Lake Central Airlines Flight 527 was a regularly scheduled

Convair 580 The Convair CV-240 is an American airliner that Convair manufactured from 1947 to 1954, initially as a possible replacement for the ubiquitous Douglas DC-3. Featuring a more modern design with cabin pressurization, the 240 series made some inroa ...

flight on March 5, 1967 from

Chicago (''City in a Garden''); I Will , image_map = , map_caption = Interactive Map of Chicago , coordinates = , coordinates_footnotes = , subdivision_type = Country , subdivision_name ...

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita ...

Detroit Detroit ( , ; , ) is the largest city in the U.S. state of Michigan. It is also the largest U.S. city on the United States–Canada border, and the seat of government of Wayne County. The City of Detroit had a population of 639,111 at th ...

Michigan Michigan () is a state in the Great Lakes region of the upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the 10th-largest state by population, the 11th-largest by area, and the ...

with stops at

Lafayette, Indiana Lafayette ( , ) is a city in and the county seat of Tippecanoe County, Indiana, United States, located northwest of Indianapolis and southeast of Chicago. West Lafayette, on the other side of the Wabash River, is home to Purdue University, whi ...

Cincinnati, Ohio Cincinnati ( ) is a city in the U.S. state of Ohio and the county seat of Hamilton County. Settled in 1788, the city is located at the northern side of the confluence of the Licking and Ohio rivers, the latter of which marks the state line wit ...

Columbus, Ohio Columbus () is the state capital and the most populous city in the U.S. state of Ohio. With a 2020 census population of 905,748, it is the 14th-most populous city in the U.S., the second-most populous city in the Midwest, after Chicago, and t ...

and

Toledo, Ohio Toledo ( ) is a city in and the county seat of Lucas County, Ohio, United States. A major Midwestern United States port city, Toledo is the fourth-most populous city in the state of Ohio, after Columbus, Cleveland, and Cincinnati, and according ...

. The aircraft crashed near

Marseilles, Ohio Marseilles is a village in Wyandot County, Ohio, United States, located at the western edge of the Killdeer Plains Wildlife Area. The population was 93 at the 2020 census. History The village was named after Marseille, France. On March 5, 1967, ...

, killing all 38 passengers and crew on board.

Synopsis

On March 5, 1967, Lake Central Airlines Flight 527 was scheduled from Chicago, Illinois to Detroit, Michigan. The flight, operated by one of the company's

aircraft and flown by captain John W. Horn (45) and first officer Roger P. Skillman (33), left Chicago at 4:04 p.m. CST and proceeded normally to Lafayette, Cincinnati and Columbus. No problems were reported. The aircraft was serviced in Columbus and departed at 7:52 p.m. EST for Toledo. At 8:05 p.m., the flight was cleared by air traffic control to descend from as it approached Toledo. Air traffic control requested that the flight report its descent and to report crossing . The crew acknowledged leaving 10,000 feet. This was the last transmission from the aircraft. Witnesses in the vicinity of

reported hearing sounds from an aircraft at times between 8:05 and 8:10 p.m. Some reported sounds similar to that of an engine starting. Shortly thereafter, the sound of an explosion was reported. By 9:00 p.m., the authorities had confirmed that an aircraft had crashed in the area. Rain mixed with snow was reported at the time of the accident.

Cause

The aircraft was found to be loaded within normal limits, and the crew was found to be properly qualified for the flight, with no deficiencies reported. The aircraft was equipped with a

flight data recorder A flight recorder is an electronic recording device placed in an aircraft for the purpose of facilitating the investigation of aviation accidents and incidents. The device may often be referred to as a "black box", an outdated name which has b ...

, which sustained no damage in the crash and was successfully read by investigators. Approximately 14 minutes after departing Columbus, the aircraft was on a heading of 322 degrees when it abruptly veered right 40 degrees, and then left 55 degrees, before power to the recorder was abruptly terminated. The

cockpit voice recorder A flight recorder is an electronic recording device placed in an aircraft for the purpose of facilitating the investigation of aviation accidents and incidents. The device may often be referred to as a "black box", an outdated name which has b ...

lost power at the same time, although investigators heard a sound resembling "the first few seconds of an air raid siren" just before shutoff. The aircraft crashed in a farm field on a heading of 360 degrees. The front fuselage was separated from the main part of the aircraft, and debris was recovered from a , trail on a heading of 135 degrees from the main wreckage. The right propeller was completely detached from the engine, as were the blades. In reconstructing the wreckage, the investigators discovered that the right propeller had separated during flight and severed the fuselage. During manufacture, propeller pistons, which control the pitch of the propellers, are coated through a process called

nitriding Nitriding is a heat treating process that diffuses nitrogen into the surface of a metal to create a case-hardened surface. These processes are most commonly used on low-alloy steels. They are also used on titanium, aluminium and molybdenum. Ty ...

, which hardens them and increases their resistance to surface wear. They are supposed to be inspected to ensure that the process is completed, but investigators could not determine why N73130's propeller was not nitrided and did not fail inspections. During the life of the engine, the piston had been slowly wearing away. During the flight, the piston finally failed, causing the propeller to speed beyond its limits. The stress caused the propeller to fail one to two seconds later. When the propeller failed, the blades were hurled through the cabin, severing control cables and compromising the plane's structural integrity. The investigators determined that the crash was caused solely by the propeller defect and subsequent failure.

References

External links