Japanese Airlines Flight JL123 crashed into the mountains of Gunma Prefecture in 1985. Video / AP
Japanese plane spotters were alarmed to spot the tail fin of infamous Japanese Airlines Flight JL123 at a Tokyo airport, almost 35 years to the day after it had crashed – killing 520 onboard.
Spooked aviation fans shared screenshots across social media to check that other had seen this ghostplane appear on radars, on August 5.
In Japan the flight number is synonymous with one of the county's worst air disasters. In 1985 flight JL123 took off from Tokyo's Haneda Airport bound for Osaka, disappearing in the mountains of Gunma Prefecture.
The plane which suffered from faults to the bulkhead lost its tail section around half an hour into the flight, causing it to crash into the mountainside killing all onboard.
But now, almost 35 years later there was flight JL123 taking off from Toyko, and 30 minutes later it had vanished.
"I mean it is Obon season. Maybe they have returned," speculated another.
The chilling sighting caught people's imagination online, particularly because it is so close to both Obon - the national "Holiday of Souls" on August 13 - and the anniversary of the air disaster on August 12.
A spokesperson for Japanese Airlines confirmed that the plane was appearing on radar, however the spooky plane sighting had a less supernatural explanation.
The airline apologised explaining that there were no bad intentions, merely a badly executed technical test.
The plane appearing on radars was JAL flight 712 preparing to fly from Tokyo to Singapore. A technical test conducted earlier by the plane preflight had "randomly selected" these numbers, according the J Cast. A further glitch meant that it was falsely appearing on radars for about 30 minutes, before switching back to the correct flight ID.
The airline apologised and told Kyodo news that it would be reviewing how tests were conducted in future to avoid similar spooky coincidences and offence to families affected.
JL 123 crashed half an hour into the flight killing 520 onboard. Photo / nattou, CC
At a highly superstitious point in the Japanese Buddhist calendar, some were less willing to ascribe the "mistake" to technical glitches. The tradition of Obon that says ancestors' spirits return to visit the living to share messages and omens.
"It's almost 35 years since the tragic accident. Perhaps this wasn't a mistake, but rather 520 spirits telling us to never forget what happened," said twitter user Mikami.
