On 30 January 1979, Varig flight 967, a Boeing 707-323C freighter, left Tokyo Narita for Los Angeles with six crew aboard. Its last radio contact came about thirty minutes after departure. It never arrived, and no trace of it has ever been found.
The cargo
The flight is remembered partly for what it was carrying: 153 paintings by the Japanese-Brazilian artist Manabu Mabe, being shipped after an exhibition in Tokyo. Their loss made the disappearance a cultural story as well as an aviation one, and the value of the cargo generated speculation about theft that has never had any evidence behind it.
What is known
Very little, which is the point. The aircraft made a normal departure and a normal position report. Then it stopped transmitting. Search efforts covered the Pacific east of Japan and found nothing — no debris, no slick, no emergency beacon signal.
The Brazilian and Japanese investigations were unable to establish a cause. The aircraft was over deep ocean, and in 1979 the ability to search a seabed several kilometres down over a wide area did not exist in any practical form.
The context that matters
Varig had suffered a strikingly similar loss six years earlier — a 707 that experienced an in-flight fire and crashed near Paris in 1973, killing 123 people. That accident was traced to a fire in a rear lavatory, and it led directly to changes in lavatory smoke detection and to smoking restrictions.
Investigators of Flight 967 considered whether a cargo fire could produce a rapid loss with no distress call. A freighter carries its load in the main deck cabin, and a fire there in an aircraft of that era, without modern cargo compartment fire suppression, could develop very fast. This remains a hypothesis; nothing supports it beyond its plausibility.
Why it is rarely discussed
Flight 967 disappeared with six people aboard rather than hundreds, and it was a cargo flight, so it attracted a fraction of the attention that a passenger loss would have. It is nonetheless one of the very small number of large jet airliners that have disappeared without trace in the modern era — a list that includes MH370 and almost nothing else.
That list is short for a reason. Aircraft of this size are rarely lost without leaving something: floating debris, a beacon, a radar track, an eyewitness. When one is, it is almost always over deep water, at night or far from land, with a sudden event that leaves no time to transmit.