For over a decade , the nonscheduled airlines ' safety record earned the envy of the aviation industry . Most of them had won the National Safety Council 's Aviation Safety Award for a year without accident and three years with below-average accident rates ; many had earned the honor twice . But a 1961 study by the Federal Aviation Administration found that airlines suffering financially tended to experience a drop in safety standards , and by 1960 several of the extant supplementals were in poor fiscal health . The years of battling protean regulations and competing for a fluctuating supply of contracts had whittled the once-abundant non-skeds down to a few dozen companies , many of which barely limped along despite their updated classification . On 19 September 1960 , a World Airways Douglas DC-6A took off from Guam carrying military personnel and their families , 80 of whom were killed when the plane crashed shortly thereafter . A C-46 flown by Arctic-Pacific Airlines crashed over Ohio on 29 October 1960 , killing 22 of the 48 members of California Polytechnic Institute 's returning football team . After making a wrong turn , President Airline 's DC-6B crashed into the River Shannon on 10 September 1961 leaving 83 dead . 74 soldiers aboard an Imperial Airways flight died on 8 November 1961 when the Lockheed 069 Constellation hired to transport them crashed near Richmond , Virginia while attempting an emergency landing . Subsequent investigations found that crew fatigue , mechanical failures resulting from incompetent maintenance , and poorly trained pilots lay behind each disaster . In one case the crew had been flying without rest for more than 25 hours ; in another the pilot had failed his flight test three times . These needless — and widely publicized — tragedies bore heavily upon the House representatives and senators as they crafted Public Law 87-528 , passed on 10 July 1962
crashed over Ohio
Cal Poly football team C-46 crash
History of non-scheduled airlines in the United States