| ASR |                             string
 |                                         Airport surveillance radar (ASR) |         
                              | 
                            
        
                            | ARA |                             string
 |                                         Airborne radar approach (ARA) |         
                              | 
                            
        
                            | ARSR |                             string
 |                                         Air Route Surveillance Radar |         
                              | 
                            
        
                            | PAR |                             string
 |                                         Precision Approach Radar |         
                              | 
                            
        
                            | ILS |                             string
 |                                         Instrument landing system (ILS) |         
                              | 
                            
        
                            | ILS_DME |                             string
 |                                         Instrument landing system with Direction measuring equipment |         
                              | 
                            
        
                            | ILS_PRM |                             string
 |                                         Instrument landing system using a Precision runway monitor |         
                              | 
                            
        
                            | LDA |                             string
 |                                         Localizer Type Directional Aid |         
                              | 
                            
        
                            | LDA_DME |                             string
 |                                         Localizer Type Directional Aid with Distance Measuring Equipment. |         
                              | 
                            
        
                            | LOC |                             string
 |                                         Localizer |         
                              | 
                            
        
                            | LOC_BC |                             string
 |                                         Localizer Back course |         
                              | 
                            
        
                            | LOC_DME |                             string
 |                                         Localizer with Distance Measuring Equipment |         
                              | 
                            
        
                            | LOC_DME_BC |                             string
 |                                         Localizer with Distance Measuring Equipment back course |         
                              | 
                            
        
                            | MLS |                             string
 |                                         Microwave Landing System |         
                              | 
                            
        
                            | MLS_DME |                             string
 |                                         Microwave Landing System with Distance Measuring Equipment. |         
                              | 
                            
        
                            | NDB |                             string
 |                                         Non-Directional Beacon. |         
                              | 
                            
        
                            | NDB_DME |                             string
 |                                         Non-Directional Beacon with Distance Measuring Equipment. |         
                              | 
                            
        
                            | SDF |                             string
 |                                         Simplified Directional Facility. |         
                              | 
                            
        
                            | TLS |                             string
 |                                         Transponder Landing System. |         
                              | 
                            
        
                            | VOR |                             string
 |                                         VHF Omnidirectional Radio |         
                              | 
                            
        
                            | VOR_DME |                             string
 |                                         VHF Omnidirectional Radio with Distance Measuring Equipment. |         
                              | 
                            
        
                            | TACAN |                             string
 |                                         UHF Tactical Air Navigation beacon |         
                              | 
                            
        
                            | VORTAC |                             string
 |                                         VHF Omnidirectional Radio with UHF Tactical Air Navigation beacon |         
                              | 
                            
        
                            | DME |                             string
 |                                         Distance Measuring Equipment |         
                              | 
                            
        
                            | DME_DME |                             string
 |                                         Distance Measuring Equipment with Distance Measuring Equipment. |         
                              | 
                            
        
                            | RNP |                             string
 |                                         Required Navigation Performance. |         
                              | 
                            
        
                            | GPS |                             string
 |                                         Global Positioning System |         
                              | 
                            
        
                            | GLONASS |                             string
 |                                         GLONASS |         
                              | 
                            
        
                            | GALILEO |                             string
 |                                         GALILEO |         
                              | 
                            
        
                            | RNAV |                             string
 |                                         Area Navigation |         
                              | 
                            
        
                            | IGS |                             string
 |                                         Instrument Guidance System |         
                              | 
                            
        
                            | OTHER |                             string
 |                                         Other |         
                              |