Foreign Object Debris (FOD)
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Foreign Object Debris (FOD) at airports includes any object found in an inappropriate location that, as a result of being in that location, can damage equipment or injure personnel. FOD includes a wide range of material, including loose hardware, pavement fragments, catering supplies, building materials, rocks, sand, pieces of luggage, and even wildlife. FOD is found at terminal gates, cargo aprons, taxiways, runways, and run-up pads.
The three main areas that require specific attention are:
- Runway FOD - this relates to various obects (fallen from aircraft or vehicles, broken ground equipment, birds, etc.) that are present on a runway that may adversely affect fast-moving aircraft (during take-off and landing). Runway FOD has the greatest potential of causing damage.
- Taxiway/Apron FOD - while this type of FOD may seem less harmful than the previous one, it should be noted that e.g. jet blast can easily move small objects onto the runway.
- Maintenance FOD - this relates to various objects that are used in maintenance activities (e.g. aircraft maintenance, construction works, etc.) and can cause damage to aircraft (e.g. tools, materials, small parts, etc.)
FOD can cause damage in a number of ways, the most notable being:
- Damaging aircraft engines if ingested;
- Cutting aircraft tyres;
- Lodging in aircraft mechanisms preventing them from operating properly;
- Injuring people afer being propelled by a jet blast.
The resulting damage is estimated to cost the aerospace industry $4 billion a year.
A dramatic example of FOD damage is the loss of the Air France Concorde, which struck FOD on the runway during take-off from Paris Charles de Gaulle Airport in 2000 (see Accidents and Incidents section for details).
A number of factors can affect the presence and handling of FOD, e.g.:
- Poor maintenance of buildings, equipment and aircraft.
- Inadequate staff training.
- Pressure on staff not to delay movements for inspection.
- Weather (e.g. FOD may be created by strong winds or may be blown onto the airfield or its detection can be hampered by adverse weather).
- Presence of uncontrolled (e.g. contractors') vehicles on the airfield.
Defences against FOD include the following activities:
- Regular and frequent inspection of the airfield, including aircraft manoeuvring areas and adjacent open spaces.
- Suspension of runway operations upon notification to ATC about FOD on or near the runway until FOD has been removed and the runway inspected, as necessary.
- Regular and frequent inspection of the airfield buildings and equipment and immediate repair or withdraw from service of items likely to create FOD.
- Inspection of the parking gate to ensure that it is free of FOD, including ground equipment, and of ice, snow or other material capable of reducing braking action (normally the responsibility of the airline representatives).
- Removal of FOD as soon as it is identified.
- Use of constant inspection systems (see subsection below for details).
- Implementing a FOD control program (see subsection below for details).
Constant inspection systems
Constant inspection systems use a combination of radar and electro-optical sensors which facilitate FOD detection 24/7 under all weather conditions. Such systems are used at some of the busiest aerodromes in the world, including Heathrow, Vancouver, Dubai, Doha and others. The benefits of such a system over conventional vehicle inspections are:
- Constant monitoring, including night time and low visibility conditions.
- Detection of FOD is faster and more reliable.
- More efficient (uninterrupted by inspections) traffic flow.
- Reduced risk of runway incursions (by the inspecting vehicle e.g. due to a controller error)
- Reduced risk of birdstrikes (birds are recognised by the optical sensors)
FOD Control Program
A program to control airport FOD is most effective when it addresses four main areas:
- Training. All airport and airline personnel and airport tenants should receive training in the identification and elimination of FOD, including the potential consequences of ignoring it. This training can supplement the general FOD awareness incorporated into the airside driver-training curriculum at many airports. FOD training for flight crews includes following the recommended procedures identified in the Flight Crew Operating Manual and pre- and post-flight inspection procedures covered during line training. Effective training include procedures for removing and eliminating FOD at its source, and should be reinforced through the use of posters and signs. Recurrent training is necessary to help maintain an awareness of FOD.
