> For the complete documentation index, see [llms.txt](https://arcsky.gitbook.io/x55-public-knowledge-base/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://arcsky.gitbook.io/x55-public-knowledge-base/aircraft-description-and-functions.md).

# Aircraft Description & Functions

- [System Overview](https://arcsky.gitbook.io/x55-public-knowledge-base/aircraft-description-and-functions/system-overview.md)
- [Flight Modes](https://arcsky.gitbook.io/x55-public-knowledge-base/aircraft-description-and-functions/flight-modes.md)
- [Failsafe](https://arcsky.gitbook.io/x55-public-knowledge-base/aircraft-description-and-functions/failsafe.md): The X55 has a number of failsafe mechanisms to ease X55 recovery/prevent complete loss in the event that the X55 control is lost. The main failsafe topics are listed below. The failsafe triggers and a
- [Herelink Controller](https://arcsky.gitbook.io/x55-public-knowledge-base/aircraft-description-and-functions/herelink-controller.md)
- [Flight Control Software](https://arcsky.gitbook.io/x55-public-knowledge-base/aircraft-description-and-functions/flight-control-software.md): Flight control software is used with the X55 for mission planning, to update parameters, and to adjust settings of the aircraft.
- [QGC (QGroundControl) and Arcsky Control](https://arcsky.gitbook.io/x55-public-knowledge-base/aircraft-description-and-functions/flight-control-software/qgc-qgroundcontrol-and-arcsky-control.md)
- [Mission Planner (PC only)](https://arcsky.gitbook.io/x55-public-knowledge-base/aircraft-description-and-functions/flight-control-software/mission-planner-pc-only.md)