8 collide ~Appleton, WI– 13

lornajarrettblanchard June 29, 1972

–13 Bureau of Aircraft Accidents Archives. “Crash of a Convair CV-580…Appleton: 5 Killed.”
–13 Eckert. “Fatal commercial air transport crashes, 1924-1981.” AJFMP, 3/1, Mar 1982, Table 1.
–13 Kebabjian, Richard. “Accident Details…June 29, 1972.” Planecrashinfo.com
–13 NTSB AAR. North Central Air…and Air Wisconsin…near Appleton, WI 29Jun1972. 1973.

Narrative Information

Kebabjian: “Both aircraft were proceeding under VFR [Visual Flight Rules] getting ready to land when there was a midair collision. Both aircraft crashed into Lake Winnebago and sank. The failure of both flightcrews to detect visually the other aircraft in sufficient time to initiate evasive action.” All 13 on-board the two planes were killed – combined crews of five and eight passengers. The North Central Airlines plane was registered as N90858. The Air Wisconsin was registered as N4043B. (Kebabjian. Planecrashinfo.com)

National Transportation Safety Board Synopsis:

“A North Central Airlines Allison Convair 340/440 (CV-580) and an Air Wisconsin Incorporated DHC-6 collided over Lake Winnebago near Appleton, Wisconsin, at approximately 1037 central daylight time, June 29, 1972. The two passengers and three crewmembers aboard the CV-580 and the six passengers and two crewmembers aboard the DHC-6 were fatally injured. Both aircraft were destroyed as a result of the in-flight collision and the subsequent water impact.

“Both flights were operating in accordance with visual flight rules and were within minutes of landing at their respective destinations. Visual meteorological conditions existed in the accident area.

“The National Transportation Safety Board determines that the probable cause of this accident was the failure of both flightcrews to detect visually the other aircraft in sufficient time to initiate evasive action. The Board is unable to determine why each crew failed to see and avoid the other aircraft; however, the Board believes that the ability of both crews to detect the other aircraft in time to avoid a collision was reduced because of atmospheric conditions and human visual limitations.” (NTSB 1973, p.1.)

“History of the Flights

“North Central Airlines, Inc., Flight 290, an Allison Convair 3401440 (commonly known as a CV-580), N90858, was a regularly scheduled passenger flight between Houghton, Michigan, and Chicago, Illinois, with intermediate stops at Ironwood, Michigan, and Green Bay, Oshkosh, and Milwaukee, Wisconsin.

On June 29, 1972, the Houghton-to-Green Bay portion of Flight 290 was cancelled because of adverse weather conditions in northern Michigan. Consequently, Flight 290 originated at Green Bay on the day of the accident. Because of this change in the flight schedule, a replacement flightcrew was required and was sent to Green Bay from Chicago.

“At approximately 1026:28, CV-580 called Green Bay ground control and stated, ‘…ready to taxi, like to go VFR to Oshkosh.’ The flight was cleared to taxi and was given the Green Bay altimeter setting.

“At 1028:14, Green Bay tower requested a clarification of the crew’s intentions by asking, ‘… VFR or IFR?’ The crew replied, ‘VFR’.

“At approximately 1030, the flight departed from Green Bay and climbed to 2,500 feet. The flight then proceeded on an approximate course to Oshkosh.

“At 1035, the CV-580 made an ‘in range’ call to the company office at Oshkosh, stating that this landing would be accomplished with 8,400 pounds of fuel remaining.

“At 1035:46 the flight made its initial contact with Oshkosh tower stating, ‘…we’re about, seven northeast, two thousand five hundred, VFR.’ The tower acknowledged the transmission from NC290 and gave the crew the latest weather, altimeter setting, and runway information at the airport.

“At 1036:11, the crew requested clearance to land on Runway 27. The controller confirmed the runway and cleared the flight for landing.

“At 1036:16, the crew acknowledged the landing clearance. This was the last known radio transmission from the flight.

“Air Wisconsin Incorporated, Flight 671, a DeHavilland DHC-6 Twin Otter, N4043B, was a regularly scheduled passenger flight between Chicago and Appleton, Wisconsin, with an intermediate stop at Sheboygan, Wisconsin.

“The flight departed from Chicago at 0928 in accordance with an IFR flight plan. Prior to their arrival at Sheboygan, the flightcrew cancelled the IFR flight plan and continued VFR to Sheboygan.

“At 1023, 13 minutes later than scheduled, the flight departed from Sheboygan. The flightcrew did not reopen the filed IFR flight plan prior to their departure from Sheboygan but rather elected to proceed VFR direct to Appleton.

