Air Asia QZ8501: Equalateral convection and aviation

[winterymix]

 

 

 

Meteorologists and anyone interested:  I'm interested in the possibility of very rapid formation of convection and perhaps an overshooting cumulonimbus system that could have contributed to the downing of Air Asia QZ8501.  NB:  The black boxes have not been found yet.  It is too early to know for sure what happened.  Scientific speculation given with integrity can be discussed while respecting that all the information is not available quite yet.

 

Some decent information is found here:

 

http://www.weathergraphics.com/awq8501/

 

Does anyone here have links that they can share to highest possible satellite imagery and weather radar imagery in the area of interest at the time of interest?

 

An interesting talk forum is www.pprune.com and the thread of interest is here:

 

http://www.pprune.org/rumours-news/553569-air-asia-indonesia-lost-contact-surabaya-singapore.html

 

 

I made the following comment there (post# 1766):

 

 

Discussing meteorology for a moment, convection is often fueled by daytime heating. The AirAsia event happened at sunrise. Was the convective system particularly unusual/the monsoon process particularly energetic? It seems that the AirAsia flight may have self-diverted into a rapidly developing thunderhead that blossomed up into the flight path at a rate that wasn't evident on the plane's radar. Unusual to have so much convective energy at sunrise but not impossible. It seems that recorded images of weather radar for this event merit further scrutiny.

I received the following response:

 

convection intensity over the open ocean doesn't vary much day/night since sea surface temperatures have very little diurnal variation. However convection over the land not far from the LKP would decrease overnight leaving more 'airspace' over the adjacent sea for CBs to develop and peak towards dawn (without going into the broader scale MET dynamics). Also, the developing phase of CBs is the most active in terms of turbulence/hail/lightning/vertical motion so it's the brand new (towering CU/CB) cell which has just become visible to radar which is often the most dangerous.

and then I received this response:

 

 

This paper: Analysis of overshooting top detections by Meteosat Second Generation: a 5-year dataset - Proud - 2014 - Quarterly Journal of the Royal Meteorological Society - Wiley Online Library shows that, at least in Tropical waters off Africa, convection peaks at around 08 or 09 local time. In the ocean far from land it's around midnight and over land it's in the evening. The same is, at least on the day of the accident, true for the region around Indonesia/Singapore. Because there's so much land over there the sea is never truly isolated so we get the 'coastal' convection system with peak intensity around daybreak.

and then I received this response:

 

 

All the above omits mention of the other driver for rapid high level CB development. That is cooling from above, rather than heating from below. Cold advection [wind backing with height] can and does throw petrol on the fire of a hitherto modest CB. Believe me, it happens.

and then this response:

 

 

If the crew failed to find the weather on radar that likely took them down, the first warning would likely be the sound of ice pellets hitting he aircraft.

So my questions are: 

 

1.  is convection in the location of the downing of Air Asia QZ8501 unusually unpredictable in late December and is there anything different about the monsoon season this year?

 

2.  are there useful weather radar images available in great detail that will yield insights into whether this aircraft flew into a suddenly developing dangerous cumulonimbus system? 

 

3.  Is current radar adequate to detect these systems?

 

4.  Did the other eight or so flights in the area at the time get lucky or did they have better radar or better decision making?

[donsutherland1]

Winterymix,

 

I don't have much to add. The early evidence suggests that there were very likely thunderstorms in the vicinity where the plane crashed. According to the Jakarta Post, there was a “statement made by the Indonesian Meteorology, Climatology, and Geophysics Agency (BMKG), which confirmed that waters around Bangka Belitung, where the plane lost contact with air traffic control in Jakarta, were heavily covered by cumulonimbus clouds…” The article also noted that the cumulonimbus clouds around Indonesia are typically "far stronger" than those in other areas.

 

http://www.thejakartapost.com/news/2014/12/29/airasia-plane-may-have-hit-bad-weather.html

 

If at least one news account is correct, the other flights might well have had better decision making on account of having received timely weather-related information. There was a news report that leaked documents revealed that "Indonesia AirAsia had allegedly violated procedures which resulted in the pilots of the doomed flight QZ8501 not receiving a requested weather report before flying out into stormy weather."

 

http://www.themalaymailonline.com/malaysia/article/indonesia-airasia-pilots-didnt-get-weather-report-leaked-papers-show1

 

This is highly speculative at this point in time. But if it's accurate, the pilots might not have come across the storm until just before they requested permission to fly at a higher altitude (at which time the cell had become visible on their radar). The gap between the request for permission and granting of permission to fly at a higher altitude may well have been when the plane crashed.

 

Again, it's too soon to tell. The recovery of the flight recorders will almost certainly be crucial.

