How to protect airliners?

The shooting down of Ukraine International Airlines Flight PS752 at the start of the year made headlines around the world. What can be done to reduce the risk of similar tragedies happening again? Mark Broadbent reports.

A Boeing 737-800, UR-PSR (c/n 38124), was mistakenly shot down by the Iranian Islamic Revolutionary Guard Corps (IRGC) on January 8.
AirTeamImages.com/Matthieu Douhaire

Protecting civilian aircraft from missile attack has been placed in the spotlight once more after the recent Ukraine International Airlines tragedy.

On January 8, 2020 the Boeing 737-800 operating Fight PS752 to Kiev crashed shortly after departure from Tehran Imam Khomeini International Airport, Iran. All 176 passengers and crew aboard were killed.

A video circulated on social media, later shown by TV news networks globally, showed a burning aircraft descending in the night sky before impact.

Within hours, Western political leaders said their intelligence showed that the Iranian military had shot down the aircraft. Reuters quoted a US official as saying it had detected the heat signatures of two surface-to-air missiles (SAMs), followed by an explosion around the aircraft. The New York Times published what it said was a verified video showing a missile hitting an aircraft near Tehran Airport.

Iranian authorities initially rejected the claims, but later back-tracked, admitting the 737 had been unintentionally shot down after being mistaken for a hostile target as it turned towards a “sensitive” Islamic Revolutionary Guard Corps (IRGC) site.

The shootdown happened at a time of heightened tensions between Iran and the West. Just hours before the crash, Iran had attacked two US military targets in Iraq in response to the January 3 assassination of General Qasem Soleimani.

Iran’s admission provoked an angry global reaction and anti-government protests in Iran. The International Air Transport Association labelled the downing an “outrage” saying: “No effort should be spared to make sure that such a tragedy is ever repeated.”

Sadly, the loss of PS752 was just the latest entry to a long list of comparable incidents (see 'Airliner shootdowns' at the foot of this article). The question persists: what can be done to stop or minimise such incidents?

Man-portable air defence systems (MANPADS) pose one of the most dangerous threats to airliners because of their relative ease of use and portability.
USAF/A1C Jonathan Snyder

Sophisticated countermeasures

Man-portable air defence systems (MANPADS) pose one of the most dangerous threats to airliners because of their relative ease of use and compactness.

A December 2019 report, Acquisition and Use of MANPADS Against Commercial Aviation, was issued just days before the Tehran incident. According to the report, produced by the US-based think-tank RAND Corporation, they have been used to hit civilian aircraft in 65 incidents since 1975, “resulting in the deaths of over 1,000 civilians”.

Of course, basic infrared countermeasures such as flares and chaff can protect aircraft, but as the RAND report reveals, these are “ineffective against advanced imaging MANPADS or command-guided systems”. Further weaknesses of basic countermeasures are that they require dispensers and impose maintenance and staff training requirements.

More sophisticated self-protection is provided by directed infrared countermeasures (DIRCM), which detect and track infrared signatures with a missile approach warning system and fire a laser beam at incoming missiles to jam the weapon’s guidance head, causing it to lose lock and be diverted away.

DIRCM defence

Among DIRCM products available for large commercial aircraft, Elbit Systems has C-MUSIC, which the company says provides “effective, reliable and affordable protection”.

The system is contained in a single 352lb (160kg) fuselage-mounted, 8ft 8in (2.7m) long pod. Elbit says it “has been designed to meet the highest demands required by civil aviation, including high reliability, simple installation, low drag and no effect on crew workload”.

The company launched C-MUSIC after the attempted shootdown, in September 2002, of an Arkia Israeli Airlines Boeing 757-300 in Mombasa, Kenya. The Israeli government later mandated that every Israeli carrier must install the system on their airliners. C-MUSIC has now amassed more than 35,000 hours of use, having “proven effective in the full range of operational conditions,” so says Elbit.

The USAF tests its electronic countermeasures regularly. Here, a training surface-to-air missile is launched at a C-17A Globemaster III.
USAF/SA William Johnson

Back in the 2000s, the US Congress directed the Department for Homeland Security (DHS) to evaluate the effectiveness of DIRCM technologies for commercial aircraft. The DHS’ subsequent Counter-MANPADS Programme evaluated the BAE Systems JETEYE and Northrop Grumman Guardian DIRCM products. Three American Airlines Boeing 767-200s were equipped with JETEYE and ten FedEx Express MD-10Fs received the Guardian for the tests, which finished in 2008.

The DHS subsequently concluded that both systems could counter multiple missiles, but each fell short of reliability requirements and it would cost US$2.2bn to put such equipment on airliners in the US commercial fleet. The US Congress later shelved the idea.

There have been many high-profile incidents where airliners have been shot down by more sophisticated weapons systems than MANPADS such as ground-launched, radar-guided missiles or air-to-air missiles. Most recently, Malaysia Airlines Flight MH17 was downed over eastern Ukraine in 2014 by a Russian-linked surface-to-air missile.

The Congressional Research Service (CRS), which provides policy and legal analysis to Congress, stated in an article that it is “unlikely” DIRCM systems would be able to defend an airliner targeted by such weapons.

