Among fatal plane crashes that occurred during the past 65 years, 161 were due to pilot error, 64 were due to other human error, 411 were due to weather, 128 were due to mechanical problems, and 587 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. What is the most serious threat to aviation safety, and can anything be done about it? A. Sabotage is the most serious threat to aviation safety. Airport security could be increased. B. Mechanical problems are the most serious threat to aviation safety. New planes could be better engineered. C. Weather is the most serious threat to aviation safety. Weather monitoring systems could be improved. D. Pilot error is the most serious threat to aviation safety. Pilots could be better trained