Airlines have sent messages of remembrance and condolence marking the anniversary of the September the eleventh hijackings.
Eighteen years ago the World Trade Center was in ruins, thousands were dead or unaccounted for, and the way we looked at aircraft was changed forever.
People still eye planes on the Manhattan skyline with suspicion.
Two decades on and the world has altered utterly in a variety of ways. Though, few areas of life that have been changed as drastically by the plane hijackings as air travel.
United Airlines and American Airlines, whose aircraft were weaponised in the September 11th attacks, published statements yesterday marking the anniversary.
In an open letter United CEO Oscar Munoz remembered those who lost their lives in New York City, Arlington and Shanksville, saying:
"They were attacks on the values that make life worth living, as well as the shared purpose that make us proud of what we do as members of the United family: connecting people and uniting the world."
American Airline also marked the anniversary with a statement honouring the "colleagues, family and loved ones" killed in the attacks.
The plane hijackings on the 11th September 2001 changed the world for the worse.
However there are few things that altered more drastically or quickly than air travel.
People caught planes as casually as they might the school bus, and those born before the 90s might remember air travel before planes were thought of as weapons.
Here six ways in which air travel has changed, eighteen years on.
1. The cockpit door is now locked for good
There was once a time when passengers – especially younger ones – were allowed, even encouraged to visit the front of the plane. The room with buttons and dials on every surface was the first impression of a career in aviation.
One online commentator remembered being "left in awe" by the experience. "As a 7 year old who wanted to be a pilot it felt like meeting an astronaut," he wrote to the forum asking "What was flying like before 9/11?"
Last year, NZ Air Line Pilots Association president Tim Robinson told the Herald that the number of pilots entering the industry is just not keeping up with demand.
Airlines have recognised there is a difficulty to inspire kids and school leavers to follow the long training path to the aircraft controls.
There are a number of reasons for the current global shortage of pilots affecting airlines. However, the bullet-proof door between cabin and cockpit – though necessary for safety – might be seen as cutting off kids from an experience that many pilots point to as the first step on a vocation in aviation.
2. The barriers went up
It's a mistake to think that airports before the security screens went up it was like the opening scene from Love Actually. The arrivals gates have always been a place jet-lagged travellers loafing around in pursuit of lost luggage. However, the screening process and dividers have taken away some of the humanity of air travel.
"I think the best part was being greeted at the gates by my grandparents, parents, or family friends," Reddit user lovesheavyburden said in a rose-tinted recollection of travel before 2001.
"There was usually a swarm of people waving as you got off a plane and you had to look for a few minutes until you recognised your loved ones. Then there were hugs, and kisses, and marriage proposals at the gate."
3 The full body scanners at screening, like entering an airlock
Since security got technical there have been a many iterations of scanning technology introduced to airports. In 2013 the first generation of 'nude-o-vision' scanners were taken out of service not just for complaints about the revealing security imaging, but following concerns over the amount of radiation passengers were being exposed to.
Replacing the old, metal arches that beep to remind you of loose change in your pockets are a new breed of scanners. You've probably passed through them. There's something about being put in a space-age bell jar and told to wave your hands above your head that further distances the departure gates from the real world.
4 Appearance matters
Particularly if you are flying through the States, passengers are now scrutinised for their appearance. In 2015 it was revealed by a FOI request by The Intercept that the TSA has been trained to challenge passengers displaying "exaggerated yawning," "gazing down" or "widely open staring eyes." Security agents were even told to observe passengers for evidence of "face pale from recent shaving of beard."
However the controversial practice passed off under the euphemism of 'passenger profiling' made a certain group of passengers very aware of the personal appearance. While the effectiveness of the sanctioned 'racial discrimination' of security threats is still being debated, it did have the effect of non-white or non-European-looking passengers suddenly feel the pressure of increased security checks all the more acutely.
5 Bottled water has become a precious resource
Since a liquids were banned from international passengers' luggage in 2006 bottled water prices in duty free predictably rose.
In 2015 a lawsuit was filed against Hudson newsagents for gouging thirsty passengers with the price of water in their duty free shops. The Wall Street Journal found that the prices of certain items sold the other side of JFK Airport screening were almost double those in midtown Manhattan.
A couple of decades earlier the passengers would have been able to bring in all the food and drink they needed for their flight.
"You could bring a drink with you, even a pudding cup and a real spoon! Heck, you could carry on a full lunch and not worry about it being confiscated for containing too much moisture," wrote nostalgic Reddit contributor FellowConspirator.
6 Nothing at all. . . in parts of New Zealand
Some international guests are shocked to discover that – thanks to a particular aviation law – air travel in parts of New Zealand is still frozen in time, somewhere before the new millennium.
Domestic flights with a capacity fewer than 90 passengers are still allowed to bypass airport security screening.
Wellington Airport CEO Steve Sanderson said that recently some American guests were shocked to discover the country's lack of screening. "In their eyes it's a security issue," he told Newstalk ZB's Mike Hosking.
"For New Zealand our largest export industry is tourism, and we need to make that adjustment for tourists so they feel safe here," he said.
While air infrastructure is a unique species in New Zealand and there have been huge changes to the country's air travel since 2001, it seems there are still more changes to tighten up domestic air travel in line with the models found in America and other parts of the world.