On June 23, Airbus 330, flight NW98's speed sensors and autopilot failed
Jun 26, 2009, 10:00 am
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NTSB investigating possible sensor failure on Northwest flight
Jun 26, 2009, 4:18 pm
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On June 23, Airbus 330, flight NW98's speed sensors and autopilot failed
On Tuesday, June 23, NW98, an Airbus 330 flying from Hong Kong to Tokyo encountered icy rain and then its speed sensors and autopilot system failed. This possibly was the icing problem with th Thales pitot speed sensors on the AF 447, causing it to go down in the Atlantic off of Brazil. NW and Delta also have Thales pitot speed sensors on their A330 and A320 metal and have said they are in the process of replacing Thales pitot with another manufacturer's Pitot.
My question is did the NW 98 Airbus still have Thales speed sensors? Is NW and Delta still flying Airbus metal with these Thales pitot which Airbus advised in 2007 that airlines should replace in A320s in 2007 and in A330 in 2008?
A TAM Airlines Airbus 330 also had the same problem happen on May 21 flying from Miami to Sao Paulo.
Here is the NW pilot's testimony of what happened.
"Tuesday 23rd June, 2009 10am enroute HKG to NRT. Entering Narita Japan airspace.
"FL390 mostly clear with occasional isolated areas of rain, clouds tops about FL410.
"Outside air temperature was -50C TAT -21C (you're 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 seconds 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 Captain's, First Officer's, 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 Staab, 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."
Northwest and Delta should inform the public that have replaced all Thales pitot speed sensors on all their A319, A320, A330, and A340 planes.
My question is did the NW 98 Airbus still have Thales speed sensors? Is NW and Delta still flying Airbus metal with these Thales pitot which Airbus advised in 2007 that airlines should replace in A320s in 2007 and in A330 in 2008?
A TAM Airlines Airbus 330 also had the same problem happen on May 21 flying from Miami to Sao Paulo.
Here is the NW pilot's testimony of what happened.
"Tuesday 23rd June, 2009 10am enroute HKG to NRT. Entering Narita Japan airspace.
"FL390 mostly clear with occasional isolated areas of rain, clouds tops about FL410.
"Outside air temperature was -50C TAT -21C (you're 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 seconds 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 Captain's, First Officer's, 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 Staab, 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."
Northwest and Delta should inform the public that have replaced all Thales pitot speed sensors on all their A319, A320, A330, and A340 planes.
Jun 26, 2009, 4:31 pm
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Interesting behind the scene info there.
Jun 26, 2009, 4:45 pm
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Jun 26, 2009, 6:21 pm
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Bloomberg News June 8, says:
"Delta, the world’s biggest carrier, replaced the Pitot tubes on the last of its Airbus 319 and 320 planes today and is working on changing the sensors on its 330s, Landers said. The Airbus planes account for about 15 percent of its entire fleet including regional jets."
The Delta spokes person did not say any thing about their A330s or those of Northwest. I assume that none of the A330s have had their Thales pitot speed sensors changed.
I am flying on a Lufthansa A330 next week but Lufthansa uses Goodrich-Rosemount Pitots. I am reluctant to fly NW, Delta, United, or US Airways who all have A330s until they announce they have issue a pitot change notification.
"Delta, the world’s biggest carrier, replaced the Pitot tubes on the last of its Airbus 319 and 320 planes today and is working on changing the sensors on its 330s, Landers said. The Airbus planes account for about 15 percent of its entire fleet including regional jets."
The Delta spokes person did not say any thing about their A330s or those of Northwest. I assume that none of the A330s have had their Thales pitot speed sensors changed.
I am flying on a Lufthansa A330 next week but Lufthansa uses Goodrich-Rosemount Pitots. I am reluctant to fly NW, Delta, United, or US Airways who all have A330s until they announce they have issue a pitot change notification.
Jun 26, 2009, 7:05 pm
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At times like these it's reassuring to know most all of these guys started their mainline career flying DC-9s and doing visables into Montana airports.