“At approximately 1030, the crew contacted the company office at Appleton on the company radio frequency and reported that it would be landing at 1044 with 300 pounds of fuel remaining. This is the last known radio contact with the flight.

“The in-flight collision occurred at 1036:47 at an altitude of approximately 2,500 feet. The collision point, as established by witness statements and wreckage location, was over Lake Winnebago, 6 nautical miles south of Appleton, Wisconsin, and 2.5 nautical miles east of Neenah, Wisconsin. (Latitude 44°11’N., longitude 88°24’W.) The accident occurred in hazy sunlight below a scattered cloud layer.

“Straight line courses drawn from each flight’s departure point to its respective destination intersect approximately at the collision point.

“Of the 38 eyewitnesses who were interviewed, 8 observed both air craft just prior to and at the time of the collision. Two witnesses stated that the DHC-6 might have initiated a turn, moments before the collision.

“Explosion and fire followed the in-flight collision and both aircraft fell into Lake Winnebago.” (NTSB 1973, pp. 2-3.)

“Statements of other pilots who were flying in the area before, during, and after the time of the accident, generally confirmed the reported weather. Most of these pilots stated that the top of the haze layer was at approximately 3,500 feet and that visibility was at least 5 miles but diminished rapidly when they turned toward the sun. The flightcrew of the CV-580 would have had to look toward the sun in order to see the DHC-6.” (NTSB 1973, p.5.)

“Neither air carrier had a formal training program regarding visual scanning, nor did the Federal Aviation Administration (FAA) require such a program.” (NTSB 1973, p.7.)

“The decision by both flightcrews to conduct their flights under visual flight rules, rather than under instrument flight rules, appears to have been influences by the expectation that some savings of time, fuel, and flightcrew workload would result. By operating in accordance with visual flight rules, both aircraft were able to proceed directly to their respective destinations at low altitudes without delay. The investigative findings and hearing testimony indicate that the savings would have been minimal.” (NTSB 1973, p.8.)

“….Had both aircraft been operating in accordance with instrument flight rules, they would have been afforded collision avoidance radar advisories and altitude separation. If only one aircraft had been IFR, it could have been given radar separation from other known IFR traffic and probably would have been given advisories regarding unidentified traffic in its vicinity. The aircraft under IFR clearance would have had an assigned altitude (i.e., 4,000, 6,000 feet) and VFR aircraft should have flown below 4,000 feet or at a proper hemispheric altitude (i.e., 4,500, 6,500 feet). Thus, altitude separation could have been maintained affectively.” (NTSB 1973, p.9.)

“….Neither captain chose to activate prestored IFR flight plans; consequently, both aircraft were operating in accordance with VFR. Neither captain requested radar in-flight advisories, even though these advisories probably could have been provided had they been requested. Chicago ARTCC had no knowledge of the intended flightpath of either aircraft or their en route locations at any point in time. The ARTCC would not have been able to identify or communicate with either aircraft if conflicting radar returns had been observed on their radarscopes….While advisories in themselves are no guarantee that pilots will always see other traffic, the flightcrews are nevertheless alerted to a target and its relative bearing. With such information available, the search area is localized, and a warning is provided that a potentially dangerous threat could suddenly appear.” (NTSB 1973, p. 14.)

“….This accident is another example of the hazard of attempting to maintain visual separation when the in-flight visibility is restricted but above the minimum required for VFR flight. This accident again illustrates that care must be taken and outside vigilance must be maintained in order to implement the ‘see and avoid’ concept to its fullest extent. Although less reliable as aircraft speeds increase, the ‘see and avoid’ concept remains the primary collision avoidance technique used by pilots who operate in visual meteorological conditions.” (NTSB 1973, p.16.)
….

Recommendations

“There is no approved, standardized method to train or grade pilots in the techniques of time sharing between scanning cockpit instruments and searching the surrounding airspace for other aircraft.

“The Board believes that an audio-visual aid, developed by the Aircraft Owners and Pilots Association Air Safety Foundation Group, could help pilots develop a better understanding of how to conduct a search for airborne targets and the necessity of improving their time at length upon any recommended scanning technique, but it does draw sharing techniques. The presentation used in this aid does not dwell the trainee’s attention dramatically to the inherent difficulties involved in sighting other aircraft and, by so doing, it emphasizes the need for the attention and concentration required to improve the possibilities of visually sighting airborne targets.

