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)
 * No. 22 Squadron (Swifts): Folland Gnat MK 1 Dumdum, then Kalaikudda, then Calcutta (WC Sikand)
 * No. 30 Squadron (Charging Rhinos): Mig 21 FL — Kalaikudda (WC Chudda) - Fighter Interceptor
 * No. 14 Squadron (Bulls): Hawker Hunter F. MK 56 - Kalaikudda (WC Sundersan) - Fighter
 * No. 16 Squadron (Rattlers): Canberra - Kalaikudda - (WC Gautum) - Bomber
 * No. 221 Squadron (Valiants): Su-7 BMK – Fighter/Bomber
 * No. 7 Squadron (Battle Axes): Hawker Hunter F. MK 56 and 2 F. MK 1 - Bagdogra (WC Ceolho, then WC Suri). The squadron was moved to Chamb after 12 December.
 * No. 104 (Alluotte 3) and No. 104 (Mi-4) Helicopter units

North East and North Western Sector: (Areas to the East of Jamuna River)

CO: Air Vice Marshal Devasher Headquarters: Shillong
 * No. 17 Squadron (Golden Arrows): Hawker Hunter F MK 56 - Hashimara (WC Chatrath)
 * No 37 Squadron (Black Panthers): Hawker Hunter F MK 10 - Hashimara (WC Kaul)
 * No. 4 Squadron (Oorials): Mig 21 FL Gauhati (WC JV Gole)
 * No. 24 Squadron (Hunting Hawks): Folland Gnat Gauhati (WC Bhadwar)
 * No. 15 Squadron (Flying Lancers): Folland Gnat — Gauhati then Agartala (WC Singh)
 * No. 28 Squadron (First Supersonics): Mig 21FL Gauhati (Wing Commander B K Bishnoi)
 * No. 105 (Mi-4) and 121 (Alouette III) Helicopter Squadrons — Agartola

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 1 in 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-7s (No. 221 Squadron), and MiG-21s (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. "Though not programmed or required to fly, Ahmad had insisted — in keeping with the PAF's tradition of its seniors leading in combat — and was soon in the thick of battle with 4 Hunters, joined minutes later by some MiG-21s and Su-7s. In the melee, the Hunters' leader shot down Ahmad’s F-86, forcing him to eject 5 miles from Kurmitola. Despite an air and ground search, he was never found. Rashidi, in the meanwhile, successfully extricated himself from the situation just as another pair of PAF F-86s - comprising Squadron Leader Afzaal and Flight Lt. Saeed - were engaging 3 Hunters a few miles away. Both Afzaal and Saeed were immediately set upon by another Hunter and Saeed shot down. Only minutes later, Afzaal avenged this loss by chasing a MiG-21 and shooting it down. Although Saeed had ejected safely, he too was never found - reportedly both Saeed and Ahmad were taken away by Mukti supporters." 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 camouflaged 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 airdropped the 2 Parachute Battalion Group in the now famous Tangail airdrop. The operation involved An-12s, C-119s, 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 21s 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.