- Inspection by airline, airport, and airplane handling agency personnel. Airline personnel, when feasible, should join the airport staff in daily airside inspections. This practice helps increase familiarity with local airfield conditions, and promotes effective communication between the airport and airlines. The International Civil Aviation Organisation (ICAO) requires a daily, daylight inspection of aircraft manoeuvring areas and removal of FOD. In addition to performing these inspections at the beginning of the day or shift, personnel on the airside should look for FOD during their normal shifts. On-going construction requires more frequent inspections. It may even be necessary to assign dedicated personnel to continually inspect for FOD during major construction activities. Flight crews should report to air traffic control and station operations any FOD they observe on runways and taxiways. Aircraft operators and handling agents should designate individuals to inspect aircraft parking stands prior to aircraft movement onto or off them.
- Maintenance, which includes:
- Sweeping. This may be done manually or with the airfield sweeper, which is the most effective equipment for removing FOD from airside. The sweeper removes debris from cracks and pavement joints, and should be used in all areas except for those that can be reached only with a hand broom. All airside areas, including aircraft manoeuvring areas, aprons and gates and the areas adjacent to them, should be swept routinely. The areas in which ground support equipment (GSE) is staged should be swept periodically.
- Magnetic bars. These can be suspended beneath tugs and trucks to pick up metallic material. However, the bars should be cleaned regularly to prevent them from dropping the collected debris. Vehicles operating on the airside should be inspected periodically to ensure that they have no loose items that can fall off.
- Rumble strips. Driving over rumble strips can dislodge FOD from the underside of vehicles. The strips, which are between 10 ft and 15 ft long, can be moved and used at transitions from the landside to the airside, or adjacent to airside construction areas.
- FOD containers. These should be placed at all gates for the collection of debris. The containers should be emptied frequently to prevent them from overflowing and becoming a source of FOD themselves. In addition, airport personnel can wear waist pouches to collect debris. Evaluating the debris collected in containers and pouches can identify its sources and indicate where personnel and equipment should be deployed for more effective control.
- Other means for preventing FOD damage include wind barriers and netting to restrict the movement of airborne FOD, fencing to prevent animals from entering the airfield, and well-maintained paved surfaces. If damaged pavement cannot be repaired immediately, aircraft should use an alternate route.
- Coordination. Airports with a FOD committee of airport tenant representatives tend to control FOD more successfully than those without such a committee because the representatives can address local conditions and specific problems. At airports served by multiple airlines, the airlines should have these representatives as well as an airport user's committee to coordinate FOD control efforts among themselves. Both airside and landside construction activities, as well as scheduled maintenance, should be communicated to airport users as early as possible. Airport preconstruction planning should include a means for controlling and containing FOD generated by the construction. This is especially true in high-wind environments where debris is more likely to become airborne. Access to and from construction sites should avoid areas of aircraft operation. Contractors must fully understand the requirements and penalties incorporated in their contracts regarding the control and removal of FOD.
Accidents and Incidents
- CONC, vicinity Paris Charles de Gaulle France, 2000 - On 25th July 2000, an Air France Concorde crashed shortly after take-off from Paris CDG following loss of control after debris from an explosive tyre failure between V1 and VR attributed to runway FOD ruptured a fuel tank and led to a fuel-fed fire which quickly resulted in loss of engine thrust and structural damage which made the aircraft impossible to fly. It was found that nothing the crew failed to do, including rejecting the take off after V1 could have prevented the loss of the aircraft and that they had been faced with entirely unforeseen circumstances.
- RJ85, Helsinki Finland 2010 - On 12 June 2010, a requested 22R runway inspection at Helsinki in normal daylight visibility carried out after a severe engine failure during the take off roll had led an Avro RJ85 being operated by Finnish Airline Blue1 on a scheduled passenger flight to Copenhagen to reject that take off at high speed. This inspection had not detected significant debris deposited on the runway during the sudden and severe engine failure. Two passenger aircraft, one being operated by Finnair to Dubrovnik, Croatia and the other being operated by Swedish airline TUIfly Nordic to Rhodes, Greece then departed the same runway before a re-inspection disclosed the debris and it was removed. Neither of the aircraft which used the runway prior to debris removal were subsequently found to have suffered any damage but both were advised of the situation en route.
