SWISS Cheese Model in Aviation

Swiss cheese Model was first invented by James T. Reason and Dante Orlandella from the University of Manchester. The model is also called the Cumulative Act Effect. The basic policy behind the model is that in an organization or system single lapses within the department will not damage the whole company. In a Swiss cheese model, the main concept is that in a complex system different layers are present just like our cheese slices. The slices may not be perfect or may have holes for penetration. Each slice in the cheese various layers of an organization like

  • Management layer
  • Training or supervision layer
  • Unsafe precondition layer
  • Unsafe acting layer

In this article, we are going to explain how accidents may occur in the aviation industry through Reason’s Swiss Cheese Model. Let us check out the above layers of a company in detail.

SWISS cheese model in aviation

Management Layer: The airline or a professional flying club applies cost-cutting tactics to lower the cost of the operations and to save money on the fleet. Some policies might have a negative influence on aviation safety and may also backfire as accidents.

Training or supervision layer: This is one of the most vital layers in the aviation industry. High-quality training is the secret to secure aircraft operation. Hurry or incomplete training might lead to an incompetent pilot who may not handle the difficult situations in the mid-air.

Unsafe Precondition Layer: Fatigue, stress, and absence in concentration might lead to a low-performance level. But some questions to yourself like “how fit am I to fly the aircraft or do I need to Fly today?” might save thousands of lives.

Unsafe Acting Layer: All of the above-mentioned layers are latent conditions in the aviation segment. This means that all the above factors are present subconsciously. But this layer is absolutely an active one. Error in the handling, some kind of failure, wrong running engine, the bad decision of the pilot, flying in the rough weather and many more are some of the active conditions that might enforce huge risks.

Each cheese slice imposes a threat to the entire aviation system. But the worst will happen if there is a hazard and the layers are placed in such a way that the hazard can pass through down to the lower level. Some of the errors are:

  • Low maintenance due to cutting of costs resulting in invisible technical issues
  • An improperly trained pilot who might not know how to handle adverse situations
  • Weather is so bad that the ground is not visible to carry out a precautionary landing
  • The attitude of the pilot is resignation resulting in CFIT


In the aviation field, accidents that happen occur rarely due to the consequences of a single problem. It is generally a chain of errors in which some of them are very obvious while others are not. To stop any accidents from happening the best way is to closely monitor all the levels and close if there is any gap. This will afterward decrease the danger of lethal error.