The IAF chopper crash on December 8 that killed Chief of Defence Staff (CDS) Gen Bipin Rawat and 13 others was due to an unexpected change in weather that led to spatial disorientation of the pilot, stated the preliminary findings submitted by the tri-services court of inquiry.

"The tri-services court of inquiry into the Mi-17 V5 accident on December 8, 2021, has submitted its preliminary findings," the Indian Air Force`s statement said on Friday. The court of inquiry has ruled out mechanical failure, sabotage or negligence as a cause of the accident, it said.