Effective protection?

The CRS said that although DIRCM systems may provide some defence, more sophisticated missiles “cannot be spoofed” and that DIRCM does “not protect against the full array of military weapons that rely on other means of guidance”.

Both the RAND analysis and the CRS study say other anti-missile technologies that can acquire, track and destroy a missile such as high-energy laser (HEL) systems have limitations. Although HELs can destroy a missile, not just deceive it, RAND reported they “vary in effectiveness” depending on the seeker type and the missile’s own infrared countermeasures.

Another high-profile incident relating to surface-to-air missiles involved a Malaysian Airlines Boeing 777-200ER which was shot down over Ukraine on July 17, 2014.
AirTeamImages.com/Serge Bailleul

It also said HELs “can only engage a single missile at a time and can only defend relatively small zones around airports” that they may “only be able to protect aircraft during limited portions of the flight” and that it might be impractical to deploy them at airports.

Some nations, such as Israel with its Iron Dome system, have installed ground-based missile defences near their hubs. The DHS even considered installing laser-based defences in unmanned aircraft flying at high altitudes above airports. According to the CRS report, the idea was scrapped after tests which “indicated that available DIRCM systems could not reliably defeat a shoulder-fired missile”.

Restrictions to reduce risk

Technology aside, a more immediate way to mitigate the risk is simply to avoid putting aircraft in harm’s way.

In the hours after PS752 crashed, international airlines moved quickly to modify flight plans through the Middle East to ensure they did not enter airspace deemed to be at high risk.

Aviation authorities conduct risk assessments and issue a notice to airmen (NOTAMs) advising on dangers and, in some cases, imposing restrictions on certain blocks of airspace.

The US Federal Aviation Administration issued a NOTAM after the Tehran shootdown, prohibiting US airlines from flying into Iran, Iraq, the Gulf of Oman and the waters between Saudi Arabia and Iran. Although the complete ban was later relaxed, subsequent NOTAMs maintained restrictions on certain parts of airspace in the Persian Gulf and Gulf of Oman, including minimising over-water operations.

The USAF trains its aircrews to react to surface-to-air missile threats using a man-portable aircraft survivability trainer.
USAF/TSgt JT May III

By February 2020, the FAA’s website also listed NOTAMs prohibiting or restricting operations in Afghanistan, Kenya, Libya, North Korea, Somalia, Syria, parts of Ukraine, Venezuela and Yemen.

Strengthening potential weaknesses in airport security is a further way to reduce the risk of shootdowns. The US Transportation Security Administration’s (TSA) Federal Air Marshal Service conducts vulnerability assessments, known as MANPADS Assist Visits (MAVs), to identify potential security gaps at an airport and recommends mitigation measures.

These visits are carried out mainly at US airports and sometimes in other nations. The TSA says it has conducted 38 MAVs since the programme began in 2003.

Stopping the supply

Another method to counter the missile threat is action to stop MANPADS or other missile systems falling into the wrong hands by undertaking what the RAND Corporation’s analysis calls “disruption and degradation” of weapons belonging to “non-state armed groups” (NSAGs).

The TSA states that, since 2003, co-operation between the US and other countries has seen more than 33,500 examples of what it calls “excess, loosely secured, illicitly held, or otherwise at-risk MANPADS in over 30 countries” destroyed.

The RAND report discloses that authorities can seize financial assets, extradite and prosecute members of NSAGs, prosecute entities that do business with them, launch military operations against specific groups, impose export control agreements and intercept illegal weapons shipments.

El Al has used anti-missile countermeasures since the early 2000s. It equips aircraft operating on more sensitive routes with Elbit’s C-MUSIC system.
AirTeamImages.com/Florent Lacressonniere

The agency maintains that tight controls on weapons storage, close monitoring of stockpiles and disablement training are other tactics. It also cites what it calls “market reduction activities” to make it more costly for NSAGs to acquire MANPADS.

It explains: “Once MANPADS are outside state control, US and allied countries could acquire them from black markets and either return them to appropriately secured stockpiles or render them inert.

“Doing so reduces the supply of MANPADS available for purchase by NSAGs. Although these programmes are unlikely to eliminate supply, they could drive up prices... which might place them beyond the financial means of NSAGs."

Tackling the issue

The report declares that the missile threat to airliners can only be tackled by combining all the different activities – preventing missiles from falling into the wrong hands, managing airspace and deploying anti-missile technology: “Employing a multi-layered approach involving several options should be pursued as part of a wider strategy to lower risk.”

It also acknowledges the risk of a MANPADS attack on civil aviation is “easy to blow out of proportion” but cautions the “threat will not disappear” adding: “Unstable countries continue to stockpile these systems, and producer countries have shown little compunction in selling them to unstable regimes. From this, it is not difficult to imagine deadly scenarios involving civilian airline passengers and MANPADS use.”

The report warns: “Ample non-state actors active in conflict settings possess [MANPADS] capability and have demonstrated the potential intent to use it to the harm of civilians.”

