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-   -   Air Asia Indonesia Lost Contact from Surabaya to Singapore (https://www.pprune.org/rumours-news/553569-air-asia-indonesia-lost-contact-surabaya-singapore.html)

Mahatma Kote 28th Dec 2014 06:22

Assuming you recognise everything is going to hell in a hand-basket, at reasonable altitude is the option of simply switching off the auto-pilot and any other automatic systems and stopping supplying control inputs a better option than trying to fly out of the situation? I.e. let the aircraft fly itself.

I get the impression that in the case of Air-France Flight 447 that would have been a good choice. In general, or at least with Airbus aircraft, is that a good choice? Or are there envelopes outside of which a pilot is required to regain stability?

Carjockey 28th Dec 2014 06:27

According to the Malaysian press the flight was roughly halfway through it's journey when the pilot requested a change of course, no distress signal had been sent.

Kompas.com reported that the flight was piloted by Captain Irianto with Emmanuel Plesel as the first officer. - See more at: AirAsia flight was halfway to Singapore when it went missing, says official - The Malaysian Insider


p.j.m 28th Dec 2014 06:29


Originally Posted by Ichiban (Post 8799260)
Ground speed of 353 at FL363.

Unlikely to have a 130 knot headwind in the tropics.

Airspeed/Mach No, very slow.

last aircraft ADSB reported airspeed was 469 kts. If the ground speed reported by primary radar of 353 is correct, then headwinds are 116 knots.

http://i.imgur.com/wvO6Io5.jpg

JCviggen 28th Dec 2014 06:32

That (last) ADS-B data point does show 32,000 feet, so it was before the climb, hence it's no surprise to see a normal speed in those normal conditions. If speed decayed it would've been later than this point.

Yaw String 28th Dec 2014 06:32

Lets put this climbing higher when there is weather around,to bed!
We all know there are times when it is sensible,and others when it's not.,20k of Worldwide ops teaches you that kind of thing...
Or maybe not!

Flightradar24 means that CNN knows where the aircraft is,before anyone else!

His trimsheet is already out there...I must smarten up my signature..Cripes!

p.j.m 28th Dec 2014 06:37


Originally Posted by JCviggen (Post 8799272)
That (last) ADS-B data point does show 32,000 feet, so it was before the climb, hence it's no surprise to see a normal speed in those normal conditions. If speed decayed it would've been later than this point.

As far as we know, ATC never gave permission to climb, so the aircraft was still at 32,000 feet, until whatever happened, happened.

fender 28th Dec 2014 06:38

There is usually a lot of traffic around that area, unusual that there is not Distress Radio Beacon signal, IF the worst has occurred!

peekay4 28th Dec 2014 06:40


As far as we know, ATC never gave permission to climb, so the aircraft was still at 32,000 feet, until whatever happened, happened.
That's not correct. Per official briefing, the flight requested (and was granted) permission from Jakarta center to deviate left and climb to FL380.

JCviggen 28th Dec 2014 06:42


As far as we know, ATC never gave permission to climb, so the aircraft was still at 32,000 feet, until whatever happened, happened.
It's true that we don't know anything for sure at the moment, but the radar pic (if it was not incorrectly interpreted) did suggest the AC was above FL360 at the very end. Not necessarily intentionally of course.

p.j.m 28th Dec 2014 06:45


Originally Posted by peekay4 (Post 8799283)
That's not correct. Per official briefing, the flight requested (and was granted) permission from Jakarta center to deviate left and climb to FL380.

thanks for the update. Who gave the briefing, and is it documented somewhere on the www?

Dog Star 28th Dec 2014 06:48

HF communication?
 
I haven't flown in that part of the world for a few years now but is it all VHF comm on that route? Were the crew loaded up with HF position reports etc. In those conditions the weather radar returns can be daunting and it looks as if a huge diversion was in order to "get around" the Cumulo Nimbus build ups. The Captain may have felt that by climbing higher he would have gained visual cues as to a best route through the CBs. The SigWx chart would have left the crew in no doubt that they could not have climbed above (max FL390 for A320) the thunderstorms in that general area. Hopefully the crew were given plenty of fuel on board for the necessary weather diversion. Some airlines have the capability to give weather advisories from their operations department while others do not. It's often times down to the pilots to use the weather radar to the best of their ability to thread their way through.

Detecting CBs on radar in this part of the world (ICTZ) is not as straight forward as in higher latitudes in my experience.

If this doesn't end well my sincerest condolences and sympathy to all concerned.

peekay4 28th Dec 2014 06:48

Briefing by BASARNAS (Indonesian National SAR).

Some info from Reuters:

AirAsia flight carrying 162 people goes missing in Southeast Asia: officials | Reuters


Flight QZ8501 was between the Indonesian port of Tanjung Pandan and the town of Pontianak, in West Kalimantan province on Borneo island, when it went missing, Atmodjo told a news conference in Jakarta.

The aircraft had been flying at 32,000 feet and had asked to fly at 38,000 feet to avoid clouds, he added.

bud leon 28th Dec 2014 06:49

p.j.m I don't think there are winds anything like that in that area right now.

peekay4 28th Dec 2014 06:49


I haven't flown in that part of the world for a few years now but is it all VHF comm on that route?
All VHF, in active radar contact with Jakarta center.

The Old Swedish 28th Dec 2014 06:54

http://up.picr.de/20516010cr.jpg

training wheels 28th Dec 2014 07:13

I'm surprised there are no reports of debris sightings or ELT signals at the moment. M635 is usually quite a busy airways with traffic coming through from Australia and Bali to Singapore and Kuala Lumpur.

peekay4 28th Dec 2014 07:25

Adam Air 574 was found.

And ELTs are NOT designed or expected to work under water.

Carjockey 28th Dec 2014 07:25

@training wheels
There is one report here: Indonesian portal reports of plane crash in Belitung Timur - The Malaysian Insider

But no verification available from other sources...

cdeanda 28th Dec 2014 07:34

Real winds and some speed calculations
 
To clarify the winds question here's a cropped pic of the winds aloft chart for FL340 on Dec 28th, 00Z.:

http://i.picresize.com/images/2014/12/28/zrxf.gif

If both the ATC Radar and the L&T sheet pictures are true, using a speed calculator we can get the following info:
GS: 353 kts
Average Tailwind according to the chart: 20 kts
TAS at 36,300ft: 333 kts
Computed MACH: 0.58
Computed equivalent airspeed: 180 kts

Now, from the A320 QRH with an actual TOW of 63.6T the calculated Green Dot speed would be around 223 kts at that altitude (The corresponding VLS and V alpha prot would be quite close to that number).

All these numbers are just a rough guess using ISA Standard conditions (Usually in this part of the World we have ISA +10 to +15 at cruise FLs)

manflexsrsrwy 28th Dec 2014 07:34

ELT activate on water contact


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