Sunday, March 22, 2009

FedEx MD-11 Crash

At 0600 Tokyo time this morning, a FedEx MD-11 crashed on landing at Narita Japan.

Reports indicate there were strongly gusting winds at the time.

The aircraft landed hard and bounced, then hit again nose gear first. Because of the nose low attitude, there was a very high sink rate. When the main gear hit the runway, the left wing failed at the root. The lift from the right wing flipped the aircraft upside down.

Both crew members were killed.

4 Comments:

Blogger erp said...

Dear lord how awful.

It's banal to say it, but we never do know when our time is up. Sympathies to you and the families of your colleagues.

March 23, 2009 5:41 AM  
Blogger Mike Beversluis said...

I saw that on the news - it looked bad. My condolences too.

I've heard that FedEx will continue to fly in much rougher/riskier conditions than passenger airlines - is that true?

March 23, 2009 6:44 AM  
Blogger Harry Eagar said...

This has got to make pilots think.
'Strongly gusting winds' (up to 40 mph commonly, 60 mph frequently) would be an ordinary condition at Kahului Airport, and except for a few days after Sept. 11, 2001, and perhaps a few hours when hurricanes were in the neighborhood, I don't recall its ever stopping operations in the past 21 years.

How strong were those winds at Narita?

March 23, 2009 11:05 AM  
Blogger Hey Skipper said...

erp:

It's banal to say it, but we never do know when our time is up.

Not infrequently, I remind myself that there is no guarantee I'll even finish the sentence I'm typing.

Or that my wife, kids, etc, will finish theirs.

Mike:

I've heard that FedEx will continue to fly in much rougher/riskier conditions than passenger airlines - is that true?

No. Our airplanes have the most advanced instrument landing equipment available (we don't even have to see to land in the MD-11), but many passenger airlines configure their airplanes the same way.

As far as things like wind and icing, each aircraft is certified to certain limits. An MD-11 is certified to land with up to 35 knots crosswind component, no matter who is flying it.

Also, the FAA has specific guidance as to what constitutes windshear, which applies to all aircraft. The MD-11 has windshear avoidance (the radar is pulse doppler, and among other things, can detect wind velocities and display any areas that are likely to contain windshear) and guidance (fly-to commands to obtain maximum aircraft performance) systems.

To add that all up, FedEx pilots and airplanes are subject to precisely the same weather, crew rest, mechanical etc constraints as the passenger carriers.

How strong were those winds at Narita?

I don't know for certain, but I think 40 knots (46 mph). As long as the wind was within about 80 degrees of runway heading, then the crosswind component would be less than 35 knots. If the gusts were less than 15 (i.e., 25 gusting to 40 knots) then the winds would not trigger the windshear flag.

Additionally, we calculate wind additives above the weight adjusted approach speed for high or gusty winds.

Landing in strong gusty winds is hard. Because the landing gear cannot tolerate landing in a crab, we have to cross control the airplane (rudder opposite the wind direction, aileron into the wind), and continually compensate for turbulence and gust induced changes in lift. Sometimes it can be a wrestling match to get the thing on the pavement.

For a couple reasons the MD-11 is probably the least forgiving transport category aircraft of any I can think of offhand. It has a very critical wing and a small horizontal stabilizer. In normal configuration, it is the fastest across the fence -- about 30 knots faster than a 737.

Almost all the MD-11s that have been lost have been in landing mishaps (Swissair 111, IIRC, might be the only non-landing accident).

March 23, 2009 4:16 PM  

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