Aviation abbreviations & their meanings

I listen to the aircraft scanner at home for about 6 hours a day (sometimes more), and when I head to the airport, I bring along a small handheld scanner too. People often ask if I can understand the transmissions and do I know what they mean. That got me thinking—I might compile a list of abbreviations and their meanings. Since the list is quite large, I’ll post it over two days.

Navigation & Approach Abbreviation Meaning

ILS - Instrument Landing System
Provides precision lateral and vertical guidance to an aircraft during an approach and landing.

RNP - Required Navigation Performance
A type of performance-based navigation that allows aircraft to fly highly accurate routes.

RNAV - Area Navigation
Allows aircraft to navigate between defined points without necessarily flying directly over ground-based navigation stations.

VOR - VHF Omnidirectional Range
Ground-based radio navigation system that provides bearing information to aircraft.

DME - Distance Measuring Equipment
Tells the aircraft its distance from a ground station.

NDB - Non-Directional Beacon
A simple radio navigation aid that allows aircraft to determine the direction to a beacon.

GPS - Global Positioning System
Satellite-based navigation system used to determine aircraft position.

GNSS - Global Navigation Satellite System
General term for satellite navigation systems such as GPS, Galileo and GLONASS.

LPV - Localizer Performance with Vertical Guidance
GPS-based approach providing lateral and vertical guidance similar to an ILS.

LOC - Localizer
Provides lateral guidance during an ILS approach.

GS - Glideslope
Provides vertical guidance during an ILS approach.

MDA - Minimum Descent Altitude
Lowest altitude permitted on certain non-precision approaches without required visual reference.

DA/DH - Decision Altitude/Decision Height
Point during an approach at which the pilot must decide whether to land or go around.

MORA - Minimum Off-Route Altitude
Provides terrain clearance for aircraft operating away from an established route.

Communications Abbreviation Meaning

SELCAL - Selective Calling
Allows ground stations to alert a specific aircraft by sending a coded signal to the aircraft.

VHF - Very High Frequency
Radio frequency range commonly used for aircraft communications, mainly over land and in short distances.

HF - High Frequency
Used for long-range communications, particularly over oceans and remote areas.

CPDLC - Controller–Pilot Data Link Communications
Allows ATC and pilots to communicate using text-based digital messages.

ACARS - Aircraft Communications Addressing and Reporting System
Digital system used to exchange operational messages between aircraft and ground stations.

ATC - Air Traffic Control
The service responsible for managing aircraft movements at airports and in controlled airspace.

ATIS - Automatic Terminal Information Service (on VHF)
Continuously broadcasts information such as weather, runway in use and airport conditions.

VOLMET - Meteorological Information for Aircraft in Flight (on HF)
Provides weather information to aircraft in flight.

HF - High Frequency
Long-range radio communication, particularly useful over oceans.

SATCOM - Satellite Communications
Uses satellites for aircraft communications.

Aircraft & Flight Operations

APU - Auxiliary Power Unit
Small turbine engine that provides electrical power and air when the main engines aren't running.

GPU - Ground Power Unit
Ground equipment that supplies electrical power to an aircraft.

FADEC - Full Authority Digital Engine Control
Computer system that automatically controls an aircraft engine.

FMS - Flight Management System
Computer system used for navigation, flight planning and performance management.

MCDU - Multipurpose Control and Display Unit
Pilot interface used to operate systems such as the FMS.

EICAS - Engine Indicating and Crew Alerting System
Displays engine information and alerts to pilots.

ECAM - Electronic Centralized Aircraft Monitor
Airbus system displaying aircraft systems information and warnings.

FBW - Fly-by-Wire
Electronic system that replaces conventional mechanical flight controls.

TCAS - Traffic Collision Avoidance System
Warns pilots of nearby aircraft and can issue avoidance instructions.

TAWS - Terrain Awareness and Warning System
Warns pilots about potential terrain conflicts.

GPWS - Ground Proximity Warning System
Warns pilots when the aircraft is dangerously close to terrain.

Airports & Runways

RWY - Runway

Standard aviation abbreviation for runway.

TWY - Taxiway

Aircraft route connecting runways with aprons and terminals.

APRON - Apron

Area where aircraft park, load, unload and receive servicing.

ILS CAT I

Category I ILS

Precision approach with relatively high minimum visibility and decision height.

ILS CAT II

Category II ILS

Allows approaches in lower visibility than CAT I.

