1. ACAS = Airborne collision avoidance system
2. ACC = Area control center or area control
3. ADF = Automatic direction finding equipment
4. ADGS = Aircraft Docking Guidance System
5. ADIZ = Air defense identification zone (to be pronounced “ADIZ”)
6. AFS = Aeronautical fixed service
7. AFTN = Aeronautical fixed telecommunication network
8. APAPI = Abbreviated precision approach path indicator
9. AIC = Aeronautical information circular
10. AIP = Aeronautical information publication
11. AIS = Aeronautical information services
12. AMS = Aeronautical mobile service
13. AMSC = Aeronautical Message Switching Centre
14. AMOS = Automatic meteorological abbreviation system
15. AOC = Aerodrome obstacle chart
16. APP = Approach control office or approach control or approach control service
17. ARO = Air traffic services reporting office
18. ATA = Actual time of arrival
19. ATC = Air traffic control (in general)
20. ATD = Actual time of departure
21. ATIS = Automatic Terminal Information Service
22. AIRAC = Aeronautical information regulation and control
23. ATM = Air traffic management
24. ATN = Aeronautical telecommunication network
25. ATS = Air traffic service
26. ATZ = Aerodrome traffic Zone
27. CAT = Category or clear air turbulance
28. CNS = Communications, navigation and surveillance
29. COM = Communication
30. CTA = Control area
31. CTR = Control zone
32. DA = Decesion altitude
33. DS = Direct speech
34. DGAC = Directorate General of Air Communication
35. DME = Distance measuring equipment
36. DVOR = Doppler VOR
37. EAT = Expected approach time
38. EET = Estimated elapsed time
39. ELBA = Emergency location beacon – aircraft
40. EOBT = Estimate off-block time
41 ETA = Estimated time of arrival or estimating arrival
42. ETD = Estimate time of departure or estimating departured
43. FA = Flight approval
44. FIC = Flight information Centre
45. FIR = Flight information Region
46. FIS = Flight Information Service
47. FISA = Automated flight information service
48. FL = Flight level
49. GCA = Ground Controlled approach system or ground controlled approach
50. GNSS = Global navigation satellite system
51. GP = Glide path
52. GPS = Global positioning system
53. HF = High frequency (3000 to 30,000 KHz)
54. HIAL = High intensity approach and runway lighting
55. IAF = Indonesia air force
56. ICAO = International civil aviation organization
57. IDENT = Identification
58. IFR = Instrument flight rules
59 ILS = Instrument landing system
60. IMC = Instrument meteorological conditions
61. INS = Inertial Navigation system
62. LC = Landing chart
63. LDA = Landing distance available
64. LF = Low frequency (30 to 300 KHz)
65. LLZ = Localizer
66. LORAN = LORAN (Long range air navigation System)
67. MWARA = Major world air route area
68. NAV = Navigation
69. NDB = Non-directional beacon
70. NM = Nautical miles
71. NOTAM = Notice to Airmen
72. PALS = Precision approach lighting system (specipy category)
73. PAPI = Precision approach path indicator
74. PIB = Pre-flight information bulletin
75. PSR = Primary surveillance radar
76. RADAR = Radio detection and ranging
77. RAF = Royal air force
78. RCC = Rescue co-ordination centre
79. RDARA = Regional domestic air route area
80. RLLS = Runway lead-in lighting system (to be pronounce “AR-NAV”)
81. RNAV = Area navigation
82. RPI = Radar position indication
83. RVR = Runway visual range
84. SAR = Search and Rescue
85. SELCAL = Selective calling system
86. SID = Standard Instrument Departure
87. SMC = Surface movement control
88. SMR = Surface movement radar
89. SSR = Secondary surveillance radar
90. STAR = Standard Instrument arrival
91. TMA = Terminal control area
92. TODA = Take-off distance available
93. TORA = Take-off run available
94. TWR = Aerodrome control tower or aerodrome control
95. UHF = Ultra high frequency (300 to 3000 MHz)
96. UIR = Upper flight information region
97. UTA = Upper control area
98. VFR = Visual flight rules
99. VHF = Very high frequency
100. VLF = Very low frequency (3 to 30 MHz)
101. VOR = VHF omnidirectional radio range
102. VORTAC= VOR and TACAN combination
103. VSCS = Voice Switching and Control System
104. WAC = World Aeronautical Chart ICAO 1:1,000.000
105. WDI = Wind direction indicator