What is FOD on Boeing 737? (Foreign Object Damage)

Foreign Object Damage (FOD) refers to any damage caused to an aircraft due to the presence of foreign objects, debris, or substances. These foreign objects may include loose hardware, tools, rocks, gravel, or other items that can get inadvertently or intentionally introduced onto the aircraft’s surfaces or systems. FOD can be a serious issue in aviation, as it can lead to equipment failures, engine damage, or even catastrophic accidents if not identified and addressed promptly.

The Boeing 737, a widely used aircraft in commercial aviation, is not exempted from the potential risks of FOD. As it operates in various environments and undergoes frequent ground handling operations, there is always a chance for foreign objects to come into contact with the aircraft. Understanding the implications of FOD and implementing effective preventive measures are crucial to ensuring the safety and reliability of the Boeing 737 fleet.

Types and Causes of Foreign Object Damage on Boeing 737

1. Runway FOD

One of the significant sources of FOD for the Boeing 737 is the runway. As the aircraft takes off or lands, it travels at high speeds and creates a wake turbulence, which can dislodge loose debris or objects from the runway surface. These objects can then be ingested by the aircraft’s engines or impact critical areas such as the landing gear.

To combat runway FOD, airports implement regular runway inspections, sweeping operations, and cleaning procedures. Additionally, aircrews perform pre-flight walk-arounds to visually inspect the aircraft for any signs of FOD contamination before departure. This proactive approach helps identify and remove any potential hazards that could jeopardize the aircraft’s safety during takeoff or landing.

2. Maintenance and Hangar FOD

Foreign object damage can also occur during maintenance operations or while the aircraft is parked in hangars. Loose screws, wiring fragments, broken parts, or even small tools can inadvertently be left behind and pose a risk to the aircraft’s systems, engines, or structure.

To mitigate maintenance and hangar FOD, strict protocols are in place to ensure that all tools, equipment, and materials are accounted for and properly secured. Regular inspections and routine maintenance assessments are carried out to identify any potential FOD risks and rectify them promptly.

3. Bird Strikes

Bird strikes can also lead to FOD on Boeing 737 aircraft. These incidents occur when birds collide with the aircraft’s windshield, engines, or other critical areas, causing damage to the aircraft or its components.

Airports and airlines take several measures to minimize the risk of bird strikes. These include implementing bird control programs, using various deterrent devices, conducting wildlife management, and educating pilots on bird strike avoidance techniques. Additionally, the Boeing 737’s design incorporates bird strike resistance features, such as strengthened windshield materials and reinforced engine structures.

Consequences and Prevention of Foreign Object Damage

The consequences of FOD on the Boeing 737 can range from minor operational disruptions to major accidents. FOD can lead to engine damage, reduced fuel efficiency, interference with control surfaces, or compromised structural integrity. These issues not only affect the aircraft’s performance but also pose a threat to the safety of passengers and crew.

To prevent FOD incidents, airlines and ground crews adopt various strategies:

  1. Employee training: All personnel involved in ground handling, maintenance, and operations receive comprehensive training on FOD prevention and detection techniques.
  2. Tool and equipment control: Strict control over tools and equipment is maintained to prevent any items from being left behind in or around the aircraft.
  3. Regular inspections: Regular inspections are performed before, during, and after flights to identify and address any FOD risks.
  4. Runway maintenance: Airports conduct routine runway inspections, cleaning operations, and implement measures to minimize loose debris on the surface.
  5. Bird control measures: Airports and airlines implement bird control programs and utilize various deterrent methods to minimize bird strike risks.

By proactively addressing FOD risks and implementing preventive measures, the aviation industry can significantly reduce the occurrence of FOD-related incidents. This ultimately ensures the safety and reliability of the Boeing 737 aircraft, allowing passengers to travel with peace of mind.


Foreign Object Damage (FOD) poses a constant threat to the safety and integrity of the Boeing 737 aircraft. It encompasses damage caused by foreign objects, debris, or substances that come into contact with the aircraft during ground handling, maintenance, or flight operations. Understanding the various sources and types of FOD, along with implementing preventive measures, is essential to minimize the risks associated with this issue.

Through effective employee training, rigorous inspection processes, and the implementation of bird control programs, the aviation industry can mitigate FOD risks and enhance the safety of the Boeing 737 fleet. By proactively addressing FOD, we can ensure that one small debris doesn’t lead to significant consequences.

For More: What is DPCT on Boeing 737? (Differential Protective Current Transformer)