ATIS
Aviation Training and Information System
Automatic Terminal Information Service
Air Traffic Indicator System
Aircraft Traffic Inspection System
VFR
Visual Field Reference
Vertical Flight Regulation
Visual Flight Rules
Vector Following Radar
IFR
Instrument Flight Rules
In-Flight Regulations
Initial Flight Routing
International Flight Reference
ICAO
International Cargo Air Operations
Instrument Control and Operations
Independent Civil Air Operations
International Civil Aviation Organization
ILS
International Light System
Independent Landing Signal
Instrument Landing System
Integrated Landing Standard
SID
Secondary Instrument Display
Station Identification Data
System Integration Design
Standard Instrument Departure
STAR
System Tracking and Radar
Secondary Traffic Area Regulation
Standardized Tracking and Approach Route
Standard Terminal Arrival Route
METAR
Measurement of Aeronautical Runway
Meteorology and Aviation Resource
Mission Event Traffic and Reports
Meteorological Aerodrome Report
NOTAM
Navigation Over Terrain and Maps
Notice of Temporary Airspace Movement
Notice to Airmen
Notification of Air Traffic Management
TCAS
Traffic Collision Avoidance System
Traffic Control Advisory Signal
Tactical Communication and Alert System
Terrain and Cloud Avoidance System
APU
Air Pressure Utility
Aircraft Propulsion Unit
Auxiliary Power Unit
Automatic Pilot Utility
EGPWS
Electronic Ground Procedure Warning Signal
Enhanced Ground Proximity Warning System
Engine Ground Propulsion Warning System
Emergency Ground Power and Weather Station
RVSM
Radar Vertical System Management
Required Vertical Space Monitoring
Real-Time Vertical Safety Measure
Reduced Vertical Separation Minimum
ETOPS
Emergency Takeoff and Operational Protocol System
Extended Twin Operations Procedure Standard
Extended-range Twin-engine Operational Performance Standards
Engine Takeoff Optimization Procedure Standard
MNPS
Multi-Navigation Pilot Specification
Maximum Navigation Performance System
Minimum Navigation Performance Specification
Mandatory Navigation Procedures and Standards
PBN
Performance-Based Navigation
Predictive Beacon Network
Precision-Based Network
Pilot-Based Navigation
