News Air Asia flight QZ8501 missing

[Urwumpe]

You're right Urwumpe but Airbus has changed things as I think dual input has more priority is certain circumstances, certainly it isn't heard once during AF-447's stall.

Yeah. But the visual indication also exists, so it really is no great moment if you miss it.

 

[kamaz]

Is the Airbus inherently stable i.e. if power and trim are set and controls are neutral, can the Airbus eventually recover level flight without input, even if it stalls completely?

I've posted this in the AF447 thread:

ETA: The important part here is that you will only get the stall warning in Alt law -- in Normal law, the plane will just increase throttles for you without complaining.

 

[tl8]

Reports coming through that debris that look like plane parts have been seen.
http://www.abc.net.au/news/2014-12-...ts-of-plane-spotted-in-airasia-search/5993438

 

[Urwumpe]

Reports here state a 95% chance that the found debris is of QZ8501, including information that six corpses have been found and three recovered.

The debris seems to be an aircraft door and parts of the cargo deck of an A32x aircraft.

 

[steph]

So another case of "aircraft flies into big cumulonimbus, gets ripped apart"?
I'm getting a bit intrigued by this weather vs civil aviation subject. How much do airplane radars see? Aren't the pilots trained to avoid storms if at all possible?
With Cbs as high as they get in the equatorial region, overflying them should have been a no-no for most aircraft. And ending up in the upper region of a storm cloud and close to the service ceiling must be nasty.

 

[Urwumpe]

Well, thats a bit much to answer, so in small chops:

So another case of "aircraft flies into big cumulonimbus, gets ripped apart"?

Maybe. Possibly not.

How much do airplane radars see?

That file should be a very good resource there for you to get an idea:

http://www.airbus.com/fileadmin/med...ems/AirbusSafetyLib_-FLT_OPS-ADV_WX-SEQ07.pdf

Especially note the tiny detail, that applies to any modern weather radar despite all technological advances: Shapes tell you more than colors.

Aren't the pilots trained to avoid storms if at all possible?

Usually, its OK to assume that you can fly over the storms, if you are in cruise altitude. But that does not apply to tropical thunderstorms, which can reach 50% higher than thunderstorms in higher latitudes.

With Cbs as high as they get in the equatorial region, overflying them should have been a no-no for most aircraft. And ending up in the upper region of a storm cloud and close to the service ceiling must be nasty.

The problem is: You have not just one thunderstorm. You have many. And as the file above describes well: The black calm behind the storm can easily be another huge thunderstorm hiding in the shadow. You can't just navigate around them easily. You often have to fly right through them because you have no better path that you know with certainty.

And then, you also have to include the characteristics of large Cb clouds - a clear notch in the cloud can really mean free air. Or the most turbulent place filled with ice you have ever seen. As the article by Airbus already explains: Ice has a lower reflectivity as rain: It would appear with less red colors than actually safer regions.

But in this case, you still should remember: Many more planes flew through that region without problems. And the plane was constantly flying much slower than it usually should have been flying. Its thus pretty much possible that the accident is way more complex and technical than just "aircraft flies into big cumulonimbus, gets ripped apart".

 

[Quick_Nick]

The news last night was saying that they requested permission to ascend out of the clouds but were denied permission due to other traffic. So they may well have wanted to avoid it but there was no option.

 

[MattBaker]

Well, that doesn't seem like a good reason to me.

"Hey, we can't fly into a huge thunderstorm, can we go up a few flight levels?"

"Nope."

"Alright, thanks. We'll keep on flying into the thunderstorm then even though us requesting a higher flight level basically just confirmed that we don't think we should do that."

 

[Urwumpe]

The news last night was saying that they requested permission to ascend out of the clouds but were denied permission due to other traffic. So they may well have wanted to avoid it but there was no option.

They were allowed to turn left though.

 

[Quick_Nick]

They were allowed to turn left though.

I didn't know that. Indeed, they apparently were allowed to turn left and may have started to do so but it seems there was a very short period of time between communication with ATC and the incident. Hmm...

 

[kamaz]

Yes it appears that the turn was related to the crash.

Im increasingly suspecting that Airbus pilots have learned to rely on alpha protection to automatically increase thrust during maneuvers. That works until pitots freeze and the plane drops to alt law... The a/c stalls, and they cant recover because they have never seen this situation before...

