The accident was investigated by the Canadian Aviation Safety Board ( CASB ) , which determined the probable cause of the crash was the aircraft 's unexpectedly high drag and reduced lift condition , most likely due to ice contamination on the wings ' leading edges and upper surfaces , as well as underestimated onboard weight . A minority report stated that the accident could have been caused by an onboard explosion of unknown origin prior to impact , with one of these dissenting investigators later telling a United States congressional committee that it was impossible for a thin layer of ice to bring down the aircraft . The dissenting report led to delays in changes to de-icing procedures , with a thin layer of ice causing the deadly crash of Air Ontario Flight 1363 in Canada in 1989 . In response to lack of confidence in accident investigations by the CASB , the Government of Canada shut down that board in 1990 , replacing it with an independent , multi-modal investigative agency &ndash; the Transportation Safety Board of Canada
Air Ontario Flight 1363
Air Ontario Flight 1363
Arrow Air Flight 1285