At 7:30 on the evening of Friday, June 23, 1950, Northwest Orient Airlines Flight 2501 departed New York City on a transcontinental flight to Seattle, Washington, with a scheduled stopover in Minneapolis, Minnesota, with fifty-five passengers, one captain, one copilot, and one stewardess onboard. The weather that evening was warm and pleasant, and when the plane took off there was no reason to suspect that it would be anything other than a routine flight, and for the first leg of the journey it was. However, Flight 2501 was about to fly into the annals of great unsolved aviation mysteries, disappearing with its passengers and crew to never be seen again.
The flight had been totally uneventful as it passed over Cleveland, Ohio and continued west toward Minneapolis, Minnesota, with the pilot, 35-year old Captain Robert C. Lind, radioing in to say the flight was on schedule. The DC-4 aircraft was about 3,500 feet (1,100 m) over Lake Michigan when Lind called again to request permission from air traffic control to descend to 2,500 feet. Although he gave no reason for this sudden altitude change, the request was perfectly normal and calm, with no mention of bad weather or anything amiss, although there were known to be storms at that time over some portions of Lake Michigan in other areas. The request was denied due to other air traffic in the area, and Lind merely confirmed this and ended the call with no further issue. It would be the last time anyone on the flight would be heard from.
When the plane did not arrive at its destination on schedule, there were efforts to make contact on all frequencies but this proved to be fruitless. There was no further word on the fate of the plane, no communications, no sign, and by the time dawn came with no sight of the flight it was clear that something was very wrong. It was assumed that the plane had crashed perhaps due to a storm that had suddenly changed direction, so a massive search and rescue operation was immediately launched, involving the US Navy, US Coast Guard, and State Police from Illinois, Michigan, Wisconsin and Indiana, who scoured the area but at first found nothing. It would not be until 13 hours later that Coast Guard vessels were able to locate some rather grim traces of the missing plane. They managed to find an oil slick and various miscellaneous debris bobbing about in the foggy, cold water, including a piece of a fuel tank float, seat cushions, clothing, blankets, luggage, cabin lining, a seat armrest, fragments of upholstery and an airline logbook, with all of the various debris being very small pieces reported as “no bigger than your hand.”
There was also the macabre discovery of human body parts, although these were also just fragments, including hands, fingers, and ears. Efforts were made to find any other traces or the wreckage of the plane, using divers, sonar, and dragging the bottom of Lake Michigan with trawlers, but nothing more could be found, it could not be determined where or why the plane had gone down, and there were no further signs of any bodies or wreckage. All anyone knew was that the plane had met some dire fate, and with 58 people aboard it was up to that point the worst aviation disaster in United States history. As the extensive search efforts were going on, authorities were trying to piece together just what had happened. Eyewitnesses would report having seen a bright flash of light in the vicinity of where the plane had made it last radio transmission, and there were at least two reports of seeing an explosion in the sky. One such witness of these aerial phenomena was a retired U. S Navy man, Lt. Cmdr. R. T. Helm, who saw the plane fly over his home near Benton Harbor and said:
I heard the plane over my home about 12:20 AM Saturday. I took a look out of the window and he seemed to be flying pretty low. How low, I don’t know. There was a terrific electrical storm raging at the time. A few minutes later, I looked out over the lake, I noticed a plane was heading east and that its landing signals were flashing. The lights kept coming closer to my house. Minutes later, there was a terrific flash out in the lake.
Another report was from a woman who saw the plane and then a flash, of which she would say, “All of a sudden there was this flash. It was a funny light. It looked like the sun when it goes down. It only lasted a second and then was gone.” Due to reports like these, the tiny fragments of debris, and the small body pieces, it was thought that Flight 2501 had perhaps experienced a catastrophic mid-air explosion that had completely disintegrated it. However, how such an explosion had happened was unknown and there was no real hard evidence that this was the case. Another theory was that the plane had been taken down by lightning, and still another theory has been that the flight had encountered a sudden and unexpected squall and that the pilot had tried to fly around it, with this probably being the reason that Lind had requested a change of altitude, but he never mentioned this in his final radio report. The cause is still unknown, and no one really knows what happened to Flight 2501 or where it went.
The official search was eventually called off, but in the decades since there have been continuing efforts and expeditions to try and find the mysterious missing plane. The author and explorer Clive Cussler famously launched a massive annual search for the missing plane along with the Michigan Shipwreck Research Associates (MSRA), a Michigan-based non-profit organization. Starting in 2004, for 13 years straight they covered hundreds of square miles that they had calculated to be the most likely area where it went down, using the most advanced equipment available, but although they found 10 shipwrecks, there was no trace of Flight 2501, not even a single scrap of wreckage.
One of the most dogged researchers hunting for Flight 2501 is Valerie van Heest, MSRA co-director and author of a book on the incident called Fatal Crossing, who has found all sorts of new information on the disappearance and its aftermath. Her team has made great progress in using advanced weather predicting technology and computer simulations to map the paths of debris and greatly narrow the search area of where the plane likely went down. To do this, Van Heest enlisted the help of a retired scientist with the National Oceanic and Atmospheric Administration (NOAA) named Dr. David Schwab, an expert in predicting changes in weather above the Great Lakes. He says of his role in their research:
I study the interaction of physics of the Great Lakes with the atmosphere over the Great Lakes. My job was to help guess where the plane might have gone down based on where the debris was found. Based on those currents, and the winds over the lake, we can simulate how a piece of debris would move and where it would go hour by hour after it had started at some location. I got meteorological date from the weather stations at Muskegon, South Bend, Chicago and Milwaukee, and interpolated those winds over the lake. We get a good estimation of what kind of wind was prevalent during that period when the plane went down. Currents don't always go in the same direction as the wind. If something's floating real high in the water, it's more affected by the wind than the current. All of the pieces of debris were released at the same time, which was around midnight when reports came in that the plane crashed. We tried to find the pieces of debris whose trajectory took them closest to the places and times debris was sighted by the rescue teams. Based on the correlation of the paths of these pieces of debris, with the location and times where actual debris was found, we can take the pieces of debris that came closest and look where they started, offering us a probability map of where the plan might have gone down.
With this information, the team believes that they are in a position to finally find the answer to the mystery, but the plane has still never been found, turning it into something akin to an ongoing treasure hunt. The case has as of yet not reached a resolution, and we are left to wonder what happened to this plane and all of those on board. It seems that something awful happened out there on that fateful evening, but what that was or where the plane and its crew and passengers went have gone on to remain one of aviation's great unsolved mysteries.