ប្រវត្តិសាស្រ្តបិទមុខ

Among the victims of the North Vietnamese sapper attack against Pochentong in 1971 were these Cessna T-37Bs. Cambodia had received four of them that were used not only as trainers but also as light strikers - together with Fouga CM.170 Magisters. (Ken Conboy via A. Grandolini)


These two KAF T-28Ds seemingly escaped major damage during the North Vietnamese sapper attack. They were among the few survivors of an attack that had completly wiped out the Cambodian air power. (Ken Conboy via A. Grandolini)


Another victim of the Pochentong attack was this Antonov An-2 transport aircraft. The last An-2s were withdrawn from service in 1971 - parked outside their hangars and nearly without spare parts left, they were destroyed during a storm. (Ken Conboy via A. Grandolini)

So Satto was actually requesting jets fighters – especially to replace the destroyed MiG-17Fs. He hoped for new F-5As but the Americans proposed instead former F-86Fs – at the time in the middle of the process of being withdrawn from service with the 4th Wing RTAF. An inspection of the airframes by a Cambodian delegation, however, showed that they were in a very bad shape and so nothing became out of this plan. Nevertheless, in part due to the help of MEDTC members the AVNK was completely rebuilt from its own ashes, in the course being renamed again – this time into Khmer Air Force (KhAF). Its first new aircraft were two AC-47s, the crews of which were trained in Udorn, in Thailand. By the end of 1971 also 16 new T-28Ds were delivered, together with a complete fleet of UH-1Hs, partially supplied from the South Vietnamese stocks. Under these circumstances, already in November 1971 the Cambodians were capable to launch the Operation “Chenla II”, with the task of supporting the their troops on the ground. Some 24 UH-1Hs and eight South Vietnamese UH-1Gs were deployed, together with few SVAF AC-47s and AC-119s, many of which had Cambodian pilots in the cockpit, to learn and act as observers. From early 1972 also some Taiwanese and Australian instructors were deployed to Pochentong.



On 15 Devember 1971 the KhAF became a fully independent service, separated from the Army, and with its own budget, and by February 1972 it boasted 23 T-28Ds, three AC-47s, nine own UH-1Hs, and several T-41s. Several pilots were meanwhile qualified to fly FAC-missions. In general, however, the problem of the elack of trained flying crews was still persistent, and several pilots were killed in accidents, while others were shot down and killed by the North Vietnamese. Early in 1972 the KhAF lost four T-41s and four pilots in different mishaps. In March the Khmer Rouge attacked Pochentong again, destroying at least three U-1As. In August the North Vietnamese shot down one UH-1H using SA-7s, and by the time the KhAF suffered also a loss of 14 T-28Ds, of which eight crashed due to pilot mistakes. No air force – and especially not the KhAF – could sustain such a rate of loss, and consequently drastic measures to improve the situation were needed.

The most crucial problem for the KhAF at the time was the lack of personnel to fullfill its rapid expansion program. The Air Academy, meanwhile transfered from Pochentong to Battambang, was forced to reorganize its training syllabus: instead of a French-inspired training program, a new crash-training program was put into practice. Pilots were trained in a hurry; attack pilots received only a 100-130 basic flight hours program before being posted to an operational T-28D squadron. The new student then received was was called an “on job traing” in combat situation. The losses were heavy, with many young inexperienced pilot killing themselves in accidents. The same thing happen with all the transport, observation and helicopter pilots. The technical personnel training was more thorough but the standard syllabus was also cut short. The departure of the French instructors caused further problems to the Air Academy: they were partly replaced by Taiwanese instructors, but - contrary to many rumours - no Thai or Australian ever served as instructors in Cambodia. Australia indeed had delivered some six C-47s in 1971 but no personnel were send to support the KhAF. Some Taiwanese transport pilots flew with the KhAF C-47 squadron to replace Khmer aircrafs needed for the AC-47 program.

In general, however, the KhAF was an organization independent from Thai and US advisors: the MEDTC role was meanwhile limited only to logistic support. Contrary to the situation in South Vietnam or Laos, no US officers were directly involved even in the planning of operations.

By October, reinforced by five new T-28Ds and additional O-1Ds, the KhAF considerably improved the training of remaining crews, mainly with help of six Taiwanese instructors for C-47s and T-28s. To support the training program, the Air Academy's 16 Gardan Horizon trainers, as well a half a dozen surviving MS.733s and Yak-18/BT-6s were reinforced and later replaced by a dozen of Cessna T-41Ds as well as 12 T-28B/Cs. The later were painted in light gray with engine cowling and wings and tail tips in orange-dayglo, while the T-41Ds were painted in an olive-drab scheme. Additional students were sent to the USA for training, and the KhAF was able to increase the number of combat sorties flown by up to 60 percent.

