East Pakistan Air Operations , 1971 East Pakistan Air Operations incorporate the interdiction , air defense , ground support , and logistics missions flown by the Indian Air Force and the Bangladesh Air Force in support of the advancing Mitro Bahini ( called Operation Cactus Lilly ) in the eastern theater of the Indo - Pakistani conflict of 1971 . Although the first of the engagements between the opposing airpowers occurred before the formal declaration of hostilities , the events described below include only those conducted after the declaration of war . The Indian Air force also helped the Mukti Bahini organize a formation of light aircraft ( called " Kilo flight " ) which were manned and serviced by Bengali pilots and technicians who had defected from the Pakistani Air Force . This unit had launched attacks on targets in Bangladesh on 3 December 1971 , prior to the start of formal combat between India and Pakistan . Background . The short but intense engagements between the Mitro Bahini and the Pakistani Army lasted only 14 days , between 3 December and 16 December 1971 . The speedy conclusion was only possible because the objectives set by the Mitro Bahini in the east were achieved within that time frame , and can be attributed to the excellent co - ordination between the Indian Army , Air Force , Navy , and the Mukti Bahini . Although the western theater saw engagements that helped define the rules of 20th century warfare , including the Battle of Longewala , Operation Trident , and the Battle of the Bases between the two rival Air Forces , the eastern theater would be marked by a near - total domination by the Indian forces and the Mitro Bahini . Two major reasons stand out : the first , and likely the most important , was the fact that the Bengali population and the Awami League - led resistance had already greatly weakened Pakistani forces . The second major reason is the total air supremacy that the IAF gained in the opening days of the war . The Eastern Theater : Historical Background . East Pakistan saw no air combat when Pakistan and India came to blows over Kashmir in 1947 , although both countries possessed functional air forces . All Pakistani air assets were deployed in West Pakistan at the time , and India concentrated on the Western front as well . India began upgrading its air capabilities on its eastern border only after the war . In 1958 , the Eastern operational group was formed in Kolkata , and was upgraded into a command the following year . Following the Sino - Indian War of 1962 , the Eastern Air Command Headquarters shifted to Shillong , and extensive efforts to increase its operational capabilities in terms of number of squadrons and modernization of its warplanes and operational infrastructure began , as added emphasis was given to countering any possible Chinese threat . In contrast , Pakistan High Command posted only 1 squadron of 12 F - 86 Canadair Sabres in East Pakistan . The Sabres were deployed at Dhaka on October 1964 , while the Air Force infrastructure development in the province was largely ignored . However , the Indian Air Force had six combat squadrons posted under its Eastern Air Command by 1965 . 1965 Indo - Pakistani War : Eastern Theater . As soon as hostilities commenced in September 1965 , the air forces of both countries launched attacks against each other in the eastern theater . The IAF bombed airfields and airstrips located in East Pakistan ( at Chittagong , Dhaka , Lalmanurhat , and Jessore ) , while the PAF managed to launch two celebrated raids on the Indian Air Force base at Kalaikundda , West Bengal . The PAF raids , a five - plane strike followed up by a four - plane attack , took place on 7 September , destroying several Canberra bombers and Vampire aircraft on the ground , while the IAF claimed 2 aerial kills ( Pakistani sources record 1 F - 86 lost ) . The first PAF Kalaikundda raid ( by 5 Sabres ) achieved total surprise , but the second wave was opposed by Indian interceptors , leading to the loss of the aircraft . The PAF also launched attacks on Bagdogra on 10 September and Barrackpur on 14 September , with varying results . While the IAF hit back with more airstrikes on Dacca , Jessore , and Lalmunirhat , these failed to destroy any aircraft . Mid - air interceptions and dogfights rarely happened , and barring some skirmishing between the EPR and BSF along the border , the air forces of both countries were