Indonesia AirAsia had allegedly violated procedures which resulted in the pilots of the doomed flight QZ8501 not receiving a requested weather report before flying out into stormy weather 

[downeastnc]

http://avherald.com/h?article=47f6abc7&opt=0

 

There seems to be several theories over on A-Nethttp://www.airliners.net/aviation-forums/general_aviation/read.main/6278628/ mostly that the aircraft had severe sudden icing ( from running into strong updrafts in storms )causing engine or control surface failures resulting in loss of control or the pitot tube froze giving incorrect info to the autopilot that would then disengage and due to the darkness and storms the pilots became disoriented and loss control a la AF447.... Planes at that altitude are harder to control off autopilot and it takes more effort to hold them steady since input from the pilots do not instantly reflect with changes in flight due to the thinner air. Also the Airbus has a side stick control instead of a traditional yoke and its been noted that this does not "translate" the feel of the aircraft to the pilots well and tend to lead to more spatial issues since the input has no feedback. 8501 was the lowest of the flights in the area.

[winterymix]

... 8501 was the lowest of the flights in the area.

OOOPPPSSS, perhaps.

 

Don is likely correct of course.  More information will be available soon.

The black boxes are soon to be recovered.

 

My hunch is that the damage shown indicates the plane pancaked onto the ocean.

It is possible that the engines stalled do to ice ingestion and that the pilots attempted

to recover and to do a controlled ditching.  I'm guessing that the conditions were too violent

to allow a complete recovery. 

[downeastnc]

OOOPPPSSS, perhaps.

 

Don is likely correct of course.  More information will be available soon.

The black boxes are soon to be recovered.

 

My hunch is that the damage shown indicates the plane pancaked onto the ocean.

It is possible that the engines stalled do to ice ingestion and that the pilots attempted

to recover and to do a controlled ditching.  I'm guessing that the conditions were too violent

to allow a complete recovery. 

 

It will be surprising to me if there wasn't some kind of catastrophic loss of control at high altitude, otherwise they would have had time to get a mayday off, also some of the folks over on ANET seem to think that the images they have seen of the tail and the way the damage is indicates a inflight breakup while in a terminal dive ( this would also explain why the debris is somewhat close together ) versus impact damage......but again a ditching attempt could produce similar tearing type damage but if they ditched why no mayday etc......

[winterymix]

Updated analysis:

 

https://irishweatheronline.wordpress.com/2014/12/29/indonesia-air-asia-8501-a-meteorological-analysis/

 

 

Satellite imagery, current time:

 

http://www.bom.gov.au/australia/satellite/?tz=AEST&unit=p23&domain=15&view=34&satSubmit=Refresh+View

 

 

Another image from www.pprune.com

indicating the original role of the debris that has been recovered.   This

gives a good idea of the horror involved.

 

 

[NaoPos]

From WSI twitter page:

@WSI_Energy: Based off the current ENSO + VPM (MJO) index, there are no years that match the current MJO event's magnitude. http://t.co/iVadAhszRh

[AvantHiatus]

There are similarities to the Air France 447 crash over the Tropical Atlantic in which weather contributed to aircraft failure but did not directly cause the crash. Both accidents occured during nocturnal conditions with bursting thunderstorm activity.

[stellarfun]

There are similarities to he Air France 447 crash over the Tropical Atlantic in which weather contributed to aircraft failure but did not directly cause the crash. Both accidents occured during nocturnal conditions with bursting thunderstorm activity.

 

Air Asia crashed in daylight, local time.

 

In July 2014, a Swiftair MD-83 crossing the ITCZ at night encountered a Cb and crashed.in Mali.

 

http://www.flightglobal.com/assets/getasset.aspx?itemid=56958

 

http://www.flightglobal.com/assets/getasset.aspx?itemid=56959

 

The CDR was retrieved but so badly damaged to be unreadable.  Because of the terminal velocity there was no recovery of remains.

 

Tim Vasquez did a comprehensive assessment of the meteorological conditions encountered by AF 447.

http://www.weathergraphics.com/tim/af447/

 

Preliminary analysis from him on Air Asia, referenced first post.  I have not seen anything from him on Swiftair.

http://www.weathergraphics.com/tim/

 

___________

1.  is convection in the location of the downing of Air Asia QZ8501 unusually unpredictable in late December and is there anything different about the monsoon season this year?

> The ITCZ is in this location during the Southern Hemisphere summer.

 

2.  are there useful weather radar images available in great detail that will yield insights into whether this aircraft flew into a suddenly developing dangerous cumulonimbus system? 

>  Probably not.

 

3.  Is current radar adequate to detect these systems?

> Probably.  The rule of thumb is stay clear of Cb's.

 

4.  Did the other eight or so flights in the area at the time get lucky or did they have better radar or better decision making?

> At least one other preceding flight appeared to deviate left of the track.  Most of the other flights were on different tracks.  In the instance of AF447, most/all? other flights on that track deviated left or right, often by several hundred kilometers.