Malaysia Airlines flight MH17: Why do planes fly over war zones?

The crash site of the MH17 flight between the two villages of Rozsypne and Hrabove (AP)

Flight MH17 pushed back from Schiphol airport in Amsterdam shortly after noon yesterday, just as the Malaysia Airlines jet had done on Thursday. The Boeing 777 crossed the Netherlands, and entered German airspace over the town of Vreden. But at that point, yesterday’s flight track deviated sharply from the previous day.

Thursday’s doomed flight had stuck closely to the “Great Circle” route – the most direct track between the capitals of the Netherlands and Malaysia. Counterintuitively, this meant it flew a little north of east, even though its intended destination was far to the south in the tropics.

As the drinks service got under way, the plane with 298 souls on board passed Warsaw, where it turned slightly south. About 20 minutes later it crossed into Ukrainian airspace. As with many thousands of previous journeys, the flight plan took it in a shallow arc across northern Ukraine – traversing the largest country wholly within Europe, which typically takes 80 minutes.

On airway A87, just short of the Russian frontier and six miles above the violently disputed territory of eastern Ukraine, the cabin crew was clearing meal trays in preparation for a long overnight stretch. Then, three hours after leaving Amsterdam, all on board were murdered.

Yesterday’s flight MH17 followed a very different track, keeping much further south of the geographically optimum route. The south-eastern trajectory took it well clear of the former Soviet Union. It flew over Bulgaria, and once over the Black Sea gave the Russian-controlled Crimea a wide berth; warnings to pilots to avoid the peninsula have been in place for months.

The southerly route added hundreds of miles to the direct 6,336-mile route, costing thousands of dollars extra in fuel. This is why, in common with many rivals, Malaysia Airlines had previously chosen to route its aircraft over Ukraine – and why many other carriers continue to operate over zones of conflict.

Until the loss of MH17, aviation authorities had ordered a no-fly zone over eastern Ukraine – but only up to 32,000ft, known as Flight Level 320. The 777’s crew had asked to fly at 35,000ft over Ukraine, but were assigned 33,000ft – the lowest permissible altitude in the area.

An experienced former BA captain, Jock Lowe, questioned whether MH17 – and other flights – should have been anywhere near a region where conflict is taking place with serious military hardware. He said: “Once you’ve got one of these no-fly zones around you just avoid the area. There’s no missile that can’t get to 35,000 that could get to 32,000. To put a height cap other than about 20,000ft clear of the highest missile is surprising.”

A spokesperson for the British Airline Pilots’ Association said: “Civil aviation should never be allowed to become a part of conflict and be threatened in this way. The apparent shooting down of this aircraft is therefore of extreme concern to pilots. We note that action has been taken by many airlines and authorities to avoid this area.”

The shortest flight path on many air links takes aircraft over areas of conflict. Research by The Independent shows that the “Great Circle” route from Heathrow to Delhi traverses eastern Ukraine, and also bisects Afghanistan. The shortest distance between Glasgow and Dubai is an arc that touches the Crimea and passes over eastern Iraq. The most direct route between Manchester and Doha passes over Syria and a large slice of Iraq. And the optimum Heathrow-Nairobi track spends about 90 minutes over Libya, as well as the area between Sudan and South Sudan.

No commercial aircraft would fly these exact routes. Airlines’ precise flight plans depend on a wide range of factors including weather, predicted air-traffic bottlenecks and overflying charges. They are obliged to avoid no-fly zones, and many will avoid areas where there is a perception of possible danger. But the economic imperative is to keep flights as short as possible, to reduce everything from fuel burn to the risk of missed connections.

It remains the case that conflicts on the ground do not necessarily constitute a threat to high-flying passenger jets. Airlines will continue to overfly regions where it is considered that there is no sophisticated weaponry capable of downing an aircraft, but it may be that in the interests of passenger confidence they will divert around areas that could be perceived as presenting danger.

There is mounting anger among the aviation community about the alleged failure of Western intelligence to identify the military hardware in the separatists’ hands, and to warn of the potential threat to civilians.

On the PPRuNe pilots’ forum, one contributor wrote: “If there is any incompetence it was in the failure of the intelligence world to adequately anticipate a rogue shoot down, and follow who had access to what, and to communicate this to the aviation authorities.”