responsible for most of the combat activity in the eastern theater during the 1965 war . The final tally was 12 Indian aircraft destroyed on the ground ( PAF claim 21 aircraft destroyed ) , 2 Pakistani Sabres shot down , ( the PAF records one aircraft lost ) , and 1 PAF Sabre lost due to an accident . Following the war , the IAF continued its steady growth in combat capacity and logistical capabilities , while Pakistan boosted its squadron strength to 20 F - 86 Sabres ( although it neglected to expand its operational infrastructure substantially ) . PAF during Operation Searchlight in 1971 . PAF had 20 Canadair Sabres ( No 14 . Squadron " Tail - choppers " ) , three T - 33 trainers , and two helicopters stationed in East Pakistan , while army aviation squadron No . 4 had four helicopters . PAF operational effectiveness suffered to some degree because most Bengali pilots and technicians had been grounded during the political unrest of March 1971 . When Operation Searchlight was launched to quell the Awami League - led political movement , the PAF contribution was crucial to its success . Operation Great Fly - In . Pakistan Eastern Command had planned an operation called " Blitz " in February 1971 , and the 13th FF and 22nd Baluch battalions had arrived in East Pakistan from Karachi . between 27 February and 1 March 1971 , via PIA aircraft , before the Pakistani Air Force took over Tejgaon Airport administration as part of the newly planned operation . After the decision to launch Operation Searchlight was made , the Pakistan High Command decided to reinforce the 14th Infantry Division in East Pakistan with the 9th and 16th Infantry Divisions , doing so after Operation Searchlight was launched . These divisions began preparing for the move after 22 February 1971 , and military personnel began arriving in East Pakistan via PIA and Air Force planes . Because India had banned overflights since 20 January 1971 , all Pakistani planes had to detour to Sri Lanka during trips between East and West Pakistan . Pakistan Air Force No . 6 Squadron had 9 C - 130B / E Hercules transport aircraft available in March 1971 . 5 C - 130B and 1 C - 130E were employed to transfer troops from West to East Pakistan under Operation Great Fly - In . The PIA fleet had 7 Boeing 707 and 4 Boeing 720 planes , and 75 % of PIA transport capacity was used to ferry troops from West Pakistan . The Pakistan high command had been using four C - 130 Hercules planes , and the entire PIA fleet was employed to transfer troops to East Pakistan . After the war started , two entire infantry divisions were airlifted to East Pakistan from West Pakistan between 26 March and 2 May in an operation dubbed " Great Fly - In " . Moving two entire infantry divisions - which were sorely needed to bolster the army in East Pakistan , which was facing stiff opposition over a span of two weeks - was a vital factor in sustaining the operation of the entire army . Between 25 March and 6 April , 2 Division Headquarters ( 9th and 16th , with the 5 Brigade Headquarters , 205th , 27th , 34th , 313th and 117th Brigades ) , along with one commando and 12 infantry battalions , were moved to East Pakistan . Between 24 April and 2 May another 3 infantry battalions , along with 2 heavy mortar batteries , 2 wings each of EPCAF and West Pakistan Rangers , and a number of North West Frontier Scouts , were repositioned as well . After 25 March , two C - 130B planes were stationed in Dhaka to link the areas under Pakistani control in East Pakistan with Dhaka . Most Pakistani army bases in East Pakistan had been cut off from each other since 29 March , and helicopters and C - 130 transport planes were used to ferry troops and munitions to army bases cut off and surrounded by the Mukti Bahini . This proved critical to the initial survival and ultimate success of the Pakistani troops during the early phases of the battle . Helicopters also evacuated the Pakistani wounded from isolated bases , acted as artillery spotters , flew reconnaissance missions over hostile territory , and dropped combat troops off in remote places to outflank and cutoff Mukti Bahini positions . The PAF enjoyed total air supremacy during March – November as the Mukti Bahini lacked both planes and air defense capability to counter their efforts , and flew 100 to 170 sorties in support of the army over this period . Pakistani forces had defeated the Bengali resistance by mid - May 1971 , and