Author’s note: This is the first of a two-part series. You may view Part Two here.
When Malaysia Airlines Flight MH17, flying from Amsterdam to Kuala Lumpur, Malaysia, was shot down near Snizhe in eastern Ukraine, it had veered about 300 miles off its original course.
The original southerly course charted for the ill-fated plane would have taken it through safer airspace away from the Donetsk region, a zone of armed conflict where several planes had recently been shot down by separatists armed with increasingly sophisticated surface-to-air missile systems.
In the weeks before flight MH17 was shot down, separatist rebels brought down up to 12 Ukrainian military aircraft, including an Ilyushin Il-76 transport plane carrying about 49 Ukrainian troops and more recently an Antonov-26 military transport plane.
Flight MH17 is believed to have been shot down by a Soviet-era Buk surface-to-air missile system, known to NATO officials as SA-11 Gadfly.
Evidence that the rebels might have come into possession of a Buk missile system first emerged June 29 when a Twitter account used by pro-Russian separatists posted photo of a Buk system they claimed they captured from a Ukrainian base.
Further evidence that the rebels might be armed with Buk missile systems came July 14 when they shot down an Antonov-26 military transport plane reportedly flying at about 21,000 feet, far above the range of portable rocket launchers the rebels were known to possess.
The Wall Street Journal reports that the chief at Ukraine's national security service responded to reports that the rebels had captured a Ukrainian Buk, saying that Ukrainian Buks in eastern Ukraine were not operative.
However, the Ukrainian defense ministry later issued a statement denying that "terrorists" seized a Ukrainian Buk.
US and Ukrainian intelligence sources reportedly had information since early in the month that Russia provided the rebels with SA-11s.
Given the fact that the separatists were conducting an air war against the Ukrainian military and boasted of shooting down several Ukrainian planes, suspicion naturally fell on them as soon as news of the crash of Flight MH17 broke.
It seems likely that flight MH17 was taken down by pro-Russian rebels who mistook its large aircraft radar signature for an Antonov-26 Ukrainian transport plane.
The detail of the circumstances in which MH17 was shot down, however, compels an inquiry into the role of the Ukrainian authorities with the aim of answering two questions:
Why did Ukrainian air control leave the Donetsk airspace open to civilian flights after they had evidence that the separatists had come into possession of sophisticated missile systems that could shoot down aircraft flying at the height of commercial jetliners?
Why in particular did the Ukrainian authorities allow the diversion of flight MH17 from its original course into a danger zone?
As the Wall Street Journal notes, US and Ukrainian authorities have questions to answer about why they did not move quickly to advise commercial airlines of grave danger after obtaining intelligence that the separatists were armed with Buk systems.
Media reports say that the pilot of the ill-fated flight radioed Ukrainian air traffic control, saying he "felt uncomfortable" about the route he was flying and wanted to change course.
The Guardian reports that the plane flew the planned route safely in previous flights. Exactly why the pilot "felt uncomfortable" with the route on that particular flight remains uncertain.
But we know that he changed his flight path above safe airspace to a northerly course passing over the Donetsk warzone after obtaining approval from Ukrainian authorities.
International aviation authorities usually take advice from national governments about safe flight paths. The decision on safe routes for international flights is taken by international authorities in consultation with the national governments in control of airspaces.
Malaysia's transport minister, Datuk Seri Liow Tiong Lai, told reporters that MH17 "followed a route which was set out by the international aviation authorities" and approved by Eurocontrol.
"MH17 flew at an altitude that was set and deemed safe by local air traffic control," he added.
A number of theories have been offered to explain why the flight was diverted northward into a warzone.
CNN suggested that the flight might have been diverted to avoid a thunderstorm.
If that suggestion is true, it was not an unusual maneuver. Atmospheric turbulence associated with heavy thunderstorms has been known to cause plane crashes in the past.
But the Malaysia Airlines director of operations, Izham Ismail, has denied the thunderstorm theory, saying the airlines has no reports that suggest MH17 changed course to avoid a thunderstorm.
In fact, several other flights were in the vicinity when MH17 was shot down, showing that the airspace was left open to general air traffic despite the grave risks.
According to Bloomberg, data supplied by FlightRadar24 shows that Singapore Air Flight SQ35 and Air India Flight AI113 were in the vicinity when MH17 crashed. India Today reports that Air India Flight AI113 was only about 25 kilometers away.
Given the fact of information available to Ukrainian authorities concerning the presence of a belligerent rebel force armed with surface-to-air missile systems capable of taking down planes at twice the height that commercial flights were flying, could the Ukrainian authorities claim ignorance of the fact that an accident was only waiting to happen all the time the airspace was left open?
There was a third alternative southerly route through the Crimean peninsula that the MH17 could have passed.
The Guardian reports that airlines were advised to avoid the airspace above Crimea, the Black Sea and Sea of Azov due to the risk of conflicting instructions from Ukrainian and Russian authorities.
But it seems more likely that the instruction to avoid Crimean airspace was a political decision by Western countries and Ukraine to boycott Russia's newly claimed airspace after its annexation of Crimea.
The decision meant that flights were diverted from a safer southerly course to a dangerous airspace over a warzone.