Just as it appeared as if the Cambodian Air Force would finally recover, on 17 March 1973 Capt. So Patra, a son-in-law of Prince Sihanouk, defected with his T-28 and took a course ono Phnom Penh. After doing several turns around the Presidential Palace he finally attacked, dropping several bombs, killing 43 and injuring 35 in the process. Lon Nol, who was not in the palace at the time, immediately ordered all the members of the royal family and their relatives to be imprisoned. The KhAF was grounded for three days, until an investigation ascertained that So Patra organized his action alone: nevertheless, So Satto was removed from command, and replaced by his vice, Penn Randa.

In long term, the attack against the Presidential Palace was to have tremendous effects on the KhAF, however: the US Congress forbade any additional involvement of the US military in Cambodia and ordered a complete pull-out of all US troops by 15 August 1973. This meant that the KhAF was now left with barely five months to become an air force completely independent from any foreign help: a task that was to prove exceptionally problematic because of described problems. Nevertheless, in the final months of their direct involvement the USA managed to reinforce the KhAF by addition of five C-123K Provider transports, 12 T-28Ds, and six UH-1Gs.


AVNK UH-1H "213" seen during combat operations in 1973. (USAF, via Tom Cooper)

AVNK UH-1H "208", as seen in 1973 or 1974. Some Cambodian "Hueys" - including this one - carried prominent insignia on the nose: sadly, not much is known about the one carried on this helicopter. (Artwork by Tom Cooper)

The US Pull-Out

With the US pullout it was generally expected that Lon Nol’s regime would collapse almost immediately. However, what happened was exactly the opposite. Especially the KhAF – even if not completely developed, and most of its crews lacking training and experience – was in high spirits and ready to continue the war. Already by the end of August its T-28s flew no less but 700 combat sorties, while the new C-123s flow 94 transport missions. Some mistakes could were not corrected, however: the KhAF was still using the old operations centre in Pochentong, and therefore flew mainly missions against fixed targets instead of using the FAC-tactics. Consequently the T-28 were often too late to find their targets, or missed – sometimes by kilometres.

All US military operations in Cambodia ceased on 15 August 1973. Sensing the victory at hand, the Khmer Rouge launched an all out offensive against Phnom Penh with over 75 000 men. Lon Nol requested a last minute effort from the US airpower, and in response all the USAF aircraft still deployed in South East Asia - including over 400 B-52s, F-4s, F-111s and A-7Ds - launched repeated strikes against enemy targets on the outskirts of the capital. At times, crowds gathered on the west bank of the Mekong River to watch them hit Khmer Rouge targets on the opposite shore. This massive air campaign thwarted the Communist offensive. At one point, when it appeared the Khmer Rouge might block river traffic again, the USAF launched an emergency C-130 airlift from U-Tapao to Phnom Penh’s airport. It delivered munitions, rice, and military equipment. The USAF transports also parachuted supplies to several towns under siege by enemy. By mid-August 1973, the C-130s had flown some 666 sorties.

As the deadline drew near, the USAF was involved in a tragic accident. On 6 August 1973, a B-52 mistakenly dropped 20 tons of bombs on the friendly city of Neak Luong, 38 miles southeast of Phnom Penh. The town was situated on the Mekong River bank and served as an important base for both the Cambodian and South Vietnamese Navies. The raid killed or wounded more than 400 people.

The last US air strike in Cambodia occured on the morning of 15 August 1973 with a last bombing mission carried out by a flight of A-7Ds. According to official statistics, the USAF had flown some 39 999 tactical sorties from March 1970 to August 1973 in Cambodia, dropping 78 154 tons of bombs. The B-52s flew an additional 5 979 sorties during the same period, and dropping 125 706 tons of bombs. Exact figures about USN operations over Cambodia remain unknown, but it is known that the carrier USS Coral Sea (CVA-43) made a combat cruise in the Gulf of Siam, in 1973, and that her aircraft flew combat sorties over Cambodia as well.