had occupied the entire province by June 1971 . The PAF had also requisitioned and rigged with light weapons numerous cropdusters and other light civilian aircraft to augment its reconnaissance and ground attack capabilities during this period . PAF preparations for Indian intervention . The Pakistan high command was fully aware that the IAF considerably outnumbered the PAF eastern detachment , and that they held the qualitative edge as well in the eastern theater . Pakistani planners had anticipated the PAF being neutralized within 24 hours of the IAF commencing combat operations over East Pakistan . There was only one fully functional , extended combat - capable airbase ( at Tejgaon near Dhaka ) in all of East Pakistan , as all satellite air bases lacked the service facilities for sustaining prolonged operations . The PAF had plans to deploy a squadron of Shenyang F - 6 planes at Kurmitola ( now Shahjalal International Airport ) in 1971 . These planes were temporarily deployed but ultimately withdrawn because , although the runway was functional at that base , the base was not fully functional enough to support the planes , and the lack of infrastructure meant PAF could not deploy any additional planes . This marginalization and neglect of East Pakistani defenses since 1948 had hamstrung the PAF Eastern contingent in 1971 , when its capabilities were put to the test . Pakistan deployed no additional air defense assets other than one light antiaircraft " Ack - Ack " regiment and a few additional batteries to assist the PAF in 1971 . The 6th Light Ack - Ack guarded Dhaka , the 46th Light Ack - Ack battery was in Chittagong , and elements of the 43rd Ack - Ack were present in areas around East Pakistan . The caliber of the regiment was not enhanced to " heavy " , and no surface - to - air missiles ( SAMs ) were deployed in East Pakistan . The only long - range radar , a Russian P - 35 model , was also taken to West Pakistan , along with all the C - 130 Hercules transport planes . Several " dummies " were deployed at the airbases to deceive the IAF , however . To augment short range radar cover , which could provide only 3 – 5 minutes warning to the planes , observers were deployed around the country , armed with radios and telephones . These were exposed to Mukti Bahini attacks , however , which tended to reduce their effectiveness . The IAF had flown reconnaissance flights over East Pakistan since June 1971 , and had engaged their opponents earlier in the east than they did in the west , having clashed with PAF over the Salient of Boyra in West Bengal on 22 November . Between then and 3 December 1971 , there were no engagements of the two air forces . Pakistan had lost 3 planes ( 2 shot down and 1 damaged ) on 22 November over Boyra , and as no replacement aircraft had been sent from West Pakistan , were down to 16 operational Sabres by December 1971 . IAF Operations in 1971 . The IAF had assembled units from the Central and Eastern Air commands in Eastern command bases for the campaign by December 1971 . The Central Air Command Headquarters was located at Allahabad and the Eastern Command was headquartered in Shillong , so Air Marshal P . C . Lal created an advanced headquarters at Fort William so as to better coordinate matters after a consultation with Lt . Gen . Jacob , COS Army Eastern Command . Redrawing of the operational boundaries of the respective commands for the campaign were also undertaken after this meeting . In addition , several Central Command units were temporarily housed in Eastern Air Command bases for the duration of the campaign . Eastern Air Command Order of Battle 1971 . Western Sector : ( Operating on the west of Jamuna river ) North East and North Western Sector : ( Areas to the East of Jamuna River ) CO : Air Vice Marshal Devasher Headquarters : Shillong Mukti Bahini airforce : Kilo Flight . The Indian Army had been helping the Mukti Bahini , through Operation Jackpot , since May 1971 , while the Indian Navy had helped set up the Bengali Naval commando unit and had provided command staff for the Bengali gunboats , which were busy mining riverine craft and harassing merchant marine operations in East Pakistan . The IAF could not come to grips with the PAF until formal hostilities commenced , but the Bengali airmen joined in as 9 Bengali pilots and 50 technicians - formerly of the PAF and serving with the Mukti Bahini in various capacities - were