* Increase goto altitude accuracy (ALT xyz)
* Implement weather subsystem (use existing stubs)
* Rewrite command parsing
* Implement Conflict Alert (CA; conflicting trajectories checker)
* Implement Minimum Safe Altitude Warning (MSAW; plane flying too low)
* Implement System Coordination (SYSCO; negotiate the release of flights from sector to sector)
* Implement Area Penetration Warning (APW; aircraft in restricted area warning)
* Implement Arrival and Departure manager
* Implement communication breakdown
* Implement emergency situations
* Implement nav beacons
	* ILS
	* VOR