Historical FOD Incidents and the Hidden Costs of FOD

What FOD Is and Why It Matters

Foreign object debris (FOD) is any object, substance or material in an inappropriate location that has the potential to injure personnel, damage aircraft or equipment, or compromise product integrity. The term covers two related ideas: foreign object debris, meaning the object itself, and foreign object damage, meaning the consequence when that debris causes harm.

FOD is not a housekeeping issue. It is a safety, operational and financial risk that runs through every domain where precision engineering meets human activity. A single washer ingested into a jet engine can cause millions of dollars in damage. A piece of safety wire left in a flight control assembly can become a catastrophic failure at a critical phase of flight. A rock on a runway can puncture a tire at takeoff speed and set off a high-speed rejected takeoff with its own cascade of risks.

The Scale of the Problem: Why the Cost of FOD Has to Be Local

You will often see large industry-wide figures quoted for the cost of FOD. The guide is deliberately cautious about them, because studies use different years, currencies, populations and definitions of direct and indirect cost, which makes them hard to compare. It does not present an unsupported global total. Instead it recommends building the case from your own records: damage events, repair cost, downtime, disruption and investigation hours. If you do borrow a historical estimate, cite the original document, page, currency year and cost definition, and do not multiply it by an indirect-cost factor unless that factor has its own matching source.

The same logic applies outside aviation. In semiconductor fabrication, a single microscopic particle in a cleanroom can affect an entire wafer lot. In medical device manufacturing, FOD contamination can trigger product containment, rework or a recall, and it can put patients at risk. In automotive engine and transmission plants, FOD in assembly areas can contribute to equipment stoppages, defects, warranty claims and premature component failure. In every case the right move is to quantify the consequence with your own quality and cost data.

Three Historical Incidents That Shaped FOD Prevention

To understand why FOD programs exist, it helps to look at what happens when they fail. The guide describes three incidents, each investigated by an official body with a published report.

Concorde, Air France Flight 4590 (2000). On 25 July 2000, during the takeoff roll at Paris Charles de Gaulle, the left main landing gear tire struck a metal wear strip lying on the runway. The strip, roughly 43 cm long, had fallen from the thrust reverser cowl door of a Continental Airlines DC-10 that departed the same runway five minutes earlier. It had been installed in Houston in July 2000 and did not conform to the manufacturer’s specified procedures. Tire fragments punctured fuel tank 5, the leaking fuel ignited, and the aircraft crashed into a hotel in Gonesse, killing all 100 passengers, 9 crew members and 4 people on the ground. The BEA investigation identified the runway debris as the initiating event. The lessons: runway inspections must be timely and capable of detecting debris that originates from aircraft, foreign object reporting and recovery must follow every departure, and prevention has to cover the whole airport movement area, including coordination between operators, airport operations and air traffic services.

Flashlight ingested by an F-35A engine, Luke Air Force Base (2023). During a maintenance ground run, a maintainer used a handheld flashlight for a pre-run inlet inspection because of limited light. On leaving the inlet, the flashlight was placed on the inlet lip, and the required post-task tool inventory and inlet clearance checks were not completed correctly. Seven minutes into the run the aircraft’s debris sensors detected foreign objects in the inlet and exhaust, and after shutdown the team found extensive blade damage. The USAF Accident Investigation Board attributed the mishap to a failure to complete a full inlet inspection and a failure to complete a tool kit inventory before the engine run. Estimated engine damage was $3,933,106, the engine could not be repaired locally, and nobody was hurt. The lessons: complete a tool inventory after entering an inlet, not only before; physically verify that the cavity is clear; and make sure the tool control system makes an unreturned item immediately visible and forces a stop before an engine run or release to service. See our FOD return to service checklist for how that verification is structured.

Clipboard ingested by a Jetstar A320 engine, Auckland (2017). In rain and wind, a ground handling leading hand placed his clipboard inside the right engine cowling to shelter his paperwork, intending to retrieve it later. During the pre-departure walk-around, a dispatcher noticed the clipboard but assumed the leading hand would remove it, so she did not report it. The engines were started, the clipboard was ingested into the No. 2 engine, and the aircraft returned to Auckland after departure. Inspection found paper throughout the engine and minor damage to a fan blade and the fan case liner. The ATSB investigation identified two failures: ground personnel used an engine cowling as a temporary work surface, and the dispatcher saw a foreign object during a walk-around but assumed someone else would handle it. The lessons: a cowling or inlet must never be a work surface, every object seen near an intake needs positive removal or escalation, and adverse-weather procedures must say how paperwork and loose items are protected without putting them in or near aircraft systems.

