AF447: NTSB looking at other incidents (apparently!)

What if they put out a press release and nobody believed it? Slightly surreally the NTSB issued a press release last night giving brief details of two AF447-like incidents of which they’ve become aware, but because of how they did it some people are very sensibly questioning if it’s real. Quite right too.

The problem is that although the press release was e-mailed via the NTSB’s automatic notification system, it wasn’t, and still hasn’t been, placed on their website. So if you weren’t on the e-mail address list then you had to rely on news reports for the information. And the news reports, as is sadly the way these days, carry no additional information or quotes from the NTSB confirming the authenticity. So given the reputation of the media, people are doubting the press release’s provenance.

A couple of people are even saying the grammar is so lousy on the press release that it can’t be authentic. A lovely thought, but it’s hard to think of a public document that would survive that test in 2009. (AAIB report maybe??)

Anyway I’ve come in to find this situation this morning. I’ve got the release direct from the NTSB overnight myself in the usual way that I do and I’m happy that it’s for real. (Though I confess I don’t know that for a fact, so I’m adding to the problem.)

Below is the text, followed by the text of an informal document circulating on the internet via email and websites before the NTSB document emerged, and is purportedly from a pilot on the Northwest flight mentioned by the NTSB. There’s no proof of its authenticity of which I’m aware, but please leave a comment if you can help with that.

The TAM incident is interesting in that the crew reported a sudden drop in outside air temperature rather than the real or indicated increase that has been associated with other incidents (such as Air Caraibes). The NWA incident recorded in the supposed pilot report includes an account of a sudden increase too.


                       NTSB ADVISORY



National Transportation Safety Board

Washington, DC 20594


June 25, 2009











The National Transportation Safety Board is investigating

two recent incidents in which airspeed and altitude

indications in the cockpits of Airbus A-330 aircraft may

have malfunctioned.


The first incident occurred May 21, 2009, when TAM Airlines

flight 8091 (Brazilian registration PT-MVB) flying from

Miami, Florida to Sao Paulo, Brazil, experienced a loss of

primary speed and altitude information while in cruise

flight.  Initial reports indicate that the flight crew noted

an abrupt drop in indicated outside air temperature,

followed by the loss of the Air Data Reference System and

disconnections of the autopilot and autothrust, along with

the loss of speed and altitude information.  The flight crew

used backup instruments and primary data was restored in

about 5 minutes.  The flight landed at Sao Paulo with no

further incident and there were no injuries and damage.


The Safety Board has become aware of another possibly

similar incident that occurred on June 23 on a Northwest

Airlines A-330 (registration unknown) flying between Hong

Kong and Tokyo.  The aircraft landed safely in Tokyo; no

injuries or damage was reported.  Data recorder information,

Aircraft Condition Monitoring System messages, crew

statements and weather information are being collected by

NTSB investigators.


Further information on both incidents will be released when

it becomes available.




NTSB Public Affairs

(202) 314-6100

Ted Lopatkiewicz

Here’s the non-authenticated pilot report:

Yesterday while coming up from Hong Kong to Tokyo, a 1700nm 4hr.flight, we experienced the same problems Air France had while flyingthru bad weather. I have a link to the failures that occurred on AF447. My list is almost the same.

The problem I suspect is the pitot tubes ice over and you loose yourairspeed indication along with the auto pilot, auto throttles andrudder limit protection. The rudder limit protection keeps you fromover stressing the rudder at high speed.


Tuesday 23, 2009 10am en-route HKG to NRT. Entering Nara Japan airspace.

FL390 mostly clear with occasional isolated areas of rain, clouds tops about FL410.

Outside air temperature was -50C TAT -21C (your not supposed to get liquid water at these temps). We did.

As we were following other aircraft along our route. We approacheda large area of rain below us. Tilting the weather radar down we couldsee the heavy rain below, displayed in red. At our altitude the radarindicated green or light precipitation, most likely ice crystals wethought.

Entering the cloud tops we experienced just light to moderateturbulence. (The winds were around 30kts at altitude.) After about 15sec. we encountered moderate rain. We thought it odd to have rainstreaming up the windshield at this altitude and the sound of the planegetting pelted like an aluminum garage door. It got very warm and humidin the cockpit all of a sudden. Five seconds later the Captains, FirstOfficers, and standby airspeed indicators rolled back to 60kts. Theauto pilot and auto throttles disengaged. The Master Warning and MasterCaution flashed, and the sounds of chirps and clicks letting us knowthese things were happening.

Jerry S, the Capt. hand flew the plane on the shortest vector out ofthe rain. The airspeed indicators briefly came back but failed again.The failure lasted for THREE minutes. We flew the recommended 83%N1power setting. When the airspeed indicators came back. we were within 5knots of our desired speed. Everything returned to normal except forthe computer logic controlling the plane. (We were in alternate law forthe rest of the flight.)

We had good conditions for the failure; daylight, we were rested,relatively small area, and light turbulence. I think it could have beenmuch worse. Jerry did a great job flying and staying cool. We did ourprocedures called dispatch and maintenance on the SAT COM and landed inNarita. That’s it.

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5 Responses to AF447: NTSB looking at other incidents (apparently!)

  1. Ken Panting June 26, 2009 at 11:45 am #

    Is the A330 the only aircraft fitted with this type of pitot tube or is this a protection scheme for the 787 since the 330 and 350 can do the same job. Seems a bit of a coincidence for this to be released now.

  2. Frank June 26, 2009 at 5:32 pm #

    Considering a) the gravity of AF447, b) the scarcity of good information, and, c) the number of carriers and passengers who may be directly affected now and in the future, any deflection to Boeing is totally out of line. Protection scheme!?!? Ridiculous!

  3. Alberto Jimenez February 19, 2010 at 7:06 am #

    It could be posible a dual flame out due to ice crystal ingestion?

  4. Raul Muscatello July 1, 2010 at 1:01 am #

    Sounds like there are some very interesting stories there indeed. It must have took time gathering the research here and so well done. Great stuff

  5. Mutuelle October 1, 2010 at 8:06 am #

    NTSB’s description of the two main causes were well-explained: a)airspeed ; b) altitude information espcially in the TAM Airlines flight 8091. In the second incident the solutions have been well identified and were effective: 1.Data recorder information, 2.Aircraft Condition Monitoring System messages.

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