Next week, I shall be boarding a plane and going on a mini-break with my good wife. We will likely pass close to Mount Fuji. I am not particularly happy about this. Mount Fuji, you see, may have had a hand in one of Japan’s worst aviation disasters.
Back in March 1966, a Boeing 707 operated by British Overseas Airways Corporation took off from Haneda Airport, bound for Hong Kong. It left Tokyo just before 2 o’clock in the afternoon. As it climbed, it took a right turn over Tokyo Bay, passed north of the town of Odawara and then turned right again towards Gotemba City and Mount Fuji. The plane broke up in mid-air and crashed near the mountain. All 113 passengers and 11 crew members died.
The pilot of the craft was an experienced and capable man and speculation immediately began that severe weather conditions were at least partly responsible for the accident. The subsequent investigation led to a belief that the plane had experienced clear-air turbulence which, as the name suggests, is turbulence without any visual clues as to its presence. Such turbulence is often caused by lee-waves, where changes of atmospheric pressure and temperature are caused when the wind blows over the mountains and causes vertical displacement within the currents. The motion forces changes in the speed and direction of the air within the current, and if you happen to be in a passing plane things will likely get quite hairy. You certainly wouldn’t want the crew to be pouring your coffee at that moment.
At the time of the accident, The New York Times reported that the vicinity of Mount Fuji was notorious for its difficult currents. They don’t tell you that when you fly into Tokyo. The pilot never comes on in his posh reassuring voice to say, ‘Now, ladies and gentleman, if you look out of the window to your left you will see Mount Fuji, looking splendid with her snowy peak and notorious difficult currents that can cause pilots to lose control of their aircraft.’
At the time of the accident, winds at the summit of Mount Fuji were measured at 60 to 70 knots. Shortly after the crash a United States navy helicopter flew into the area to search for wreckage. The pilot experienced such severe turbulence that he feared his craft may break up, too. Fortunately he managed to land safely, but it was clear the conditions near the mountain were treacherous.
One of the passengers left an important clue behind. That person, in all the horrific terror that must surely have occurred, managed to shoot an 8mm cine film. Despite the fact that the flight data recorder was destroyed by fire, the film footage somehow survived the accident. It showed that just before the accident the plane was indeed experiencing severe turbulence. Debris was scattered over 16 kilometres. The probable cause given by the Aviation Safety Network was this: ‘The aircraft suddenly encountered abnormally severe turbulence over Gotemba City which imposed a gust load considerably in excess of the design limit.’ Today a memorial to the victims of that disaster stands on the Gotemba side of Mount Fuji.
Now, hearing this tale has me a bit worried. I have travelled to and from Japan often, and until now had always quite liked the bit when the pilot announces that we are just passing Mount Fuji. I used to look out the window and smile and agree that, yes, she does look splendid. It’s going to be a bit harder to enjoy that next time, though. I suspect while others crane their necks and ‘ooh and ahh’ there will be one tall chap adopting the brace position quietly incanting a shaky mantra of, ‘Please don’t crash, please don’t crash, please don’t crash.’
There were some reports that it may even have been the pilot’s desire to show his passengers the pleasing sight of the volcano that inadvertently led to the crash in 1966. Before take-off, the crew amended their clearance request in order to climb westbound on a route that would take them nearer to Mount Fuji. The pilot, of course, wouldn’t have seen any evidence of the turbulence that awaited, and if he did just want to please the passengers, the whole event is all the more tragic.