1972 Lake Winnebago mid-air collision
Encyclopedia
On June 29, 1972, North Central Airlines
Flight 290 collided in mid-air with Air Wisconsin
Flight 671 over Lake Winnebago
near Appleton
, Wisconsin
, in the United States
. Both aircraft crashed into the lake, killing all 13 people on board.
, Michigan
, and stopped at Ironwood
, Michigan, and Green Bay
, Oshkosh
, and Milwaukee
, Wisconsin, before terminating at Chicago, Illinois
. On June 29, 1972, however, bad weather in northern Michigan necessitated cancellation of the Houghton-Ironwood and Ironwood-Green Bay legs, and the flight originated at Green Bay, using a replacement crew sent from Chicago to Green Bay.
The flight, a Convair CV-580, departed Green Bay at around 10:30 a.m. CDT, proceeding to Oshkosh under visual flight rules
(VFR). At 10:36:11 a.m. CDT, the air traffic controller
at Oshkosh cleared Flight 290 to land; the flight crews acknowledgment five seconds later was the last communication with North Central Flight 290.
, Wisconsin. Operating a de Havilland Canada DHC-6 Twin Otter
, it departed Chicago at 9:28 a.m. CDT on June 29, 1972, bound for Sheboygan under an instrument flight rules
(IFR) plan; en route, the flight crew abandoned its IFR plan and completed the first leg of the flight under VFR.
The flight departed Sheboygan 13 minutes late, at 10:23 a.m. CDT bound for Appleton, operating under VFR. At about 10:30 a.m. CDT, the flight crew contacted the Air Wisconsin office in Appleton, stating that they anticipated arriving at Appleton at 10:44 a.m. CDT. This was the last communication with Air Wisconsin Flight 671.
about 6 nautical mile
s (6.9 mi, 11 km) south of Appleton and 2.5 nautical miles (2.9 mi, 4.6 km) east of Neenah
, Wisconsin, at an altitude of about 2,500 feet (762 m). A mid-air explosion and fire ensued, and both aircraft crashed into the lake.
The National Transportation Safety Board
noted that the North Central crew would have had to look toward the sun to see the approaching Air Wisconsin plane and concluded that they took no evasive action. Some eyewitnesses believed that the Air Wisconsin Twin Otter began a turn seconds before the collision, but the NTSB did not find sufficient evidence to conclude that the Air Wisconsin crew took evasive action. The rate of closure during the final five seconds before the collision was 688 feet (210 m) per second, i.e., 469 mph (755 km).
– on board, while the Air Wisconsin flight was carrying a crew of two (the captain and first officer) and six passengers. All 13 people aboard the two planes died in the collision and subsequent crash, and the NTSB observed that the accident was not survivable.
support, and that such support to even one of the aircraft would have ensured sufficient separation to avoid a collision.
The NTSB recommended that the Federal Aviation Administration
create a standardized method for training and grading flight crews in visual search techniques and time-sharing between instrument checks and visual searches, and that the FAA expedite the development of anticollision systems.
North Central Airlines
North Central Airlines was founded as Wisconsin Central Airlines in 1944 in Clintonville, Wisconsin. It was headquartered in Minneapolis, Minnesota.-Early history:...
Flight 290 collided in mid-air with Air Wisconsin
Air Wisconsin
Air Wisconsin Airlines Corporation is an airline based at Outagamie County Regional Airport in the town of Greenville, Wisconsin, United States, near Appleton. Air Wisconsin is the largest privately held regional airline in the United States...
Flight 671 over Lake Winnebago
Lake Winnebago
Lake Winnebago is a freshwater lake in eastern Wisconsin, United States. It is the largest lake entirely within the state.-Statistics:...
near Appleton
Appleton, Wisconsin
Appleton is a city in Outagamie, Calumet, and Winnebago Counties in the U.S. state of Wisconsin. It is situated on the Fox River, 30 miles southwest of Green Bay and 100 miles north of Milwaukee. Appleton is the county seat of Outagamie County. The population was 78,086 at the 2010 census...
, Wisconsin
Wisconsin
Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...
, in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. Both aircraft crashed into the lake, killing all 13 people on board.