 

[Urwumpe]

Im increasingly suspecting that Airbus pilots have learned to rely on alpha protection to automatically increase thrust during maneuvers. That works until pitots freeze and the plane drops to alt law... The a/c stalls, and they cant recover because they have never seen this situation before...

If you are a hammer, every problem starts to look like a nail. :facepalm:

 

[Thunder Chicken]

Wreckage and human remains have been found.

http://www.cnn.com/2014/12/30/world/asia/airasia-missing-plane/

Looks like it went down in a fairly shallow region of ocean, so hopefully that will make the investigation easier. Sad day for a lot of people.

---------- Post added at 11:06 AM ---------- Previous post was at 10:47 AM ----------

Another AsiaAir jet went off the end of the runway at Kalibo airport, no word of injuries, but the plane is upright on its gear.

 

[Eccentrus]

the waters in the area sits on top of a continental shelf if I remember my geography lessons in HS correctly, so it should be shallow and searches and evacuation can be done in relative ease. It is sad to see that there probably no soul who survived the accident, and then news broke in that the same carrier have a mishap in landing on an airport just now, this turns into an Annus Horribilis of south east asian air travels indeed.

 

[Urwumpe]

the waters in the area sits on top of a continental shelf if I remember my geography lessons in HS correctly, so it should be shallow and searches and evacuation can be done in relative ease. It is sad to see that there probably no soul who survived the accident, and then news broke in that the same carrier have a mishap in landing on an airport just now, this turns into an Annus Horribilis of south east asian air travels indeed.

Relative ease - the currents could be a problem in that region.

 

[MattBaker]

The sea levels during the last glacial maximum seem to confirm that, everything between Java and Borneo doesn't seem to be deeper than a hundred meters or so.

 

[Evil_Onyx]

Yes it appears that the turn was related to the crash.

Im increasingly suspecting that Airbus pilots have learned to rely on alpha protection to automatically increase thrust during maneuvers. That works until pitots freeze and the plane drops to alt law... The a/c stalls, and they cant recover because they have never seen this situation before...

It is still way too early to come to any conclusions in this case, nether the CVR or FDR have been recovered or analysed.

All we actually know is that the Airbus A320-216 registration PK-AXC stopped flying sometime after 23:12 UTC (last communication) and before 23:16 UTC (last radar contact).

 

[garyw]

It is still way too early to come to any conclusions in this case, nether the CVR or FDR have been recovered or analysed.

All we actually know is that the Airbus A320-216 registration PK-AXC stopped flying sometime after 23:12 UTC (last communication) and before 23:16 UTC (last radar contact).

True enough but as nosy people, we speculate. It's in our nature.

It looks like the wreckage has been found.

Indonesian officials have confirmed that bodies and debris found in the Java Sea off Borneo are from AirAsia flight QZ8501 that went missing on Sunday, a statement by AirAsia says.

AirAsia CEO Tony Fernandes said he was "devastated" by the news.

President Joko Widodo told media he had instructed all search teams to focus on finding the passengers and crew.

The Airbus A320-200, carrying 162 people from Surabaya in Indonesia to Singapore, disappeared on Sunday.

The head of Indonesia's search operation, Bambang Soelistyo, says three bodies have been retrieved, not 40 as previously stated by naval officials.

source and more: http://www.bbc.co.uk/news/world-asia-30634081

 

[ex-orbinaut]

Sorry, can't help noticing on that map in the source above that the debris was found south of the "last reported position". Don't know how accurate that BBC map is regarding the positions, but take a look at the currents in the Java Sea at the moment. More likely debris would have drifted north, I think. Whether this hints at anything or not is not for me to ponder.

As for icing again, well yeah, granted, but allow me to just say there are at least a couple more dangers involved with flying near and through storms, one (lightning), which is slightly more mitigated by design than the potential effects other (severe convective currents).

I have speculated enough with that, for my part, and I would not dare say I have any idea at all what might have happened...

RIP, to all those people, it is very sad.

 

[Urwumpe]

More likely debris would have drifted north, I think.

South - most of the currents go south there, only few places at the eastern shores of the Java Sea have northern currents.