I bought the Carenado Phenom 100 which has a Navigraph expansion pack. What is an expansion pack? Doesn't the plane come with a Navigraph database already? Since it's on sale I'm wondering if I should buy the expansion pack. Thank you.

I think that the Prodigy system on the Phenom 100 which is based on Carenado’s G1000 just uses a basic FSX/P3D flight plan and is very limited in its scope. The expansion pack adds a Navigraph database from 2013 and is supposed to confer additional functionality including SIDS and STARS but I think that it is still constrained by the inherent limitations of the Carenado G1000. 

A far better, but somewhat more expensive option, would be to buy one of the commercially available Garmin GTN750 addons (Flight1 or RXP) which can be used not only with the Phenom but also with other add-on aircraft and are functionally very capable. There are actually freeware modifications available to incorporate the GTN750 into the VC panel of the Phenom 100 as well as a number of other aircraft panels and indeed some Carenado/ Alabeo aircraft include the option to include the GTN750 in the panel if you own it. However it can also be opened in a 2D pop-up window in any aircraft and will function with the autopilot of most aircraft with a few exceptions.

Bill

Agreed.  The Navigraph Packs for Carenado have been disasters.  Waste of money.

As mentioned, your best bet is the GTN750 from RXP and Mr Pieke's mods for some Carenado/Alabeo offerings.

I should have checked here before buying the item because it was on sale. That being the case, the sale wasn't cheap. Thank you both.