North Central Airlines Flight 290
North Central Airlines Flight 290 was a regularly scheduled flight which usually originated in HoughtonHoughton, Michigan
Houghton is a city in the U.S. state of Michigan's Upper Peninsula and largest city in the Copper Country on the Keweenaw Peninsula. As of the 2010 census, the city population was 7,708. It is the county seat of Houghton County...
, Michigan
Michigan
Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....
, and stopped at Ironwood
Ironwood, Michigan
Ironwood is a city in Gogebic County in the U.S. state of Michigan, about south of Lake Superior. The population was 6,293 at the 2000 census. The city is on US 2 and is situated opposite the Montreal River from Hurley, Wisconsin. It is the westernmost city in Michigan, situated on the same line...
, Michigan, and Green Bay
Green Bay, Wisconsin
Green Bay is a city in and the county seat of Brown County in the U.S. state of Wisconsin, located at the head of Green Bay, a sub-basin of Lake Michigan, at the mouth of the Fox River. It has an elevation of above sea level and is located north of Milwaukee. As of the 2010 United States Census,...
, Oshkosh
Oshkosh, Wisconsin
As of the census of 2000, there were 62,916 people, 24,082 households, and 13,654 families residing in the city. The population density was 2,662.2 people per square mile . There were 25,420 housing units at an average density of 1,075.6 per square mile...
, and Milwaukee
Milwaukee, Wisconsin
Milwaukee is the largest city in the U.S. state of Wisconsin, the 28th most populous city in the United States and 39th most populous region in the United States. It is the county seat of Milwaukee County and is located on the southwestern shore of Lake Michigan. According to 2010 census data, the...
, Wisconsin, before terminating at Chicago, Illinois
Illinois
Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...
. On June 29, 1972, however, bad weather in northern Michigan necessitated cancellation of the Houghton-Ironwood and Ironwood-Green Bay legs, and the flight originated at Green Bay, using a replacement crew sent from Chicago to Green Bay.
The flight, a Convair CV-580, departed Green Bay at around 10:30 a.m. CDT, proceeding to Oshkosh under visual flight rules
Visual flight rules
Visual flight rules are a set of regulations which allow a pilot to operate an aircraft in weather conditions generally clear enough to allow the pilot to see where the aircraft is going. Specifically, the weather must be better than basic VFR weather minimums, as specified in the rules of the...
(VFR). At 10:36:11 a.m. CDT, the air traffic controller
Air traffic controller
Air traffic controllers are the people who expedite and maintain a safe and orderly flow of air traffic in the global air traffic control system. The position of the air traffic controller is one that requires highly specialized skills...
at Oshkosh cleared Flight 290 to land; the flight crews acknowledgment five seconds later was the last communication with North Central Flight 290.
Air Wisconsin Flight 671
Air Wisconsin Flight 671 was a regularly scheduled flight from Chicago, Illinois, to Appleton, Wisconsin, with a stopover at SheboyganSheboygan, Wisconsin
-Airport:Sheboygan is served by the Sheboygan County Memorial Airport, which is located several miles from the city.-Roads:Interstate 43 is the primary north-south transportation route into Sheboygan, and forms the west boundary of the city. U.S...
, Wisconsin. Operating a de Havilland Canada DHC-6 Twin Otter
De Havilland Canada DHC-6 Twin Otter
The DHC-6 Twin Otter is a Canadian 19-passenger STOL utility aircraft developed by de Havilland Canada and currently produced by Viking Air. The aircraft's fixed tricycle undercarriage, STOL abilities and high rate of climb have made it a successful cargo, regional passenger airliner and MEDEVAC...
, it departed Chicago at 9:28 a.m. CDT on June 29, 1972, bound for Sheboygan under an instrument flight rules
Instrument flight rules
Instrument flight rules are one of two sets of regulations governing all aspects of civil aviation aircraft operations; the other are visual flight rules ....
(IFR) plan; en route, the flight crew abandoned its IFR plan and completed the first leg of the flight under VFR.
The flight departed Sheboygan 13 minutes late, at 10:23 a.m. CDT bound for Appleton, operating under VFR. At about 10:30 a.m. CDT, the flight crew contacted the Air Wisconsin office in Appleton, stating that they anticipated arriving at Appleton at 10:44 a.m. CDT. This was the last communication with Air Wisconsin Flight 671.
