Jeremy McMillen


Human Factors in Aviation

23 January 2014

What Causes Aircraft Accidents

Jeremy McMillen

     What comes up must come down, the old adage says a lot about planes or any type of aircraft for that matter, if it goes up it will eventually come back down to earth. Most times it comes down to earth in a safe normal matter, but what about the times it does not we call those accidents. In 2013, according to the Aviation Safety Network there were 2801 Aviation accidents. That is a staggering number, and from the top three reasons for aircraft accidents are Pilot Error, Mechanical Error and Weather.

     The number one reason for an Aircraft Accident is Pilot Error. Now what is Pilot Error? According to the FAA’s own Risk Management Handbook (FAA-H-8003) Pilot Error is defined as “An accident in which an action or decision made by the pilot was the cause or a contributing factor that led to the accident.”(FAA-H-8003). According to Plane Crash info ( in the 2000s 54% fatal aircraft accidents were caused by Pilot Error. And NTSB data shows for part 121 operators there was a total of twenty Pilot error events (Ground Collision, and abnormal runway contact) These number are surprisingly not a very large considering the amount of flights per year is in the 100s of millions. Now for the hard truth according to Pilot Error accounts for more then half of all of the worlds aviation incidents or accsidents.

     The number two reason is Mechanical Error. The Defintion of Mechanical Error according to is ”Mechanical error differs from pilot error, because when a critical system fails, the pilot may be at the mercy of the plane” So what they are saying is Mechanical error is basicly where something breaks on the plane and causes the plane to crash it is not pilot error but due to mechanics, or something breaking. According to an NTSB report about aircraft accidents between 2007 and 2009 there were a total of 6 Mechanical Related but excluding power plant for Part 121 operators. For Part 35 General Aviation there were a total of 149 Mechanical related but excluding power plant related accidents between 2007 and 2009. If one were to throw in Power plant related Mechanical caused Accidents for Part 35 there was a total of 566 accidents so if we were to add that to the other 149 mechanicals which do not relate to power or power plant we come up with a total  715 over a two year period or about 357.5 per year. These number once again are small compared to the total number of flights per year which is in the 100s of millions, but when one looks at mechanical error relates to just over 22% of all aviation accsidents. And even more shocking is the percentage of fatal aircraft accidents caused by aircraft maintenance issues is 24% between 2000 and 2010.

     Now finally out of the top three according to the thrid highist cause of aircraft accsidents or incidents is weather. Weather accounts for 12% of all aviation accidents. Data from the NTSB shows between 2007 and 2009 Part 35 accidents relating to weather (unintended Flying into IMC and windshear/thunderstorms) there was a total of 72 accidents. And data from shows weather at 8% in causing deadly aircraft accsidents.

     To Sum up the top three causes for aircraft accidents are well all near avoidable for one thing. Second  if we learn from our mistakes we can all be safer thus it is this authors hope that the numbers will go down and more of the flying public and pilots will be safe. As the old saying goes what goes up must come down lets hope we start to see aircraft coming down not as an accident but landing.

Works Cited

"5 Most Common Causes of Plane Crashes." R&Blaw. Rommanucci&Blandin LLC, 23 Apr. 2013. Web. 25 Jan. 2014. <>.

"Aviation Safety Network ASN Aviation Safety WikiBase Year Index 2013." Aviation Safety Network ASN Aviation Safety WikiBase Year Index 2013. Flight Safety Foundation, n.d. Web. 25 Jan. 2014. <>.

Kebabjian, Richard. "STATISTICS." Accident Statistics. N.p., n.d. Web. 14 Jan. 2014. <>.

Review of U.S. Civil Aviation Accidents 2007-2009. Rep. NTSB, n.d. Web. 19 Jan. 2014. <>.

"Risk Management Handbook." FAA, 2009. Web. 24 Jan. 2014. <>.