The US fixed-wing losses in Cambodia were considerable too: the USAF alone lost 39 aircraft, including eight F-4 Phantom IIs, one F-111A, six F-110s, two A-7Ds, and five A-37Bs. Numerous reconnaissance aircraft were shot down as well, including two RF-4Cs, six OV-10As, six O-2As, and two O-1s. A lone USAF C-123K was also destroyed while in Cambodia.


US Operations after August 1973

If after August 1973 all US combat operations ceased in Cambodia, air resuply missions continued. At the year’s end the air bridge brought to Phnom Penh an average of 7000 tons of fuel and amunition per month, against 4900 tons brought in by ships sailing up the Mekong River. The aircraft belonged mostly from the USAF 317th Airlift Wing of Pope AFB that operated rotational detachments from U Tapao in Thailand and used the radio-code name of “Klong”. The USAF transport missions continued until summer 1974, with many paradrops made in profit of the Cambodian garissons of Kompong Thom, Takeo and Kampot as well as dozens other small drop zones (DZ) scattered throughout the country. These DZs were located and their status assesed by reconnaissance flights of USAF RF-4Cs that also flew intelligence sorties in profit of the Cambodians. The aircraft now faced increasing anti-aircraft oppositions, notably several firing of SAM-7s. From April to August 1974, the Klongs were supplemented by some MC-130s from the 1st Special Operation Group with specially equipped aircraft allowing independant precise navigation and high altitude droppings.

Nevertheless, the US open military air transport operations over Cambodia was now facing growing political oppositions. Washington then decided to swicth to a more discrete type of missions. It was envisaged initially to use Air America aircraft but at that date the CIA connection to this company was too well known. Instead, a contract was passed with a former CIA conected air company entrepreneur, William Bird, who had run paramilitary operations in profit of the Agency in Laos in the early 1960s with his Bird and Sons Inc airline.

On 28 August 1974 a contract was signed with the Bird Air Company to run the transport air ressuply operations in Cambodia. The USAF handed over five of its own C-130Es to the Bird Air, in addition to the company own DC-6s. The Hercules were “satinazed” with all the national and military marking removed but retained the camouflage scheme! Only a tiny serial number is painted on the tail. Officially the planes were considered as being “US government furnished” but not “leased”. The first Bird Air mission took place on 26 September 1974 while all USAF airlift missions were suspended on 8 October.

Fighting the Lost Battle

While the USAF B-52s could be dangerous for Cambodian civilians, KhAF attacks sometimes went off as well: in October 1973 the T-28Ds hit a unit of the Cambodian Army and killed 20 troops. As if this would still not be enough, on 19 November there was another incident with a disaffected KhAF pilot, when Lt. Lim Khun bombed the Presidential Palace.

The furious Lon Nol then ordered the CO KhAF to be replaced, and in the future every KhAF formation that took off for a combat sortie had to be lead by a pilot considered “loyal”, the aircraft of which was armed with smoke rockets and guns only, and who had a standing order to shot down any member of his formation that might turn towards Phnom Penh. In the end this order had a very negative effect on the KhAF, as now its best pilots were limited to leading their formations and forbidden to bomb the enemy – and this happened just at the time the Khmer Rouge encircled almost the whole capital, putting it under a siege in the process. Only trust in the KhAF and the US support could now save Lon Nol’s regime – but the amount of both was permanently decreasing.

Contrary to Lon Nol, the Cambodian Army felt no distrust to the KhAF, and continued calling for close-air-support at a high tempo. By the late January 1974 the KhAF T-28s flew up to 40 combat sorties a day. This was in part possible because of its new commander, the French-trained Brigadier Ea Chhong, that introduced very high standards of leadership and command. Under Chhong’s leadership the KhAF was to see its best times in the spring of 1974, with the precision of air-drop sorties of the C-123s reaching 98%, while a number of AC-47- and helicopter-pilots began flying by night as well. Thanks to intense KhAF support, for example, the Army was capable of holding the city of Takeo. The FAC-tactics was reintroduced, and the T-28s improved their precision considerably as well: in July 1974 ten T-28Ds lead by a single O-1D attacked a North Vietnamese truck park in the Kratie Province, destroying no less but 125 vehicles in the process.