ILS CAT III

Category III ILS

Enables approaches and landings in extremely low visibility, depending on the specific CAT III approval.

PAPI - Precision Approach Path Indicator

Lights beside the runway that help pilots maintain the correct approach angle.

VASIS - Visual Approach Slope Indicator System

Visual system providing approach slope guidance.

RESA - Runway End Safety Area

Area beyond the runway designed to reduce the consequences of an aircraft overrunning or undershooting the runway.

ASDA - Accelerate-Stop Distance Available

Runway length available for an aircraft to accelerate and safely stop.

TORA - Take-Off Run Available

Length of runway available for the ground run during take-off.

TODA - Take-Off Distance Available

TORA plus any suitable clearway.

LDA - Landing Distance Available

Runway length available for an aircraft landing.

Passenger strips naked mid-flight on American Airlines

Late Friday evening, an American Airlines flight arriving at Miami International Airport was met by law enforcement after reports that a female passenger had completely undressed and was behaving indecently and made loud groaning noises. 

American Airlines was operating flight AA1779 from Baltimore/Washington International Thurgood Marshall Airport (BWI/KBWI) to Miami (MIA/KMIA), running about 90 minutes late. As the plane headed south, flight attendants notified the cockpit of a developing situation in the cabin when a female passenger in seat 9D began to undress.

The crew of an Airbus A319 sent an ACARS message after the lead flight attendant reported that a passenger in row 9 had completely undressed. According to AirLive, the woman allegedly began engaging in explicit and indecent acts in plain view of nearby passengers.

The incident led to one of the most unusual ACARS messages in recent memory.

The full ACARS message is below:

FA1 REPORTS THAT PAX IN SEAT 9 D HAS TAKEN OFF ALL HER CLOTHES AND WAS SEEN BY OTHER PAX TOUCHING HERSELF IN AN INDECENT MANNER. FOM SAYS THIS MUST BE REPORTED TO IOC/OSM AND HAVE LAW ENFORCEMENT MEAT THE AIRCRAFT AT THE GATE.

Flight crew quickly swung into action and followed the expected standard security procedure in the flight operations manual, with the crew immediately contacting the American Airlines Integrated Operations Center (IOC), which then requested law enforcement to meet the flight on arrival in Miami.

American's scheduled service to Miami on Friday continued without diversion, and after the two-hour and 25-minute service, the plane touched down at 11:32 PM. The aircraft taxied to Gate D2, where it was met by officers at the airport's North Terminal. The female passenger was then taken into custody, and the Miami-Dade Sheriff's Office is currently investigating the incident.

Passengers restrained on Melbourne flight after making threats

Two male passengers on a flight from Melbourne (MEL/YMML) to Doha (DOH/OTHH) had to be restrained by fellow passengers after they allegedly made threats to other passengers and flight crew onboard.

The incident took place on Virgin Australia’s daily VA7 Melbourne-to-Doha flight, operated by Qatar Airways, on Friday. Videos posted online seem to show the crew struggling with two male passengers. Another clip shows uniformed police boarding the plane in Doha, as other passengers applauded. Australian radio host Jacqui Felgate shared that one passenger told her during an on-air interview they had helped “get the cable ties on” one of the men.

“Then another fella and a cabin crew sat with one of them. The second guy was lying down cuffed by a cabin crew also for the flight,” she said. When the plane landed it was met by authorities.

Felgate said another woman told her that her 63-year-old mother was on board next to the suspects for what she said was a “terrifying and disgraceful” ordeal.

“She was texting us from the plane Wi-Fi as it was escalating,” she said. 

“Apparently, they were continuously headbutting and spitting on flight attendants.

“Apparently the men were shouting that they had a gun, and it required six to seven men each to restrain them in the galley until they could land.”

Qatar Airways confirmed two male passengers “were involved in a physical altercation on board flight VA7 from Melbourne to Doha, operated by them”.

“Both passengers were restrained and, upon arrival in Doha, were handed over to local authorities,” the airline said in a statement.

Airline Information:

Airline: Qatar Airlines (Flying for Virgin Australia)

Code: QR/QTR

Aircraft: Boeing 777-3DZ

Registration: A7-BEH

Serial Number: 60334

Engines: 2 x GE GE90-115B

First Flew: February 2016

Age: 10.7 Years

First-class passenger ‘bites’ cabin crew - flight diverts

An unruly first-class passenger has forced an international flight to make an unplanned landing after they allegedly became aggressive towards cabin staff.

