Three chilling details uncovered about missing Pan Am Flight 7 which killed all on board

More than seven decades on, the baffling disappearance of Pan American World Airways Flight 7 still preoccupies experts after debris and 19 bodies surfaced in the Pacific Ocean. Dubbed PAA-944, its demise remains an enigma, with floating remains discovered far from its scheduled Hawaiian destination on a storied global voyage.

The incident is marked by perplexing details that mire it in ambiguity - the doomed "Romance of the Skies" plummeted into the waves at breakneck speed, well away from the Californian coast it had departed from. Investigators are still puzzled by three haunting details, such as elevated carbon monoxide levels found in victims, the aircraft's continued flight long after contact ceased, and the absence of any distress signals.

Recent revelations in Smithsonian Magazine underscore the perturbing nature of these elements.

Abnormal carbon monoxide concentrations in the deceased

Following extensive probes, contemporary Civil Aeronautics Board examiners - now part of today's National Transportation Safety Board - pronounced the mystery of the vanished PAA-944 unsolvable. Periodic reports theorised catastrophic meteor strikes or even extraterrestrial interferences as reasons behind the Clipper's fall from the skies, reports the Mirror US.

Although there was no conclusive proof of an onboard fire, several bodies, including the pilot's, showed unusually high levels of carbon monoxide. However, the CAB attributed this to the naturally increased levels of the gas that occur during decomposition.

In contrast, the army pathologist who performed the autopsies disputed the CAB's conclusion, suggesting that the excess carbon monoxide in some bodies may have been caused by a fire or explosion before the crash, rather than natural decomposition.

The mystery surrounding the carbon monoxide in some bodies remains unsolved. Additionally, with 38 people on board, the circumstances of the deaths of the other half of the cabin and crew may never be fully understood.

No clear distress signal was sent

The location of the debris suggested that the Clipper had continued flying for an additional 23 minutes after its last routine position report, without the crew sending a distress call. Two months later, the government released its final report on the loss of Romance of the Skies.

The CAB acknowledged that it was "entirely possible" that the crew had sent a distress call, but "the Board could not definitely establish that any emergency transmissions came from Clipper 944."

Former Pan Am employees who knew the crew of Flight 944 shared a crucial piece of information that was overlooked by the CAB's investigators: a tape recording believed to contain a faint and distorted distress call, transmitted just as the airliner reached the mid-Pacific - the point of no return. Before the advent of cockpit voice recorders, radio communications between the cockpit crew and air traffic control were recorded by a company known as Aeronautical Radio Incorporated, or ARINC.

The airline, which had ceased operations in 1991, was still archiving materials at the University of Miami in 2004, with archivists estimating it would be three years before the documents were available for research.

However, it took not three, but 10 years. In 2014, thanks to a grant from the Pan Am Historical Foundation, on the second day of the hearings, CAB investigators pondered whether the crew of Flight 944 did send a distress call, but an unknown factor, such as a severed antenna, prevented it from being clearly heard.

Radio transmissions

In a separate development, a group of Pan Am pilots who were close friends with the crew of 944 also examined the tapes. They asserted that the recordings did indeed contain a message, but the words were faint and either undecipherable or nonsensical.

Ultimately, the pilots informed the CAB "that the majority of the words and phrases used in the message... are foreign to our radio telephone practices [and]...certain of the words are clearly not appropriate to the situation under investigation."

They deemed it "unlikely that the message as read in the report originated from [PAA-944]."

CAB investigators have revealed that after the emergency onboard Flight 944 began, there was an absolute absence of any distress signals: "No radio message was received from the aircraft after the emergency situation began."

Nevertheless, during the inquiry, not all experts were certain of this assertion.

Chilling details emerged as it was suggested that the ill-fated airliner may have stayed airborne for a harrowing 23 minutes post its final contact without sending any SOS calls. In the midst of probing the mystery on day two of the hearings, CAB's teams speculated whether an unheard distress signal might have been sent by Flight 944's crew, only to be lost due to reasons like a severed antenna.

Adding to the puzzle, the Honolulu receiving station was non-operational at the critical time, prompting authorities to secure the communication records and whisk them away for analysis by sound specialists at Bell Labs. Despite meticulous efforts, Bell Labs' audio wizards managed to extract just a jumbled phrase from the recordings: a cryptic "four-four" spoken 15 minutes subsequent to the Clipper's last known report, possibly hinting at the aircraft's Pan Am code, 944.

The enigma of the 1958 crash remained unresolved as Bureau of Safety experts disbanded on January 16, having sifted through 16 hours of testimony and countless documents without identifying a common cause for the catastrophe.

Following the official inquiry's conclusion on January 17, audio technicians from Dictaphone Corporation stepped in, keen to scrutinise the ARINC tapes once again. Equipped with advanced equipment borrowed from Voice of America, they spent two weeks meticulously working and claimed to have discovered a faint communication from Romance of the Skies, approximately seven minutes and 30 seconds after the Clipper's last known position.

Dictaphone provided the CAB with an annotated transcript that appeared to capture a distressed Mayday signal along with a crucial exchange between crew members, transmitted over an open mic.