Collision
Operating in heavy sunshine beneath a scattered cloud layer, Flights 290 and 671 collided at 10:36:47 a.m. CDT over Wisconsins Lake WinnebagoLake Winnebago
Lake Winnebago is a freshwater lake in eastern Wisconsin, United States. It is the largest lake entirely within the state.-Statistics:...
about 6 nautical mile
Nautical mile
The nautical mile is a unit of length that is about one minute of arc of latitude along any meridian, but is approximately one minute of arc of longitude only at the equator...
s (6.9 mi, 11 km) south of Appleton and 2.5 nautical miles (2.9 mi, 4.6 km) east of Neenah
Neenah, Wisconsin
Neenah is a city on Lake Winnebago in Winnebago County, Wisconsin, United States. Its population was 24,507 at the 2000 census. The city is bordered by, but is politically independent of, the Town of Neenah. Neenah is the southwestern-most of the Fox Cities of Northeast Wisconsin...
, Wisconsin, at an altitude of about 2,500 feet (762 m). A mid-air explosion and fire ensued, and both aircraft crashed into the lake.
The National Transportation Safety Board
National Transportation Safety Board
The National Transportation Safety Board is an independent U.S. government investigative agency responsible for civil transportation accident investigation. In this role, the NTSB investigates and reports on aviation accidents and incidents, certain types of highway crashes, ship and marine...
noted that the North Central crew would have had to look toward the sun to see the approaching Air Wisconsin plane and concluded that they took no evasive action. Some eyewitnesses believed that the Air Wisconsin Twin Otter began a turn seconds before the collision, but the NTSB did not find sufficient evidence to conclude that the Air Wisconsin crew took evasive action. The rate of closure during the final five seconds before the collision was 688 feet (210 m) per second, i.e., 469 mph (755 km).
Aircraft
The North Central aircraft involved, N50858, had been completed as a Convair CV-340/440 on May 25, 1953; it later was converted to CV-580 standard. The Air Wisconisn Twin Otter had been completed on October 6, 1966. Both aircraft were destroyed by the collision and subsequent water impact. Their wreckage was found on the lake bottom scattered over an area roughly one mile (1.6 km) long by one-half mile (0.8 km) wide.Casualties
The North Central plane had two passengers and a crew of three – the captain, the first officer, and a flight attendantFlight attendant
Flight attendants or cabin crew are members of an aircrew employed by airlines primarily to ensure the safety and comfort of passengers aboard commercial flights, on select business jet aircraft, and on some military aircraft.-History:The role of a flight attendant derives from that of similar...
– on board, while the Air Wisconsin flight was carrying a crew of two (the captain and first officer) and six passengers. All 13 people aboard the two planes died in the collision and subsequent crash, and the NTSB observed that the accident was not survivable.
Investigation
The National Transportation Safety Board released its report on the accident on April 25, 1973. While it was “unable to determine why each crew failed to see and avoid the other aircraft,” it concluded that the crash resulted from "the failure of both flight crews to detect visually the other aircraft in sufficient time to initiate evasive action,” and stated that it believed “that the ability of both crews to detect the other aircraft in time to avoid a collision was reduced because of the atmospheric conditions and human visual limitations." The NTSB speculated that both flight crews could have been scanning instruments in preparation for descent to their respective destinations at the time of the collision, and this could have reduced their chances of spotting one another. The report also noted that the decision by both flight crews to fly under VFR rather than IFR and the fact that neither captain requested in-flight advisories deprived both aircraft of air traffic controlAir traffic control
Air traffic control is a service provided by ground-based controllers who direct aircraft on the ground and in the air. The primary purpose of ATC systems worldwide is to separate aircraft to prevent collisions, to organize and expedite the flow of traffic, and to provide information and other...
support, and that such support to even one of the aircraft would have ensured sufficient separation to avoid a collision.
The NTSB recommended that the Federal Aviation Administration
Federal Aviation Administration
The Federal Aviation Administration is the national aviation authority of the United States. An agency of the United States Department of Transportation, it has authority to regulate and oversee all aspects of civil aviation in the U.S...
create a standardized method for training and grading flight crews in visual search techniques and time-sharing between instrument checks and visual searches, and that the FAA expedite the development of anticollision systems.