These are some of the measures that could make travelling by plane safer

While there aren't any signs of international travel resuming any time soon, and the EU has advised against making summer holiday plans, it's hard not to speculate about when and - crucially - how flights will restart safely.

Last week, Aer Lingus announced it was reviewing its procedures, after a photo from a flight from Belfast to Heathrow revealed a lack of social distancing measures.

The image showed passengers sitting side-by-side, despite government guidance that people should remain two metres apart.

Travellers were reportedly “left to their own devices” as soon as they went through security, according to the photographer, Sean Mallon.

While this flight revealed what airlines ought not to do, here are some suggestions as to how flights may be made safer in the future.

Leaving the middle seat empty

Easyjet is one of several airlines which has announced plans to keep the middle seats on planes empty, once the lockdown is lifted. Other airlines with similar plans include the US airline, Delta, and Emirates.

Easyjet said such a measure would be undertaken for a short period of time after lockdown had lifted and flying resumed, to ensure the safety of its passengers.

However, other airlines have not been so keen on the idea.

Michael O'Leary, CEO of Ryanair, has said flying with empty middle seats was not financially viable and would not ensure safe social distancing for passengers.

Additionally, John Holland-Kaye, CEO of Heathrow Airport, warned that airports were not designed for social distancing.

"It's just physically impossible to socially distance with any volume of passengers in an airport," he said.

Mandatory face masks

Some airlines are already insisting passengers wear face masks on planes and at the airport.

Air France and American Airlines have made face masks mandatory for all passengers, starting from 11 May, while Emirates has had this rule in place since April.

Mr Holland-Kaye has proposed we look to Asia for ideas on how to travel more safely in a post-coronavirus world, suggesting travellers wear face masks at the airports just "as people from Asia have been doing ever since Sars.”

New additions to flight attendant uniforms

Flight attendants could find themselves required to wear hospital grade gloves and protective masks when serving customers, to prevent the spread of the virus.

New food and beverage rules

Some airlines across the pond are reportedly asking passengers to bring their own food to cut down on interactions between flight attendants and passengers.

Others have changed the way customers receive inflight beverages. Both United and Alaska Airlines are providing new cups to passengers every time they order a drink, even if it is just a refill.

While it is not the most eco-friendly of methods, it prevents the flight attendants from handling used cups, so this could very well be the standard procedure going forward.

Staggered boarding processes

Other suggestions regarding the way travellers board planes come from Nick Careen, Senior Vice President from the International Air Transport Association (IATA).

Careen has predicted that a staggered boarding process may become standard procedure at airports going forward, to maintain an element of social distancing.

Blood tests prior to boarding

Emirates has recently partnered with the Dubai Health Authority to run quick result blood tests prior to some flights, to check passengers for coronavirus before boarding. While this approach is unique to Emirates, further health checks and testing could offer a way of ensuring passenger safety in the future.

Airport temperature checks for passengers

Another suggestion for making flights safer in a post-lockdown world is airport temperature checks before boarding.

While Public Health England (PHE) reached a verdict that checking passengers' temperatures before they board would be ineffective, Heathrow boss Mr Holland-Kaye has suggested an international standard for health screening at airports could “build confidence in international travel".

He has also asked for PHE’s evidence behind their claim to be made public.

On 6 May Heathrow airport announced that it will start trialling thermal cameras to carry out temperature checks on passengers, with the aim of forming the basis of a Common International Standard for health screening at all global airports.

The trial is to begin by Wednesday 20 May, in Terminal 2.

New cleaning procedures

In future it may be mandatory for airlines to provide additional cleaning equipment to passengers, such as in-flight hand sanitisers, as well as ensuring all hard surfaces that are touched by passengers are disinfected with hospital grade steriliser.

Such areas would need to include the overhead cabins, armrests, seat screens, trays, seat belts, and window shades.

However it is not just in-flight cleaning changes that need to be made to prevent the spread of the virus. Airlines have already begun changing the way they clean their aircrafts between flights.

One method that has been recently introduced after every flight by Delta Airlines, is aircraft fogging, during which a fog machine aerosolises high-grade disinfectant, that then coats every surface of the cabin.

In an online video, Azim Mistry, director of Airport Operations for Delta Airlines describes the process as “highly effective against many communicable diseases, including coronaviruses”.