GAUHATI, India – A helicopter hit a wall and burst into flames as it was trying to land in India's remote northeast on Tuesday, killing at least 17 people, police said.

The MI-17 helicopter with 23 people on board was trying to land in the Buddhist pilgrimage town of Tawang near the border with China, said S.N. Mosobi, a police superintendent.

The police officer said the six who survived were in a hospital in Tawang, where the condition of at least three of them was described as critical. Seventeen people were killed.

There were 18 passengers and five crew members aboard the Pavan Hans helicopter, which was on a regular flight between Tawang and Gauhati, the capital of Assam state.

It was not immediately clear whether the crash was caused by bad weather or a technical snag, said Jambey Tsering, an official from Arunachal Pradesh state, where Tawang is located.

Helicopters are commonly used for travel in India's remote northeastern states, where dense forests and mountains coupled with poor roads that often become blocked during the monsoon season make land travel difficult.

Government-owned Pavan Hans and a few private helicopter companies conduct regular daily helicopter flights among the capitals of India's seven northeastern states.

One of the worst aviation tragedies in recent memory — the helicopter crash in Tawang in April that claimed 19 lives — was a “survivable accident”, the final investigation report to the government has stated. The MI-172 helicopter, with 23 people on board including crew, was about to land at Tawang civil helipad, when it suddenly flared up and crashed on April 19. An investigation committee was appointed by the government to probe the accident.

In an explosive report, the committee has concluded that, “This was a survivable accident. However, people died mainly due to inadequate fire services and non-availability of crash equipment and trained personnel”. The state authorities maintained the heliport.

The report, accessed by the Hindustan Times, has blasted the government-owned helicopter operator, Pawan Hans, saying it violated Indian Aircraft Rules for more than two years.

“The aircraft had been making routine flights from Guwahati to Tawang for more than two years. In all this period, Pawan Hans violated Rule 78 (4) of the Indian Aircraft Rules 1937, which states that operator should not knowingly operate without proper fire fighting facilities,” the report said.

The report is likely to raise many questions about Pawan Hans. “Helicopter operations in India is not safe as it ignores pilot fatigue and proper maintenance. So many fatal crashes is not an acceptable standard,” said Captain Mohan Ranganathan, member of a government committee on air safety.

“Whoever gave the clearance for such deficiencies during safety audits would be held accountable. None of the heliports meet safety criteria,” added Ranganathan.