Why do Planes Crash?

Why do aircraft crash? A look at the satistics behind plane accidents

What phase of flight is the most dangerous?

Why do planes crash?

Aircraft never crash because of one single issue. It’s almost always a combination of factors that lead to an accident and therefore it’s very difficult to provide accurate statistics as to what the cause of an aircraft crash is.

For example, if the aircraft suffers a serious technical problem (but one that shouldn’t result in the loss of an aircraft) and it’s subsequently mishandled by the pilots resulting in a crash, does that count as pilot error or mechanical breakdown? The mechanical breakdown on it’s own shouldn’t have meant the plane crashed, but could have been handled correctly by the pilots.

Therefore the statistics for the causes of aircraft crashes are not always clear. It is however widely accepted that the following statistics are a reasonable representation:

  • 55% Pilot Error
  • 17% Aircraft Mechanical Error
  • 13% Weather
  • 8% Sabotage
  • 7% Other (ATC, Ground Handling, Unknown)

Examples of Pilot Error include “Loss of Control in Flight” and “CFIT” (Controlled Flight Into Terrain).

Swiss Cheese Model

Aircraft accidents never occur due to one particular reason, there are always a multitude of factors which contribute towards an aircraft crash or incident. An example might be pilot fatigue, coupled with bad weather and a technical problem. If any one of these single factors were not present, the crash wouldn’t have happened. In the industry, this is called the “Swiss Cheese Model”. If you imagine lots of different slices of Swiss Cheese, from different blocks of cheese, all lined up next to each other, the chances are that you won’t be able to see all the way through one of the holes, as the holes will all be in different places. Each slice of cheese represents an individual factor such as fatigue, poor weather or poor standard of training. On rare occasions all the holes line up together, that is to say all the factors come together to cause an accident.

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Which phase of flight is a crash most likely to occur?

Boeing released the following statistics for the worldwide Commercial Jet Fleet between 2005 – 2014.

Percentages of fatal accidents based on phase of flight:

13% Take-off
8% Climb
27% Cruise
17% Decent Initial Approach
38% Final Approach / Landing

Therefore, statistically, the most dangerous phase of flight is landing.