Northwest Turbulence Incident - Tokyo

[A300Man]

CNN International is reporting a NW Boeing 744 en-route from Manila to Tokyo (Honolulu extension?) encountering severe turbulence 20 minutes prior to scheduled landing at Narita. 35 people have been injured according to live reports on tv at the moment, although CNN's website report is now slightly outdated reporting only 30 injuries (obviously therefore a mixture of pax and crew) and taken to hospital upon landing. Some of the injuries are reported as serious.

Heavily laden flight - 408 passengers on board, plus 14 crew.

CNN INTERNATIONAL:
TOKYO, Japan (CNN) -- About 30 people were injured Friday when a Northwest Airlines flight suffered turbulence before landing at Japan's Narita International Airport, a Northwest spokesman said.

Three people where seriously injured, fire officials said.

There were 408 passengers and 14 crew members on the Boeing 747-400 flight from Manila, Philippines

[Airbubba]

This time of year it is unusual to fly into NRT without some forecast turbulence. Often the forecast is for areas of moderate to severe. Most airlines have policies forbidding flight into severe turbulence but you don't know if it's severe until you or someone else tries it. It's a judgment call and, no matter what happens, it's the captain's fault.

[daelight]

not much to go on at this stage, small article from japantoday.com -

Northwest Airlines said the ‘‘fasten seatbelt’’ light was turned on when the plane was hit by turbulence.

A 55-year-old American passenger said he heard screams when the plane suddenly descended and then made an ascent about 30 minutes before landing. Some people who did not have their seatbelts fastened hit their heads on the ceiling and injured their necks, he said."

There's some conflicting numbers, the transport ministry saying 10 seriously injured and 10 slightly injured.

[blueloo]

Anyone know if the Japanese Authorities did their typical response, and arrest the crew?

[Locked door]

Don't forget BOAC lost a 707 to inflight breakup in that area. It can get pretty rough there, and not just in the truck.

[AnthonyGA]

What remedial action, if any, is required for the aircraft after an encounter with turbulence of this magnitude? Does it require an inspection? Repairs? What affect does it have on the life expectancy of the airframe?

[HarryMann]

AnthonyGA

The max and min 'G' would need to be looked at, to see if it got anywhere near certified load limits. The more fuel in the wings the better, reducing wing stresses considerably. Some plastic deformation can be allowed in aircraft structures, but the manufacturer would be consulted if the recorded 'g' loads were close to those certified, necessitating a structural inspection.


Limit load
The maximum static or dynamic load an aero-space vehicle or its structural elements are expected to experience at least once during its service life.

Proof load
The amount of load that a structure or part or fastener can withstand without deformation. Proof load is often used interchangeably with yield strength.

[PointySquare]

A quick question from some SLF; this case seems quite extreme but, in your normal everyday mild shaking style turbulence, how far does the plane actually move? Are we talking a few centimetres, or metres, or more? Just curious.

As an aside, I had a bad flight that sounds similar to this between Orlando and Miami many years ago, with the 737 moving very violently, and people lifting out of their seats and banging against the top of the cabin. Weather conditions were atrocious, with numerous huge thunderstorms. we were delayed while some bags were unloaded by people who were refusing to fly after seeing the skyline. I actually quite enjoyed watching the wings bend!

[Jonty]

Not much to go on at this stage. BBC report here: BBC NEWS | World | Asia-Pacific | Tokyo flight turbulence hurts 47 (http://news.bbc.co.uk/1/hi/world/asia-pacific/7900892.stm)

Sounds a bit wakey to me! (the turbulance I mean)

[5Y NJB]

"We were flying and then the seatbelt sign came on and when we were trying to get back to the seats, the plane dropped and so some people went up and hit the [ceiling]."

Reading the above, from the BBC website, I have to concede that perhaps I was a little hasty in my judgement of the situation; if the flight, as reported, was 30 minutes out, my guess is that quite a few of the injured were possibly pax who were out of their seats in order to use the toilets in the few minutes before descent commenced and the FSB light was turned on. And I'm often one of the SLF who does that.