At the time, the KhAF was organized as follows:
1st Intervention Group
- 3 Attack Squadrons with 45 T-28Ds
- 1 Gunship Squadron with 14 AC-47Ds
- 1 Gunship Squadron with 14 AU-24As

1st Transport Group
- 1 Transport Squadron with 12 C-123Ks
- 1 Transport Squadron with 20 C-47s
- 1 Light Transport Squadron with 8 U-1As
- 1 VIP Transport Flight with 1 DC-6, 1 DC-4, 2 UH-1Ns

1st Observation Group
- 45 Cessna O-1s

1st Helicopter Group
- 38 UH-1Hs
- 13 UH-1Hs (gunships)

Air Academy
- 12 T-28B/C
- 13 T-41Ds
- 10 GY-80s

By September 1974 the KhAF was flying more than ever, with T-28s mounting 127 combat sorties a day on average in order to support the Army in the defence of a Khmer offensive in the Kompong Chhong Province. However, like already several times before, just in the moment the KhAF started to function better than ever before, something happened that changed the whole situation again. Namely while the KhAF air strikes finally started showing their effects, in October 1974 the USA decided to stop supporting Lon Nol, by limiting the worth of ammunition the Cambodians were permitted to spend daily to $82.000. This meant that from that moment the KhAF would not be able to fly more than 49 combat sorties with T-28s, six with AC-47s, and ten with AH-1Gs every day, even if it was clear that much more was needed if the Khmer and the North Vietnamese were to be held under pressure, and all the besieged enclaves supplied from the air.

The situation was immediately exploited by the enemy, and in the late 1974 the Khmer and the North Vietnamese – after recovering from the blows of the previous summer – put the Cambodian Army under heavy pressure. The KhAF was now to start suffering from poor communications with the Army too: the Army was meanwhile counting with air support for most of its operations, but all too often Chhong was not informed in time. Under such circumstances, the Khmer Rouge was able to organize a large offensive in the early 1975, hitting the Army heavily in several places. When this happened, the KhAF was forced to fly intensively and spend more ammunition than officially assigned from the USA. The US President Nixon was not to give up supporting Nol that easily however. In the Operation “Fly Catcher”, in January 1975 over 100 USAF technicians were flown in to Pochentong to service and refurbish all the remaining T-28s. Simultaneously also six C-123Ks were supplied to the KhAF, and there were plans to increase the number of Providers to 18 by July of the same year.

The End of Lon Nol

With the KhAF being limited in the amount of ammunition it could expend every day, its capability to support different branches of the military decreased considerably. One of the most problematic issues was that of escorting boats that were moving supplies to isolated forwards posts along the Mekong River. Without the support from the air these boats became exceptionally vulnerable and no less but 19 were lost within a single month.

The last convoy to reach Phnom Penh arrived after suffering heavy casualties on 19 January 1975. With the supply route via Mekong River being effectivelly cut off, it was decided to increase the Bird Air number of sorties to 13 per day. This, however, were clearly insufficient, even if five C-130Es from the USAF 374th Airlift Wing were then handed over to Bird Air. Simultaneously, another contract was granted to Flying Tigers Lines for the use of three DC-8-63s to transport rice to Phnom Penh from U Tapao. The first DC-8 sorties took place on 15 February 1975. From 27 February, the DC-8 operations were transfered to Tan Son Nhut in South Vietnam. By early March the number of DC-8s involved had been increased to seven with aircraft from Airlift International, World Airways and Trans International joining those of the “Tigers”. The air bridge continued despite now appaling working conditions at Phnom Penh, since the Khmer Rouge had brought in 105mm howitzers and 107mm MRLs to pound the Pochentong airbase.

The KhAF continued to operate and tried to protect the airbridge despite constant artillery fire: over three thousands artillery rounds hit the airport perimeter in February and March 1975. Each transport plane arrival and departure was protected by a flight of T-28Ds or AU-24As patrolling overhead and dive-bombing each detected artillery positions. Thanks to this gallant effort the daily average quantity of rice delivered to Phnom Penh rose from 2.300 tons in January to 8.200 tons in March, allowing an eleven-days stock inside the city. Some days the shelling was so intense that the operations were suspended.

Meanwhile, the Army garrisons outside Phnom Penh were left without supplies, and - one after the other - had to give up, in turn enabling the Khmer to tighten their grip on the Cambodian capital and surrounding areas. By 13 March the Communists reached the Pochentong area. Their first attack with multiple-rocket-launchers calibre 107mm hit the ammunition and supply depots, both of which were blown sky-high as a result. The defenders of the airfield, however, held out and were able to keep the Khmer Rouge and the North Vietnamese outside the perimeter.

