While authorities said the wing came in contact with the ground, independent tracking service Flightradar24.com posted data suggesting that the approach was unusual even before the jet reached the airport.

Two hours

Flightradar24 showed the plane circled for about two hours after an initial landing attempt — consistent with a report by Rossiya-24 — and then descended and slowed down before abruptly pulling up and accelerating at the last minute. The final Flightradar24 readings then showed the plane losing altitude and still gaining airspeed. FlyDubai said both flight recorders, the plane’s so-called black boxes, have been recovered.

Two hours is in general an unusually long time for circling, Ismail Al Hosani, a representative of the U.A.E.’s civil aviation body, said at the Dubai press conference, in response to speculation that the plane had been delaying its final approach.

A preliminary list showed 33 women, 18 men, four children and seven crew on the single-aisle 737, which Ghaith said was inspected on Jan. 21. The passengers were mostly Russian, with Ukrainian, Uzbek and Indian nationals also on board. The Cypriot pilot and Spanish co-pilot were “quite experienced,” having logged more than 11,000 flying hours between them, Ghaith said. The pilot was identified as Aristos Sokratous, Ria Novosti reported, citing transportation prosecutors.

‘Unstable approach’

Bad weather “may have resulted in an unstable approach situation leading the crew to initiate a go-around, execute a missed approach procedure and review the options to either divert or attempt another landing,” said Mark Martin, an aviation analyst and founder of Dubai-based Martin Consultancy.

Rostov-on-Don Airport is considered a straightforward airport to land at, Viktor Gorbachev, head of a Russian airport lobby group, said in an interview with Rossiya-24. The only danger could have been a crosswind, he said. There were several airports within 30 minutes flying time that could have been used instead, he said.

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“Holding a plane for whatever convenience, weather or slots, is a judgment call at the moment,” FlyDubai’s Ghaith said. “As far as we’re concerned, we’ve not seen anything that would suggest that an alternative airport was on the cards, but again we’d not know until all the information is put in front of us.”

Russian Transportation Minister Maxim Sokolov and head of Federal Aviation Authority Alexander Neradko are in Rostov-on- Don and will visit the site soon, Zhanna Terekhova, a spokeswoman for the Transportation Ministry, said by phone.

Insurance coverage

FlyDubai is covered by insurance worth $500 million, Sokolov said during a news conference broadcast by Rossiya-24.

The airport is operated by a unit of billionaire Viktor Vekselberg’s Renova Group. It has two runways and serves more than 2 million passengers per year on domestic and international flights. The airport will remain closed until midnight, spokeswoman Olga Ladeyschikova said by phone.

The city of Rostov-on-Don is near the Black Sea, not far from the border with Ukraine in the south of the country. Body parts have been found near the wreckage, Interfax reported, citing Igor Oder, head of the southern region branch of the Emergency Ministry.

In between the FlyDubai jet’s first attempt to land and the crash, another plane made three landing efforts and then diverted, FlightRadar 24, which tracks airline movements, said in a Twitter posting.

“Diversion is a judgment call,” Ghaith said in a statement.

Boeing aware

Boeing is aware of the incident and is gathering further details, the planemaker said in an e-mailed statement. The 737 is the workhorse of the global airline fleet and the model is Boeing’s biggest source of profit.

The United Arab Emirates’ civil aviation authority has sent representatives and advisers to work closely with the Russian authorities to conduct the investigation under international standards, Saif Mohamad Al Suwaidi, director-general of the regulatory body, said.

FlyDubai, owned by the government of Dubai, is one of two no-frills airlines in the United Arab Emirates. It began operations in 2009 and has an all-Boeing fleet of 50 aircraft with a network of about 90 destinations.

The year 2015 was pronounced one of the safest years for airlines globally by the International Air Transport Association. The number of fatal accidents fell by two thirds last year, excluding more than 300 deaths resulting from a pilot suicide and possible terror attack.

--With assistance from Janet Ong, Torrey Clark, Kyunghee Park and Ann Koh.

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