Indonesia: AirAsia plane climbed too fast, then disappeared

[webfact]

Indonesia: AirAsia plane climbed too fast, then disappeared
By NINIEK KARMINI

JAKARTA, Indonesia (AP) — An AirAsia plane that crashed last month with 162 people on board was climbing at an abnormally high rate, then plunged and suddenly disappeared from radar, Indonesia's transport minister said Tuesday.

Ignasius Jonan told Parliament that radar data showed the Airbus A320 was climbing at about 6,000 feet a minute before it disappeared on Dec. 28.

"It is not normal to climb like that, it's very rare for commercial planes, which normally climb just 1,000 to 2,000 feet per minute," he said. "It can only be done by a fighter jet."

He said the plane then plunged toward the sea and disappeared from radar.

Jonan did not say what caused the plane to climb so rapidly.

In their last contact with air-traffic controllers, the pilots of AirAsia Flight 8501 asked to climb from 32,000 feet to 38,000 feet to avoid threatening clouds, but were denied permission because of heavy air traffic. Four minutes later, the plane disappeared. No distress signal was received.

An excessively rapid ascent is likely to cause an airplane to go into an aerodynamic stall. In 2009, an Air France Airbus A330 disappeared over the Atlantic Ocean in bad weather while flying from Rio de Janeiro to Paris. Investigators were able to determine from the jet's "black boxes" that it began a steep climb and then went into a stall from which the pilots were unable to recover.

Airbus spokesman Justin Dubon said Tuesday that it was too early to comment on possible similarities between the two crashes.

Survey ships have located at least nine big objects, including the AirAsia jet's fuselage and tail, in the Java Sea. The plane's black boxes — the cockpit voice recorder and flight data recorder — have been recovered but are still being analyzed.

"So far, we've managed to download and transcribe half of the cockpit voice recorder," said Nurcahyo Utomo, a commissioner with the National Transportation Safety Committee. "It is too early to draw any conclusion yet because we don't know what is in the remaining half."

He said there was no indication of terrorism, and there were no other voices in the cockpit other than the pilot and co-pilot.

The plane was en route from Surabaya, Indonesia's second-largest city, to Singapore.

Only 53 bodies have been recovered so far. Rough sea conditions have repeatedly prevented divers from reaching the wreckage.
___

Associated Press writers Ali Kotarumalos in Jakarta and Greg Keller in Paris contributed to this report.


-- (c) Associated Press 2015-01-21

[alant]

eek, that would be a worry, fly by wire aircraft climbing so steeply they stall, crikey.

[Mosha]

eek, that would be a worry, fly by wire aircraft climbing so steeply they stall, crikey.

Prepared to be told otherwise, but I don't think fly by wire was the problem here.

[smedly]

This crash was caused by

1. Sensor failure

2. Pure Pilot error

3. Pilot error linked to (1.)

4. Auto pilot error linked (1.)

or a very unlikely mechanical failure - although in saying that - it is interesting to note that several reports have already indicated an urgent call to revise maintenance procedures which could be a hint that they already know why the aircraft got out of control

[hugh2121]

The pilots acknowledged that they needed to take action to avoid the storm. Having been denied the altitude they required to do so, surely they should have either flown around the storm or, if the storm was over a very large area, turned back or diverted.

[Mosha]

At the altitude it was already at, it would have been physically impossible to get the aircraft to climb at that rate. Normal rate of climb up there is around 1000 to 1200 fpm.

Edited January 21, 2015 by Mosha

[tigermonkey]

Nothing new here. Old news and equally old speculation. Please keep in mind that these comments were made by a politician giving a speech to other politicians.

The ADS-B data upon which the comments and speculation are based were known three weeks ago. Nothing new has emerged that is factual. Lets wait for the preliminary report, which will include data from the CVR and FDR before jumping to conclusions. That report is due January 28.

[tigermonkey]

At the altitude it was already at, it would have been physically impossible to get the aircraft to climb at that rate. Normal rate of climb up there is around 1000 to 1200 fpm.

Nonsense. The A320 is quite capable of a 6000fpm climb at FL340 under some conditions - for example a sudden increase in jetstream headwind or an immense updraft. Never say "impossible" when you are dealing with weather.

[whaleboneman]

At the altitude it was already at, it would have been physically impossible to get the aircraft to climb at that rate. Normal rate of climb up there is around 1000 to 1200 fpm.

So the radar data is wrong?

Or as often the case the translation is suspect?

[tartempion]

Can't they just wait for the transcription of the voice recorder before opening their mouth?

Should be done by this Friday 23rd January

[sweatalot]

"So far, we've managed to download and transcribe half of the cockpit voice recorder,"

I don't understand why it takes so long to downlaod the recorder

[Mosha]

At the altitude it was already at, it would have been physically impossible to get the aircraft to climb at that rate. Normal rate of climb up there is around 1000 to 1200 fpm.

So the radar data is wrong?

Or as often the case the translation is suspect?

I'm saying an extremely strong updraft was pushing it up and when that stopped. It stalled.

Edited January 21, 2015 by Mosha

[siampolee]

sweatalot post # 11.

"So far, we've managed to download and transcribe half of the cockpit voice recorder,"

I don't understand why it takes so long to downlaod the recorder

Tape transcript editing purposes perhaps?

Edited January 21, 2015 by siampolee

[tigermonkey]

sweatalot post # 11.

