Have you ever looked at a boarding pass, flight confirmation or airport information screen and wondered what all the abbreviations mean? Aviation uses a lot of shortened terms, from ETA and ETD to PNR, SSR and ATC. Some are useful when checking a flight’s progress, while others matter when arranging assistance for an autistic or disabled passenger.
This guide explains common aviation abbreviations in plain English, with examples of where you might encounter them. It focuses on terms that passengers are most likely to see, alongside a few operational abbreviations that can help make sense of flight information.
If you’d like to see what we are getting up to as it’s happening, please give our Instagram a follow @autismfamilytravelguide
If you want to understand airport identifiers, airline flight-number prefixes and specialist service codes in more detail, read my separate guide to airport and airline codes. This article is a broader glossary rather than another list of airport codes.
Quick Wins: Aviation Abbreviations Worth Knowing
- ETA means Estimated Time of Arrival.
- ETD means Estimated Time of Departure.
- PNR means Passenger Name Record, the booking record associated with your reservation.
- SSR means Special Service Request, used to record particular passenger services and assistance needs.
- PRM means Person with Reduced Mobility in many airport accessibility contexts.
- IATA and ICAO are different international aviation organisations.
- ATC means Air Traffic Control.
Common Aviation Abbreviations: Quick Reference Table
| Abbreviation | Meaning | Why You Might See It |
|---|---|---|
| ATC | Air Traffic Control | Flight delays and aircraft movements |
| ETA | Estimated Time of Arrival | Arrival updates |
| ETD | Estimated Time of Departure | Departure updates |
| STA | Scheduled Time of Arrival | Published arrival schedule |
| STD | Scheduled Time of Departure | Published departure schedule |
| ATA | Actual Time of Arrival | Flight tracking and operational records |
| ATD | Actual Time of Departure | Flight tracking and operational records |
| PNR | Passenger Name Record | Airline booking records |
| SSR | Special Service Request | Assistance, meals and other passenger services |
| PRM | Person with Reduced Mobility | Airport and transport accessibility information |
| IATA | International Air Transport Association | Airline and airport identification systems |
| ICAO | International Civil Aviation Organization | International aviation standards and operational codes |
| FIDS | Flight Information Display System | Airport departure and arrival screens |
| GDS | Global Distribution System | Travel-agent booking systems |
| APIS | Advance Passenger Information System | Passenger information supplied to border authorities |
| NOTAM | Notice to Airmen / Notice to Air Missions, depending on jurisdiction | Operational alerts affecting aviation |
| UTC | Coordinated Universal Time | Aviation time references |
| UMNR | Unaccompanied Minor | Airline services for children travelling without an accompanying adult |
Helpful guides in relation to the aviation abbreviations in the table above:
Flight Times and Status Abbreviations Explained
ETA, ETD, STA and STD
ETA and ETD are estimates: they tell you when a flight is currently expected to arrive or depart. STA and STD are scheduled times: the times in the published timetable. The estimated time may change after a delay even though the original scheduled time remains the same.
For example, a flight with an STD of 14:00 and an ETD of 15:10 is currently expected to leave later than scheduled. Continue checking the airline or airport screens, as an estimate is not a guarantee.
ATA and ATD
ATA and ATD refer to actual arrival and departure times. Different tracking systems may use different operational milestones, such as leaving the gate or taking off, so a displayed departure time does not always mean the moment the aircraft became airborne.
UTC and Zulu Time
UTC stands for Coordinated Universal Time. Pilots, air traffic services and aviation systems use a common time reference to avoid confusion across time zones. You may also hear UTC described as Zulu time. Passenger tickets normally show local departure and arrival times, so do not assume the times on a booking are UTC.
UTC time right now, for your reference:
Airport and Airline Organisation Abbreviations
IATA and ICAO
IATA is the International Air Transport Association, an airline industry association. Its three-letter airport location codes, such as LHR for Heathrow, are familiar to passengers.
ICAO is the International Civil Aviation Organization, a United Nations specialised agency that develops international civil aviation standards. ICAO airport location indicators are generally four letters, such as EGLL for Heathrow. These systems serve different purposes.
Airport codes are particularly important when a city has several airports. My guide to London’s six airports explains why checking the exact airport on your ticket matters.
ATC, CAA, FAA and EASA
ATC means Air Traffic Control. Controllers help manage aircraft movements on the ground and in controlled airspace. If an airline mentions an ATC restriction, it may relate to traffic management or airspace capacity, although the precise reason should be checked with the airline.
CAA can mean Civil Aviation Authority, including the UK’s aviation regulator. FAA is the United States Federal Aviation Administration. EASA is the European Union Aviation Safety Agency. Their responsibilities and jurisdictions are not identical.
Booking and Boarding Pass Abbreviations
PNR: Passenger Name Record
A PNR is the booking record containing details of a passenger’s reservation. Airlines commonly provide a booking reference or record locator that lets you retrieve the reservation. The reference is not the same thing as the longer e-ticket number.
