Welcome back to our Word of the Week!

Every week, we look together at a word that is either interesting, funny or mysterious and that appeals to all of us in the aviation community.

FOD: FOD is an acronym for Foreign Object Damage or Debris

Foreign object damage (FOD) is any article or substance, alien to an aircraft or system, which could potentially cause damage.

External FOD hazards include bird strikes, hail, ice, sandstorms, ash-clouds or objects left on the runway. Internal FOD hazards include items left in the cockpit that interfere with flight safety by getting tangled in control cables, jam moving parts or short-out electrical connections.

The term FOD is used to describe both the foreign objects themselves, and any damage attributed to them.

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 jet blast can easily move small objects onto the runway;
  • Maintenance FOD – this relates to various objects, such as tools, materials or small parts) that are used in maintenance activities (e.g. aircraft maintenance, construction works, etc.) and can cause damage to aircraft.
Foreign object damage to the compressor blades of a Honeywell LTS101 turboshaft engine on a Bell 222, caused by a small bolt that passed through the protective inlet screen

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 or prop wash.

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.

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

For example, on aircraft carriers, as well as military and some civilian airfields, sweeps are conducted before flight operations begin. A line of crewmen walk shoulder to shoulder along the flight operations surfaces, searching for and removing any foreign objects.

All hands participate in a Foreign Object Damage (FOD) walk down on the flight deck aboard the conventionally powered aircraft carrier USS John F. Kennedy (CV 67). This task is performed each day and night before flight operations to ensure the flight deck is clear of all foreign objects.

Have a nice week, and see you next Wednesday for a new word of the week!