The Aircraft Accident Investigation Bureau (AAIB), which comes under the Civil Aviation Ministry, has wrapped up its initial probe into the chopper accident and submitted its report, a source said.
"The initial probe into the crash-landing of Fadnavis' helicopter last month has prima facie found lapses on the part of the pilot as one of the probable causes of the accident," an AAIB official said.
Mr Fadnavis had a narrow escape when his helicopter got entangled in overhead wires and crash-landed in Latur district in Maharashtra on May 25 after the pilot tried to descend due to bad weather, soon after take-off.
"The pilot failed to assess the load on the helicopter on a day of high temperature. Since heat makes it harder for a chopper/aircraft to get off the ground, he should not have taken off with almost full load," the official added.
Besides, the Standard Operating Procedures (SOP) required for the helicopter operations, were also not followed properly, a source from the AAIB said.
The state government's six-year-old Sikorsky chopper was damaged beyond repair in the accident.
After taking-off, the pilot observed a variable wind pattern and decided to land. In the process, the helicopter got entangled in wires.
According to the source, while the areas surroundings the helipad should be cleared off any obstacle like electric polls or wires, among others, a part of the SOP, the AAIB official said adding, "It was also not followed properly."
The AAIB probes all accidents and serious incidents involving Indian aircraft.
The accident occurred when the helicopter was landing at Nilanga town of the district where the chief minister had held a programme.