The convenience of buying electronic tickets for airline travel has ended after the US Federal Aviation Administration (FAA) imposed stricter airport security rules following last week's tragedy.
As part of its tighter security policies at US airports, the FAA announced that there would be no more curbside check-ins, and said that "only ticketed passengers with photo IDs will be allowed beyond the security checkpoint".
It further stated that, if a passenger has an e-ticket, "the airline will determine what ticket documentation [tickets, boarding passes or reservation confirmations] their screeners will allow".
Brian Ek, a spokesman for travel website Priceline.com, said that his company is honouring requests for refunds. A note posted on its site said it would accept refund requests for flights scheduled over the next three days.
Travelocity.com, owned by Sabre, said: "The FAA will require the following from all passengers: photo ID and printed passenger receipt for e-ticket and ticket-less travellers or paper tickets. If you do not have one of these documents, you will be required to go to the ticket counter to obtain a copy."
Southwest Airlines, which said that 80 per cent of its customers use e-tickets, acknowledged that the new rules would take away much of the appeal of ticket-less travel. A spokesman said the company plans to have supervisors inspecting travel receipts at security checkpoints in each of the airports in which Southwest is active.
Under the tightest airport security since the Gulf War in 1991, knives and other cutting tools, even plastic ones, are prohibited.
Mail and cargo are temporarily banned from passenger flights, and Federal marshals are on hand at many airports. All carry-on baggage will be subject to search, the FAA said.
The Administration also said that all US carriers are now permitted to fly domestic and international routes. Flights from Canada to the US on Canadian carriers are also allowed.
In addition, international carriers may fly to and from the US if they meet the FAA's new security guidelines, depending on their point of origin.
Cotton seedling freezes to death as Chang'e-4 shuts down for the Moon's 14-day lunar night
Fortnite easily out-earns PUBG, Assassin's Creed Odyssey and Red Dead Redemption 2 in 2018
Meteor showers as a service will be visible for about 100 kilometres in all directions
Saturn's rings only formed in the past 100 million years, suggests analysis of Cassini space probe data
New findings contradict conventional belief that Saturn's rings were formed along with the planet about 4.5 billion years ago