US tech and aerospace firm Honeywell has submitted a patent proposal which would see airliners protected from shoulder-fired terrorist missiles by drone escorts.
Flight International reports that Honeywell lawyers filed the proposals last month. The idea would be that as an aircraft took off, the unmanned escort would fly automatically in formation with it. In the event of a missile attack, the drone would attempt to spoof or blind the incoming weapon's seeker head. If this failed, the robot aircraft would take the hit.
"This formation drone aircraft, which carries various missile detection and diversion equipment, is controlled by a wireless data link that is coupled directly into the airliner's flight control system," the Honeywell documents state.
"When the formation drone determines that a missile is being viewed by a missile sensor head, the formation drone lays down a predetermined pattern of exploding flares to divert the missile away from the airliner, attempts to spoof the missile using laser countermeasures or sacrifices itself to protect the airliner."
In the normal case where no attack took place, the drone would stay with the escorted airliner to an altitude of 18,000 feet, well above the service ceiling for shoulder-fired missiles. Then it would peel off and return to the airport to pick up its next charge, or land for refuelling and maintenance if required.
Homing anti-aircraft missiles, aka Man Portable Air Defence Systems (MANPADS) are much less commonly available than basic armour-piercing unguided rockets like the RPG. Nonetheless they are seen as a credible threat by security and counter-terrorism officials. Examples of such weapons include the Russian SA-14, said to have been supplied to Iran and thence onward to Iraqi insurgents. An SA-14 was used to shoot down a British military helicopter over Basra in 2006. Israeli airliners were also targeted (unsuccessfully) by MANPADS above Kenya in 2002.
The US Department of Homeland Security is currently trialling protective laser anti-MANPADS systems aboard commercial flights in America. The DHS goal is thought to be the widespread adoption of such systems, but the aviation industry belief is that this would be prohibitively expensive.
Honeywell's patent application argues that the approach of operating suitably equipped escort drones at airports makes more sense, as it is only during the takeoff and landing phases of flight that airliners are vulnerable to MANPADS.
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