"So far, we've managed to download and transcribe half of the cockpit voice recorder,"

I don't understand why it takes so long to downlaod the recorder

Tape transcript editing purposes perhaps?

Almost impossible to edit the tape. There are so many observers to the process, including the BEA, Airbus, AirAsia. etc.

The tape input typically has four channels - Left, Right, Communications and Cockpit Ambient. The part that they have transcribed will be the part of the tape from previous flight and perhaps some of the recording from flight QZ8501. When it starts to get busy, the transcribing job becomes immense. Every sound, including warnings, clicks, etc must be separated out and accurately identified. This is far from an easy job with multiple alarms sounding and pilots fighting for control of the aircraft. It is not unusual for transcribing of a complex minute of tape to last more than one day.

By the way, they have listened to all of the tape, but are proceeding now with accurate transcription.

Of interest is that the Indonesian government has just announced that the 28 January preliminary report will not be made public.

http://www.reuters.com/article/2015/01/21/us-indonesia-airplane-idUSKBN0KU09X20150121

[Chicog]

"So far, we've managed to download and transcribe half of the cockpit voice recorder,"

I don't understand why it takes so long to downlaod the recorder

It doesn't. It takes time to not only hear and transcribe the words, but they will also be attempting to identify from the sounds what else was going on; what control inputs might have been made, what alarms sounded, if there were any abnormal noises indicating equipment failure, etc.

[Chicog]

There an interesting story from a 320 driver over on PPRUNE....

Some years ago I was flying an A320 through France ,sound bound .
We were riding the core of a very tight jet stream at 330 ,with about 100 kit tailwind , ATC advised turbulence in 20nm so we requested 370 to avoid .
The aircraft was light so no problem . The initial climb at 1500 fpm was ok ,but as we exited the side of the jet into about 50 kts less tailwind the roc increased to 6000 fpm with speed increasing rapidly.
Even with rapid disconnect and gentle handling we zoomed through 390 and topped out at 400 at which point the indicated airspeed fell back rapidly.
We had little time to think about what was going on and traffic and ATC were an issue . Firm but gentle handling got us safely back to 370 .
The event was reported ASR and put down to unusually extreme wind gradient .
not saying this was the case here but perhaps we are not always aware of the potential of a jet upset due to upper air boundaries.

One thing the FDR will tell them is the airspeed when they peaked at the top of the climb.

If it did stall then perhaps either they didn't or couldn't respond in time to regain control of the aircraft.

IIRC, the damage to AF447 they discerned from the initial wreckage found told them very early on that the plane literally fell out of the sky and pancaked into the sea.

I haven't heard that mentioned here.

However, as they match the FDR with the CVR I don't think it will be long before they can issue a near-certain summation of what went wrong. The big question will as usual be why?

[NomadJoe]

This crash was caused by

1. Sensor failure

2. Pure Pilot error

3. Pilot error linked to (1.)

4. Auto pilot error linked (1.)

or a very unlikely mechanical failure - although in saying that - it is interesting to note that several reports have already indicated an urgent call to revise maintenance procedures which could be a hint that they already know why the aircraft got out of control

So with this statement you've ruled out what, alien abduction?

[smedly]

This crash was caused by

1. Sensor failure

2. Pure Pilot error

3. Pilot error linked to (1.)

4. Auto pilot error linked (1.)

or a very unlikely mechanical failure - although in saying that - it is interesting to note that several reports have already indicated an urgent call to revise maintenance procedures which could be a hint that they already know why the aircraft got out of control

So with this statement you've ruled out what, alien abduction?

if you want to go with that up to you

One thing that I mentioned a couple of weeks ago was that this may prompt a rethinking of the use of the AP to make altitude/course adjustments during severe weather, punching numbers into a screen instead of flying the plane may no longer be recommended, I'm actually and always have been convinced that this was caused by the AP and pilots having too much confidence in it's capabilities especially in adverse weather, so I'll add one more 5. Auto pilot trying to fly the plane outside of it's program capabilities and pilots unable to recover the error in time

[khaosai]

This crash was caused by

1. Sensor failure

2. Pure Pilot error

3. Pilot error linked to (1.)

4. Auto pilot error linked (1.)

or a very unlikely mechanical failure - although in saying that - it is interesting to note that several reports have already indicated an urgent call to revise maintenance procedures which could be a hint that they already know why the aircraft got out of control

So with this statement you've ruled out what, alien abduction?

if you want to go with that up to you

One thing that I mentioned a couple of weeks ago was that this may prompt a rethinking of the use of the AP to make altitude/course adjustments during severe weather, punching numbers into a screen instead of flying the plane may no longer be recommended, I'm actually and always have been convinced that this was caused by the AP and pilots having too much confidence in it's capabilities especially in adverse weather, so I'll add one more 5. Auto pilot trying to fly the plane outside of it's program capabilities and pilots unable to recover the error in time

You don't punch numbers into a screen to avoid weather.

It's a simple task in the flight deck carried out by a pilot engaging the heading select switch with the autopilot remaining engaged throughout the maneuvre unless pilot intervention is required. What is important is a healthy respect is maintained for thunderstorm activity and ensure adequate lateral deviation, not vertical deviation as has been mentioned.

Autopilots and flight director systems on modern aircraft are exceptionally good, however they need proper monitoring and a good understanding. If they are not performing as expected then early pilot intervention will be required.

[BlackJack]

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