Keep your booking reference private rather than posting screenshots of boarding passes or confirmations online. Combined with other personal details, it may allow someone to access booking information.
GDS: Global Distribution System
A GDS is a booking and distribution platform used by travel businesses to search and manage travel services. Most passengers do not need to interact with a GDS directly, but the term may appear in travel-agent correspondence.
APIS: Advance Passenger Information System
APIS refers to systems for collecting and transmitting advance passenger information to relevant authorities. Airlines may ask for passport details before departure to meet destination or transit requirements. The exact information required varies by journey.
SSSS: Secondary Security Screening Selection
SSSS may appear on boarding passes for flights subject to US security procedures. It indicates selection for additional security screening. It does not, by itself, tell you why you were selected. Learn more about the SSSS airline code in our guide.
Disability and Special Assistance Abbreviations
For autistic travellers, disabled passengers and families, these may be the most useful aviation abbreviations to understand. They help airlines record support requirements, but the code alone may not explain every detail of the assistance you need.
SSR: Special Service Request
SSR stands for Special Service Request. Airlines use SSR codes to record specific services, including wheelchair assistance, medical arrangements and special meals. These are generally four-letter codes. My airline disability codes guide explains the different assistance categories in more detail.
PRM: Person With Reduced Mobility
PRM commonly means Person with Reduced Mobility. It is used in airport and transport accessibility contexts and can cover people who need assistance for a range of reasons. Read my guide to PRM for a clearer explanation of who may qualify for support.
DPNA, WCHR, WCHS and WCHC
| Code | General Meaning | What to Check |
|---|---|---|
| DPNA | Assistance for a passenger with an intellectual or developmental disability | Explain the particular communication, sensory or practical support required. |
| WCHR | Wheelchair assistance for a passenger who can manage steps and reach their seat | Clarify distances and assistance through the terminal. |
| WCHS | Wheelchair assistance for a passenger unable to manage aircraft steps but able to reach their seat | Confirm boarding arrangements. |
| WCHC | Wheelchair assistance for a passenger requiring help all the way to the aircraft seat | Confirm transfer and seating assistance. |
| BLND | Blind or visually impaired passenger | Describe any guiding or communication support needed. |
| DEAF | Deaf or hearing-impaired passenger | Explain communication preferences. |
| MEDA | Medical assistance or clearance-related request | Ask the airline whether medical documentation or approval is required. |
Helpful guides in relation to the aviation abbreviations in the table above:
- DPNA – What Does the DPNA Airline Code Mean?
- WCHR – What Does the WCHR Airline Code Mean?
- WCHS – What Does the WCHS Airline Code Mean?
- WCHC – What Does the WCHC Airline Code Mean?
- BLND – What Does the BLND Airline Code Mean?
- DEAF – What Does the DEAF Airline Code Mean?
- MEDA – What Does the MEDA Airline Code Mean?
Not every autistic passenger needs the same support. If you are requesting assistance, explain what will actually help, such as clearer instructions, extra processing time or support through unfamiliar areas. The DPNA code guide provides further context, while my guide to getting help at the airport explains how to arrange assistance.
Ask your airline to confirm that your request is recorded and whether anything else needs arranging. Do not assume a code automatically guarantees priority security, early boarding or a particular facility at every airport.
Airline Meal and Dietary Abbreviations
Special meals are another reason airlines use abbreviations. The code helps identify the type of meal requested, but menus, availability and ingredients vary between airlines and flights.
| Code | Meal Type |
|---|---|
| VGML | Vegan meal |
| VLML | Lacto-ovo vegetarian meal |
| GFML | Gluten-free meal |
| KSML | Kosher meal |
| MOML | Muslim meal |
| CHML | Child meal |
| BBML | Baby meal |
| DBML | Diabetic meal |
Helpful guides in relation to the aviation abbreviations in the table above:
- VGML – What Does the VGML Airline Code Mean?
- VLML – What Does the VLML Airline Code Mean?
- GFML – What Does the GFML Airline Code Mean?
- KSML – What Does the KSML Airline Code Mean?
- MOML – What Does the MOML Airline Code Mean?
- CHML – What Does the CHML Airline Code Mean?
- BBML – What Does the BBML Airline Code Mean?
- DBML – What Does the DBML Airline Code Mean?
If someone in your family has a food allergy, do not assume that a meal code guarantees a meal free from a particular allergen or cross-contact. Read our guide to airline allergy meal codes and confirm ingredients and preparation arrangements directly with the airline. See our complete airline meal codes guide for further explanations and all of the airline meal codes in one place.
