In late September, an experienced pilot at low-cost European airline Wizz Air felt anxious after learning his plane would fly over Iraq at night amid mounting tensions between nearby Iran and Israel.

He decided to query the decision since just a week earlier the airline had deemed the route unsafe. In response, Wizz Air's flight operations team told him the airway was now considered secure and he had to fly it, without giving further explanation, the pilot said.

"I wasn't really happy with it," the pilot, who requested anonymity from fear he could lose his job, told Reuters. Days later, Iraq closed its airspace when Iran fired missiles on Oct. 1 at Israel. "It confirmed my suspicion that it wasn't safe."

In response to Reuters' queries, Wizz Air said safety of crew and passengers was its utmost priority and would not be compromised "in any circumstances", adding its decisions on where to fly are based on stringent risk assessments in collaboration with third party intelligence specialists.

"Our aircraft and crews will only fly in airspace that has been deemed safe and we would never take any risks in this respect," Wizz Air also said in a statement.

Reuters spoke to four pilots, three cabin crew members, three flight security experts and two airline executives about growing safety concerns in the European air industry due to escalating tensions in the Middle East following Hamas' attack on Israel in October 2023, that prompted the war in Gaza.

The Middle East is a key air corridor for planes heading to India, South-East Asia and Australia and last year was criss-crossed daily by 1,400 flights to and from Europe, Eurocontrol data show.

The safety debate about flying over the region is playing out in Europe largely because pilots there are protected by unions, unlike other parts of the world.

Reuters reviewed nine unpublished letters from four European unions representing pilots and crews that expressed worries about air safety over Middle Eastern countries. The letters were sent to Wizz Air, Ryanair, airBaltic, the European Commission and the European Union Aviation Safety Agency (EASA) between June and August.

"No one should be forced to work in such a hazardous environment and no commercial interests should outweigh the safety and well-being of those on board," read a letter, addressed to EASA and the European Commission from Romanian flight crew union FPU Romania, dated Aug. 26.

In other letters, staff called on airlines to be more transparent about their decisions on routes and demanded the right to refuse to fly a dangerous route.

There have been no fatalities or accidents impacting commercial aviation tied to the escalation of tensions in the Middle East since the war in Gaza erupted last year.

Air France opened an internal investigation after one of its commercial planes flew over Iraq on Oct. 1 during Tehran's missile attack on Israel. On that occasion, airlines scrambled to divert dozens of planes heading towards the affected areas in the Middle East.

The ongoing tensions between Israel and Iran and the abrupt ousting of President Bashar al-Assad by Syrian rebels at the weekend have raised concerns of further insecurity in the region.

The use of missiles in the region has revived memories of the downing of Malaysian Airlines Flight MH17 over eastern Ukraine in 2014 and of Ukraine International Airlines flight PS752 en route from Tehran in 2020.

Being accidentally shot-down in the chaos of war is the top worry, three pilots and two aviation safety experts told Reuters, along with the risk of an emergency landing.

While airlines including Lufthansa and KLM no longer fly over Iran, carriers including Etihad, flydubai, Aeroflot and Wizz Air were still crossing the country's airspace as recently as Dec. 2, data from tracking service FlightRadar24 show.

Some European airlines including Lufthansa and KLM allow crew to opt-out of routes they don't feel are safe, but others such as Wizz Air, Ryanair and airBaltic don't.

AirBaltic CEO Martin Gauss said his airline meets an international safety standard that doesn't need to be adjusted.

"If we start a right of refusal, then where do we stop? the next person feels unhappy overflying Iraqi airspace because there's tension there?" he told Reuters on Dec. 2 in response to queries about airBaltic flight safety talks with unions.

Ryanair, which intermittently flew to Jordan and Israel until September, said it makes security decisions based on EASA guidance.

"If EASA says it's safe, then, frankly, thank you, we're not interested in what the unions or some pilot think," Ryanair CEO Michael O'Leary told Reuters in October, when asked about staff security concerns.

EASA said it has been involved in a number of exchanges with pilots and airlines on route safety in recent months concerning the Middle East, adding that disciplining staff for raising safety concerns would run counter to a "just culture" where employees can voice worries.

