Alpha Numeric
1 PPS = One Pulse Per Second
1:1 = 1 to 1 relationship 2D = 2 Dimensional 3D = 3 Dimensional 4D = 4 Dimensional
4D FMS = 4 Dimensional Flight Management System
4-MAST = 4-MAST Group
4D-NAV = 4 Dimensional navigation
4DTN = 4D Trajectory Negotiation
5-STRSSG = 5 States Route Structure Steering Group
5ST-RSG = 5 States Route Structure Group
5SWG = 5 States Route Structure Working Group
A
A = Surface Actual
A&A = Authorisation and Approaches
A&AEE = Aeroplane and Armament Experiment Establishment
A&AS = Airports and Airways Services A&D = Arrival and departure
A&I = Architecture and Integrity
A&R = Analysis and Research (NATS); formerly R&DG
A-ENPRM = Advanced – EUROCONTROL Notice of Proposed Rulemaking
A-Gear = Arrester Gear
A-RIOT = Async remote Input Output Terminal A-S = Anti-Spoofing
A-A = Air to Air
A/C = Air Carrier (USA)
A/C = Aircraft
A/D = Aerodrome
AA = Approved Agency
AA = Active Addressing
AA = Administrative Assistant
AA = Air-to-Air
AA = Anti-Aircraft
AA = Aviation Authority
AAA = Airports and Airways Aids
AAA = Amsterdam Advanced Air Traffic Control System
AAA = Anti-Aircraft Artillery
AAAA = Army Aviation Association of America
AAAD = All Arms Air defence (UK) AAAM = Advanced Air to Air Missile
AAAS = American Association for the Advancement of Science
AAAVTAG = Azienda Autonoma Assistienza al Volvo per ill Traffico Aereo Generale
AAC = Airline Administrative Control
AAC = Aeronautical Administrative Communication
AAC = Alpha Attenuation Coefficient AAC = Alaskan Air Command
AAC = Army Air Corps
AAAC = Airport Associations Coordinating Council
AAAC = Army Airborne Command and Control (US Army)
AACE = Airfield Approach Control Element
 
AACS = Australian Airspace Classification Scheme AACS = Automated Access Control Systems
AAD = Assigned Altitude Deviation
AADGE = Allied Command Europe Air Defence Ground Environment (NATO) AADM = Allocators Activity Display
AAEM = Advanced Airborne Expendable Decoy AAF = Adaptation Approval Form
AAF = Auxiliary Air force
AAFCE = Allied Air Forces Central Europe (NATO) AAFG = EATCHIP B ATM Added Functions Sub-Group AAG = EATCHIP B AIS Automation Group
AAGDI/AGADE = Automated Air/Ground Data Interchange AAH = Advanced Attack Helicopter
AAH = Autonomous Aircraft Hybrid
AAI = Angle of Approach Indicator
AAI = Average Arrival Interval
AAIB = Air Accidents Investigation Branch
AAIM = Aircraft Autonomous Integrity Monitoring
AAIM = Avionics/Aircraft Autonomous Integrity Monitoring AAIS = Automated AIS
AAIU = Air Accident Investigation Unit
AAL = Above Aerodrome Level
AAL = ATM Adaptation Level
AALAAW = Advanced Air Launched Anti-Armour Weapon AALS = Advanced Approach and Landing System