Nevertheless, when the KhAF struggling to defend its own bases it could not fight the Khmer elsewhere. Consequently, during the rest of March 1975 some 150 supply flights to Phnom Penh were cancelled due to artillery shelling and eight aircraft damaged. The KhAF T-28Ds now often operated from a road outside the airbase in Pochentong that was less targeted by the enemy artillery. On 22 March, one DC-8 and one C-130 were badly hit and the airbridge completly suspended for two days. The situation was so desperate that President Gerald Ford ordered to use some USAF “Kong” C-130s to reinforce the airbridge. From 18 March and for a week they flew some 5 sorties per day to Phnom Penh.

Without any support from the air or chance to be relieved, on 2 April 1975 the last Army garrison on Mekong River fell to the Khmer. In his final radio message the commander of the unit in question explicitly requested a T-28 to strike his command post.


Although the USA started delivering T-28Ds to Cambodia already in August 1962, the type did not see any prominent service before the early 1970s. In fact, by 1969 most Trojans of the AVRK were inoperationall due to the lack of spares. After Gen. Nol came to power all were brought to operational condition by USAF technicians, and have got new markings: the exact position and size of these remains unconfirmed, however. 5(1)-2693 was destroyed by Vietnamese sappers in January 1971 attack on Pochentong, together with (5)0-13699, (5)0-17735, and (5)0-17833. (Artwork by Tom Cooper)


With the situation becoming desperate Lon Nol has lost nerves and left Phnom Penh. The KhAF continued fighting nevertheless: several C-123Ks were modified to carry up to 21 Mk.81 or CBU-25 bombs, that were then rolled over the rear loading ramp. They flew at least 36 combat sorties in the final days of the fighting, before the Khmer Rouge advanced into the suburbs of Phnom Penh, on 7 April 1975.

Meanwhile, KhAF T-28s were ordered to cover the Operation "Eagle Pull" - the evacuation of the US embassy and all the US citizens, starting with 3 April 1975. Instrumental for this operation was the helicopter carrier USS Okinawa (LPH-3), that operated two squadrons of helicopters, as well as the remaining Cambodian UH-1Hs, most of which were based on the football stadium in Phnom Penh. DC-8s and C-130s were also used to evacuate, and both the American and Cambodian personnel were involved in the air bridge. Eventually, over 1.000 people were evacuated, including 52 orphans. On 11 April the airbridge was suspended. Throughtout the operation, an average of 1.100 tons of supply were landed each day at Phnom Penh but at a heavy price: at least nine Cambodian personnel of the Pochentong Airport had been killed and several dozens wounded. Amazingly no aircraft were lost!

Until the fall of Phnom Penh on 18 April 1975, the Bird Air C-130s continued to drop an average of 83 tons per day of supply to various Cambodian garissons, while the KhAF C-47s and C-123Ks also flew supply missions until the bitter end.
However, when on 16 April the guerrilla penetrated the Pochentong AB and captured the control centre, the remaining T-28 crews could only drop their last napalm bomb on the building – obliterating it completely – and then fly out to Thailand.

By 18 April the last 18 KhAF aircraft were evacuated to Thailand, where already dozens of other were flown: a total of 97 Cambodian aircraft and helicopters eventually ended in Thailand, while exactly 100 others – including 22 T-28Ds, six AC-47s, nine C-123Ks, and some 24 UH-1Hs and UH-1Gs – were captured by the Khmer Rouge. With this, the early history of the Cambodian Air Force – an air arm that grew to a considerable size, capability, and effectiveness in the final five years of its existence - came to an end.


The last US air strikes into Cambodia took place on 15 August 1973. American airpower saved the Cambodian regime during that summer. This USAF A-7D was seen while flying toward a target in the vincinity of Phnom Penh, in July 1973. (USAF via A. Grandolini)



The Mayaguez Incident

Upon bringing Phnom Penh and most of Cambodia under their control, the Khmer Rouge – led by their secretive leader Saloth Sar, better known by his “nom de guerre” Pol Pot – immediately embarked upon developing one of the most radical, merciless, and dreadful regimes of our times. In his “Reconstruction” project, Pot searched to “re-built” the entire Cambodian society: any contact to the outside world was severed; education and religion were considered subversive, no modern technology was permitted and all the cities were emptied, the entire possession of all citizens was confiscated and thousands forced into labour camps. For the next three and a half years Cambodia was plunged into a bloody hell. Out of a population of some seven millions over two millions were killed: many perished due to exhaustion, malaria, and malnutrition while being forced to work on huge agricultural construction projects entirely reliant on manual labour. Cambodia’s economy – the country was once considered a “rice bowl” of south-east Asia – was completely ruined in this giant and tragic failure.

