Airlines can't of course be blamed for causing Covid-19 but with deadly efficiency they almost guaranteed it became a pandemic with lightning speed.
Air connections from the epicentre in Wuhan, China could theoretically have meant infected people could have flown anywhere in the world within 24 hours.
Within the last six months international air travel has changed from a usually pleasurable experience to an anxious flight into what many now see as a germ-filled world - if they can fly internationally.
Airlines around the world have been pushing back against this with campaigns highlighting health measures and one offering to cover medical expenses if any passenger catches Covid-19. Although the recovery is choppy, global capacity has limped back to about 50 per cent of last year.
In this country Air NZ is today on the offensive against intensifying concerns about the threat its aircrew (pilots and flight attendants) pose, going into detail about what it is doing to minimise the risk to its staff - and the border.
Air NZ says it is going beyond what has been imposed by the Ministry of Health while an airline umbrella group says airlines are doing their bit to help stop the spread of Covid-19 and warns of the economic consequences of rules becoming too complex.
Both point out that since there have been no reported aircrew cases of the disease since April. In March an Air NZ flight attendant who returned from the United States was linked to Bluff wedding cluster.
The airline's chief executive Greg Foran today spoke with Health Minister Chris Hipkins who had expressed some doubts about systems around international aircrew entering New Zealand.
Foran said his airline supports any improvements to the Government's current testing regime.
The protocols it currently has in place to prevent staff from contracting Covid-19 have been established in conjunction with the Ministry of Health.
''We know these have been working because since early April, we haven't had a case of Covid-19 in the airline,'' he says.
What's Air NZ doing?
The airline revealed details of the measures taken on international flights depending on whether they are high, medium or low-risk destinations are set by the ministry. The risk matrix is reviewed regularly.
On all flights crew wear masks and gloves when interacting with passengers and full personal protective equipment (PPE) when dealing with unwell passengers.
Air New Zealand is flying a limited international schedule - less than 20 per cent of this time last year, with many flights freight only.
On its network medium-risk layovers, included Narita in Japan, Hong Kong and Shanghai.
Crew wear masks and gloves when moving through the terminal, use private crew transport to hotels, not mixing with other passengers and isolate in hotels, limiting trips outside to one hour for every 24-hour period.
They don't use the hotel gym or pool while on layover and are not allowed to meet with other crew while on layover.
High-risk layovers are San Francisco and Los Angeles, in the worst-hit country.
In addition to the measures at medium-risk layovers, crew isolate in hotels for duration of layover, all food must be delivered to rooms and on return home, aircrew must isolate for 48 hours, complete a Covid-19 test, then isolate until test results are known.
The ministry rules are strict around self-isolation and include sleeping and eating alone but some commentators have pointed out that those living with them aren't in turn required to self isolate.
In addition to the New Zealand Government's requirements, several of Air NZ's international destinations including Hong Kong, China and Samoa require Covid-19 testing of aircrew before departure, on arrival, or both.
Foran says any crew who are symptomatic, or who have had to break isolation offshore to seek medical attention, for example, must enter quarantine on return to New Zealand.
Questions have been raised about what checks are made on crew of domestic flights carrying returnees to Wellington or Christchurch when Auckland isolation facilities are full.
The airline says domestic crew and those operating the managed isolation flights are not required to be routinely tested as they are wearing appropriate PPE (gloves and masks) on board and in the terminal.
''We are following the Ministry of Health guidance in full, have assessed the risks according to international best practice and have addressed these appropriately. Our crew are wearing gloves to prevent transmission through touch and masks to prevent transmission via droplets,'' a spokeswoman says.
The airline's hospital grade Hepa filters on jets are acknowledged as being effective in eliminating more than 99 per cent of bacteria and viruses although some research suggests they are not so effective with larger droplets from coughing or sneezing which is why wearing masks is important.
Foran today outlined additional measures including segregating A320 crew so they do not operate both internationally and domestically, requiring passengers on board domestic and international services to wear masks which are replaced every 3-4 hours on long-haul flights.
He says the airline ensures aircrew have multiple channels through which to raise concerns.
What the unions say
The flight attendants' union, E tū, says for crew flying internationally, protective and quarantine measures are stringent
''Crew are being compliant, very careful and conscientious,'' says E tū director, Alan Clarence.
International crew are satisfied with the current testing arrangements in place.
''The company has also not prevented concerned crew from getting a test, and we do not know of any crew who have refused or been reluctant to take one.''
However, testing is only one part of the picture – safety is first and foremost about prevention, said Clarence.
''This includes appropriate risk mitigation, such as using PPE, and for international crews, quarantine and self-isolation measures, all of which are already required.''
E tū fully supported the ministry's involvement in meeting with Air New Zealand to work to ensure the ongoing safety of all airline crew and passengers.
'However, any additional testing requirements or safety measures would need to take into account the needs of airline crew - not to be kept continually isolated and/or at work, without necessary time to see family and the like.''
The NZ Air Line Pilots Association - not shy about raising safety concerns - says Air NZ's response had been good, although stresses the psychological and emotional impact of long periods of self-isolation.
Foran said Auckland Airport-based staff were being encouraged to get tested in response to the recent outbreak and this has resulted in huge numbers of staff presenting for voluntary tests.
"It's fair to say our pilots and cabin crew have borne the brunt of the impact of Covid-19, on a very personal level. This has tremendous impact on their everyday life and wellbeing. As does having to self-isolate back at home upon returning from higher risk destinations. This causes disconnection from family, friends and everyday activities," he says.
Other airlines and the economic risk
The Board of Airline Representatives ((Barnz) represents 11 airlines still flying internationally in New Zealand - just over a third of the number which were flying here at the start of the year.
Its executive director Justin Tighe-Umbers says the aircrew coming into New Zealand were subject to similar rules as Air NZ overseas.
"The Ministry of Health requirements for overseas-based air crew are pretty specific. Basically after using dedicated transport from the airport, air crew have to self-isolate in their hotel rooms during any stop over. Meals are delivered to their rooms and they cannot use the pool, gym or any other recreational area.
''The ministry can do spot checks, or audits to see if those conditions are being met and he knew of seven airlines that have been audited and their systems at their hotels checked.
Apart from the mandatory use of masks and gloves and other personal protective equipment and measures, the actual number of Covid-19 cases that have crossed the New Zealand border is very small.
"Official statistics we have been provided show that of the approximately 25,000 people who have come to New Zealand between April 9 – August 3 there has been 75 people test positive – that's around 0.3 per cent of travellers."
His organisation had also checked on the conditions covering grooms who look after horses that are air freighted. They follow ministry agreed protocols, are tested regularly and there are no reported cases of Covid-19 infection for any of the grooms.
Tighe-Umbers ends on the economic versus the gold plated health response, a debate that is getting louder.
''While New Zealanders should not be fearful about the risk from aircrew or grooms, they should be worried about the economic shock if airlines pull out of the country should conditions become too stringent for them to operate.''