- E190, Oslo Norway, 2010 - On 23 October 2010, an Embraer 190 commenced its night rolling takeoff from runway 01L at Oslo with the aircraft aligned with left runway edge lights instead of the lit centreline before correcting to the runway centreline and completing the takeoff and flight to destination. Engine damage caused by ingestion of broken edge light fittings, which was sufficient to require replacement of one engine before the next flight, was not discovered until after completion of an otherwise uneventful flight. Tyre damage requiring wheel replacement was also sustained. The Investigation concluded that "inadequate CRM" had been a Contributing Factor.
- Vehicle / B712, Perth Western Australia, 2014 - On 26 July 2014, the crew of a Boeing 717 which had just touched down on the destination landing runway at Perth in normal day visibility as a heavy shower cleared the airport area after previously receiving and acknowledging a landing clearance saw the rear of a stationary vehicle on the runway centreline approximately 1180 metres from the landing threshold. An immediate go around was called and made and the aircraft cleared the vehicle by about 150 feet. The same experienced controller who had issued the landing clearance was found to have earlier given runway occupancy clearance to the vehicle.
- B734, Aberdeen UK, 2005 - Significant damage was caused to the tailplane and elevator of a Boeing 737-400 after the pavement beneath them broke up when take off thrust was applied for a standing start from the full length of the runway at Aberdeen. Although in this case neither outcome applied, the Investigation noted that control difficulties consequent upon such damage could lead to an overrun following a high speed rejected takeoff or to compromised flight path control airborne. Safety Recommendations on appropriate regulatory guidance for marking and construction of blast pads and on aircraft performance, rolling take offs and lead-on line marking were made.
- MD82, Copenhagen Denmark, 2013 - On 30 January 2013, the crew of a Boeing MD82 successfully rejected its take off at Copenhagen after sudden explosive failure of the left hand JT8D engine occurred during the final stage of setting take off thrust. Full directional control of the aircraft was retained and the failure was contained, but considerable engine debris was deposited on the runway. The subsequent Investigation concluded that a massive failure within the low pressure turbine had been initiated by the fatigue failure of one blade, the reason for which could not be established.
- E170, Nuremberg Germany, 2013 - On 13 March 2013, smoke and fumes were immediately evident when the cable of an external GPU was connected to an ERJ170 aircraft on arrival after flight with passengers still on board. A precautionary rapid disembarkation was conducted. The Investigation found that a short circuit had caused extensive heat damage to the internal part of the aircraft GPU receptacle and minor damage to the surrounding structure and that the short circuit had occurred due to metallic FOD lodged within the external connecting box of aircraft GPU receptacle.
- B772, Singapore, 2013 - On 19 December 2013, the left engine of a Boeing 777-200 taxiing onto its assigned parking gate after arrival at Singapore ingested an empty cargo container resulting in damage to the engine which was serious enough to require its subsequent removal and replacement. The Investigation found that the aircraft docking guidance system had been in use despite the presence of the ingested container and other obstructions within the clearly marked 'equipment restraint area' of the gate involved. The corresponding ground handling procedures were found to be deficient as were those for ensuring general ramp awareness of a 'live' gate.
- B738, Auckland New Zealand, 2013 - On 7 June 2013, stabiliser trim control cable, pulley and drum damage were discovered on a Boeing 737-800 undergoing scheduled maintenance at Auckland. The Investigation found the damage to have been due to a rag which was found trapped in the forward cable drum windings and concluded that the integrity of the system which provided for stabiliser trim system manual control by pilots had been compromised over an extended period. The rag was traced to a specific Australian maintenance facility which was run by the Operator's parent company and which was the only user of the particular type of rag.
- FAA Advisory Circular 150/5210-24 "Airport Foreign Object Debris (FOD) Management", September 2010
- FAA Advisory Circular 150/5020-24 "Airport Foreign Object Debris (FOD) Detection Equipment", September 2009
- NTSB Safety Alert 054 "Control Foreign Object Debris", June 2016
- UK CAA CAP 1010 Ramp/ Aircraft Loading Operations Checklist, February 2014
- ACI Airside Safety Handbook, 4th edition, 2010