This article examines the effect of human error in aviation accidents. Aviation accidents are one of the most important factors that threaten security in air transportation, and various factors can play a role in their occurrence. One of these factors is human error, which can lead to an accident from simple to serious and uncorrectable errors, also human error is one of the important factors in plane accidents that can have serious consequences for the health and safety of passengers and aircraft employees. It may occur at any stage of the flight process from design and manufacturing to flight operations and maintenance. In the flight operations phase, this error can include pilot and air traffic control errors, ground logistics errors (such as lack of proper maintenance and repair of aircraft), and flight crew performance errors. It is clear that the detailed investigation of human errors in aviation accidents plays a significant role in increasing the safety of flights and may lead to effective improvements in the fields of pilot training and aircraft systems design. The purpose of this article is to analyze the human error in aviation accidents and the factors affecting its occurrence, which can help improve the safety and performance of airplanes and thus save people's lives in aviation accidents.