INSUFFICIENT REASSURANCES

One Abu Dhabi-based Wizz Air pilot told Reuters he was comfortable flying over the conflict-torn region as he believes the industry has a very high safety standard.

But for some pilots and crew members working at budget airlines, the reassurances of the companies are insufficient.

They told Reuters pilots should have more choice in refusing flights over potentially dangerous airspace and requested more information about airline security assessments.

"The fact that Wizz Air sends emails asserting that it's safe is irrelevant to commercial employees," read a letter from FPU Romania to Chief Operating Officer Diarmuid O'Conghaile, dated Aug. 12. "Flights into these conflict areas, even if they are rescue missions, should be carried out by military personnel and aircraft, not by commercial crews."

Mircea Constantin, a former cabin crew member who represents FPU Romania, said Wizz Air never gave a formal response to this letter and similar ones sent earlier this year, but did send security guidance and updates to staff.

A pilot and a cabin crew member, who declined to be named for fear of retaliatory action, said they got warnings from their employers for refusing to fly on Middle Eastern routes or calling in sick.

CONGESTED SKIES

Last month, 165 missiles were launched in Middle Eastern conflict zones versus just 33 in November 2023, according to the latest available data from Osprey Flight Solutions.

But airspace can only be enforcably restricted if a country chooses to shut it down, as in the case of Ukraine after Russia's full-scale invasion in 2022.

Several airlines have opted to briefly suspend flights to places like Israel when tension rises. Lufthansa and British Airways did so after Iran bombarded Israel on April 13.

But this limits the airspace in use in the already congested Middle Eastern skies.

Choosing to fly over Central Asia or Egypt and Saudi Arabia to avoid Middle Eastern hot spots is also more costly as planes burn more fuel and some countries charge higher overflight fees.

Flying a commercial plane from Singapore to London-Heathrow through Afghanistan and Central Asia, for instance, cost an airline $4,760 in overflight fees, about 50% more than a route through the Middle East, according to two Aug. 31 flight plans reviewed by Reuters.

Reuters could not name the airline as the flight plans are not public.

Some private jets are avoiding the most critical areas.

"At the moment, my no-go areas would be the hotspot points: Libya, Israel, Iran, simply because they're sort of caught up in it all," said Andy Spencer, a Singapore-based pilot who flies private jets and who previously worked as an airline pilot.

Spencer, who has two decades of experience and flies through the Middle East regularly, said that on a recent flight from Manila to Cuba, he flew from Dubai over Egypt and north through Malta before refuelling in Morocco to circumvent Libyan and Israeli airspace.

EASA, regarded by industry experts as the strictest regional safety regulator, issues public bulletins on how to fly safely over conflict zones.

But these aren't mandatory and every airline decides where to travel based on a patchwork of government notices, third-party security advisors, in-house security teams and information sharing between carriers, leading to divergent policies.

Such intelligence is not usually shared with staff.

The opacity has sown fear and mistrust among pilots, cabin crew and passengers as they question whether their airline has missed something carriers in other countries are aware of, said Otjan de Bruijn, a former head of European pilots union the European Cockpit Association and a pilot for KLM.

"The more information you make available to pilots, the more informed a decision they can make," said Spencer, who is also an operations specialist at flight advisory body OPSGROUP, which offers independent operational advice to the aviation industry.

When Gulf players like Etihad, Emirates or flydubai suddenly stop flying over Iran or Iraq, the industry sees it as a reliable indicator of risk, pilots and security sources said, as these airlines can have access to detailed intelligence from their governments.

Flydubai told Reuters it operates within airspace and airways in the region that are approved by Dubai's General Civil Aviation Authority. Emirates said it continuously monitors all routings, adjusting as required and would never operate a flight unless it was safe to do so. Etihad said it only operates through approved airspace.

Passenger rights groups are also asking for travellers to receive more information.

"If passengers decline to take flights over conflict zones, airlines would be disinclined to continue such flights," said Paul Hudson, the head of U.S.-based passenger group Flyers Rights. "And passengers who take such flights would do so informed of the risks.