To avoid regions regarded as risky, some British Airways flights to and from south Asia are following routes that increase the distance travelled by up to a quarter.
The Independent has analysed the BA link between London Heathrow and Delhi.
The “great circle” route – the most direct path between the Indian capital and the UK – crosses northern Afghanistan and eastern Ukraine, and clips a corner of Belarus.
Since the Taliban takeover, UK airlines have not been permitted to fly over Afghanistan; eastern Ukraine is off-limits after the shooting down of MH17, when 298 lives were lost, in 2014; and after a Ryanair plane was forced to land in Minsk so a dissident on board could be arrested, British flights do not enter Belarus.
Besides following instructions to avoid airspace regarded as dangerous, airlines make their decisions on routing in accordance with their own risk assessments.
British Airways has chosen to divert its aircraft southwest to avoid Pakistan, as well as Afghanistan.
Recent flight paths cross Saudi Arabia but then dip south to avoid Israel, finally turning over Egypt’s Sinai peninsula.
As a result, the 4,191-mile journey is extended by around 25 per cent – adding about two hours to journey times in either direction.
With the delays compounded, the inbound flight is typically arriving between three and four hours late back into Heathrow.
Other airlines are flying more direct routes between the two capitals. Virgin Atlantic is avoiding Iran, but flying over Iraq and therefore saving time compared with British Airways.
Both UK carriers are taking longer routes than airlines based in India that compete on the same route. Vistara and Air India are both flying over Iranian airspace.
Besides the extra fuel burn, the extended journeys mean passengers may miss onward connections.
Despite avoiding Israel and Pakistan on London-Delhi flights, British Airways serves Tel Aviv in Israel daily and Islamabad in Pakistan twice a week.