During 1971 Indo-Pak war, the burden of Pakistan Navy’s offensive effort hinged on the small but effective submarine force. PN Submarine HANGOR sailed in the early hours of 22 November 1971 to patrol off the Indian Kathiawar coast under the command of Commander Ahmed Tasnim S.J.
On 9 Dec, in an effort to locate the evasive enemy, HANGOR extended her patrol northward to investigate some radio transmissions intercepted on her sensors. Two contacts were picked up on passive sonar and were identified as warships. The initial range was 6 to 8 miles. A pursuit of the enemy began but the first attempt to attack these ships failed due to speed disadvantage. The submarine however managed to forecast target ships movement and succeeded in taking up a tactically advantageous position on the path of the patrolling frigates by 1900. At 1957 the submarine fired a down the throat shot with a homing torpedo at the northerly ship from a depth of 40 meters.
Captain Ahmed Tasnim (later Vice Admiral)(a man standing), directing the final stages of the torpedo attack on INS Khukri Lieutenant Fasih Bokhari – Captain Ahmed Tasnim – Lieutenant A.U. Khan
The torpedo was tracked but no explosion was heard. The second torpedo was therefore fired immediately on the incomming southerly ship and this was followed by a tremendous explosion. The torpedo had found its mark. The other enemy frigate came straight for the submarine when a third torpedo was fired. A distant explosion was heard subsequently and the submarine turned west towards deeper waters for evasion.
In this spectacular action, INS KHUKRI, the ship of the Squadron Commander of Indian 14th Frigate Sqn was sunk within two minutes after receiving a hit in the magazine where explosives were held. This was the first submarine kill since World War II. 18 Officers and 176 sailors including the Commanding Officer lost their lives. This came as a shattering blow to the Indian Navy. HANGOR’s action demonstrated Pakistan Navy’s tactical superiority in sub-surface warfare and after the war even the BBC commentators praised Pakistan Naval effort. Considering the shape, size and age of the ships at its command, they said that the Pakistan Navy had acquitted itself well against the Indian Navy.