London Heathrow airport is aiming to reduce the risk from undetected foreign object debris (FOD). The airport has invested in Tarsier, a millimetric-wave radar system that can detect objects on the runway surface so they can be precisely located and cleared fast, even at night and in poor visibility. Heathrow, plagued by delays because its runways operate at 98% capacity, believes the system will improve timekeeping as well as safety.

Supplied by UK-based research company Qinetiq, the Tarsier system has completed extensive trials at Heathrow and is now in operation on the southern runway. Installation of a second system for the northern runway is in progress, says the airport operator. The existing system consists of two radars that scan the 3,658m (12,000ft) runway area 24h a day, locating objects or parts that could have fallen from aircraft or vehicles. FOD poses a danger to aircraft because it can damage tyres or undercarriages, or be drawn into engines.

Tarsier is able to detect small objects, whether metal, plastic, glass, wood, fibreglass or organic matter. A display unit in Heathrow's operations centre provides the runway inspection team with a round-the-clock picture, allowing them to locate debris on the tarmac and retrieve it in a matter of minutes. This replaces the need to carry out vehicular visual runway patrols at least twice a day, during which the runway has to be taken out of operation, and improves on visual inspection, which can be unreliable in bad visibility.

Qinetiq's Heathrow contract also includes a further enhancement through the installation of high-specification day/night cameras that will allow the remote visual confirmation and identification of detected debris. The ability to identify quickly a part that has detached from an aircraft can enable the crew to be advised of the details.

The Aerospatiale/British Aerospace Concorde fatal crash just after take-off from Paris Charles de Gaulle airport in 2000 was, according to the official accident report, caused by a sharp piece of metal debris that fell from a preceding aircraft and cut one of Concorde's tyres, causing it to explode and the aircraft to catch fire.

Colin Wood, head of Heathrow's airside operations, says: "Safety is our top priority, but [Tarsier] has the additional benefit of minimising delays caused by FOD."

Qinetiq says Vancouver International airport in Canada was Tarsier's first user in 2007. Since then the system has gone operational at Dubai and Providence, Rhode Island and been ordered for Doha airport in Qatar.

Source: Flight International