The crew was experiencing fatigue due to their high roster and failed to execute the appropriate approach procedure to Pristina.

The on-duty ATC personnel accidentally forgot to track the flight during the approach phase and did not pay enough attention during radar vectoring.

Due to these issues combined with the faulty GPWS warning system, which was caused by the company's decision to postpone the rectification of the device, the aircraft failed to fly clear of terrain and crashed onto the mountain.

Due to reports of ethnic cleansing of Albanians, North Atlantic Treaty Organization (NATO) forces invaded Yugoslavia in March 1999, resulting in the closure of airspace within the area of conflict.

Following the result of agreements that was signed in June 1999 in Helsinki, the operation of Pristina Airport was handed over to the Russian Army.

There were also three Spanish citizens from UNMIK, three Britons representing their relief organizations,[4] and one each from Australia, Bangladesh, Canada, Germany, Iraq and Kenya.

It was a six-day-a-week flight and was chartered by World Food Programme for aid works in Kosovo following the war in the region.

At 10:58 a.m, Pristina gave a series of headings for the crew to intercept the airport's ILS, which was acknowledged by Flight 3275.

The controller stated that he could hear them loud and clear, adding that they were number two for landing and giving the crew an advice regarding the presence of another aircraft which was located approximately 5 miles (8.0 km; 4.3 nmi) ahead of them.

[7][13] The wreckage of the aircraft was found later on the evening of 12 November, on a steep mountainside approximately 7 miles (11 km) from the town of Mitrovica.

Moments after impacting terrain, the tail and the left stabilizer immediately detached while the lower fuselage disintegrated.

[1]: 28 On 20 November, French investigators recommended Pristina Airport to close operation to all civilian flights.

KFOR and UNMIK immediately followed the recommendation and temporarily suspended all civilian flights from entering and flying out of the airport on 21 November.

[18] The cockpit voice recorder revealed that during the flight the crew was not following the appropriate procedure for an approach to Pristina.

Their actions were apparently influenced by the high amount of flights to Pristina, creating a sense of routine.

This might have caused the crew to think that they didn't need to strictly follow the appropriate briefing as they would get assistance from the ATC anyway and thus would be cleared from the mountainous terrain in the area.

Based on an examination conducted by University of Paris, both flight crews were suffering from high level of fatigue, particularly the Captain.

He received approximately just five hours of training for the approach radar position and was not familiar enough with the correct civil procedure.

The rise in elevation eventually caused their radar plot to drop due to poor signal in the mountainous region.

The crew of Flight 3275 eventually stated their intention to land and the controller gave them a westerly heading.

Apparently, he thought that the aircraft was still flying visually, even though the crew had not informed him about any changes on flight conditions.

The aircraft maintained its low altitude and eventually flew into a layer of compact clouds before it impacted terrain.

Interviews from staffs indicated that the GPWS had failed for multiple times, however the defect was not included in the technical logbook.

[1]: 39–40 After the signing of the contract for Rome - Pristina sector, the number of flying activity of SiFly suddenly jumped.

For instance, the Director of Operations, identified as the Chief Pilot of the airline, claimed that he himself descended below the minimum safe altitude during radar vectoring.

[1]: 58–60 Due to the findings with the oversight of the airline, the BEA, within the final report of the investigation, quoted[1]: 60 The lack of any reaction to this ratio by the organisation responsible for oversight is astonishing.With limited number of staffs and weak finance, the newly created airline, which was also undergoing rapid development with high amount of flights, eventually caused them to be unable to acquire enough experience regarding the implementation of the appropriate structures and procedures.

[1]: 62–63 The report was released by BEA with the following conclusion:[1]: 66 The collision of KSV 3275 with high ground was due: The following factors contributed to the accident: Only 8 days after the accident, investigators issued several interim recommendations to Pristina Airport, among those were immediate evaluation regarding the infrastructure and operation in the airport.

In response to the announcement, UNMIK and KFOR immediately followed the safety recommendations and closed the airport from all civilian flights.

[1]: 67–69 In November 2018, European Union Rule of Law Mission in Kosovo (EULEX) held a memorial service at the crash site of Flight 3275.