The Russian-made MI-17 helicopter was on a training sortie in the mountainous district of Tawang near the border with Tibet when it crashed, the officer said.
It was not immediately clear what caused the collision.
“Five personnel have died and one is critically injured. Manpower and machines are on job to retrieve bodies and injured,” the officer told AFP on condition of anonymity.
Tawang is in the northeast Indian state of Arunachal Pradesh, which is also claimed by China.
It is a strategically important border district and came briefly under Chinese control during the 1962 war between the two neighboring countries.
India’s Air Force has a high rate of crashes owing to its aging fleet. More than 170 pilots have lost their lives over the last three decades.
India is spending billions of dollars to modernize its decades-old fleet.