The guide draws one principle from these events and from many less publicized near-misses: when an organization tolerates debris in its operating areas, it also tolerates the mindset that produced the debris. The physical hazard and the cultural hazard are inseparable.

Four FOD Damage Categories

FOD damage falls into four broad categories, each with its own mechanism and prevention focus.

• Engine ingestion: debris enters the intake and damages compressor or turbine blades, sometimes causing blade liberation and cascading failure. Prevention focuses on runway sweeps, engine covers, tool control during maintenance and intake inspection before start.
• Tire and wheel damage: cutting debris punctures or lacerates a tire, or an embedded object creates a slow leak or blowout risk. Prevention focuses on runway and ramp sweeps and immediate debris removal from movement areas.
• Structural impact: debris strikes an airframe, control surface, windshield or sensor at speed, causing immediate damage or latent weakness. Prevention focuses on control of loose items on ramps and taxiways and on securing ground support equipment and cargo.
• System contamination: debris gets into fuel, hydraulic or air systems, blocking filters, scoring pumps, jamming valves or blocking sensors and pitot-static ports. Prevention focuses on caps and covers during maintenance, clean assembly practices and system flushing afterward.

The cost of each category depends on the engine, aircraft, repair disposition, location and extent of damage, so the guide lists typical cost as organization-specific, or simply variable for system contamination, rather than quoting a number. Simple physical controls such as FOD cans and personal FOD bags support the collection side of prevention at the point of work.

FOD Walk vs. FOD Walkdown

Many organizations use the two terms interchangeably. In the guide, a FOD walk is the field activity of visually inspecting and clearing an area. A FOD walkdown is the complete process: briefing, inspection, collection, documentation, escalation, corrective action and improvement review. The distinction matters because collecting debris without logging what was found, where and how much teaches the organization nothing, and the source stays in place.

A strong walkdown produces four outputs: removal, so the item cannot cause damage today; documentation, so findings are classified, counted and tied to a location; correction, so the likely source is identified and assigned for action; and culture, so people see that FOD prevention is expected, measured and valued. The guide puts it bluntly: a walk where people stroll, talk and toss debris in a bin without logging anything is better than nothing, but it is not a serious FOD prevention system. A FOD walk checklist is a good starting point for making the walk repeatable.

The Hidden Costs of Weak FOD Control

Beyond the direct cost of damage events, weak control adds structural costs that compound over time.

• Operational disruption: an aircraft on ground event from FOD ingestion costs the engine repair plus lost revenue from cancelled flights, crew out of position, rebooked passengers and schedule disruption that persists for days. For military operations, the cost is mission capability lost, not just dollars.
• Investigation burden: a FOD-damage investigation can consume substantial engineering, quality, safety and customer time. In organizations with weak programs, teams become desensitized to repeat events, which produces superficial investigations that miss root causes and guarantee recurrence.
• Reputational damage: customers, regulators and insurers notice repeat FOD incidents. A pattern of FOD findings in customer audits signals weak process discipline across the board, and in competitive industries a reputation for quality escapes can decide who wins contracts.
• Personnel injury: sharp debris lacerates hands and knees, chemical contamination burns skin, and loose items create slip and trip hazards. These injuries are preventable, yet they recur where FOD is treated as a janitorial issue instead of a safety system.
• The compounding effect: organizations with weak programs carry a backlog of repeat findings, a pile of open corrective actions and a workforce that has learned that nothing ever changes.

Breaking out of that cycle takes more effort than preventing it in the first place. In the guide’s words, the cheapest FOD program you will ever run is the one you start today and sustain consistently.

Turning the Cost of FOD Into Action

Start by pulling your own numbers: damage events, repair invoices, downtime and investigation hours. Then look at where debris is found and who owns each area. FOD signs and zone markings make expectations visible where the work happens. If you are ready to turn this into a business case, read our companion article on the business case for FOD prevention, and download the free guide and toolkit for the forms and worksheets that put these ideas into practice.