On June 23rd, 1950, Northwest Orient Airlines Flight 2501 took off from New York en route to Seattle but never reached its destination. We take a closer look at the story behind the only large commercial aircraft in US history to go missing.

Flight 2501 loses contact with ATC

A Northwest Orient Airlines Douglas DC-4 (registration: N95425) operating a daily service between New York and Seattle disappeared on the night of June 23rd, 1950, over Lake Michigan.

At the time, it was the deadliest commercial plane crash in both US and world history and remains one of the country's most high-profile aircraft disappearances.

The Northwest flight, which had 58 passengers and crew onboard, departed from New York LaGuardia Airport at 19:31 with a scheduled stopover in Minneapolis, Minnesota, on its way to Seattle.

Douglas DC-4
The Douglas DC-4, with 58 people onboard, went missing over Lake Michigan. Photo: Tom Wigley via Flickr

The Douglas DC-4 was powered by four Pratt & Whitney R-2000 Twin Wasp engines. The pilot duo that evening was 35-year-old Captain Robert C. Lind of Hopkins and First Officer Verne F. Wolfe, also 35. In the cabin, 55 passengers (27 women, 22 men and six children) were served by the sole stewardess on duty - 25-year-old Bonnie Ann Feldman.

Aware of a storm in the area, pilots requested a cruising altitude of 4,000ft above Cleveland which was approved by air traffic control (ATC). Around 40 minutes later, ATC requested that the plane descend to 3,500ft, as another flight cruising at 5,000ft over Lake Michigan was struggling to maintain its altitude due to severe turbulence.

Flight 2501 obliged before requesting a cruising altitude of 2,500ft near Benton Harbor, a city on the banks of Lake Michigan, at 23:13. ATC rejected this two minutes later in what would be the last communication with the DC-4.

Debris and remains but no wreckage

A full-scale search was launched the next morning of June 24th. Around 13 hours into the search, a US Coast Guard vessel searching Lake Michigan discovered oil slicks and aircraft debris floating on the water.

More Coast Guard ships arrived to gather the debris, which included luggage, seat cushions, a fuel tank float and human remains. However, the main wreckage of the plane was not found and remains undiscovered to this day.

SAS_DC-4_cabin
A fully occupied cabin onboard a Douglas DC-4. Photo: Leif Krohn Ørnelund via Wikimedia Commons

Crash investigators were primarily concerned with determining if Flight 2501's fate was due to a mid-air explosion or if it impacted the water intact. The small size of the debris suggested a possible explosion, a theory supported by eyewitnesses claiming to have seen flashes of light in the sky.

Flying through an electrical storm

As the wreckage was never located, the final report of the seven-month official investigation noted "insufficient evidence upon which to make a determination of probable cause."

One probable fact of the case is that a severe electrical storm in the area played a role in the disappearance. Pilots were aware of a storm in their flight path but were not given an exact location of a possible squall line.

The Michigan Shipwreck Research Association (MRSA) has conducted an annual search for Flight 2501 since 2004, with no luck so far.

However, the group has uncovered a dozen shipwrecks in the process and recently added an improved sonar scanner to its arsenal. Keep your eyes peeled as this mystery could be solved in the coming years.

What do you think the most probable cause of the Northwest Flight 2501 crash was? Feel free to share your insights in the comments.