After a rocket fired from Gaza landed near Tel Aviv's Ben Gurion International Airport, US Airways, Delta and United have all cancelled flights into Israel, with one aircraft diverting mid-flight to Paris. have reminded carriers just how deadly flying even high above an embattled areas can be.

Update 6pm EST:

The downing of MH17 (for all our coverage, ) by a fairly advanced form of surface to air missile and the total destruction of a underlined the risks involved with operating airliners in areas where hostilities exist, especially when combatants have the capability of firing projectiles high into the air from many miles away.

The Iranian-made "Fajr-5" rockets have a range of close to 50 miles and are able to reach the outskirts of Tel Aviv, Because of the rocket's crude aiming system, Fajr-5 strikes around Israel's largest metropolis have been rare. M302 rockets of Syrian origin that have been smuggled into Gaza in recent months have a far greater range, approaching 100 miles. This makes Tel Aviv and even northern cities all within Hamas's striking range.

placed in a ring between Gaza and large Israeli population centers, is supposed to counter these rockets as they are picked up on radar. The system is very effective, with successful intercept estimates ranging from 75%-95% depending on who you ask, but it is not perfect antidote to Israel's rocket attack woes. Unguided rockets, with their sometimes unpredictable flight paths, do end up reaching Israeli population centers unmolested from time to time.

In response to relentless and indiscriminate Palestinian missile attacks over the past week, Israel

The problem is that if the sanitized airspace over Tel Aviv is seen not so be so, the risks of operating an airliner — which is really a flying swimming pool-sized fuel truck with people packed inside of it — in and out of the area increases. Also, clearly Hamas wants to strike at the heart of not only Israel's populace and their mental well-being, but also at their economy, and aiming their M302 rockets at Ben Gurion International Airport does all of these things.

Aircraft sitting at gates or taxing are at the greatest risk, as seen during . Yet aircraft on approach or departure from Ben Gurion International are not entirely immune from these rocket attacks either. Although the sky is a very big place, intersections of space, time and fate can happen, so generally it is not a good idea to fly through airspace where rockets or artillery, traveling and hundreds of miles an hour and packing high-explosive warheads, are moving through the same airspace. Hence the reason some flights have been cancelled into Tel Aviv.

The nearly week-long battle for Tripoli's International Airport continues on, and sadly, a very new

The Great Countermeasure Question

There has been much talk this week about outfitting aircraft with infrared missile countermeasures. Although this debate is highly relevant seeing that over the past few years to a degree that was once thought of as the sum of all fears to some, but these systems would have had zero effect on the MH17 incident or on the risks posed to airliners transiting in and out of Tel Aviv.

Man Portable Air Defense Systems (MANPADS), otherwise known as shoulder fired heat-seeking…

The airliner-countermeasures debate has always been in relation to the MANPADS threat posed to commercial aircraft on ascent or descent. Concepts like, Flares and will do nothing against a radar guided SAM, aside from possibly alerting the aircrew that a missile is inbound and that they were about to die.

, although it can be a decent reactionary countermeasure against some radar guided missiles, is worthless for airliners as they cannot pair it with hard maneuvering to break the missile's 'cone of no escape.' A missile system like the SA-11 can take a trained fighter pilot with active electronic countermeasures and chaff a lot of maneuvering to defeat. Even highly dated systems, like the SA-2, can fire one missile, then wait till the target has bled off enough energy trying to evade it and fire another missile, popping its target when it is at a very low energy state.

Active jamming systems are a sensitive topic when it comes to national security and they are by no means a panacea for the issue of radar guided SAMs, especially for those that 'pop' up, such as road mobile units like the SA-6/SA-11/SA-17. Also, false cuing once the system is activated can play deadly havoc on non-militarized air traffic control radar. Even bundles of chaff can blind ATC radar in the vicinity of the aircraft that releases them which could result in horrific unintended consequences. Pinpoint electronic attack is something that is just now becoming an operational possibility on aircraft equipped with powerful , and the capability is potentially so effective that it will be relegated to the military's use only.

Currently, the most effective countermeasure against radar guided SAMs are towed decoys, such as the and . Nicknamed by combat pilots as "Little Buddy," these small tethered systems are winched out of a housing located on the back end of a fighter and bomber aircraft, where they spoof, jam and distract enemy radars and SAM systems. These are very high-tech systems that work based on classified technology and software, and in some cases their job is to get shot at instead of the host aircraft. This maybe fine for a fighter aircraft, but not exactly something you want for an airliner.

On the much more relevant infrared guided MANPADS side of the equation, the is very old news. Directed energy infrared countermeasure systems are much more relevant and they would provide suitable adaptability for airliners and their unique operating environments. is one of these system, as is , which is a modular version of the military's Large Aircraft Infra-Red CounterMeasure (LAIRCM) that equips everything from C-17s to VC-25As (Air Force One). This systems uses a small turret with a laser that is cued by staring missile launch warning detectors. It fires a modulated laser beam into the seeker of the incoming missile, thus blinding it and throwing it off course.

These directed energy systems are more effective against both old and new threats and they do not throw out any super heated "expendables," visible or otherwise, that can do damage to what lies below or around the aircraft and they don't require careful arming and de-arming handling on the ground.

Even though the rapid evolution and fielding of directed energy infrared countermeasures system makes them ideal for large commercial aircraft, I would not expect to see them on airliners anytime soon, yet alone systems capable of jamming radar-guided surface to air missiles.

The cost of putting in a system like C-MUSIC is well over $1M per aircraft, which will only prove worthwhile if the thousands of shoulder-fired SAMs that were looted from Libya, were dispersed to opposition forces in Syria or given to pro-Russian separatists fighting in Eastern Ukraine start showing up around international airport perimeters in peaceful countries. Considering that intentional carriers have been flying into tumultuous places like Afghanistan and even Iraq, where the MANPADS threat is very real, yet have not equipped their aircraft with these systems is telling.

Yet even if these missile countermeasure systems were in widespread use, they would still have been worthless when it comes to stopping a random rocket attack from Gaza or a radar guided missiles in the hands of pro-Russian forces.

Pictures via AP, industry, aerospace industry, public domain.