gathered for a special mission on 28 September 1971 at Dimapur in Nagaland . A number of Bengali civilian pilots from the PIA later joined this group . Indian civilian authorities and the IAF donated 1 DC - 3 Dakota ( gifted by the Maharaja of Jodhpor ) , 1 Twin Otter plane , and 1 Alouette III helicopter for the newborn Bangladesh Air Force , which was to take advantage of the lack of night - fighting capability of the PAF to launch hit - and - run attacks on sensitive targets inside Bangladesh from the air . The Bengali rank and file fixed up the World War II vintage runway at Dimapur , then began rigging the aircraft for combat duty . The Dakota was modified to carry 500 pound bombs , but for technical reasons it was only used to ferry Bangladesh government personnel . Captain Abdul Khalek , Captain Alamgir Satter , and Captain Abdul Mukit , all destined to earn the " Bir Pratik " award , piloted the Dakota . The helicopter was rigged to fire 14 rockets from pylons attached to its side and had . 303 Browning machine guns installed , in addition to having steel plate welded to its floor for extra protection . Squadron Leader Sultan Mahmood , Flight Lieutenant Bodiul Alam , and Captain Shahabuddin , all of whom later won the " Bir Uttam " award , operated the helicopter . The Otter boasted 7 rockets under each of its wings and could deliver ten 25 pound bombs , which were rolled out of the aircraft by hand through a makeshift door . Flight Lt . Shamsul Alam , along with Captains Akram Ahmed and Sharfuddin Ahmad , flew the Otter - all three were later awarded " Bir Uttam " for their service in 1971 . This tiny force was dubbed " Kilo Flight " , the first fighting formation of the nascent Bangladesh Air force . Under the command of Group Captain A . K . Khandkar and Squadron Leader Sultan Mahmood , intense training took place in night flying and instrumental navigation . After 2 months of training , the formation was activated for combat . The first sortie was scheduled to take place on 28 November , but was moved back 6 days , to 2 December 1971 . The Otter - flown by Flight Lt . Shamsul Alam , with co - pilot F . L . Akram - was moved to Kailashsahar , and was prepared for a mission against targets in Chittagong . The helicopter , piloted by Flight Lt . Sultan Mahmood and Flight Lt . Bodiul Alam , was to hit Narayangang , flying from Teliamura . In the early hours of 3 December 1971 , the twin Otter and the helicopter took off from their respective bases and hit the oil depots at Naryanganj and Chittagong , which the Mukti Bahini guerrillas had been unable to sabotage due to tight security . Ironically , the PAF initiated Operation Chengis Khan on the same night , and the IAF commenced offensive operations in the East from 3 December 1971 . Kilo Flight would , in total , fly 12 missions in 1971 , hitting various targets in Chittagong , Naryanganj , and Bhairab . The formation base was moved from Dimapur to Shamshernagar after it was liberated on 4 December , then was finally moved to Agartala before the end of the war . The BAF contingent was present in Dhaka when the surrender ceremony took place on 16 December 1971 . IAF commences Operations : 3 December 1971 . Following the preemptive strike by the PAF on its airfields in the western sector , the IAF went into action at midnight on 3 December 1971 . The Western air campaign was , at least in the initial days , limited to striking PAF forward bases and providing ground support , and was not aimed at achieving air supremacy . In the east , however , faced with only the No . 14 Squadron defending the whole sector , the Eastern Air Command was given the task to achieve total air dominance , which ultimately it did . On 3 December , Pakistan launched what was intended to be a decisive pre - emptive strike against Indian airfields , but managed only 50 sorties . The IAF hit back with retaliatory strikes . The PAF ' s handful of Sabres at Tezgaon near Dacca in East Pakistan put up a useful resistance against all - out attacks by Indian fighters from 4 December on . Between 4 and 11 of the attackers were claimed shot down in air combat and 17 more lost to ground fire , while five Sabres were shot down in air - to - air combat . On 6 December , an IAF attack cratered the runways at both Tezgaon and Kurmitola , effectively putting them out of action for the rest of the campaign . Apart from the IAF squadrons deployed in East Bengal , India ' s only aircraft carrier INS " Vikrant " ( with its Sea Hawk fighter bombers and Breguet Alize ASW aircraft ) mounted attacks against the civilian airport at Cox ' s Bazaar and Chittagong Harbor . The embryonic Bangladeshi Air Force , with three DHC Otters ( fitted with machine guns ) of Mukti Bahini Air Wing , made an appearance on 7 December . Indian airborne troops , in battalion strength , made an assault on Dacca on 11 December , using An - 12s and Fairchild C - 119Gs . This was preceded , on 7 December , by a heliborne infantry assault by two companies in about nine Mil Mi - 4s and Mi - 8s , escorted by " gunship " Alouttes . 