ZZZ
The aircraft database in X-1FBO is pretty extensive, you are are seeing a small portion of the active aircraft in a database that includes all 10k plus ICAO codes registered with the International Civil Aviation Organization.
Every so often, especially when you have just come on board with X-1FBO you will find aircraft with the type ZZZZ (ZZZ). This is actually an ICAO Special Designator, a Special Designator is designed to group aircraft that are unique or in the case of ZZZ, have not yet been assigned a Type Designator. We use the ZZZ as a place holder for aircraft, usually imported from your previous system that did not have an aircraft type associated with it. The goal is every time you run across a ZZZ you should update it with the correct Aircraft Type.
Other Special Type Designators
With so many home and kit-built aircraft out there ICAO also has a set of Type Designators we can use for those odd, one-off, or special aircraft types. See the list below:
Type Designator Model Description
ZZZZ Aircraft Type not (yet) assigned a designator
SHIP Airship
BALL Balloon
GLID Glider / Sailplane
ULAC Microlight / Ultralight aircraft
GYRO Microlight / Ultralight Gyro
UHEL Microlight / Ultralight Helicopter
These can be used for aircraft you come across that do not have an ICAO Type Designator that you want to keep in X-1FBO.