“On January 6 , 1972, the Board made its third recommendation to the FAA concerning visual scan and time-sharing training. The FAA previously had proposed, in Notice of Proposed Rule Making (NPRM) No. 70-37, to develop a system to train pilots in methods to time-share visual outside searches and scanning of cockpit displays. The NPRM was withdrawn by the FAA on July 27, 1972, because a majority of the comments received from individuals and organizations within the aviation community did not favor the amendment. The Board then recommended that the FAA reconsider the withdrawal of the NPRM and that the rule-making be reinstituted. The FAA on November 28, 1972, advised the Board that the rule making had been premature and that additional research and development was required. They stated that such research and development was in progress and that if the results were fruitful, the rule making would be reinstituted.

“The Board, in Special Study Midair Collisions in U. S. Civil Aviation 1969 – 1970, June 7, 1972, recommended that the FAA require the daytime use of high-intensity white lights on all air carrier aircraft. The FAA responded on October 19, 1972, that ‘… An evaluation project was started on 7 April 1972 to pursue aircraft conspicuity research on a priority to substantiate rulemaking action on anticollision lights, strobe lights, and pilot warning instrument (PWI) application of the strobe lights….’ As we have previously noted, no determination could be made in this case regarding the use of the installed strobe lights on the CV-580. However, the Board continues to believe that the use of such lights in daytime operations would improve the conspicuity of aircraft and make them easier to detect by pilots of other aircraft.” (NTSB 1973, p.18.)

“The Board also noted, during the investigation of this accident, that there is no standardized flight check requirement with regard to the visual scan procedures used by a flightcrew when the flight is operating in visual meteorological conditions (VMC). This subject has been investigated in several collision accidents and to date, no satisfactory system has been reported to the Board.

“The Board continues to be concerned with the overall midair collision problem. As the Board has stated before, the midair collision hazard is one of the most urgent and serious problems confronting civil aviation in this decade.

“While the Board recognizes the continuing emphasis that the FAA is providing to resolve the midair collision problem, the Board considers that an even greater effort is needed to resolve the issues and arrive at a solution which will reduce the risk of midair collisions, especially as it relates to the wide bodied jet fleet.

“In view of the above, the National Transportation Safety Board recommends that the Administrator, Federal Aviation Administration:

1. Develop and publish standards for visual search techniques to be used by instructors
and check pilots on all training, certification, and proficiency check flights when pilots
are operating in VMC (Safety Recommendation A-73-27).

2. Establish a requirement for pilots to be trained in the techniques of time sharing between visual scanning for airborne targets and cockpit duties (Safety Recommendation A-73- 28).

3. Require that all pilots and flightcrew members training, certification, and proficiency
check forms contain a specific item on scanning and time sharing (Safety Recommendation A-73-29).

4. Require that all pilots and flightcrew members be graded in scanning and time sharing techniques when training, certification, and proficiency check flights are conducted under VMC (Safety Recommendation A-73-30).

5. Advise the Board of the status of the FAA’s evaluation project of April 7, 1972, on
aircraft conspicuity research and, if that project has not been completed, take action to
complete the project on a priority basis (Safety Recommendation A-73-31).

6. Expedite the development and issuance of national standards for systems to provide protection from midair collisions so that the industry can proceed without further delay to develop and market economically viable hardware (Safety Recommendation A-73-32).” (NTSB 1973, 18-19)

Sources

Bureau of Aircraft Accidents Archives, Geneva. “Crash of a Convair CV-580 near Appleton: 5 Killed.” Accessed 1-23-2022 at: https://www.baaa-acro.com/crash/crash-convair-cv-580-near-appleton-5-killed

Eckert, William G. “Fatal commercial air transport crashes, 1924-1981.” American Journal of Forensic Medicine and Pathology, Vol. 3, No. 1, March 1982, Table 1.
Kebabjian, Richard. “Accident Details…June 29, 1972.” Planecrashinfo.com. Accessed 1-23-2022 at: http://www.planecrashinfo.com/1972/1972-37.htm

National Transportation Safety Board. Aircraft Accident Report. North Central Airlines, Inc. Allison Convair 340/440 (CV-580), N90858 and Air Wisconsin Inc., DH-C, N4043B near Appleton, Wisconsin June 29, 1972 (NTSB-AAR-73-9). Washingto, DC: NTSB, 24 Apr 1973, 36 pp. Accessed 1-23-2022 at: http://libraryonline.erau.edu/online-full-text/ntsb/aircraft-accident-reports/AAR73-09.pdf