3 – 4 December . Canberra bombers struck Tejgaon repeatedly on the night of 3 December . The PAF No . 14 operated only Sabres , which lacked night fighting capability , so the bombers were opposed only by the guns of the Pakistani light ack - ack regiment . By the morning of 4 December , however , strike missions against Tejgaon were assigned to Hunters of the No . 7 , and Squadrons No . 14 , No . 17 , and No . 37 , Su - 7 s ( No . 221 Squadron ) , and MiG - 21 s ( No . 28 Squadron ) . The first daytime raids in East Pakistan were flown by Hunters of No . 17 Squadron , and these were given top cover by four MiG - 21s from No . 28 Squadron . It proved unnecessary , and the Hunters shot down one Sabre when intercepted before the rendezvous took place . No . 14 Squadron also struck Kurmitola AFB , hitting the hangars and installations with rockets . By the afternoon , Hunters would strike Narayangunj fuel depots , and would hit Chittagong Harbour on the morning of 4 December . In an afternoon strike on Tejgaon by MiGs from 28 Squadron , a Twin otter was destroyed on the ground . For the interceptors sent up to challenge these strikes , PAF was to suffer the loss of three Sabres in dog fights over Dhaka - two to Hunters striking Kumitola . Of these , Wing Commander S . M . Ahmed and Flight Lt . Saeed ejected safely over the village of Ghazipur , but were not found by search parties . They were listed as " missing " for the duration of the war . Later reports would suggest that both pilots were killed by a hostile local populace . The last of the Sabres lost that day was to an afternoon strike on Narayangunj . Sajjad Noor was shot down while attempting to engage a strike by Hunters from No . 14 Squadron . Noor ejected safely over the village of Zinjira and was later rescued . The IAF also suffered some of its heaviest losses on these missions , losing six Hunters and one Su - 7 . No . 7 Squadron , on a strike mission against an ammunition train at Lal Munir Hat , would suffer one pilot KIA , along with the loss of two Hunters , both hit by fierce ground fire and crashing in Indian territory . One of the pilots of the stricken planes , Squadron Leader S . K . Gupta , safely ejected at Bagdogra . No . 14 Squadron also lost two Hunters on the day to ack ack . Both the pilots , Squadron Leader K . D . Mehra and Flight Lt . K . C . Tremenhere , ejected safely . Tremenhere was taken POW , while Mehra managed to evade capture and get back to Indian territory . The highest price of the day was paid by No . 37 Squadron , which suffered the death of two pilots - Squadron Leader S . B . Samanta and Fg . Officer S . G . Khonde . No . 221 Squadron was to suffer one Su - 7 shot down with the pilot , Squadron Leader V . Bhutani , taken POW . IAF Canberra planes had also struck Chittagong airport , refinery , and oil tanks on 4 December . While 2 planes were lost , they managed to damage the installations . In total , the PAF had flown 32 operational sorties against IAF incursions on 4 December , expending 30 , 000 rounds of ammunition , while the ground - based weapons had fired 70 , 000 rounds , the highest expenditure per day per aircraft of ammunition in the history of the PAF . Pakistani authorities claimed between 10 and 12 IAF planes destroyed , and took measures to conserve ammunition in anticipation of a long war . 