The downing of Malaysia Airlines MH17 by a sophisticated surface-to-air missile is likely to cause a major shift in thinking about flying over trouble spots and war zones.
The International Civil Aviation Organisation and the International Air Transport Association had apparently declared the flight route taken by MH17 as safe, probably because of the high altitude the plane was flying.
It is understood all airspace above 30,000ft was cleared and, at the time of the tragedy, at least 50 planes were crossing Ukraine in all directions - including over the conflict area.
Among air traffic in the area at the time were a Singapore Airlines Boeing 777 and an Air India 787, only 25km from MH17 when it was shot down, according to Flightradar 24.
Malaysian Airlines says MH17 never flew into risky airspace over Ukraine, adding it's now avoiding the troubled country.
“In April, the International Civil Aviation Organization (ICAO) identified an area over the Crimean peninsula as risky,” Malaysia Airlines said in a statement.
“At no point did MH17 fly into, or request to fly into, this area. At all times, MH17 was in airspace approved by the ICAO.”
But following the disaster the airline will no longer fly near Ukraine.
“Malaysia Airlines now avoids Ukrainian airspace entirely, flying further south over Turkey,” it said.
Aircraft have been flying over trouble spots for decades without incident because, usually, insurgents lack the military hardware to reach the cruising altitudes of high-flying commercial or military jets.
Certainly, a few commercial passenger planes have been shot down in the past, but usually when they are at low altitudes or mistaken by the military.
But with rebels and terrorists becoming more sophisticated and some countries willing to supply them with more capable hardware, the threat of another attack on a high-altitude passenger plane is real.
There is also the deep concern that other terrorist groups will want to emulate the "success" of the shoot-down.
Aviation authorities and airlines will now have to go to great lengths to assure the travelling public that air routes are clear of trouble spots.
Changing air routes, particularly those from South-East Asia to Europe, will add considerably to the operational challenges because extra fuel will be required to fly more circuitous routes.
There will also be more congestion with one of the major transit routes closed. Potentially there are a number of areas that airlines may now avoid - Afghanistan, parts of Pakistan, Iraq, Syria and Ukraine.
Thursday's attack will also result in airlines that codeshare with Malaysia Airlines reassessing their relationships.
MH17 codeshared with KLM and this accounts for the 154 Dutch passengers.
Codesharing on flights, where one airline sells seats on another's flight, is a practice used across the industry.
For the wider industry, the losses will have an impact as passengers rethink their air travel in general. This is despite air travel being the world's safest mode of transport, with 100,000 flights carrying 8.25 million passengers every day.
Today, the loss of a big modern commercial jet with a first-rate airline is extremely rare - so two losses in 132 days is devastating.