The Phantom Raid

By: Jamal Hussain , Pakistani Air Force

Note: This essay was written in September 2011, four months after the raid that killed Osama bin Laden.


The computerized log register at the Air House shows that
at 0207 local time on 2 May 2011, an urgent telephone call for the air chief came in.1 When the air chief came on the line, the army chief, his land counterpart, informed him of confirmed reports of aerial activity, weapons fire, and a helicopter crash around the northeast garrison town of Abbottabad. "Is there any flying activity from the PAF [Pakistani Air Force]?" the army chief inquired. The air chief replied in the negative. The only reason PAF helicopters would be flying at that late hour of the night was if they were on a search-and-rescue mission to find a PAF aircraft reported to have crashed in the area during night flying. The air chief would have been informed about a downed aircraft, so that was not likely to be the reason for the activity. The army chief confirmed that, besides the suspicion that the air intrusion may have originated from the western border on a mission that was not yet clear and appeared to be the handiwork of the Americans, no other details were available at that time.

Unsettled by this alarming news, the air chief wondered what could be the objective of such a brazen raid. As far as his knowledge went, Abbottabad had nothing of strategic value to defend, or the PAF would have deployed point-defense radar and other air defense systems to protect it against air or land attacks. Maybe the Indians actually believed their own oft-repeated mantra about Kashmiri terrorist training camps at Manshera, adjacent to Abbottabad, and had undertaken a foolhardy venture. Or perhaps the Americans, under the misperception that some of Pakistan's strategic assets were located in Abbottabad, had conducted an airborne assault to seize them. That notion made little sense, however, because if the United States ever did mount an operation to take over or destroy Pakistan's nuclear weapons, it would conduct a mass multiple-point raid rather than a stealthy solitary one. Whatever might be the motive of the aggressor, however, an immediate response from the PAF was warranted.

While still speculating about the motive and the nature of the apparent aerial attack, around 0210 the air chief issued orders to his air defense commander to scramble a pair of F-16 fighters from the nearest base. Their instructions were to go over Abbottabad and look for any flying intruders. If any were detected, the fighters had clear orders to engage and shoot the intruders down, regardless of their country of origin. This was really a very bold and courageous decision, because by then it was becoming increasingly likely that the United States, rather than India, was the aggressor. To protect the nation's honor and assert its sovereignty, the PAF was prepared and ready to challenge and engage a far superior adversary that could boast an annual budget of US$171 billion, compared to the relatively meager annual budget for the PAF of about US$1.01 billion.2

In addition to getting regular updates on the progress of the scrambled jets, the air chief gave instructions for the immediate enhancement of the entire country's air defense alert status and directed the duty staff to report to him on the status of all air defense radars. He wanted to know whether any radars had picked up intruders from either side of the border or had experienced any jamming.

As the hours passed, news started to trickle in that confirmed an aerial intrusion from the west, apparently by US forces, that targeted a solitary compound within a kilometer of the Pakistani Army's Military Academy at Kakul. The goal of the mission appeared to be the capture or elimination of a key al Qaeda leader whom the Americans suspected was holed up in the compound. The scrambled fighters, meanwhile, had reported from over the site, and despite an extensive search, could not locate any aerial activity in or around the locale. As was later learned, the helicopters that had led the air assault had completed their operations and exited the area, and were returning to their home bases in Afghanistan by the time the Pakistan F-16s had arrived on the scene.

At around 0835 Pakistan Standard Time, US President Barack Obama appeared on television and triumphantly announced that, through a bold heliborne operation inside Pakistani territory, "a small team of Americans" had killed the number-one US enemy, Osama bin Laden. "Justice has been done," the president said.3

This news made headlines in all major international and local news sources by the following morning and dominated the news over the following days; one such headline cryptically stated, "Obama Gets Osama."4

The fact that four foreign helicopters were able to penetrate more than 100 nautical miles inside Pakistani airspace without being detected by the country's air defense network and remain there for nearly two hours (approximately 80 minutes for the ingress and exit phases and 40 minutes over the site) was of serious concern and warranted a major investigation. Later in that same morning, the air chief convened a very high-level team headed by a three-star air marshal to conduct a thorough probe into the incident and submit a report. Because all official activities at the Air House and at all the air defense units, including the status of the radars and other systems, are electronically recorded, the investigation would be able to accurately determine the status of the sensors during the critical period and whether any target was picked up or a unit experienced jamming.