Even before he managed to ruin the country, however, Pol Pot was already to collide with the USA. On 12 May 1975 Khmer Rouge seized the US container ship SS Mayaguez, while this was underway in the Gulf of Thailand. The crew of the ship managed to issue an SOS in the last moment, and the USN immediately dispatched several Lockheed P-3A Orions to search for it, finally localizing the ship underway at a very slow speed off the Koh Tong Island. In contrast to the Pueblo Crisis, when the North Koreans seized the USS Pueblo, a USN ELINT/SIGINT-gathering ship, this time the White House ordered an energic action for the recovery of the captured crew: SS Mayaguez was not a military ship, but the Americans wanted a clear message to be delivered to Pol Pot. Consequently, a rescue operation was immediately staged, mainly involving USMC and USAF units based at U-Tapao, in Thailand, as well as the USN aircraft carrier USS Coral Sea (CVA-43). The last had aboard the aircraft of the CVW-15, including F-4N Phantom IIs of the VF-51 and VF-111, A-7E Corsairs II of the VA-22 and VA-94, A-6A Intruders of the VA-95, RF-8Gs of the VFP-63 and E-1E Trackers of the VAW-11. On the following day the SS Mayaguez was detected by several AC-130 Gunships, encircled by a number of Cambodian patrol boats. In order to prevent the Khmer to bring the ship deeper into their territorial waters, the Gunships were ordered to attack: approaching at a level of 1.000m, the lead AC-130 opened fire on the boats bellow the crews of which could not effectively respond. Within minutes all the Cambodian boats were heavily damaged: five of them were finished in a strike by USAF A-7D Corsair IIs, flown on the morning of 14 May.

Meanwhile, the preparations in Thailand were finalized. Around 0700hrs of 15 May 1975, eleven CH-53 Sea Stallion helicopters approached Koh Tong at a very low level, and disgorged a party of the US Marines. The helicopters and the Marines immediately came under dreadful defensive fire and as more helicopters arrived, additional were hit: by the end of the day, eight of eleven involved CH-53s were either shot down or badly damaged. Nevertheless, three other CH-53s were meanwhile used to deploy additional Marines aboard the frigate USS Harold E. Holt (FF-1074), which has got the task of intercepting SS Mayaguez.


US Marines seen disembarking from a USMC CH-53 helicopter on Koh Sang Island. (USMC via A. Grandolini)


Since it was assumed that the Khmer were holding the hijacked crew there the Koh Tong Island was not hit by any air strikes. However, a full “Alpha-Strike” from the USS Coral Sea was launched to neutralize the Khmer Air Force. Around 0845hrs the Corsairs and Intruders hit the Ream airfield, claiming destruction of 17 T-28 Trojans: this was quite an overclaim, as barely 12 T-28s were expected in the place. Besides, the post-strike reconnaissance revealed that indeed only five Trojans were destroyed. Nevertheless, in the same strike also the fuel depot and the smaller runway at Kompong Son were hit and badly damaged, as well as a nearby oil refinery. Despite this success, the situation was now rapidly becoming precarious: even if the USS Holt was able to take SS Mayaguez under a tow, the crew was still not found, and the Marines at Koh Tong were still pinned down under tremendous fire of the Khmer. This changed in an obscure way around 0945hrs, when a Cambodian patrol boat approached the destroyer USS Henry B. Wilson (DDG-7), announcing that all the 39 Mayaguez-crewmembers were aboard and free to leave!

Now the Americans have got the free hands to act on Koh Tong: with support of a series of heavy strikes by USAF fighters, around 1215hrs the first recovery attempt was launched. This was beaten back, however, just like the second attempt, launched around 1430hrs. It was obvious that a much better planned and executed action was needed if the Marines were ever to be picked up from Koh Tong. From 1600hrs the first OV-10A Bronco aircraft arrived over the place, to act as FAC: from that moment they started to direct an increasing number of USAF A-7Ds, F-111As, and F-4Es against selected targets: finally, the air strikes began to show results. Around 1730hrs a MC-130 of the USAF dropped also one of the 7.000kg (15.000lbs) heavy BLU-82 “Big Blue” bombs, causing a shock and confusion on the Khmer side. At 1745hrs, finally the third recovery attempt was launched, and this time the remaining three operational CH-53s managed to pick all the Marines. The expensive operation costed the USA eventually 15 killed, three missing, and no less but 50 injured.