Well, that may be a case of high strangeness. He (the pilot) was flying VFR and took the decision to fly above the cloud as the other 2 helicopters and he and is copter disappear from the other 2 helicopters sight.
from the article bellow;
According to Esmaili, weather conditions early on were normal, but 45 minutes into the flight the pilot of Raisi’s aircraft said he would increase altitude to avoid a cloud and ordered the two accompanying helicopters to do the same. Once they started to gain altitude, the two other helicopters suddenly lost sight of Raisi’s aircraft, which had been flying in the middle.
“After 30 seconds of flying over the clouds, our pilot noticed that the helicopter in the middle had disappeared,” Esmaili stated, adding that his aircraft went back and circled the area several times in search of Raisi’s helicopter. However, it was forced to abandon the search attempts due to poor visibility, and landed shortly afterwards at a nearby copper mine.
from the article bellow;
According to Esmaili, weather conditions early on were normal, but 45 minutes into the flight the pilot of Raisi’s aircraft said he would increase altitude to avoid a cloud and ordered the two accompanying helicopters to do the same. Once they started to gain altitude, the two other helicopters suddenly lost sight of Raisi’s aircraft, which had been flying in the middle.
“After 30 seconds of flying over the clouds, our pilot noticed that the helicopter in the middle had disappeared,” Esmaili stated, adding that his aircraft went back and circled the area several times in search of Raisi’s helicopter. However, it was forced to abandon the search attempts due to poor visibility, and landed shortly afterwards at a nearby copper mine.
Tehran reveals more details of Raisi crash
The aircraft carrying Iran’s President Ebrahim Raisi disappeared when attempting to increase altitude to avoid a cloud bank, official says
www.rt.com