The investigation report was completed within three weeks and scrutinized at the highest level at Air Headquarters. Its salient findings were (1) all PAF radars that were deployed during the period under scrutiny were serviceable and operational; (2) no targets were picked up by any of the deployed sensors, nor did any sensors experience jamming; and (3) there were no system failures or any slackness on the part of the air defense operators on duty. 5

And yet four helicopters were able to cross the Afghan-Pakistani border undetected by a fairly sophisticated air defense network, penetrate over 100 nautical miles into Pakistan, operate for more than half an hour, and return to Afghan airspace before anyone in Pakistan's security forces knew they were there. The report highlighted system limitations and technological deficiencies against a sophisticated aggressor, along with inadequate low-level radar coverage on the western border, as possible explanations for the undetected raid.

To understand how this incident could have happened without some degree of incompetency or outright failure of the air defense network and its operators, it helps to have some basic knowledge of the nation's air defense network, its strengths, and its limitations.

The outermost layer in a nation's air defense system is the detection of incoming air raids. Ground-based radars are the primary means by which most countries with air defenses maintain a constant vigil against the intrusion of hostile air elements. Airborne radars like the airborne early warning and control platforms do supplement a country's air defense ground environment, but they are expensive alternatives and are used primarily to supplement certain limitations of ground-based radars. These systems are very useful during crises and wars, but to keep them operational on a 24/7 basis during peacetime is prohibitively expensive. Even the United States cannot afford such a luxury.

Ground-based radars come in two distinct versions: high-level and low-level. High-level radar is optimized to pick up high-flying targets and, depending on the altitude of the target and the power of the radar, can easily detect targets up to 250 miles away. Low-level radars, which have the ability to reduce the amount of "ground clutter" (i.e., signals reflected from the ground) they pick up, are used to detect low-flying targets. Because of the earth's curvature, the maximum range at which a target flying at 250 feet or less above ground level can be detected is generally about 25 miles. To overcome this limitation and the interference of natural and manmade obstacles, such as hills and buildings, a series or network of radars is needed to illuminate a particular area. Figure 1 shows a schematic diagram to illustrate the principle.

Pakistan has to monitor its airspace for both high- and low-level air incursions from its eastern, western, and southern borders. Given that high-level radars have a range of over 250 miles and a very wide cone of coverage, six to seven such units operating on a 24/7 basis can adequately cover the entire airspace of the country. Low-level monitoring of the borders, in contrast, presents a significant challenge. Because low-level radars have limited range and a much smaller cone of illumination, these units must be deployed linearly and in depth to give enough early warning of low-flying intruders to the air defense units. To cover the entire length of the country's borders would require more than 250 such radars to be deployed. Moreover, because of their specialization, low-level radar units have a limited lifespan and if operated on a 24/7 basis, will have to be overhauled at regular intervals. In less than a decade, they will have outlived their usefulness and must be replaced. Continuous low-level radar coverage of the entire border of Pakistan is, therefore, not possible. It may be remembered that even the United States, with an annual defense budget of over $700 billion, cannot afford the luxury of perfect radar coverage along its southern border with Mexico, which time and again is breached by drug smugglers flying low in small aircraft to drop their deadly merchandise. How, then, does the PAF attempt to overcome this severe limitation?

The procurement and operational deployment of the PAF's air defense radar network are governed by the threat perception, an official posture that is formalized by the service in conjunction with the relevant authorities at the highest level. In the current scenario, the PAF has complete high- and low-level radar coverage along its eastern border with India. During the Soviet invasion of Afghanistan in the 1980s, much of the western border, especially the northern border with Afghanistan, was provided with round-the-clock low- and high-level coverage, and the Air Force paid a high price in terms of the wear and tear on its equipment due to the constant vigil. After the Soviet withdrawal in 1988, the aerial threat from the west was downgraded. As long as coalition forces ruled the air "waves" in Afghanistan and Pakistan remained an ally in their war against the Taliban and al Qaeda insurgents, the PAF envisaged no serious aerial threat from that quarter. Currently, although a complete high-level umbrella covers the western border, low-level cover is limited. Only those installations in locations that have been identified as vital have point defense radars and ground-to-air defenses. There are enough gaps in low-level coverage that an adversary could penetrate Pakistan's airspace from the west and avoid detection.