United Airlines, flight UA18, was travelling from Milan, Italy (MXP/LIMC) to Newark, New Jersey (EWR/KEWR) on Tuesday when a 37-year-old Russian woman seated at the front of the aircraft started causing a scene inside the cabin, it was reported.

The mid-flight meltdown occurred when the woman, identified as Kristina Kedysheva, asked airline staff for more alcoholic drinks but was “refused” service. It was then that “non-compliant” Ms. Kedysheva became “very aggressive” and allegedly started “assaulting flight attendants,” a lead air hostess onboard the plane told investigators.

A passenger told police she grabbed the woman when she saw her “move close to the outer, rear door” out of fear she might try and open it. But Ms. Kedysheva then started yelling, prompting staff to try restraining her as she became increasingly resistant as she “fought off” and “bit” a flight attendant hard on the wrist.

“When flight crew and able-bodied people attempted to place Ms. Kedysheva in restraints, Ms. Kedysheva fought them off,’” the flight attendant added. According to another cabin crew member, Ms. Kedysheva had already consumed a number of alcoholic beverages and “appeared to be drunk” and her aggression grew as the consumed alcohol took effect .

Airline staff alerted the FBI, and the captain was forced to make an emergency landing at Bangor International Airport in Maine (BGR/KBGR).

Upon arrival, the disruptive passenger was removed from the plane and detained by US Customs and Border Patrol. United Airlines said in statement provided to People the flight landed safely in Maine after an “unruly passenger” caused the unscheduled diversion.

Under police questioning, Ms. Kedysheva denied accusations she bit airline staff, attempted to tamper with a door and made threats to airline crews. She maintained she did not do anything wrong and claimed the in-flight chaos was caused by a female flight attendant.

However, she allegedly admitted to drinking many alcoholic drinks onboard over the course of a few hours.

Ms. Kedysheva faces one count of interference with an aircraft in flight, one count of interference with a flight crew and one count of assault.

Remembering 9/11 — 25 Years On

Twenty-five years ago today, the world changed forever.

September 11, 2001, began like any other day for thousands of people. Passengers boarded four commercial airliners, crews prepared for their flights, and families went about their normal morning routines. None could have imagined the tragedy that was about to unfold.

For those of us who have a love of aviation, September 11 holds a particularly profound place in our memories. Aircraft, which normally represent travel, adventure, connection and the freedom to explore the world, suddenly became associated with unimaginable loss.

The four flights—American Airlines Flight 11, United Airlines Flight 175, American Airlines Flight 77 and United Airlines Flight 93—carried 246 passengers and crew who never reached their intended destinations. Their lives, along with those of so many others on the ground, were taken far too soon.

But September 11 is not only about the tragedy. It is also about the extraordinary courage and sacrifice that followed.

Firefighters, police officers, paramedics, emergency workers and ordinary people ran towards danger while others were trying desperately to escape it. Many never returned home. Their bravery remains one of the most powerful parts of the story of that terrible day.

Twenty-five years have now passed, but for the families who lost loved ones, the pain of that morning can never truly disappear. Children grew up without parents, parents lost sons and daughters, and husbands and wives were suddenly left without the people they loved.

The aviation world also changed forever. Security procedures, airport operations and the way we think about air travel were transformed. Every time we pass through an airport today, we are reminded in some small way of the lasting impact of September 11.

As an aviation enthusiast, I still look up whenever I hear an aircraft overhead. I still admire the beauty, engineering and freedom of flight. But September 11 reminds me that behind every aircraft is something far more important than the machine itself—people.

People with families. People with dreams. People going somewhere.

On this 25th anniversary, my family and I pause to remember every passenger and crew member who never came home, everyone who lost their life on the ground, and all those who showed incredible courage in the face of unimaginable circumstances.

Twenty-five years later, we remember their names, their lives and their stories.

We remember.
We honour.
We will never forget.

Sydney's International expands with EgyptAir and Shenzhen Airlines

Sydney Airport is preparing for the arrival of two airlines that will add some fascinating new chapters to Australia's aviation story, with EgyptAir and Shenzhen Airlines both announcing plans to begin services to Sydney. The two announcements, made within a day of each other, will see Sydney's international airline network expand to a record number of carriers and provide new links to two very different but increasingly important markets.

