The low-cost carrier will implement heightened safety measures, including fewer checked bags, online check-in, passengers holding boarding passes on their phones, as well as temperature checks at airport entry and mandatory face masks or coverings at all times.
Ryanair said social distancing will be encouraged “where it is possible” but did not mention leaving the middle seats empty.
Last week, trade body International Air Transport Association (IATA) voiced its concerns against this measure, claiming it would cause dramatic cost increases.
Ryanair also said all aircraft are fitted with HEPA air filters, similar to those used in critical hospital wards, and are disinfected daily with chemicals lasting for over 24 hours.
Refreshments will be served with cashless payments, while queuing for the toilet will be prohibited. Passengers will have to ask crew members before accessing the restroom.
At check-in, passengers flying in July and August will be asked to fill in forms to allow governments to trace and monitor mandatory isolation.
Since the coronavirus outbreak in March, the firm has been operating 30 daily flights between Ireland, the UK and Europe.
April saw a 99.6% plunge in year-on-year traffic to 40,000 passengers, including rescue and medical flights.
"A risk worth running"
"This increase in the flight schedules is encouraging but we are wary about the level of demand from UK passengers given the divergence of quarantine policies expected to be introduced in the UK later in May, just as they are starting to be relaxed in EU-27," analysts at Peel Hunt commented.
Westminster announced on Monday that all international arrivals will be required to self-quarantine for two weeks. There will be some exemptions, such as travellers from France.
Last week, the European Commission invited Schengen countries to prolong a ban on non-essential travel to the EU until 15 June, while some countries have been easing restrictions.
According to Liberum, Tuesday's announcement seems "an attempt to force the issue of when and how commercial passenger flights should be restarted", while Hargreaves Lansdown hinted at the possibility that "Ryanair’s management knows something we don’t".
"While preparing to get planes back in the air will cost money, which will be wasted if restrictions aren’t lifted, management clearly feels this is a risk worth running," said HL's analyst William Ryder.
Shares rose 2% to €9.06 on Tuesday morning.
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