An initial report into the 10 March plane crash at Velika Planina that killed Swedish businessman and former politician Carl Lundström has confirmed weather conditions were unfavourable for flying, but does not yet formally conclude poor weather as the most likely cause of the accident.

The flight was a private one operating under Visual Flight Rules (VFR). The pilot, Lundström, took off from Zagreb airport at 8:47am en route to St. Gallen-Altenrhein in Switzerland, a journey expected to last two and a half hours, according to the report by air accident investigator Toni Stojčevski as summarised by the newspaper Dnevnik on 22 April.

The pilot contacted Ljubljana air traffic control at 9:17am and spoke his last words a minute later, after which he stopped responding to the controller's calls and the aircraft soon vanished from radar.

A rescue operation was launched but hampered by very poor weather conditions and the remote, precipitous terrain. Parts of the aircraft were found the same day in and around a mountain hut belonging to Ljubljana's Faculty of Mechanical Engineering into which the plane crashed.

The hut was badly damaged and access was hampered due to the risk of collapse. Rescuers reached the pilot's body on the Velika Planina plateau in the north of Slovenia one day after the accident.

In the initial report outlining basic facts, lead investigator Stojčevski from the Infrastructure Ministry's air accident investigation service noted that at 9:20am in the Velika Planina area, a southwesterly wind was blowing with gusts around 20 knots near the ground and speeds around 30 knots higher up.

Conditions were present for moderate turbulence. The crash area was enveloped in clouds and fog with precipitation. Conditions for moderate icing also existed, according to the report.

The report also states that the meteorological service had issued a forecast for private pilots at 6:00am UTC. For air routes leading north from central Slovenia over the mountainous region of northern Slovenia, the forecast for the period between 7am and 9am UTC predicted conditions unsuitable for VFR flights. The investigator noted that actual conditions were also unfavourable for flying.

The day after the accident, Stojčevski announced that an initial report would be issued within 30 days, with a full report detailing all circumstances leading to the crash expected within 12 months.