(CNN) After circling a southern Russian airport for more than two hours because of high ground-level winds and poor visibility, a passenger jet from the United Arab Emirates crashed during a landing attempt, killing all 62 people aboard.

The flydubai Boeing 737 took off from Dubai and was scheduled to land at the Rostov-on-Don airport at 1:20 a.m. Saturday (6:20 p.m. ET Friday), Russian Emergencies Minister Vladimir Puchkov said.

But it didn't come down -- about 800 feet from a runway -- until 3:50 a.m. By that point, Russian state media reported, there were winds of about 60 mph.

Authorities have ruled out terrorism as a cause of the crash. Instead, according to investigative committee spokeswoman Oksana Kovrizhnaya, they will be looking at three possibilities: technical issues, severe weather and human error.

Kovrizhnaya said the investigations will take at least two months, as required by Russian law, but "could be prolonged," according to state-run Sputnik news

Investigators from UAE, U.S. to join Russian colleagues

The plane's pilot had circled the airport hoping the weather would clear, Russia's emergency minister said. After more than two hours, the pilot attempted to land.

Instead, the aircraft's tail clipped the ground as it approached Rostov-on-Don's airport, killing all 55 passengers and seven crew members.

The "main phase" of the search operation has been completed, said Vladimir Puchkov, the Russian emergencies minister, according to Sputnik news. The search operation is expected to end at 9 a.m. Sunday.

The victims' remains have been recovered and sent for forensic analysis, he said.

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The airport will be closed until Sunday, state-owned news channel Russia-24 quoted officials as saying. Until then, flights are being redirected 141 miles south to the city of Krasnodar.

Hundreds of personnel -- from investigators to medics to psychologists on standby to assist grieving family members -- quickly converged on the crash site, and more help is on the way.

JUST WATCHED Video said to show moment of impact Replay More Videos ... MUST WATCH Video said to show moment of impact 00:29

Four investigators will be coming from the United Arab Emirates, UAE General Civil Aviation Authority official Ismail Al Hosani told reporters in Dubai.

And the U.S. National Transportation Safety Board will send a team as well, accompanied by technical advisers from the Federal Aviation Administration and Boeing.

Boeing said in a statement it will serve as technical adviser to the investigating authority in charge, the Russian Interstate Aviation Committee.

Workers at the crash scene already had both of the plane's flight data recorders and one of two voice recorders by midday Saturday, state-run Ria Novosti reported.

4 children among victims

The UAE-based airline said 44 of the passengers were Russians, along with eight Ukrainians, two Indians and one Uzbekistani. Thirty-three of the passengers were women, 18 were men and four were children.

Our thoughts and prayers are with the passengers and crew of #flydubai flight 981 in Rostov-on-Don and their families. — Dubai Airports (@DubaiAirports) March 19, 2016

Flydubai insisted its primary concern was for the relatives of the victims.

"We don't yet know all the details of the accident but we are working closely with the authorities to establish the cause. We are making every effort to care for those affected and will provide assistance to the loved ones of those on board," flydubai CEO Ghaith Al Ghaith said.

A Russian Emergency Situations Ministry employee (L) tries to comfort a relative of the plane crash victims at the Rostov-on-Don airport.

Ghaith later told reporters the plane's pilots were "quite experienced," saying the Cypriot captain had flown 5,965 hours while the Spanish co-captain had flown 5,769 hours.

In another statement, the airline said it was contacting families of the victims.

"It is a process that will take a little time but as a mark of respect to the families of the bereaved, we want to make every effort to inform them directly prior to releasing the full passenger manifest," the statement said.

Russian President Vladimir Putin expressed his deepest condolences to the families and friends of the victims, state news agency Tass reported.

Families of passengers killed will receive 1 million rubles (about $15,000) from the government, Russian state media reported. It said Sunday has been declared a day of mourning in the Rostov administrative region, which borders the Sea of Azov and eastern Ukraine.

UAE offers its deepest condolences to the families of the victims & to the Russian government&people for the tragic accident of Fly Dubai. — Dubai Media Office (@DXBMediaOffice) March 19, 2016

And the UAE's government media office posted its sympathies on Twitter, as did Dubai's emir, Sheikh Mohammed bin Rashid Al Maktoum.

"This terrible tragedy grieves us all," tweeted Maktoum, who is also the UAE vice president. "We mourn those lost, may their souls rest in peace."

Airline CEO: Plane passed safety check

Ghaith, the flydubai CEO, said that, "as far as I can tell, there was no distress call," Ghaith said.

He added that the aircraft passed a "C-Check" on January 21.

Emergency staff found one of the plane's flight recorders amongst the wreckage, state news reported.

According to the Federal Aviation Administration, the aircraft maintenance inspections are graded from the least detailed and most frequent "A-Check," to the most comprehensive "D-check," which might occur only three to six times in a plane's service life.

Answering a question regarding the difficulty of landing, Ghaith said "as far as we know, the airport was open and we were good to operate."

Pilot disorientation?

CNN aviation expert Mary Schiavo said radar suggested the plane had flown three large, looping circles around the airport before it crashed.

"The poor visibility is probably the biggest clue," Schiavo said. "But this runway was lighted, it had good lighting at one end and passable lighting at the other and it did have an instrument landing system."

"With the clue of bad weather and making at least three different circles trying to reorient to this runway, it does look like pilot disorientation."

Aviation safety analyst David Soucie agreed with the ministry's preliminary assessment that weather was likely to blame.

"It's not likely it was a mechanical failure," Soucie said. "It's most likely a weather-related incident."