Jetstar A330 suffers possible pitot tube malfunction

Discuss aviation related topics.

Jetstar A330 suffers possible pitot tube malfunction

Postby drwayne » Tue Nov 03, 2009 5:20 pm

A Jetstar Airways A330-200 with 209 passengers and crew onboard suffered momentary erratic speed data indications from its computers in apparent bad weather and possible icing conditions on an Oct. 29 flight from Tokyo Narita to Gold Coast.

The scenario bears similarities to that which investigators believe may have been a factor in the loss of an Air France -200 over the Atlantic Ocean five months ago

Rest of the story:

http://www.atwonline.com/news/story.html?storyID=18361
User avatar
drwayne
solar system
 
Posts: 3878
Joined: Tue Nov 30, 1999 12:00 am

Re: Jetstar A330 suffers possible pitot tube malfunction

Postby scottb50 » Tue Nov 03, 2009 5:58 pm

drwayne wrote:A Jetstar Airways A330-200 with 209 passengers and crew onboard suffered momentary erratic speed data indications from its computers in apparent bad weather and possible icing conditions on an Oct. 29 flight from Tokyo Narita to Gold Coast.

The scenario bears similarities to that which investigators believe may have been a factor in the loss of an Air France -200 over the Atlantic Ocean five months ago

Rest of the story:

http://www.atwonline.com/news/story.html?storyID=18361


It seems to be another in a long line of occurrences. While one happened in a 747 other occurrences have been in the Airbus. Both use the same reference unit. The scenarios are also pretty close. That it could be an over-reaction from the flight control system on the Airbus or crew inattention are two possibilities, other may contribute.
User avatar
scottb50
solar system
 
Posts: 2127
Joined: Tue Nov 30, 1999 12:00 am

Re: Jetstar A330 suffers possible pitot tube malfunction

Postby drwayne » Wed Nov 04, 2009 7:11 am

Based upon my reading, it sounds like the autopilot hands the pilots the plane in a state in which
the autopilot is unsure of, and the pilots probably are too, and one in which correction in the wrong
direction can be "bad".

Not a good place to be in at night in a storm...
User avatar
drwayne
solar system
 
Posts: 3878
Joined: Tue Nov 30, 1999 12:00 am

Re: Jetstar A330 suffers possible pitot tube malfunction

Postby scottb50 » Wed Nov 04, 2009 11:30 am

drwayne wrote:Based upon my reading, it sounds like the autopilot hands the pilots the plane in a state in which
the autopilot is unsure of, and the pilots probably are too, and one in which correction in the wrong
direction can be "bad".

Not a good place to be in at night in a storm...


It's more like the computers get the wrong information and shutdown. Since the crew gets its direct information from the same source they have little to work with and little time to respond. Because it all seems be related to sensors rather then the computers themselves I would think a fix would be relatively simple.
User avatar
scottb50
solar system
 
Posts: 2127
Joined: Tue Nov 30, 1999 12:00 am

Re: Jetstar A330 suffers possible pitot tube malfunction

Postby drwayne » Wed Nov 04, 2009 1:31 pm

As I understand it, the computer doesn't shut down - it is really the autopilot handing the plane back to
the pilots because it has a situation it can't handle.

There seems to be a number of questions floating around regarding training, and whether the pilots
are getting enough real "stick time" to be able to handle off nominal conditions. Being in a position
where your speed is in a very narrow acceptable window, and not being able to easily tell the difference
between too fast and too slow, and being given alarms that may be wrong (stall instead of overspeed
or vice versa), at night, and in a storm really tests how well someone flies and makes judgements.

Thanks goodness they don't have a putz like me up there driving. I induced a stupid osciallation the
other day in a simulation that I wrote!

Wayne
User avatar
drwayne
solar system
 
Posts: 3878
Joined: Tue Nov 30, 1999 12:00 am

Re: Jetstar A330 suffers possible pitot tube malfunction

Postby scottb50 » Wed Nov 04, 2009 7:34 pm

drwayne wrote:As I understand it, the computer doesn't shut down - it is really the autopilot handing the plane back to
the pilots because it has a situation it can't handle.

There seems to be a number of questions floating around regarding training, and whether the pilots
are getting enough real "stick time" to be able to handle off nominal conditions. Being in a position
where your speed is in a very narrow acceptable window, and not being able to easily tell the difference
between too fast and too slow, and being given alarms that may be wrong (stall instead of overspeed
or vice versa), at night, and in a storm really tests how well someone flies and makes judgements.

Thanks goodness they don't have a putz like me up there driving. I induced a stupid osciallation the
other day in a simulation that I wrote!

Wayne


It seems like a pretty abrupt handover of control with little outside reference available. Maybe there needs to be a default to a more benign reaction. I would say default should be to last assigned heading and airspeed.
User avatar
scottb50
solar system
 
Posts: 2127
Joined: Tue Nov 30, 1999 12:00 am

Re: Jetstar A330 suffers possible pitot tube malfunction

Postby Kerberos » Thu Nov 05, 2009 12:06 am

drwayne wrote:There seems to be a number of questions floating around regarding training, and whether the pilots
are getting enough real "stick time" to be able to handle off nominal conditions. Being in a position
where your speed is in a very narrow acceptable window, and not being able to easily tell the difference
between too fast and too slow, and being given alarms that may be wrong (stall instead of overspeed
or vice versa), at night, and in a storm really tests how well someone flies and makes judgements.


That very issue has been a constant source of discussion in airline training depts for years. Training is expensive, and companies naturally want to keep costs down, but one 30 minute module in the simulator just doesn't cut it for upset recovery training.

Honestly, though, I think the situation you describe above may be unrecoverable anyway. When you get to that point, you're just sol.
User avatar
Kerberos
star
 
Posts: 1197
Joined: Wed Nov 14, 2007 10:35 pm

Re: Jetstar A330 suffers possible pitot tube malfunction

Postby scottb50 » Thu Nov 05, 2009 12:29 pm

Kerberos wrote:
drwayne wrote:There seems to be a number of questions floating around regarding training, and whether the pilots
are getting enough real "stick time" to be able to handle off nominal conditions. Being in a position
where your speed is in a very narrow acceptable window, and not being able to easily tell the difference
between too fast and too slow, and being given alarms that may be wrong (stall instead of overspeed
or vice versa), at night, and in a storm really tests how well someone flies and makes judgements.


That very issue has been a constant source of discussion in airline training depts for years. Training is expensive, and companies naturally want to keep costs down, but one 30 minute module in the simulator just doesn't cut it for upset recovery training.

Honestly, though, I think the situation you describe above may be unrecoverable anyway. When you get to that point, you're just sol.


So far only one suspected incident has resulted in a crash of 6-7 reported. Either it is not the cause or only part of the cause in the Air France crash.
User avatar
scottb50
solar system
 
Posts: 2127
Joined: Tue Nov 30, 1999 12:00 am

Re: Jetstar A330 suffers possible pitot tube malfunction

Postby drwayne » Thu Nov 05, 2009 4:39 pm

Understood...

My take is this - I have not seen any of the other incidents feature the night-time, heavy storm, over the sea scenario
that AF was in. Conditions that can lead to degraded awareness of state...
User avatar
drwayne
solar system
 
Posts: 3878
Joined: Tue Nov 30, 1999 12:00 am

Re: Jetstar A330 suffers possible pitot tube malfunction

Postby Shpaget » Sat Nov 14, 2009 8:25 am

Don't big planes like A330 and 747 have both digital and analog instruments, just for this reason?
User avatar
Shpaget
asteroid
 
Posts: 350
Joined: Fri Aug 21, 2009 1:07 pm

Return to Aviation