Airborne assault at tangail involved airdropping a battalion group north of Tangail, the aim being the capture of the Poongali bridge on the Jamalpur-Tangail road. The main para drop operation was undertaken on 11 Dec 71 by 48 aircraft operating from Dum Dum and Kalaikunda.The airdrop landed most of the Para Battalion Group along with their supply and heavy drops north of Tangail between 1600 and 1630 hrs. The main drop commenced with An-12s delivering the heavy loads followed bby packets with platform loads and troops. The Dakotas brought up the rear carrying mostly men. The actual airdrop consisted of 750 officers and men of 50 para bridage with their arms equipments and light vehicles. It was the first time in the history of the Indian Armed Forces that an airborne operation over enemy territory was undertaken, and that too on such a large scale. It was a strategic move to isolate Dacca, which was the main center of gravity in East Pakistan.