Accidents of Pawan Hans Helicopters in the last three decades were caused more due to “organisational lapses than technical reasons”, investigation by the Directorate General of Civil Aviation has found. The reports indict the state-owned company for violation of safety norms and improper maintenance, The Indian Express reported on Saturday.

The reports studied 20 of 25 accidents involving the company’s helicopters since 1988. These accidents killed 91 people, including 31 in 2011 alone. Five of these accidents, including one this month, are still under investigation. In the last 30 years, the company lost 21 helicopters in accidents, the reports showed.

The reports include recommendations to the DGCA and the Ministry of Civil Aviation on the need for licensed helipads, regular inspections and adequate fire safety facilities.

In response, the company said it had put several safety measures in place. Pawan Hans Executive Director TA Vidyasagar attributed many of the accidents to the fact that it is a government company with a “social responsibility” to fly in difficult conditions.

“One has to see the quantum of our flying and difficult terrains we fly in,” Vidyasagar told The Indian Express. “Seven to eight crashes took place only in Arunachal Pradesh. We are a government company and have the obligation of social responsibility. Though any accident is undesirable, our accident rate is much below the global average per hour.”

The helicopter crashes that were studied include one that killed then Arunachal Pradesh Chief Minister Dorjee Khandu on April 30, 2011.