title: General aviation accidents related to exceedance of airplane weight/center of gravity limits.
abstract: BACKGROUND
  Obesity, affects a third of the US population and its corollary occupant weight adversely impacts safe flight operations. Increased aircraft weight results in longer takeoff/landing distances, degraded climb gradients and airframe failure may occur in turbulence. In this study, the rate, temporal changes, and lethality of accidents in piston-powered, general aviation aircraft related to exceeding the maximum aircraft weight/center of gravity (CG) limits were determined.
  
  
  METHODS
  Nation-wide person body mass were from the National Health and Nutrition Examination Survey. The NTSB database was used to identify accidents related to operation of aircraft outside of their weight/CG envelope. Statistical analyses employed T-tests, proportion tests and a Poisson distribution.
  
  
  RESULTS
  While the average body mass climbed steadily (p<0.001) between 1999 and 2014 the rate of accidents related to exceedance of the weight/CG limits did not change (p=0.072). However, 57% were fatal, higher (p<0.001) than the 21% for mishaps attributed to other causes/factors. The majority (77%) of accidents were due to an overloaded aircraft operating within its CG limits. As to the phase of flight, accidents during takeoff and those occurring enroute carried the lowest (50%) and highest (85%) proportion of fatal accidents respectively.
  
  
  CONCLUSIONS
  While the rate of general aviation accidents related to operating an aircraft outside of its weight/CG envelope has not increased over the past 15 years, these types of accidents carry a high risk of fatality. Airmen should be educated as to such risks and to dispel the notion held by some that flights may be safely conducted with an overloaded aircraft within its CG limits.
authors.affiliation: University of Texas, Houston, 7777 Knight Road, TX 77054, USA. Electronic address: douglas.boyd@uth.tmc.edu.
authors.forename: Douglas D
authors.initials: DD
authors.lastname: Boyd
mesh_terms: D000060:Accidents, Aviation / Q000706:statistics & numerical data*; D000401:Aircraft / Q000706:statistics & numerical data*; D001359:Aviation / Q000706:statistics & numerical data*; D001835:Body Weight; D016208:Databases, Factual; D005260:Female; D006112:Gravitation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D009765:Obesity / Q000453:epidemiology*; D012307:Risk Factors
keywords: Aircraft weight and balance; General aviation accidents; Obesity