- ±6°
- 14 CFR
- 100-hour inspection
- A.C
- A/FD
- A-la-carte
- A la Carte Bar
- A&P
- AA
- ABC
- Abeam
- Above Ground Level (AGL)
- Absolute accuracy
- Absolute altitude
- Absolute Ceiling
- Absolute pressure
- AC
- ACAS
- Accelerate-go distance
- Accelerate-stop distance
- Accelerated Stall
- Acceleration
- Acceleration error
- Accelerometer
- Accessible Tourism
- Accessible Travel
- Accommodation
- Activities
- Actual Time of Arrival
- AD
- ADC
- Add-on
- ADF
- ADF (Automatic Direction Finder)
- ADI
- Adiabatic cooling
- Adiabatic heating
- Adiabatic Lapse Rate
- Adjoining rooms
- Adjustable-pitch propeller
- Adjustable stabilizer
- ADM
- Adoption Rate
- ADS-B
- ADT
- Advance Purchase Fare
- Advance purchase requirement
- Advection fog
- Adventure tour
- Adventure travel
- Adventure Traveler
- Adverse yaw
- aerodrome
- Aerodynamics
- aerodyne
- aeronaut
- Aeronautical chart
- Aeronautical Decision-Making
- Aeronautical decision-making (ADM)
- Aeronautical Information Manual
- Aeronautical Information Manual (AIM)
- aeroplane
- aerostat
- AF
- Affiliated Aircraft
- Affinity Card
- Affinity group
- Aft
- After-departure charge
- Agent
- AGL
- Agonic line
- Agreement Aircraft
- AHRS
- AI
- Aileron
- ailerons
- AIM
- AIM (Aeronautical Information Manual)
- AIO variables
- air base
- Air Crewmember Essential for the Mission
- Air data computer (ADC)
- Air Defense Identification Zone (ADIZ)
- air force
- Air mass
- Air mile
- Air route surveillance radar (ARSR)
- Air route traffic control center (ARTCC)
- Air-Sea
- Air Speed Indicator (ASI)
- Air Taxi Operator
- Air Traffic Control (ATC)
- Air traffic control radar beacon system (ATCRBS)
- Air Travel
- Air Travel Card
- Airalo
- Aircraft
- Aircraft Accident
- Aircraft Acquisition
- Aircraft age
- Aircraft altitude
- Aircraft approach category
- Aircraft Incident
- Aircraft lessor
- Aircraft livery
- Aircraft type
- Airfoil
- Airline
- Airline Alliance
- Airline fare
- Airlines Reporting Corporation (ARC)
- airman
- Airmen’s Meteorological Information (AIRMET)
- AIRMET
- airplane
- Airplane Flight Manual (AFM)
- Airplane Owner/Information Manual
- airport
- Airport access fee
- Airport code
- Airport Codes
- Airport diagram
- Airport/Facility Directory (A/FD)
- Airport surface detection equipment (ASDE)
- Airport surveillance radar approach
- Airport surveillance radar (ASR)
- Airport Tax
- Airport transfer
- airship
- Airspace Classes
- Airspace Conflict
- Airspeed
- Airspeed indicator
- airstair
- Airtanker
- Airway
- Airworthiness
- Airworthiness Certificate
- Airworthiness Directive
- Airworthiness Directive (AD)
- Alert area
- All Inclusive
- All-inclusive package
- All-inclusive resort
- Alliance
- Almanac data
- Alpha Code
- ALS
- Alternate airport
- Alternate static source
- Alternate static source valve
- Alternative Tourism
- Alternative Travel
- Altimeter
- Altimeter Setting
- Altitude
- Altitude engine
- Altitude indicator
- Alumni tour
- AM
- Ambassador
- Ambient pressure
- Ambient temperature
- AME
- Amendment status
- Amenities
- Amenity
- Amenity kit
- Amenity package
- American plan
- AMEX
- Amidships
- Ammeter
- AMT
- an airplane. ELT