Shenzhen Airlines is scheduled to begin four-times-weekly flights between Shenzhen and Sydney on the 14th of December 2026, while EgyptAir plans to return to Sydney in 2027 with a Cairo–Singapore–Sydney service. The announcements will take Sydney Airport's number of international airlines to 55, with EgyptAir becoming number 54 and Shenzhen Airlines number 55.

Perhaps the more surprising announcement though is the return of EgyptAir.

Egypt's national carrier has announced plans to reconnect Cairo and Sydney via Singapore from 2027, subject to regulatory approvals and the finalisation of the operating schedule. While this will be promoted as a new service, it is actually a return to Australia for the Egyptian flag carrier.

EgyptAir previously operated Cairo–Singapore–Sydney flights but suspended the service in July 2002. The proposed 2027 operation will therefore bring EgyptAir back to Sydney after an absence of around 25 years. The new service is particularly significant because there is currently no direct air connection between Sydney and Cairo.

The route will also be significant for the large Egyptian Australian community in New South Wales, which Sydney Airport says numbers more than 31,000 people.

The planned routing is:
Cairo → Singapore → Sydney

and then the return journey:
Sydney → Singapore → Cairo

While EgyptAir represents a return to Sydney, Shenzhen Airlines will be an entirely new carrier for the airport. The service will operate four times a week using an Airbus A330-300. Sydney Airport says the new operation will add approximately 130,000 seats annually and support an estimated 100,000 passengers each year.

The initial schedule is:
ZH815
Shenzhen (SZX) → Sydney (SYD)
00:20 – 13:40
ZH816
Sydney (SYD) → Shenzhen (SZX)
22:30 – 05:25+1

Riverfire 2026: Brisbane takes to the skies

There are plenty of great events on Brisbane’s calendar, but few can match the excitement, colour and sheer noise of Riverfire. For aviation enthusiasts like us, Riverfire isn’t just about the fireworks. The build-up is every bit as exciting, particularly when some of the Royal Australian Air Force’s most impressive aircraft come roaring through the skies above Brisbane.

 
So, what is Riverfire?
Riverfire by Australian Retirement Trust is Brisbane’s spectacular annual fireworks celebration and one of the signature events of the Brisbane Festival. Held along the Brisbane River, Riverfire combines a massive fireworks spectacular with military aircraft fly-past's and displays, creating an unforgettable evening against the backdrop of Brisbane’s city skyline.

This year Riverfire took place on Saturday the 5th of September, officially kicking off the Brisbane Festival. The fireworks are always scheduled to begin at 7pm, with the aerial displays taking place beforehand.

For Brisbane locals, it has become something of an annual tradition — find a spot along the river, look skyward and wait for the unmistakable sound of fast jets approaching the city.
And that’s exactly what we did this year.

 
Thursday – the mighty C-17A Globemaster III
My family and I headed out to watch the rehearsal flight of the Royal Australian Air Force C-17A Globemaster III as it made its way over Brisbane. Scheduled for approximately 12:30pm around the Victoria Bridge precinct, the rehearsal gave aviation enthusiasts a fantastic opportunity to see one of the RAAF’s giant strategic airlift aircraft operating over the heart of the city.

There’s something special about watching a huge aircraft like the C-17 flying above Brisbane’s skyscrapers. It may not have the speed or noise of a fighter jet, but its sheer size makes it an impressive sight.

My wife and daughter headed to the outdoor bar on the top floor of the casino while I stayed on the ground at Southbank.  

Friday – the Super Hornets arrive
If Thursday was impressive, Friday turned the volume up considerably!
On Friday we were back again for another Riverfire rehearsal — this time for two RAAF F/A-18F Super Hornets.

The two individual rehearsal flights were scheduled around 20–30 minutes apart, with the aircraft operating around the Victoria Bridge and Brisbane CBD area at approximately 12:30pm.

And what a difference there is when those twin-engine fighters come screaming through the Brisbane skies.

The sound arrives almost as quickly as the aircraft themselves, and for anyone who loves military aviation, seeing two Super Hornets operating against the Brisbane skyline is something you simply don’t get tired of.

Once again, our family was there to watch the action, again my wife and daughter headed for the casino and this time I changed locations and went to the Kangaroo Point cliffs.

And now for the big one!

After enjoying both rehearsal days, we were looking forward to the main event on Saturday night.

At 7.05 pm the fireworks light up the Brisbane skyline from multiple locations along the river, with displays launched from barges, rooftops and bridges. It's not unusual for half a million people or more to head into Brisbane for the celebrations, but my family and I headed to the top floor level of the airport carpark to watch the spectacular.