Other Aviation Abbreviations You May Encounter
| Abbreviation | Meaning | Context |
|---|---|---|
| FIDS | Flight Information Display System | Airport screens |
| NOTAM | Notice to Airmen or Notice to Air Missions, depending on the authority | Operational notices for aviation personnel |
| METAR | Routine aviation weather report | Current aerodrome weather observations |
| TAF | Terminal Aerodrome Forecast | Aviation weather forecasts |
| IFR | Instrument Flight Rules | Aircraft operating rules |
| VFR | Visual Flight Rules | Aircraft operating rules |
| UMNR | Unaccompanied Minor | Children travelling without an accompanying adult |
| ULD | Unit Load Device | Containers or pallets used to load baggage and cargo |
| GPU | Ground Power Unit | Electrical power supplied to aircraft on the ground |
| APU | Auxiliary Power Unit | Onboard system providing power and other functions |
| FOD | Foreign Object Debris or Damage, depending on context | Airfield safety |
Most of these are operational terms rather than instructions for passengers. If you hear one in a delay announcement, ask staff what it means for your own flight rather than trying to interpret a technical update on its own.
Why Understanding Aviation Abbreviations Can Help Autistic Travellers
Airports involve many unfamiliar processes, and short codes can make information harder to understand. Learning the terms most relevant to your journey may help you prepare a visual schedule, explain flight changes and check that assistance has been requested.
Before travelling, write down your flight number, airport names, scheduled departure time, booking reference and any assistance arrangements in plain language. If you use visual supports, separate the day into clear stages such as check-in, security, waiting, boarding and arrival.
You do not need to memorise aviation terminology. Knowing a handful of useful abbreviations and asking for clarification when needed is enough. If your family would benefit from more advance preparation, the Hidden Disabilities Sunflower Lanyard guide explains one way to communicate that additional support may be needed.
Frequently Asked Questions About Aviation Abbreviations
What does ETA mean at an airport?
ETA means Estimated Time of Arrival. It is the current predicted arrival time and can change as the flight progresses.
What does ETD mean on a flight status screen?
ETD means Estimated Time of Departure. It may differ from the originally scheduled departure time.
What does PNR mean on an airline booking?
PNR means Passenger Name Record. It is the booking record; the associated reference or record locator helps you retrieve your reservation.
What does SSR mean in aviation?
SSR means Special Service Request. Airlines use SSR codes for additional services such as assistance and special meals.
What is the difference between IATA and ICAO?
IATA is an airline industry association whose codes are common on passenger documents. ICAO is a United Nations agency responsible for international civil aviation standards and uses separate operational identifiers.
What does PRM mean at an airport?
PRM commonly means Person with Reduced Mobility. It is used in accessibility information for passengers who may need assistance with their journey.
Understanding Aviation Abbreviations Makes Travel Easier
Aviation abbreviations can seem confusing at first, particularly when they appear on flight bookings, boarding passes, baggage tags or airline websites without any explanation. However, understanding what these codes mean can make planning a journey much easier.
Whether you are trying to understand an airport code, arrange special assistance, check your baggage allowance or make sense of information provided by an airline, knowing the terminology can help you travel with greater confidence.
For families travelling with autistic children, disabled passengers or anyone requiring additional support, understanding aviation abbreviations can be particularly useful when communicating with airlines and airports.
We hope this guide has helped explain some of the most common aviation abbreviations and what they mean. You can also explore our other guides to airline codes, special assistance and airport accessibility for more information to help you prepare for your next journey.
More Guides to Airline Codes and Airport Assistance
- Airline and airport codes and what they mean
- Learn what airline SSR codes or disability codes are and who should use them
- Download a copy of all of the airline SSR disability codes for free
- Airline meal codes explained
- Download a list of all of the airline meal codes for free
- Learn which airline meal codes are for travellers with allergies
- What does LSML mean?
Continue Planning Your Trip With Autistic Children
- Find out about the help available if you are travelling through an airport
- Discover whether a cruise with an autistic child would work for your family
- Find out how to make travelling with ADHD manageable
- Learn more about the Hidden Disabilities Sunflower Lanyard
- Check out guides to all of the different destinations we have travelled to with autistic children
- Learn step-by-step how to set up the accessibility feature on Google maps
- Learn more about our favourite sensory toys for travelling
- Discover an app that helps you locate a playground anywhere in the world
- Always alerted at the last minute that the little one needs a toilet? Find a toilet anywhere with this app
Continue Planning Your Trip as a Traveller With ADHD
- First, check out my travel guide for ADHD travellers for practical planning advice
- Learn what to include on a doctors letter for travelling with medication so you get your letter right the first time
- Find out more about flying with medical luggage and equipment and what extras you can bring for free
- Check out why you should learn important phrases related to your disability before you travel and download the free eBook with accessible travel translations from my guide
- Find out about the different codes airports and airlines use, especially disability codes
- Learn more about the DPNA code and what it means for travellers with hidden disabilities
- Find out more about the Sunflower Lanyard and how it can support ADHD travellers
- Learn more about getting help at the airport as someone with ADHD and how it can support your travel plans
- Find out how to use the PRM Assist app to book special assistance at the airport
Continue Planning Your Accessible Travels Using My Guides
You can click on each image to go directly to the guide for that topic.