[procede]

Even if you do not encounter clean air turbulence, you can always encounter wake turbulence (Armavia) or even a broken ADIRU (QANTAS).

[Airbubba]

50 hurt in turbulence on Japan-bound flight
By SHINO YUASA – 5 hours ago

TOKYO (AP) — Severe turbulence jolted a Tokyo-bound Northwest Airlines flight from the Philippines on Friday, injuring 50 passengers and crew members, a company spokesman said.

Four passengers were hospitalized, including one person with a serious neck injury, said Masashi Takahashi, spokesman for Northwest Airlines in Tokyo.

The 46 others, including seven crew members, received light injuries, he said.

Turbulence hit the plane while it was circling off the coast of Chiba, east of Tokyo, about 30 minutes before landing at Tokyo's Narita airport, he said. The plane suddenly descended, sending passengers without their seatbelts fastened lurching from their seats, he said...

The Associated Press: 50 hurt in turbulence on Japan-bound flight (http://www.google.com/hostednews/ap/article/ALeqM5gkCVEMOZxeXcogTNdO97YLMHdC2QD96FBNV01)

Coming into NRT from the south you often get a late restriction to cross MAMAS intersection at FL160 or lower. The aircraft may have started down earlier than anticipated when given the restriction.

Also, you need to be at 250 knots at 10,000 feet, not 250 below 10,000 feet as in the U.S. so the descent needs to be initiated a little sooner than normal in my experience.

[Springer1]

Interesting that it happened to NWA as they have one of the most comprehensive turbulence avoidance programs of any major airline.

[Two's in]

Interesting that it happened to NWA as they have one of the most comprehensive turbulence avoidance programs of any major airline.

...but do the air currents know about the program?

Update from Delta (NWA's new owner);

Advisory: Northwest Airlines Flight #2, traveling from Manila to Narita on February 20, experienced severe turbulence upon approach to the Narita airport. The plane, a Boeing 747-400 with 408 passengers and 14 crew members on board, landed safely. Approximately 45 people were taken to a local hospital for medical care and five people remain hospitalized. There were no fatal injuries.

Northwest Airlines has activated Family and Friends assistance lines:
United States: 1-800-225-2048
Manila: 001 - 612-727-5703

The Japan Civil Aviation Bureau (JCAB) is also investigating the incident.

Media calls should be directed to (612) 726-2331.

[Southernboy]

Anyone know how to check the sigmet for the period?

[Fratemate]

Coming into NRT from the south you often get a late restriction to cross MAMAS intersection at FL160 or lower

Ahh, use caution Airbubba San. MAMAS at FL180, not 160. One of the great secrets in Japanese ATC is the flight levels required at various points on the approaches. Levels such as the one above do not appear on the approach plates and always mean you have to drag the approach in from a l..o..n..g way out. (Bit like JFK really).


It can get pretty rough there, and not just in the truck

Sorry to be the bearer of bad news, Locked Door, but the Truck is no longer. For a bit of a wail and a sing-song it's really just the Cage now but the Air Pac crew don't seem to have started going there yet, so not too many fights reported thus far :ouch:

[Airbubba]

Ahh, use caution Airbubba San. MAMAS at FL180, not 160.

I agree FL180 is the normal clearance, I've been given a lower restriction at times during morning rush hour, I presume to separate me from traffic and make sure JAL gets there first.:)

Those Tokyo Control folks sure know what they're doing, sometimes I just don't know...

[Reimers]

I think no one answered this yet:

A quick question from some SLF; this case seems quite extreme but, in your normal everyday mild shaking style turbulence, how far does the plane actually move? Are we talking a few centimetres, or metres, or more? Just curious.

Yes, it is only a couple of centimeters. Compare it to your car hitting a patch of rough road. From the outside you propably wouldn't notice any movement of the fuselage at all.
Or go into the kitchen and put a cup of water on a tray. Move it around, simulating turbulence - and see how far you have to move the tray to get the water splashing around. During the "mild shaking style turbulence" the water in the cup on the table in front of you will stay there.

Perhaps answers to such questions will come quicker in the SLF forum...