It's hard to believe that something so simple could cause such a disaster. Yet, FOD on airport runways causes about US$4bn damage to aircraft every year.

Because of high kinetic energy levels on active runways, FOD can lead to severe consequences, causing potential loss of the aircraft and on extremely rare occasions, such as the abovementioned Concorde disaster, loss of life.

At airports, especially those that cater for jets, runway debris can come from jet blast effects, eg an aircraft turning from an active runway onto a narrow taxiway can blow material from the shoulders and in-field areas backwards onto the runway. Items may also fall from aircraft or other vehicles, causing a hazard for subsequent users of the runway.

Debris can take many forms: nuts and bolts, pavement fragments, washers, rivets, stones, sand and gravel, metal tools, aircraft parts and drink bottles, even birds and animals. All are hazardous to aircraft and need to be removed as quickly as possible.

Sydney Airport Manager Frank Mondello welcomed the trial and said that safety, including prevention of aircraft damage from runway debris, was a major issue.  

"While our safety record is excellent, we are conscious of the need to maintain and improve standards, particularly where new technology is available," Mondello says.

The system, based on high-resolution millimetre wave radar, is able to detect small, potentially hazardous objects on a runway, to within an accuracy of three metres at a range of up to two kilometres. The system is also able to detect a range of different materials, including metal, plastic, glass, wood, fibreglass and animal remains. Images are relayed to a computer that pinpoints the location of the item, while an alarm sounds to alert staff.

Checking for runway debris is currently performed manually, which is time consuming, expensive and open to human error. It can take as long as 45 minutes to check a runway between aircraft movements and this is particularly difficult in bad weather and at night. This can result in runway closures, delays in both arrival and departure slots and, most importantly, could potentially put passenger and staff safety at risk - making debris on runways an issue for both airports and airlines.

"With this technology we can check the runway between every flight," says QinetiQ spokesman Michael Burns. "It scans 24 hours a day, it doesn't worry about fog and other weather or climatic conditions." 

FOD Boss
Australian company Aero Sweep in the 1990s developed a speed sweeping system that has grown into arguably the most popular device of its kind in the world.

Known as FOD*BOSS, the system grew from a product designed to clean and groom suburban tennis courts.

Aero Sweep director Brook Tozer told Airports that the FOD*BOSS is now in operation at hundreds of airports worldwide and at 70 airports throughout Australia and New Zealand.

Any member of an airport team can operate the FOD*BOSS with a standard road vehicle fitted with a 50mm tow ball. "It replaces the need for vacuum and sweeper trucks costing hundreds of thousands of dollars," Tozer says. "Most debris collected by the FOD*BOSS is well under 50mm, so seeing it from a truck cabin or aircraft cockpit is almost impossible."

Debris such as wheel nuts, rivets, stones and luggage hardware is all capable of doing massive damage to aircraft engines, tyres or blasted by jets seriously endangering passengers and ground support staff." 

Brisbane Airport
At Brisbane Airport runway operations officers conduct runway inspections four times a day. Extra inspections may also be made at the request of the control tower after adverse weather, on pilot reports, or if anything untoward is noted by officers.

Brisbane Airport operations safety and standards manager John McCaffery told Airports that the major reason for such regular runway checks was to enable the "safety of aircraft operations, and to ensure the integrity, reliability and consistency of the runway and taxiway systems."

Two officers, one each side of the runway centreline, generally conduct inspections, which can take between 20 minutes to over an hour to complete.

"There has been a wide variety of objects found during inspections at Brisbane," McCaffery says. "We've found pieces of aircraft tyre, aircraft components, bolts, pieces of metal, rocks thrown up by mowers, broken lights, hats, grass, and soil. The debris is collected or swept and removed by the operations officers but on occasion the vacuum sweeper is needed to remove large amounts of debris."

Gold Coast Airport
Gold Coast Airport trains operational and ground staff to deal with FOD.
The most common debris encountered at Gold Coast Airport is associated with ground handling operations. Baggage tickets, locks, paper and other litter being the most common.

Ground staff conduct a minimum of two daily inspections plus irregular inspections as required, while the runways, taxiways and apron are swept three times a week using a FOD*BOSS.

In addition, senior management, including the technical services manager and the operations and security manager, complete runway, taxiway and apron inspections once a week.

Gold Coast is also investigating new technologies, including the Tarsier runway detection radar system, to assist in the identification of debris and to minimise risks associated with FOD.

Townsville Airport
Townsville completes runway, taxiway and apron FOD inspections before every jet landing and takeoff, with the most common debris being strapping that comes off cargo and baggage locks.

A combination of contract and fulltime staff clear runways and taxiways weekly with a vacuum sweep, while the apron is cleared once a week with a FOD*BOSS and vacuumed once a month. Technical staff inspect the runways, taxiways, and aprons weekly while more detailed inspections are carried out every six months.

Mt Isa Airport
Like Townsville, Mt Isa conducts runway, taxiway and apron FOD inspections before every jet landing and takeoff. Due to the geographical nature of Mt Isa Airport, the most common form of debris found there are rocks. The airport trains a safety officer in the hazards and risks associated with FOD.

The main apron is swept using a FOD*BOSS and a sweeper is used on the taxiway and runway monthly or as required. Technical inspections of the runway, taxiway and aprons are completed every six months.

Foreign Object Debris is indeed a danger of which airports must be wary, but with the correct housekeeping can be managed effectively. There are costs involved in conducting this housekeeping but the costs of not doing so are inevitably far greater.

Original version of article is online at:
http://www.airportsmag.com/detail_article.cfm?ID=52

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