5 – 7 December . The people of Dhaka witnessed thrilling low - level dogfights throughout 4 and 5 December . The IAF concentrated in attacking aircraft on the ground . However , for the dear price paid , it failed to cause significant damage to the PAF assets in well - dispersed and camouflage d locations . IAF also flew ground support missions , and the lessening pressure meant that the PAF managed to fly some ground support missions over Comilla and other areas . In total 20 operational sorties were flown by the Sabres , and 12 , 000 rounds of ammunition were used up during 5 December by the PAF . By the evening of 5 December , the IAF realized that a change of tactics was necessary . The ack - ack regiment managed to successfully defend the airbase during 5 December and the night of the early hours of the 6th against Indian attacks . On the morning of 6 December , four MiG - 21s from No . 28 Squadron , flying from Gauhati under the command of Wing Commander B . K . Bishnoi at very low level , climbed up to 5 , 000 meters altitude and then dived at 900 km / h , hitting Tejgaon airstrip with 500 kg . bombs , scoring several hits on the runway and rendering it unusable for operations . The airport was without air cover at that time , as a PAF ground support mission had just landed and the duty flight had not yet taken off . Two craters , each ten meters deep and twenty meters wide and separated by 1200 meters , had rendered the runway unusable ( the bombs were BETAB - 500 , anti - airstrip ordnance ) . However , Kurmitola was to remain operational until the morning of 7 December , when Mig - 21s of No . 28 Squadron again hit that runway . Although No . 7 Squadron was pulled out of the eastern operations on 6 December to help the army in the west , repeated attacks by MiG - 21s and Hunters of No . 14 and No . 28 Squadrons kept the runway cratered . An aviation website stated , " " A notable fact remains that the MiG - 21FL was neither as easy to fly nor to operate in combat under conditions the IAF had to expect in the case of a new war with Pakistan . It was designed as simple point - defense fighter - interceptor that was to operate under close GCI - control and attack its targets from the rear hemisphere with R - 3S ( ASCC - Code AA - 2 Atoll ) heat - seeking missiles . However , pleased with the speed and handling of the MiGs during operational conversions , Indian pilots trained intensively and gained not only considerable confidence , but also expertise . The Indians were to use it as an air superiority fighter as well as fighter bomber over extended ranges and well inside the enemy airspace , with minimal or no GCI - support at all . " " Effectively , the MiG - 21 had success as an interdiction - strike aircraft , taking out an important air base with only eight sorties . The results of the IAF ' s assault were that , by 7 December , the PAF in the East was effectively grounded . The IAF also bombed other airfields , including the abandoned World War II airfields of Comilla , Lal Munir Hat , and Shamsher Nagar throughout the war , denying their use to PAF planes that may be moved by road , as well as to any external aerial reinforcement . Jessore Airfield had come under Mitro Bahini control by this time , so it was spared . Pakistani authorities made repeated attempts to repair the runways . Air force and army engineers , helped by civilian workers , worked around the clock during 6 and 7 December , and by 4 : 50 AM 7 Dec , only 8 hours of respite was needed to regain fully operational status at Tejgaon . However , the IAF hit the base on the 7th , and it was estimated 36 hours of work without further damage was needed to make the base operational again . The IAF ensured no such respite took place . In desperation , it was suggested that the broad streets at second capital be used as runways , but technical problems ruled out that possibility , effectively grounding the PAF Sabres in East Pakistan for the duration . PAF fighter pilots were sent to West Pakistan via Burma on 8 December and 9 December when it became clear at least 36 hours of uninterrupted work was needed to fix the runways and the ack - ack units were unable to keep the IAF away . Pakistani authorities claimed that between 4 – 15 December the IAF lost 22 to 24 aircraft ( 7 to the PAF and the rest to ack - ack units ) . The IAF records 19 aircraft lost in East Pakistan , 3 in air combat , 6 to accidents and the rest to ack - ack , while 5 Sabres were shot down by IAF planes . After the liberation of Dhaka , 13 airframes were found at the Tejgaon airport by the Mitro Bahini in various states of sabotage . 2 T - 33 trainers were inoperable , but 8 Sabres were made operational later . 