FlightPrep doesn’t provide a full printed manual, though they do have a comprehensive online help system and a quick reference guide. A printed version of the online help is available for $29.95.

Pricing for the ChartBook-S starts at $1,295 for the 64 GB model. Built-in vector data is free, but the raster charts require a subscription, which runs $124 to $299 per year depending on whether you want VFR charts, IFR charts or both. A wide range of accessories are available at additional cost. For more information, visit


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