0-8

Incident: LOT B763 near Toronto on Jun 19th 2009, severe turbulence and unreliable airspeed

This particular incident seems to have largely avoided media coverage.

One would have thought that considering recent events, a widebody aircraft forced to descent while experiencing severe turbulence and unreliable airspeed would be of particular interest.

I'm sure that if this had been from manufacturer 'A' rather than manufacturer 'B' there would be media hysteria.

cwarbu01

We did have an intense weather system move through today.
It was quite severe on the ground at least.

Davy07

Sixth one down!

LiveATC Recordings | LiveATC.net

WhatsaLizad?

Not really 0-8,

I experienced one encounter with severe turbulence on a 767-300, and while we experience some erratic airspeed info, just like LOT, it returned to normal after the event stopped.

I will add that we were also unable to maintain altitude, and descended. All ended well without injuries. The yoke, thrust levers and flight controls behaved normally, and even though not a single digit on any instrument was readable due to the shaking, the blue above/brown below on the ADI worked just fine. I don't remember the EEC lights, nor cared to look at anything on the overhead panel during the event.

Ask yourself if we would have ended up in some other flight control law or had many more blinking lights and distracting warning bells, alerts or tones had we been in manufaturer "A"'s aircraft (I don't know)

0-8

Did you read the link?

There is a very big difference between 'erratic airspeed info' caused by turbulence/sheer and the textbook definition of unreliable airspeed.The LOT aircraft experienced 'unreliable speed' in the textbook sense.

While the problem was initially resolved as they descended through FL280 it's interesting to note that the problem reoccurred much lower in the descent at around 16000ft.

They had overspeed warnings followed by stick shaker which are indications consistent with a blocked pitot/static system which has led to several fatal accidents including:

Aeroperú Flight 603 - Wikipedia, the free encyclopedia

Birgenair Flight 301 - Wikipedia, the free encyclopedia

I would have thought that bearing in mind the recent interest in unreliable speed problems that this incident would bear further scrutiny.

punkalouver

The Polskie Linie Lotnicze LOT SA (LOT Polish Airlines SA) Boeing 767-300 series aircraft was on a scheduled IFR flight from Chicago (O'Hare) International Airport, IL (U.S.A.) (KORD) to Warsaw (Okecie) International Airport, Poland (EPWA). The aircraft was en-route when the flight crew reported severe turbulence vicinity of North Bay at approximately 0203Z. The aircraft lost 5,000 feet of altitude (dropping from FL330 down to FL280). The flight crew elected to divert back to Toronto (LBPIA) at 0215Z. The aircraft completed a fuel dump from 0225Z to 0248Z. At 0255Z, the flight crew requested and were given a hold vicinity of the Simcoe VOR at 10,000 feet. At 0248Z (sic), the flight crew advised that they were unable to maintain their altitude and the aircraft climbed through 10,600 feet. At the time, JZA7927 was at 11,000 feet and their flight crew reported receiving a TCAS alert and flew their aircraft in a climb to 12,000 feet. The LOT flight crew commenced their approach to runway 23 at 0302Z. The aircraft landed without incident on runway 23 at 0316Z with ARFF services on standby. Ops. impact -- unknown. Aircraft landed safely runway 23 at 0316 Zulu. Emergency equipment on standby

UPDATE Supplemental information received from T.S.B. Initial Notification [#A09O0117]: The Boeing 767-300 series aircraft (SP-LPA, operated as Polish Airlines flight number LOT2) departed Chicago, O'Hare destined for Warsaw, Poland. In the vicinity of North Bay, Ontario, while cruising at FL330, the aircraft experienced a sudden and uncommanded overspeed condition, stick shaker and illumination of left and right electronic engine control (EEC) caution lights. The aircraft descended to FL280 before the situation was resolved. The aircraft diverted to Toronto (LBPIA) and landed without further incident. The T.S.B. deployed investigators to the site. Note: the class of investigation is being assessed.