5 of these frames were incorporated in the Bangladesh Air Force in 1972 . Pakistan Armed Forces Headquarters had issued orders to blow up the aircraft , but Air Commodore Enam had pointed out that the sight of burning planes would demoralize the Pakistani troops defending Dacca . Therefore , PAF personnel destroyed the ammunition stocks and sabotaged the electric and hydraulic systems of the aircraft on 15 December . The PAF continued to use helicopters at night to airlift munitions and to fly troop reinforcements to remote bases . Prior to the surrender of Pakistan Eastern Command on 16 December , the Army Aviation squadron , commanded by Lt . Col . Liaquat Bokhari , escaped to Burma with selected personnel , including Maj . Gen . Rahim Khan ( GOC 39th Ad Hoc division ) . Operations in Support of Ground Forces . With the PAF in the east effectively neutralized , the IAF could now concentrate on supporting their advancing army . Movements of Pakistani troops during daytime came to a virtual halt due to relentless IAF air attacks . Ferries across major river crossings were sunk by the IAF , thus denying the Pakistani army its line of retreat to Dhaka . On 7 December , INS " Vikrant " , the Navy ' s sole aircraft carrier at the time , joined the operations . Sea Hawks , operating from the deck of " Vikrant " , struck Chittagong harbor , Cox ' s Bazaar , and Barisal . Whatever remained of the Pakistani Navy was destroyed or sunk , and the airfields in Cox ' s Bazaar , Chiringa , and Feni were made inoperative . On 10 December , IAF helilifted troops of the IV Corps from Ashuganj to Raipura and Narsingi in what came to be termed " Operation Cactus - Lilly " ( also known as the " Helibridge over Meghna " ) . Entire Brigade strength units were lifted over the River Meghna , allowing the Indian Army to continue their advance in the face of stiff resistance at the Ashuganj , where the retreating Pakistani Army also blew up the bridge . To the south of this area , near Chandpur , the 39th Division ( under General Rahim Khan ) Headquarters had requested evacuation by river on 8 December . Under the escort of a gunboat , the flotilla , made up of local launches , sailed in the early hours of 10 December . The IAF spotted and bombed the ships , which were either sunk or beached themselves and failed to reach Dhaka . The survivors later were evacuated by ships operating at night and by helicopters . On 11 December , India airdrop ped the 2 Parachute Battalion Group in the now famous Tangail airdrop . The operation involved An - 12 s , C - 119 s , 2 Caribous and Dakotas from various squadrons . In total , about 700 troops were airdropped . The only hitch was one paratrooper , Hav Mahadeo , who had a static line hangup . Gnats from No . 22 Squadron provided top cover for the operation , which ultimately went unhindered . Also , on 11 December , three converted An - 12s from the No . 44 Squadron struck the Jaydebpur Ordnance factory in East Pakistan . On the morning of 14 December , a message was intercepted by Indian Intelligence concerning a high - level meeting of the civilian administration in East Pakistan . A decision was then made to mount an attack . Within 15 minutes of the interception of the message , a strike was launched against Dhaka . Armed with tourist guide maps of the city , four Mig 21 s of No . 28 Squadron became airborne . Only a few minutes had passed after the meeting had started when the IAF aircraft blasted the Governors House with 57 mm . rockets , ripping the massive roof off the main hall and turning the building into a smoldering wreck . The Governor of East Pakistan , Mr . A . H . Malik , was so shocked after the incident that he resigned on the spot by writing his resignation on a piece of paper , thereby renouncing all ties with the West Pakistani administration . He then took refuge at the Red Cross Center in Dhaka . Fate of the Pakistani Navy in East Pakistan . Pakistan Forces General Headquarters had declined to provide a substantial naval contingent for the defense of East Pakistan , for two reasons . First , they had an inadequate number of ships to challenge the Indian navy on both fronts . Second , the PAF in the east was not deemed strong enough to protect the ships from Indian airpower ( i . e . both the IAF and the Indian Navy air arm ) . The fate of Pakistani naval vessels in December was ample proof of the soundness of this decision , and the repercussions of neglecting East Pakistan defense infrastructure , which was the reason the PAF could only station 1 squadron of planes there . Pakistan Eastern Command had planned to fight the war without the Navy , and faced with a hopeless task against overwhelming odds , the Navy planned to remain in port when war broke out . The Pakistan Navy had 4 Gunboats ( PNS " Jessore " , PNS " Rajshahi " , PNS " Comilla " , and PNS " Sylhet " ) . All were 345 ton vessels , capable of attaining a maximum speed of 20 knots , crewed by 29 sailors , and fitted with 40 / 60 mm . cannons and machine guns , in East Pakistan . One patrol boat ( PNS " Balaghat " ) and 17 armed boats ( armed with 12 . 