Jun 26, 2009, 7:14 pm
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Jun 26, 2009, 8:38 pm
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Also somewhat misleading to state that the autopilot "failed." It didn't. It did exactly what it was supposed to do which is "disconnect." Big difference there. You want A/P disconnect and to be able to hand fly when something goes badly wrong like this. Last thing you want is an A/P chasing unreliable/conflicting airspeed data.
Last edited by Herb687; Jun 26, 2009 at 8:39 pm Reason: spelling
Jun 27, 2009, 7:19 am
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On Tuesday, June 23, NW98, an Airbus 330 flying from Hong Kong to Tokyo encountered icy rain and then its speed sensors and autopilot system failed. This possibly was the icing problem with th Thales pitot speed sensors on the AF 447, causing it to go down in the Atlantic off of Brazil. NW and Delta also have Thales pitot speed sensors on their A330 and A320 metal and have said they are in the process of replacing Thales pitot with another manufacturer's Pitot.
My question is did the NW 98 Airbus still have Thales speed sensors? Is NW and Delta still flying Airbus metal with these Thales pitot which Airbus advised in 2007 that airlines should replace in A320s in 2007 and in A330 in 2008?
A TAM Airlines Airbus 330 also had the same problem happen on May 21 flying from Miami to Sao Paulo.
Here is the NW pilot's testimony of what happened.
"Tuesday 23rd June, 2009 10am enroute HKG to NRT. Entering Narita Japan airspace.
"FL390 mostly clear with occasional isolated areas of rain, clouds tops about FL410.
"Outside air temperature was -50C TAT -21C (you're 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 seconds 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 Captain's, First Officer's, 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 Staab, 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."
Northwest and Delta should inform the public that have replaced all Thales pitot speed sensors on all their A319, A320, A330, and A340 planes.
My question is did the NW 98 Airbus still have Thales speed sensors? Is NW and Delta still flying Airbus metal with these Thales pitot which Airbus advised in 2007 that airlines should replace in A320s in 2007 and in A330 in 2008?
A TAM Airlines Airbus 330 also had the same problem happen on May 21 flying from Miami to Sao Paulo.
Here is the NW pilot's testimony of what happened.
"Tuesday 23rd June, 2009 10am enroute HKG to NRT. Entering Narita Japan airspace.
"FL390 mostly clear with occasional isolated areas of rain, clouds tops about FL410.
"Outside air temperature was -50C TAT -21C (you're 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 seconds 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 Captain's, First Officer's, 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 Staab, 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."
Northwest and Delta should inform the public that have replaced all Thales pitot speed sensors on all their A319, A320, A330, and A340 planes.
Jun 27, 2009, 8:08 am
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From today's StarTribune...
"Northwest had been replacing the sensors on its A330 planes before the Air France crash and has since accelerated the replacement, Black said. That work should be finished by the end of the summer, he said.
In recent years Northwest had replaced the Pitot tubes on its smaller Airbuses, A319s and A320s, that are used for domestic trips, Black said."
"Northwest had been replacing the sensors on its A330 planes before the Air France crash and has since accelerated the replacement, Black said. That work should be finished by the end of the summer, he said.
In recent years Northwest had replaced the Pitot tubes on its smaller Airbuses, A319s and A320s, that are used for domestic trips, Black said."
Jun 28, 2009, 6:06 am
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Jun 28, 2009, 6:15 am
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great post with interesting information
superb work from the flight crew it seems
superb work from the flight crew it seems
Jun 28, 2009, 9:08 am
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I'm pretty sure NW has been saying since the AF 447 incident that the smaller Airbii have already been updated. It's only the A330s that have the suspect speed pitots.
If anyone's paranoid, stick to 767's. The 777's with Trent engines have their own problem with fuel icing (one crash @ Heathrow, one single-engine shutdown on a DL 777 over Montana), and there is no immediate fix.
If anyone's paranoid, stick to 767's. The 777's with Trent engines have their own problem with fuel icing (one crash @ Heathrow, one single-engine shutdown on a DL 777 over Montana), and there is no immediate fix.