Among fatal plane crashes that occurred during the past 60 years, 410 were due to pilot error, 74 were due to other human error, 276 were due to weather, 658 were due to mechanical problems, and 194 were due to sabotage. @ Construct the relative frequency distribution. What is the most serious threat to aviation safety, and can anything be done about it? . . . Complete the relative frequency distribution below. Relative Cause Frequency Pilot error % Other human error % Weather % Mechanical problems % Sabotage (Round to one decimal place as needed.)