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
June 25, 2009
************************************************************
NTSB INVESTIGATING TWO RECENT INCIDENTS
INVOLVING
POSSIBLE A-330 SPEED AND ALTITUDE INDICATION
ANOMALIES
************************************************************
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
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
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
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
lopatt@ntsb.gov
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 flying thru bad weather. I have a link to the failures that occurred on AF 447. My list is almost the same. http://www.eurocockpit.com/images/acars447.php
The problem I suspect is the pitot tubes ice over and you loose your airspeed indication along with the auto pilot, auto throttles and rudder limit protection. The rudder limit protection keeps you from over stressing the rudder at high speed.
Synopsis;
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 approached a large area of rain below us. Tilting the weather radar down we could see the heavy rain below, displayed in red. At our altitude the radar indicated green or light precipitation, most likely ice crystals we thought.
Entering the cloud tops we experienced just light to moderate turbulence. (The winds were around 30kts at altitude.) After about 15 sec. we encountered moderate rain. We thought it odd to have rain streaming up the windshield at this altitude and the sound of the plane getting pelted like an aluminum garage door. It got very warm and humid in the cockpit all of a sudden. Five seconds later the Captains, First Officers, and standby airspeed indicators rolled back to 60kts. The auto pilot and auto throttles disengaged. The Master Warning and Master Caution flashed, and the sounds of chirps and clicks letting us know these things were happening.
Jerry S, the Capt. hand flew the plane on the shortest vector out of the rain. The airspeed indicators briefly came back but failed again. The failure lasted for THREE minutes. We flew the recommended 83%N1 power setting. When the airspeed indicators came back. we were within 5 knots of our desired speed. Everything returned to normal except for the computer logic controlling the plane. (We were in alternate law for the 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 been much worse. Jerry did a great job flying and staying cool. We did our procedures called dispatch and maintenance on the SAT COM and landed in Narita. That's it.
on June 26, 2009 11:45 AM | Reply
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.
on June 26, 2009 5:32 PM | Reply
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!
on February 19, 2010 7:06 AM | Reply
It could be posible a dual flame out due to ice crystal ingestion?
on July 1, 2010 1:01 AM | Reply
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
on October 1, 2010 8:06 AM | Reply
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.