The success of US Operation Trident Spear, as the bin Laden operation was called, was vital for the United States in general and the Obama administration in particular. The planners left no stone unturned in their efforts to ensure that the raid achieved its objective, utilizing every operational, electronic, and avionic option available to them. To avoid detection, they carefully mapped the footprint of some of the low-level radars en route and chose a path beyond the array's surveillance ranges. In addition, the aircraft flew very fast at very low altitude and through valleys wherever possible, thus further reducing the chances of detection. Furthermore, the two Blackhawk helicopters that carried out the actual mission had been specially modified to incorporate stealth technology. Special paints and modified design features made these platforms virtually invisible to the current generation of radars. Not satisfied with these measures, the planners made sure the helicopters were equipped with radar warning receivers and jammers. Should Pakistani radars have illuminated the choppers despite their stealth capability, the US pilots would have gotten a warning through their radar warning receiver and been able to resort to jamming. From an operational viewpoint, jamming is a last resort to be used only when it is confirmed that the opponent's radar system has detected the intrusion. In the event, the raid went undetected, and no jamming was required.

The US planners had one final ace up their sleeves. While the operation was in progress, they were continuously monitoring Pakistan's communications for any sign of reaction. If Pakistan had reacted in time by scrambling fighters, Admiral Mike Mullen, the chairman of the Joint Chiefs of Staff, was standing by to ring up his counterpart and inform him that it was an American raid and that Pakistan should not interfere. If Pakistan decided to engage the intruding helicopters anyway, the United States would free its own fighters, which were already patrolling the Afghanistan-Pakistan border armed with the latest beyond-visual-range missiles. The PAF fighters would then be challenged by a force of significant numerical and technological superiority. Very few episodes in the history of aviation can match the meticulous planning, deployment of cutting-edge technology, and professional execution that characterized the helicopter-led assault on the Abbottabad compound, deep in Pakistani territory.

Could the current air defense network of Pakistan have done any better against such a sophisticated operation? Perhaps not. What needs to be done to prevent another such intrusion? Given the severe imbalance between the capabilities of the US Air Force and the PAF, the answer probably lies in negotiations and diplomacy. If negotiations should fail and it is called upon to defend the nation, the PAF is ready to take on any adversary, even the US Air Force, and will fight to the bitter end, regardless of the cost.

About the Author(s):

Air CDR Jamal Hussain (Ret.) is the director of Pakistan's Center for Air Power Studies.

  1. The Air House is the official residence of the chief of staff of the Pakistani Air Force.go back up
  2. Figures are approximate. For details of the US Air Force budget estimate for Fiscal Year 2010, see Department of the Air Force, SAF/FMB, United States Air Force: FY 2010 Budget Overview (Washington, D.C.: Dept. of the Air Force, May 2009): . For the Pakistani Air Force's figures, see "Defence Budget for FY-2012–2013 Announced," Pakistan Military Review (blog), n.d.: go back up
  3. For a transcript and video of President Barack Obama's remarks announcing the death of Osama bin Laden, see Macon Phillips, "Osama Bin Laden Dead," What's Happening (blog), 2 May 2011: go back up
  4. Will Durst, "Obama Gets Osama," The Blog (blog), Huffington Post, 6 May 2011: back up
  5. The low-level radars deployed on the northwestern border were of vintage German origin, dating back to 1978. US aircraft would have the electronic countermeasure capability to plot and jam these radars with relative ease. Pakistan's radar inventory currently also includes units from several nations, including the United States and Germany. The performance of all radars is recorded and preserved in cassettes and tapes, which allowed the investigators to determine whether the protocol for radar deployment (determined by the current security status) was followed, and whether the ones that were operating in the border sector in question experienced any jamming. The investigation's recommendations included a revision of the deployment protocol. go back up
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