The Russia Analyst doesn't have much to add to what's being reported, which is that terrorism as a cause is being ruled out both by the airline and the authorities. We would only mention here that the timing of an airliner flying from the United Arab Emirates (UAE) crashing on Russian soil, given the recent warming of relations between Moscow and Dubai/Abu Dhabi, is somewhat odd.
A spokeswoman for Russia's Investigative Committee suggesting pilot error in difficult weather conditions as the likely cause of the crash. Russian media sources are already saying that Rostov on Don air traffic controllers tried to divert the plane to the Krasnodar airport (which serves Sochi and the Black Sea coast region), but ultimately under international aviation rules it was the pilot's decision to attempt a landing in high wind gust conditions. Russia's Ministry of Emergency Situations (known by its Russian acronym pronounced M-cheh-S) says the plane crashed about fifty meters to the left of the runway, suggesting that it may have been blown off course. The flight recorders from the American-made Boeing 737-800 airliner have already been sent to Moscow for data analysis.
UPDATE 12:30 a.m. EDT Sunday, March 20, 2016:
Ft. Russ has published more confirmation from TASS that the decision not to divert to Krasnodar was made by the UAE pilots, who circled around the airport for about two hours reducing their fuel load before attempting to land. There were two flights, one from Prague and another from Moscow Sheremetyevo, that diverted to Krasnodar, around the same time FlyDubai981 was circling and another flight from Istanbul returned to the Turkish city due to the adverse weather forecast. (You can get some idea of the wintry mix weather conditions from the video released by the Emergency Situations Ministry of the crash site below):
You can listen to the communications between Rostov-on-Don tower and the UAE flight crew discussing the bad weather in English (mixed with some Russian language communications) in the YouTube video embedded below.
The Russia Analyst would like to note for the record the contrast here between the immediate release of this audio within 24 hours, and the Dutch Safety Board (DSB) for MH17's refusal to release audio recordings of all conversations between Kiev/Dnepropetrovsk ATC and pilots of the doomed Boeing 777 Malaysian Airliner, which was shot down on July 17, 2014. Instead the DSB report declared that there was nothing out of the ordinary recorded by MH17's cockpit flight recorder and released only a partial transcript. According to Dutch media reporting in January 2016, the DSB and the lead criminal investigatory authority, the Dutch-led Joint Investigative Committee (JIC), have STILL not been permitted to interview air traffic controllers from UkSATSE who communicated with MH17 the day it was shot down:
UPDATE2 6 a.m. EDT March 20, 2016: The captain of the FlyDubai jet was a Greek Cypriot, and his co-pilot was a Spaniard. Both men leave behind pregnant wives. Gulf News has published a list of the crew's names and spoken with some of their relatives.