Error in piloting is understood to have been found as the reason behind the crash of Air Force's C-130J Super Hercules aircraft in March in which five service personnel, including four officers, were killed near Gwalior.
The Court of Inquiry is almost complete and error in piloting is believed to have been the reason behind the crash, highly placed IAF sources said here.
The aircraft, worth over Rs 900 crore, had crashed while practicing a tactical operation along with another C-130J Super Hercules aircraft after taking off from Agra on March 28.
All the crew on board - four officers and one Warrant Officer - lost their lives in the mishap.
The IAF Court of Inquiry under an officer of the rank of Air Commodore (equivalent to a Brigadier in Army) is in the final stages and the report will be soon submitted to the Defence Ministry, IAF spokesperson Group Captain Gerard Galway said.
India recently inducted six C-130J Super Hercules aircraft which were bought from the US at a cost of around Rs 6,000 crore (USD 1 billion) four years ago.
The inquiry was held back for some time in the early stages as the black box of the aircraft had suffered damage and had to be sent to the original equipment manufacturer Lockheed Martin Corporation's facility in the US.
The home base of the 77 squadron 'Veiled Vipers' operating the ill-fated aircraft is Hindan in Ghaziabad near here.
The aircraft were recently landed at Ladakh's Daulat Beg Oldie air field near the Sino-India border and have helped in boosting IAF's capability to airlift troops closer to the border in times of emergency.
IAF has also placed orders for another six such aircraft, which are planned to be deployed in Panagarh, West Bengal, near the headquarters of Indian Army's 17 Strike Corp being raised to counter the threat along the border with China.