 
The C-MUSIC system is contained within a single 352lb fuselage-mounted pod measuring 8ft 8in x 1ft 9in x 1ft 6in.
Elbit Systems

Slow progress

In the 2000s, the International Civil Aviation Organization (ICAO) launched Regional Aviation Safety Groups as “focal points to promote the reduction of aviation safety risks through the involvement of all aviation safety stakeholders” to co-ordinate the mitigation of safety risks.

The high-profile downing of MH17 led an ICAO to form an international task force on civilian aircraft operating in conflict zones. The ICAO also established roles and responsibilities for states, airlines, air navigation service providers and other stakeholders, and launched a Conflict Zone Information Repository, a website where countries can share details about potential risks worldwide.

Despite this, the IATA’s annual meeting last June saw the association’s senior vice-president for safety and flight operations, Gilberto Lopez Meyer, complain about a lack of progress with airlines needing better information. There remains no international agreement on how or when to close airspace, with individual regulators and airlines making their own risk assessments and decisions.

Elbit Systems manufactures directed infrared countermeasure devices that can be fitted to the underside of commercial aircraft. Elbit Systems

‘Two out – all out’?

The European Cockpit Association (ECA), an umbrella organisation representing 40,000 pilots across Europe, recently called for more urgency in addressing commercial aircraft flying in conflict zones.

One ECA proposal is a so-called ‘two out, all out’ rule: if two European Union (EU) member states or two major airlines decide to suspend flights to a conflict zone, then all EU carriers would stop links to that area.

ECA president Jon Horne said: “What we urgently need is a method of sharing and acting, not upon closely guarded intelligence, but upon the outcome of risk analysis about conflict zones. No European airline or pilot should be left in the dark – all have the opportunity to benefit from… the privileged information of the best informed.”

Horne added: “Whilst many believe there should be an EU or international authority to take responsibility for the closure of hostile airspace, it is not something that shows any sign of happening soon, and so we need a pragmatic, industry-based setup that can provide meaningful protection in the here and now.”

ECA secretary general Philip von Schöppenthau added: “The international failure to effectively cope with flying over and into conflict zones keeps costing lives. We can continue to analyse and point fingers at individual states or institutions, but this will not help us save those lives.”

Launched in 2002, C-MUSIC has amassed more than 35,000 hours of use over a wide range of operational conditions.
Elbit Systems

Airliner shootdowns

The highest-profile airliner shootdowns have involved radar-guided missiles launched from the ground or air-to-air missiles from other aircraft.

Korean Airlines Flight 007 was shot down in 1983 by a Soviet Air Force Sukhoi Su-15, Iran Air Flight 655 was hit in 1988 by a radar-guided missile launched by the US Navy cruiser USS Vincennes, and a Siberia Airlines Tupolev Tu-154 was shot down in 2001 over the Black Sea during a Ukrainian military exercise.

Most recently, Dutch Safety Board investigators were looking into the July 2014 shooting down over eastern Ukraine of a Malaysia Airlines Boeing 777, operating Flight MH17 between Amsterdam and Kuala Lumpur, which killed 298 people. It concluded a radar-guided Buk missile fired from pro-Russian separatist territory had downed the aircraft.

However, most airliner shootdowns are caused by man-portable air defence systems (MANPADS). According to the US Transportation Safety Administration, 40 civilian aircraft have been struck by MANPADS missiles since 1975, causing about 28 crashes and more than 800 deaths.

Notable incidents in the 1970s included an Air Vietnam Douglas C-54D-5-DC crashing into Vietnamese territory in March 1975 after being hit by MANPADS (all 26 aboard were killed) and an Air Rhodesia Vickers Viscount crash-landing in Zimbabwe in 1978, which was caused by MANPADS fired by forces from the People’s Revolution Army (four crew and 34 of the 56 passengers were killed).

In December 1988, two Douglas DC-7 spray aircraft chartered by the US Agency for International Development to eradicate locusts were hit by MANPADS fired by militants in the Western Sahara; one crashed, killing all five crew. September 1993 saw Transair Georgia Tu-134 and Orbi Georgian Airways Tupolev Tu-154B shot down within a day of each other during the war in Abkhazia, killing 135 people.

A Congolese Airlines Boeing 727 was downed over the Democratic Republic of the Congo in 1998, killing 41, and two United Nations-chartered C-130 Hercules were shot down in Angola within weeks of each other in December 1998 and January 1999, killing 23.

In November 2002, terrorists fired two missiles at an Arkia Airlines Boeing 757 carrying 271 passengers and crew as it departed Mombasa, Kenya. Both weapons missed their target, but the incident led directly to the development by Elbit Systems of its C-MUSIC technology (see main article).

A year later, a DHL Airbus A300B4-203F transporting mail in Iraq was struck and damaged by a MANPADS-launched missile. The weapon hit the aircraft’s left fuel tank, but the jet landed safely in Baghdad. In March 2007, a TransAVIAexport Airlines Ilyushin Il-76TD cargo aircraft was allegedly brought down by a surface-to-air missile over Mogadishu, Somalia, killing the crew of 11.