7mm . / 20mm . guns and / or . 50 or . 303 Browning machine guns ) , in addition to numerous civilian - owned boats requisitioned and armed with various weapons by Pakistani forces , were also part of the Pakistani naval contingent . The improvised armed boats were adequate for patrolling and anti - insurgency operations , but hopelessly out of place in conventional warfare . Before the start of hostilities in December , PNS " Jessore " was in Khulna with 4 other boats , PNS " Rajshahi " , PNS " Comilla " , and PNS " Balaghat " were at Chittagong , and PNS " Sylhet " was undergoing repairs at a dry - dock near Dhaka . The outbreak of hostilities on 3 December found most of these boats scattered around the province . Indian aircraft attacked the " Rajshahi " and " Comilla " near Chittagong on 4 December , with the " Rajshahi " damaged and the " Comilla " sunk . The " Balaghat " , which was not attacked , rescued the Comilla crew and returned to Chittagong with the surviving ships . On 5 December , Indian planes sank two patrol boats in Khulna . The PNS " Sylhet " was destroyed on 6 December and the " Balaghat " on 9 December by Indian aircraft . PNS " Jessore " , which had withdrawn from Khulna to Dacca , was destroyed on 11 December while escorting boats evacuating Pakistani troops from Chandpur . PNS " Rajshahi " was repaired , and under the command of Lt . Commander Sikander Hayat , managed to evade the Indian blockade and reach Malaysia before the surrender on 16 December . From there , it sailed to Karachi and continued to serve in the Pakistan navy . Blue on Blue : Tragedy near Khulna . Indian Army Eastern Command had ordered Bangladesh Navy gunboats BNS " Palash " and BNS " Padma " , accompanied by INS " Panvel " and under the overall command of Commander M . N . Samant , to sail to the port at Chalna . These ships , carrying Bengali seamen and Indian command crews , had been operating against Pakistani shipping since November , and under the advice of Indian Eastern Air command , had painted their superstructure yellow to avoid misidentification . This had been reported back to Eastern Air Command . This task force sailed on 6 December , entered Mangla at 7 : 30 AM on 10 December , and took over the port facility . Commander Samant knew that Khulna was an IAF target , but decided to push on anyway . Around 11 : 30 AM , when the 3 ships were closing in on Khulna dockyard , 3 airplanes dived on them . Commander Samant recognized the IAF planes and ordered the ships to hold fire , but all 3 ships were strafed and sunk by the planes . 3 Bengali naval commandos and 7 Bengali sailors were killed , while 6 naval commandos , 1 BSF JCO , 3 Indian officers , and 7 Bengali seamen were injured . The Indian Navy gave 14 awards ( including 3 Mahavir Chakras and 6 Vir Chakras ) to the Indian rank - and - file involved in this incident . Bengali Seaman Ruhul Amin , who tried to save M . V . Palash despite being wounded and ordered to abandon ship , and who had later had died under torture , was awarded the Bir Shershtra by the Bangladeshi government . 21 Indian and Bengali sailors also became POWs . The IAF continued flying interdiction missions for the remainder of the war , shooting up ammunition dumps and other fixed installations . Gnats and Sukhoi Su - 7s flew many missions in support of army units as they moved swiftly towards Dhaka , delivering ordnance ( such as iron bombs ) to take out enemy bunkers which occasionally posed an obstacle to the advancing infantry . Canberras repeatedly struck Jessore , forcing the enemy to abandon this strategic city . The IAF was also prepared to hit any Chinese troop incursions into Indian territory in the eastern Himalayas , but as it turned out , the Chinese did not stir . In popular culture . The 1973 Hindi film , " Hindustan Ki Kasam " , directed by Chetan Anand , and starring Raaj Kumar , was based on Operation Cactus Lilly .